WO2011028571A1 - Taxane analogues, their use, pharmaceutical compositions containing them, and processes for their preparation - Google Patents

Abstract

The present invention relates to novel taxane analogues, processes of making the novel taxane analogues, compositions containing the novel taxane analogues, and their use in treating cancer and neurodegenerative disorders. In some embodiments, the taxane analogues are represented by the generic structure of formula (I) : wherein R¹, R²,R³ and A are defined herein; and esters especially pro-drugs thereof wherein one or more of the hydroxy! groups is esterified to form an in-vivo hydrolysable ester group; or pharmaceutically acceptable salts thereof.

Description

TAXANE ANALOGUES, THEIR USE, PHARMACEUTICAL

COMPOSITIONS CONTAINING THEM, AND PROCESSES FOR THEIR PREPARATION

Field of the Invention

The present invention is directed, in part, to novel taxane analogues useful in treatment of cancer and/or neurodegenerative disorders. The present invention is also directed, in part, to compositions containing the taxane analogues and processes of making the taxane analogues.

BACKGROUND OF THE INVENTION

US Patent No 5,352,806 discloses 10β- substituted taxanes which may have bridges between the 7- and 9- hydroxyl groups of the formula:

wherein R¹¹ and R¹² are independently hydrogen, alkyl, phenyl or substituted phenyl; or, taken together, R¹¹ and R¹² or a single atom selected from the group consisting of oxygen or sulphur; or one of R¹¹ and R¹² is hydrogen, alkyl, phenyl or substituted phenyl, and the other is -OR¹³ or -NR¹³R¹⁴ where R¹³ and R¹⁴ are independently alkyl, alkanoyi, substituted alkanoyi, phenyl or substituted phenyl. It was expected that these compounds would be useful in connection with the treatment, or in the preparation of taxol derivatives for use in the treatment of cancer. Although the above formula does not extend to compounds in which R^u or R¹² is a hydroxyalkyi group, a compound was drawn in reaction Schemes 3 of US Patent No 5,352,806 which had one of the R¹¹ and R¹² groups as hydrogen and the other as CH₂CHOHCH₂OH. This was also prepared in Example 13 and tested in-vitro where Table 3 showed it was not amongst the most active compounds prepared. This is seen by the following extract relating to bridged compounds and their parent dihydrotaxol:

Other taxanes are described in EP 1 228 759; EP 1 285 920; EP 1 148 055; WO 01/56564; WO 01/57027; WO 94/10996; FR 2 715 846; US 5,352,806; FR 2 707 293; WO 94/08984; WO 92/09589; WO 94/20485; WO 93/21173; Klein LL, "Synthesis of 9- Dihydrotaxol: a novel bioactive taxane", Tetrahedron letters, vol. 34, no. 13, 1993, pages 2047-2050; Datta A et al, "Synthesis of novel C-9 and C-10 modified bioactive taxanes", Tetrahedron letters, vol. 36, no. 12, 1995, pages 1985-1988; Klein LL et al, Journal of Medicinal Chemistry, no. 38, 1995, pages 1482-1492; J Demattei et al, "An efficient synthesis of the taxane-derived anticancer agent Abt-271", Journal of Organic Chemistry, vol. 66, no. 10, 2001, pages 3330-3337; Gunda I Georg et al, "The chemistry of the taxane diterpene: stereoselective reductions of taxanes", Journal of Organic Chemsitry, vol. 63, no. 24, 1998, pages 8926-8934. However, apart from paclitaxel and docetaxel, no taxane has received regulatory approval to be marketed for use as an anticancer agent and no taxane has received regulatory approval to be marketed for use by oral administration. WO 2005/03150 and US Application No 2005/0148657 Al disclose taxane analogues and derivatives possessing a 9a, 10a configuration and an acetal or ketal bridge between the hydroxyl groups at the 7- and 9- positions. Synthesis of taxane analogues is also disclosed in WO 2007/073383, WO 2007/126893 and WO 2007/075870.

Zamir et al, Tetrahedron Letters, 37, 6435-6438 (1996) discloses taxane analogues containing a five membered A-ring and a position 1 C(CH₃)₂OH group. These analogues were abeo-taxanes lacking the four membered oxatane ring. The compounds possessed a 10β- , stereochemistry. No anti-cancer activity was ascribed to the compounds.

Zamir er al, Tetrahedron Letters, 53. 15991-16008 (1997) discloses abeo-taxane analogues and also trapped intermediates containing a 5 membered A-ring and a position 1 C(CH₃)20H group. The compounds possessed a 10β- stereochemistry and an acetoxy group at position 13. Numerous structural analogues were disclosed but no biological data was provided on any compound.

Wahl et al, Tetrahedron, 48, 6965-6974 (1992) discloses a wide range of modified taxane analogues including one which had a 5 membered A-ring and a 1 position C(CH₃)₂OH group. The compound had a 10β- hydroxyl group and a 9-keto group and was said to be active in the tubulin disassembly assay although no data was provided. The compounds were said to being studied in order to obtain new analogues of taxol and taxotere. The new compounds were thought to provide information regarding structure-activity relationships from structural modifications of the ester groups at C-2 and C-4.

Other publications relating to taxane analogues include Hue et al, Magne Reson Chemis, 45, 527-530 (2007); Nicolaou et al, Ang. Chem. Int. Ed. 44, 1012-1044 (2005) ; Zamir et al, Tetrahedron Letters, 40, 7917-9920 (1999) ; Torregiani ef al, Gaz. Chim. Italiana, 126, 809-814 (1996) ; Appendino et al, 3, Chem. Soc. Comman., 1587-1589 (1993) ; Samaranayake et al, J. Org. Chem., 56, 5114-5119 (1991) ; Georg et al, Bioorg. Med. Chem. Lett. 3, 1345-1349 (1993); and Georg et al, Bioorg. Med. Chem. Lett. 3, 1349-1350 (1993);

None of these publications on taxane analogues relate to compounds having a lOa-configuration, none relate to compounds having an acetal bridge between 7- and 9- hydroxy groups, none provide data showing the compounds are active in-vivo, none suggest the compounds can be employed orally and none relate to the treatment of brain or pancreatic cancers.

None of the five drugs approved by the U.S. Food and Drug Administration (FDA) for treating the cognitive symptoms of Alzheimer's disease (Namenda®, Reminyl®, Exelon®, Aricept® and Cognex®) is a taxane analogue. All are cholinesterase inhibitors except Namenda®, which acts by a different mechanism. Each of the cholinesterase inhibitors acts in a different way to delay the breakdown of acetylcholine, a neurotransmitter important for memory. Namenda® protects neurons from overexposure to another neurotransmitter, called glutamate, excess levels of which reportedly contribute to the death of brain cells in people with Alzheimer's. However, Reminyl^®, Exelon^® and Aricept^® are most effective when treatment is begun in the early stages. Additionally, at least half of the people who take these drugs do not respond to them. Therefore, there is an urgent need for pharmaceutical agents for treating Alzheimer's disease and other neurodegenerative disorders.

Despite their diverse clinical manifestations and disease progression, neurodegenerative disorders share some common characteristics: all these diseases (except Huntington disease) have both sporadic and inherited types, the onset of all these diseases is usually after the fourth or fifth decade of life, and their pathology involves neuronal loss and protein aggregation. For instance, a normal soluble cellular protein is converted into an abnormal insoluble aggregated protein rich in β-sheets that is toxic such as β- amyloid in AD. Emerging evidence for a causal role of the conformational changes of proteins in neurodegenerative diseases has become clearer recently from genetic studies (Hardy,J. and Gwinn-Hardy^., "Genetic Classification Of Primary Neurodegenerative Disease," Science 1998, 282, 1075-1079). Mutations in the genes that encode the protein components of fibrillar aggregates are genetically associated with the inherited form of neurodegenerative diseases (C. Soto "Unfolding The Role Of Protein Misfolding In Neurodegenerative Diseases," Nat. Rev. Neurosci. 2003, 4, 49-60). These include mutations in genes for the β-amyloid (Αβ) precursor protein, causing Alzheimer's disease (AD); a-synuclein, causing Parkinson disease (PD); or in microtubule-associated protein tau, causing frontotemporal dementia (FTD) with parkinsonism. Though these mutations cause mainly the familial type of neurodegenerative diseases, the pathology of both familial and sporadic forms is either identical or very similar (J.L.Cummings, "Neurodegenerative Disorders As Proteinopathies: Phenotypic Relationships" in "Genotype- Proteotype-Phenotype Relationships In Neurodegenerative Diseases," Springer-Verlag, Berlin Heidelberg, New York, New York, 2005, pp.1-10).

AD is the most common neurodegenerative disease and afflicts ~5% of those over 65 years. It is an insidious and progressive neurodegenerative disorder that accounts for the vast majority of age-related dementia and is characterized by global cognitive decline and the accumulation of Αβ deposits and neurofibrillary tangles (NFTs) in the brain. Family history is the second-greatest risk factor for the disease after age, and the growing understanding of AD genetics has been central to the knowledge of the pathogenic mechanisms leading to the disease. Genetically, AD is complex and heterogenous and appears to follow an age-related dichotomy: rare and highly penetrant early-onset familial AD (EOFAD) mutations in different genes are transmitted in an autosomal dominant fashion, while late-onset AD (LOAD) without obvious familial segregation is thought to be explained by the "common disease/common variant" (CD/CV) hypothesis (R. E. Tanzi, "A Genetic Dichotomy Model For The Inheritance Of Alzheimer's Disease And Common Age-Reiated Disorders," 3. Clin. Invest. 1999, 104, 1175-1179). Neurodegenerative diseases, including AD, progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD), which have pathological fibrillar aggregates of the microtubule associated protein, tau, in the brain collectively belong to a group of disorders known as the tauopathies. Tau protein was first identified as a "factor essential for microtubule (MT) assembly", a heat stable protein that induced the assembly of MTs from purified tubulin and belonging to the family of MT-associated proteins (G.B. Witman et al. "Tubulin Requires Tau For Growth Onto Microtubule Initiating Sites," Proc. Natl. Acad. Sci. U.S.A 1976, 73, 4070-4074). Tau is abundantly expressed both in the peripheral and central nervous system (L. I. Binder et al., "The distribution of tau in the mammalian central nervous system," J. Cell Biol. 1985, 101, 1371- 1378), where it is enriched in the axons of mature and growing neurones and, low levels of tau are also present in oligodendrocytes and astrocytes (Y. Gu et al. "Tau Is Widely Expressed In Rat Tissues," J. Neurochem. 1996, 67, 1235-1244; P. LoPresti et al., "Functional Implications For The Microtubule-Associated Proteintau: Localization In Oligodendrocytes," Proc. Natl. Acad. Sci. U.S.A 1995, 92, 10369-10373). The level of protein phosphorylation is highly elevated in foetal tau and pathological tau found within the insoluble, fibrillar inclusions that define tauopathies, when compared to normal adult brain tau (K. Kanemaru et al., "Fetal- Type Phosphorylation Of The Tau In Paired Helical Filaments," J. Neurochem. 1992, 58, 1667-1675).

In the healthy adult human brain, tau protein exists as six major isoforms (M. Goedert et al., "Multiple Isoforms Of Human Microtubule-Associated Protein Tau: Sequences And Localization In Neurofibrillary Tangles Of Alzheimer's Disease," Neuron 1989, 3, 519-526). Several tauopathies are associated with imbalances in the ratios of two tau isoforms, namely the isoforms with three MT- binding repeats (3R-tau) and four MT-binding repeats (4R-tau). For example, the insoluble tau deposits in the different tauopathies have different tau-isoform compositions; in Pick's disease (PiD), the classical Pick bodies consist mainly of 3R-tau isoforms (R. de Silva et a I., "An Immunohistochemical Study Of Cases Of Sporadic And Inherited Frontotemporal Lobar Degeneration Using 3R-And 4R- Specific Tau Monoclonal Antibodies," Acta Neuropathol. (Berl) 2006,111, 329-340; A. Delacourte et al., "Vulnerable Neuronal Subsets In Alzheimer's And Pick's Disease Are Distinguished By Their Tau Isoform Distribution And Phosphorylation," Ann. Neurol. 1998, 43, 193-204), whereas in PSP, CBD and argyrophilic grain disease (AGD), both neuronal and glial inclusions contain mostly 4R-tau isoforms (R. deSilva et al., "An Immunohistochemical Study Of Cases Of Sporadic And Inherited Frontotemporal Lobar Degeneration Using 3R-And 4R-Specific Tau Monoclonal Antibodies," Acta Neuropathol. (Berl) 2006,111, 329-340; T. Arai et al., "Distinct Isoforms Of Tau Aggregated In Neurons And Glial Cells In Brains Of Patients With Pick's Disease, Corticobasal Degeneration And Progressive Supranuclearpalsy," ActaNeuropathol.(Berl) 2001, 101, 167-173; T. Togo et al., "Argyrophilic Grain Disease Is A Sporadic 4-Repeat Tauopathy," J. Neuropathol. Exp. Neurol. 2002, 61,547- 556; N. Sergeant et al., "Neurofibrillary Degeneration In Progressive Supranuclear Palsy And Corticobasal Degeneration: Tau Pathologies With Exclusively" Exon 10" Isoforms," J. Neurochem. 1999, 72, 1243-1249; R. deSilva et al., "Pathological Inclusion Bodies In Tauopathies Contain Distinct Complements Of Tau With Three Or Four Microtubule-Binding Repeat Domains As Demonstrated By New Specific Monoclonal Antibodies," Neuropathol. Appl. Neurobiol. 2003, 29, 288-302), and roughly equal amounts of 3R-and 4R-tau make up the paired helical filaments and straight filaments observed in AD (R. deSilva et al., "Pathological Inclusion Bodies In Tauopathies Contain Distinct Complements Of Tau With Three Or Four Microtubule-Binding Repeat Domains As Demonstrated By New Specific Monoclonal Antibodies," Neuropathol. Appl. Neurobiol. 2003, 29, 288-302; "Two-Dimensional Characterization Of Paired Helical Filament-Tau From Alzheimer's Disease: Demonstration Of An Additional 74-kDa Component And Age-Related Biochemical Modifications," J. Neurochem. 1997, 69, 834-844). Microtubule (MT)-binding compounds are potentially therapeutically beneficial in tauopathies, including Alzheimer's disease (AD), Parkinson's disease (PiD), progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD), by functionally substituting for the MT-binding protein tau and/or reverse fast axonal transport deficits in the tauopathies.

SUMMARY OF THE INVENTION It has now been found that the taxane analogues and derivatives of the present invention have anticancer properties that render them particularly favourable, for example in comparison to clinically approved taxane derivatives such as paclitaxel and docetaxel. Compounds of the present invention are not only effective in the treatment of cancers including cancers resistant to paclitaxel and other agents but they have the potential to be employed to treat particularly difficult cancers such as brain cancers, to be orally administered, and to be co-administered with other medicinal agents.

The blood-brain barrier (BBB) effectively prevents microtubule (MT)-stabilizing drugs from readily entering the central nervous system (CNS). A major limiting factor for microtubule-stabilizing drug permeation across the BBB is the active efflux back into the circulation by the overexpression of the multidrug-resistant gene product 1 (MD 1) or P-glycoprotein (P-gp). It has now been found that the compounds of the present invention, unlike clinically approved taxane derivatives such as paclitaxel and docetaxel, not only have the ability to penetrate CNS, but also have efficacy in the CNS. Because of the ability of these compounds to cross the blood- brain barrier they are not only potentially beneficial in the treatment of neurodegenerative disorders, but also potentially more effective than dinically approved taxane derivatives such as paclitaxel and docetaxel in the treatment of the neurodegenerative disorders, including Alzheimer's disease (AD), Parkinson's disease (PD), progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD).

The present invention relates, in part, to novel taxane analogues, processes of making the novel taxane analogues, compositions containing the novel taxane analogues, and their use in treating cancer and/or neurodegenerative disorders.

In certain embodiments, the present invention provides the compounds of the formula (I):

wherein R¹ is hydrogen, lower alkyl, aryl, lower alkylaryl, lower alkenyl or hydroxyloweralkyl, lower alkoxy or aryloxy; R² is hydrogen, lower alkyl, aryl, lower a\ky\ aryl, lower alkenyl or hydroxyloweralkyl; R³ is hydrogen, lower alkyl, aryl, lower alkylaryl, lower alkenyl, hydroxyloweralkyl or COR⁴ where R⁴ is hydrogen, lower alkyl, aryl, loweralkylaryl, lower akenyl or hydroxyloweralkyl; and A is a group having at least two atoms which are not hydrogen atoms and is of the formula -(CHA^n-A² wherein n is 0 or 1; and A² is -CH₂A²⁰, -CH=CH₂, -C≡CH or CHO and A¹ and A²⁰ are independently selected for each occurrence from hydrogen, hydroxyl, amino, lower alkyl amino, dilower alkyl amino, or dilower alkyi amino in which the alkyi groups are joined to form a 4, 5, 6 or 7 membered ring, or a -N-iinked morpholino group; or A¹ and A²⁰ jointly represent an oxygen atom, a sulphur atom or a -1MH- moiety; and esters especially pro-drugs thereof wherein one or more of the hydroxyl groups is esterified to form an in-vivo hydrolysable ester group; or pharmaceutically acceptable salts thereof.

In an embodiment, a compound may comprise a mixture of stereoisomers of the 7-, 9- position bridge, for example diasteromeric mixtures, or it may comprise single isomer with respect to that position. In an embodiment, a single isomer is greater than 95% pure. In a preferred embodiment, a single isomer is greater than 99% optically pure.

In an embodiment, a compound of the formula (I) is a single isomer of formula (II):

wherein A and R¹, R² and R³ are as defined in relation to formula (I). In an embodiment, R¹ can be OtBu, R² can be CH₂-CH(CH₃)2 and R³ can be COCH₃. In an embodiment, the invention provides a process for preparation of the compounds of formulae (I) and (II) above. In another embodiment, the present invention provides a pharmaceutical composition which comprises a compound of the invention and a pharmaceutically acceptable carrier. In yet another embodiment, the present invention further provides for a method of treatment of one or more cancers selected from the group consisting of brain, hepatocellular, breast, renal, melonoma, colorectal, lung (small cell and non-small cell), prostate, pancreatic, sarcoma, leukemia, lymphoma, and other bone marrow dyscrasias, pancreatic cancers, and cancers resistant to paclitaxel and other agents in a mammal, preferably a human being. The method comprising administering a therapeutically effective amount of the compound of the above-defined Formulae I and II or a pharmaceutically acceptable salt thereof, to a mammal in need thereof or a member of a population susceptible thereto.

The terms "treating" and "treat", as used herein, include their generally accepted meanings, i.e., preventing, prohibiting, restraining, alleviating, ameliorating, slowing, stopping, or reversing the progression or severity of a pathological condition, or sequela thereof, described herein.

In certain embodiments, the compounds of formulae (I) and (II) and pharmaceutically acceptable salts thereof are useful in the manufacture of a medicament for use in treating a mammal, preferably a human being, afflicted with or susceptable to dementia or a neurodegenerative disorder, or in preventing a mammal from getting dementia or a neurodegenerative disorder, including Alzheimer's disease, for helping prevent or delay the onset of Alzheimer's disease, for treating a mammal with mild cognitive impairment (MCI) and preventing or delaying the onset of Alzheimer's disease in a mammal, including a human being, who would progress from MCI to AD, for treating Down's syndrome, for treating a mammal, including human being, who has Hereditary Cerebral Hemorrhage with Amyloidosis of the Dutch-Type, for treating cerebral amyloid angiopathy and preventing its potential consequences, i.e. single and recurrent lobar hemorrhages, for treating other degenerative dementias, including dementias of mixed vascular and degenerative origin, dementia associated with Parkinson's disease, dementia associated with progressive supranuclear palsy, dementia associated with cortical basal degeneration, diffuse Lewy body type of Alzheimer's disease and any mammal, including, human being, who is in need of such treatment. The method comprising administering a therapeutically effective amount of the compound of the above-defined Formulae I and II or a pharmaceutically acceptable salt thereof, to a mammal in need thereof or a member of a population susceptible thereto.

In other embodiments, the invention includes treatment and/or prophylaxis of neurological neurodegenerative disorders and/or nerve cell death (degeneration) resulting from e.g. hypoxia, hypoglycemia, brain or spinal chord ischemia, ischemia, brain or spinal chord trauma or post-surgical neurological deficits and the like. In other embodiments, the invention includes treatment of a person susceptible or suffering from stroke or heart attack or neurological deficits relating to cardiac arrest, a person suffering or susceptible to brain or spinal cord injury, or a person suffering from the effects of ischemia or degeneration. In other embodiments, the invention includes treatment and/or prevention of various neurodegenerative diseases such as Parkinson's disease, Huntington's disease, Amyotrophic Lateral Sclerosis, Alzheimer's disease, Down's Syndrome, Korsakoff's disease, cerebral palsy and/or age-dependent dementia. In yet another embodiment, the present invention includes prevention of age-associated cognitive decline.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a synthetic scheme for a process for making El and ΤΡΪ- 432.

FIG. 2 is an alternative synthetic scheme for the process for making a mixture of El and TPI-432. Finally purified to afford El.

FIG. 3 is a synthetic scheme for a process of making compounds E2 and E3. FIG. 4 illustrates a synthetic scheme of a process for preparation of hyper-deutrated tert-butyl 4-nitrophenyl carbonate

FIG. 5 illustrates a synthetic scheme of a process for preparation of hyper-deutrated di-tert-butyl tricarbonate 17.

FIG. 6 illustrates a synthetic scheme a process for preparation of deutrated compound 22b.

FIG. 7 illustrates a synthetic scheme for a process for preparation of deutrated compound 29.

FIG. 8 illustrates a synthetic scheme for an alternate process for preparation of compound 22b. FIG. 9 illustrates a synthetic scheme for a process for preparation of compounds 31. 32 and 33. FIG. 10 is a graph of percent tumor volume in female CD-I nu/nu mice implanted with H526 sclc (small cell lung cancer) as a function of time (in days). The graph demonstrates the in vivo efficacy of the compounds E1-E6 and E8 in inhibiting H526 sclc tumor growth.

FIG. 11 is a graph of percent body weight of female CD-I nu/nu mice implanted with H526 sclc (small cell lung cancer) as a function of time (in days). The graph demonstrates the in vivo efficacy of the compounds E1-E6 and E8 on (body weight changes some measurement of toxicity of compound at the dose given)

FIG. 12 is a table illustrating results of MTS proliferation assay wherein the compounds E1-E6 and E8 were applied to A2780-A5, A2780-DXR1 (MDR+), HCT-15 (MDR+), MDAH2774, MV522 and 22Rvl cell lines. The numbers in the table are IC₅₀ values of the tested compounds. The numbers in bold have IC₅₀ (nM) higher than that for El (all the MDR cell types).

FIG. 13 illustrates results of microsomal stability investigation of the compounds E1-E6 and E8. Microsomal stability assay is commonly used to rank compounds according to their metabolic stability. In one embodiment, the protein assembly assay was conducted according to the procedures as described by Mathew AE, Mejiilano MR, Nath JP, Himes RH, Stella VJ, "Synthesis and Evaluation of Some Water-Soluble Prodrugs and Derivatives of Taxol with Antitumor Activity" J. Med. Chem., 35, 145-151 (1992) and Georg GI, Cheruvallath ZS, Himes RH, Mejiilano MR, Burke CT, "Synthesis of Biologically Active Taxol Analogues with Modified Phenylisoserine Side Chains" J. Med. Chem., 35, 4230 (1992). Both references are incorporated herein in their entirity. FIG. 14 illustrates the results of microtubule protein assembly assay. The results demonstrate the ability of compounds E1-E6 and E8 to induce microtubule protein polymerization. FIG. 15 illustrates dose-dependent effects of El alone on neuronal viability. The graph shows percent neuronal cell survival for concentrations 10 nM, 50 nM, 100 nM, 200 nM, 1 μΜ and 10 μΜ.

FIG. 16 illustrates dose-dependent effects of El on neuronal viability when added 2 hours before addition of 10 mM Αβ peptide. The graph shows percent neuronal cell survival in control, in presence of El alone, in presence of Αβ-only and in presence of El and Αβ. FIG. 17 illustrates dose-dependent effects of E2 alone on neuronal viability. The graph shows percent neuronal cell survival for concentrations 1 nM, 20 nM, 50 nM, 100 nM, 400 nM, 600 nM and 800 nM and 1 μΜ. FIG. 18 illustrates dose-dependent effects of E3 alone on neuronal viability. The graph shows percent neuronal cell survival for concentrations 1 nM, 20 nM, 50 nM, 100 nM, 400 nM, 600 nM and 800 nM and 1 μΜ. FIG. 19 illustrates dose-dependent effects of E5 alone on neuronal viability. The graph shows percent neuronal cell survival for concentrations 1 nM, 20 nM, 50 nM, 100 nM, 400 nM, 600 nM and 800 nM and 1 _μΜ. FIG. 20 illustrates dose-dependent effects of E4 alone on neuronal viability. The graph shows percent neuronal cell survival for concentrations 1 nM, 20 nM, 50 nM, 100 nM, 400 nM, 600 nM and 800 nM and 1 ,uM.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates, in part, to novel taxane analogues, processes of making the novel taxane analogues, compositions comprising the novel taxane analogues, and their use in treating cancer and various neurodegenerative disorders.

In an embodiment, the present invention provides a compound of formula (I):

wherein R¹ is hydrogen, lower alkyl, aryl, lower alkylaryl, lower alkenyl or hydroxyloweralkyl, lower alkoxy or aryloxy; R² is hydrogen, lower alkyl, aryl, lower alkyl aryl, lower alkenyl or hydroxyloweralkyl; R³ is hydrogen, lower alkyl, aryl, lower alkylaryl, lower alkenyl, hydroxyloweralkyl or COR⁴ where R⁴ is hydrogen, lower alkyl, aryl, loweralkylaryl, lower akenyl or hydroxyloweralkyl; and A is a group having at least two atoms which are not hydrogen atoms and is of the formula -(CHA¹)_n-A² wherein n is 0 or 1; and A² is -CH₂A²⁰, -CH=CH₂, -C≡CH or CHO and A¹ and A²⁰ are independently selected for each occurrence from hydrogen, hydroxy!, amino, lower alkyl amino, dilower alkyl amino, or dilower alkyl amino in which the alkyl groups are joined to form a 4, 5, 6 or 7 membered ring, or a -N-linked morpholino group; or A¹ and A²⁰ jointly represent an oxygen atom, a sulphur atom or a -NH- moiety; and esters especially pro-drugs thereof wherein one or more of the hydroxyl groups is esterified to form an in-vivo hydrolysable ester group; or pharmaceutically acceptable salts thereof.

Compounds of the present invention include, by way of an non- limiting example, mixtures of the stereoisomers of the 7-, imposition bridge, for example diasteromeric mixtures. In another embodiment, compounds of the present invention comprise single isomers with respect to that position. In another embodiment, a single isomer is greater than 95%. In a preferred embodiment, a single isomer is greater than 99% optically pure.

In an embodiment of the invention, the stereochemistry of the 7-, 9- position bridge is:

In another embodiment of the invention, the stereochemistry of the 7-, 9- position bridge is:

In another embodiment, the side chain has the configuration :

In another embodiment, the side chain has the configuration:

In an aspect, compounds of formula (I) are single isomers of the formula (II):

wherein A and R¹, R² and R³ are as defined in relation to formula (I). In particular R¹ can be OtBu, R² can be CH₂-CH(CH₃)₂ and R³ can be COCH₃. Compounds of the present invention may be at least 95% optically pure, more suitably at least 98% and preferably essentially free from the non-desired optical isomer.

While not wishing to be bound by any particualr theory, it is believed that compounds comprising these isomers at the acetal bridge, offer potentially greater effectiveness than those of different stereochemistry.

An embodiment of the invention comprises compounds of formulae (1) or (II), wherein n is 0 (so that A is an A² group).

Another embodiment of the invention comprises compounds of formulae (I) or (II), wherein n is 1 (so that A is a -CHA-CHA²⁰, - CHA¹-CH = CH₂ or -CHA^CsCH group).

An embodiment of the invention comprises compounds of formulae (I) or (II), wherein A is CH₂CH₂OH. Another embodiment of the invention comprises compounds of formulae (I) or (II), wherein A is CH(OH)CH₃. Another embodiment of the invention com rises compounds of formulae (I) or (II), wherein A is

, or

NH

group. Another embodiment of the invention comprises

compounds of formulae (I) or (II), wherein A is a -CH₂CH₃ group. Another embodiment of the invention comprises compounds of formulae (I) or (II), wherein A is a -CH(OH)-CH=CH₂ group. An embodiment of the invention comprises compounds of formulae (I) or (II), wherein A is a -CH(OH)-C=CH group.

An embodiment of the invention comprises compounds of formulae (I) or (II), wherein A is a CH₂A² group, where A² is an amino or substituted amino group, for example a di-Iower alkyl amino group.

In another embodiment, A in compounds of formulae (I) or (II) comprises 1, 2 or 3 hydroxyl groups. In an embodiment, A in compounds of formulae (I) or (II) A is the CH(OH)CH₂OH group. In an embodiment, A in compounds of formulae (I) or (II) is the CH(OH)CH₂IMH₂, CH(l\IH)CH₂OH, or CH(IMH)CH₂IMH₂ group.

In another embodiment, A in compounds of formulae (I) or (II) is the CH(OH)CH₂SH, CH(SH)CH₂OH, or CH(SH)CH₂SH group.

In an embodiment, A in compounds of formulae (I) or (II) A is the CH₂N (CH₃)₂ group. In another embodiment A in compounds of the formulae (I) or (II) is the CHO group.

Lower alkyl groups include groups of 1, 2, 3, 4, 5, 6, 7 or 8 carbon atoms and can be straight or branched and can optionally be substituted with one or more cyclic moieties of 3, 4, 5, 6, 7 or 8 carbon atoms. Hence examples of lower alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, t- butyl, pentyl, neopentyl, hexyl, heptyl, octyl and examples of cyclic moities include cyclobutylmethyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl and the like. In an embodiment, lower alkyl groups are straight or branched alkyl groups of up to 6 carbon atoms.

Lower alkoxy is an oxygen atom substituted by a lower alkyl group. Particularly apt lower alkoxy groups are believed to include the tert- butyloxy group.

Lower alkenyl groups include groups of 2, 3, 4, 5, 6, 7 or 8 carbon atoms and can be straight or branched and can optionally be substituted with one or more cyclic moieties of 3, 4, 5, 6, 7 or 8 carbon atoms. Hence, examples of lower alkenyl groups include ethenyl, propenyl, butenyl, pentenyl, hexenyl, heptenyl, octenyl and examples of cyclic moieties include cyclohexenylmethyl, cyclopentenyl, cyclohexenyl, cycloheptenyl, cyclooctenyl and the like, Aryl groups include phenyl, naphthyl, 6 ring membered heteraryl including 1, 2 or 3 nitrogen ring atoms, and 5 ring membered heteroaryi including one nitrogen ring atom, one oxygen atom, one sulphur ring atom, one nitrogen ring atom and one oxygen or one sulphur atom, two nitrogen ring atoms, two nitrogen ring atoms and one oxygen ring atom or one sulphyl ring atom, or three or four nitrogen ring atoms. Valancy permitting, such aryl groups may be substituted by one or two or three moieties selected from methyl, methoxyl, ethyl, ethoxy, hydroxyl, fluorine, chlorine or trifluoromethyl groups. Particularly apt aryl groups are believed to include the phenyl group.

Aryloxy is an oxygen atom substituted by such an aryl group. In an embodiment, aryloxy group includes a phenoxy group. Alkyl groups of the invention include methyl, ethyl, propyl, butyl and the like.

Alkenyl groups of the invention include ethenyl, propenyl and butenyl and the like.

Lower alkoxy groups for R¹ are believed to include the tert-butyloxy group.

Alkyl groups for R² include the butyl groups, particularly the sec- butyl group. AlkyI groups for R³ include the methyl and ethyl group, particularly the methyl group.

Aryl groups include phenyl, mono-,di- and tri- methyl- or methoxyphenyl, mono-,di- and tri-fluoro or chloro-phenyl, or mixtures of such substituents, pyridyl and thienyl and the like. In a preferred embodiment, an aryl group comprises a phenyl group. In a preferred embodiment, an aryloxy group compries a phenyl group. In a preferred embodiment an aryloxy group phenoxy group.

In an embodiment, R³ is hydrogen or COCH3.

In an embodiment, R² is methyl, ethyl, propyl, butyl, pentyl, hexyl, isopropyl, isobutyl or phenyl.

In an embodiment, R³ is COR⁴, wherein R⁴ is methyl, ethyl or propyl. Compounds of the formula (I) and (II) include those wherein R³ is hydrogen or acetyl, R² is phenyl or butyl, particularly sec-butyl, and R¹ is phenyl or tert-butyloxy. Hence compounds of the formula (I) and (II) include those wherein R² is sec-butyl and R¹ is phenyl, those wherein R² is phenyl and R¹ is phenyl and those wherein presently preferred compounds of the invention are those of formula (II) in which R³ is COCH₃, R² is sec-butyl and R¹ is tert- butyloxy.

In another aspect, compounds of formulae (I) and (II), wherein A is CH(OH)A² such as CH(OH)CH₂OH, have the 7-9 bridge of the stereochemistry (a), (b), (c) or (d):

Such compounds may be in the form of mixtures of optical isomers, for example a diasteromeric mixture, or may be present as single optical isomers, for example, greater than 95%, 98% or 99% optical purity, or preferably essentially a single optical isomer.

Compounds of the formula (I) or (II) containing basic nitrogen atoms are optionally provided as pharmaceutically acceptable salts. Such salts may be of inorganic or organic acids such as hydrochloric, sulphuric, phosphoric, nitric, acetic, benzoic, lactic, maleic, citric, tartaric or other suitable acid.

Compounds of the invention can be prepared by the reaction of a corresponding compound of the formula (III) or (IV) :

in which any hydroxyl group present other than those at C7 and C9 is protected if desired and in which R¹, R² and R³ are defined as in relation to formulas (I) and (II), with a compound of the formula (V):

OHC-A (V) or a di-Ci-4 alkylacetal thereof, wherein A is as defined in relation to formulas (I) and (II), in which any hydroxyl groups or amino or alkylamino groups are protected; said reaction being performed in the presence of a sulphonic acid; and thereafter removing the protecting groups.

In an embodiment, the stereochemical configurations at 2' and 3' carbon centers of the compound of formula (III) or (IV) are selected from the group consisting of (2'S, 3'S), (2'S, 3'R), (2'R, 3'S), and (2'R, 3'R).

In an embodiment, the compound of formula (III) or (IV) is an R- epimer at the 3' carbon center.

In another embodiment, the compound of formula (III) or (IV) is an S-epimer at the 3' carbon center.

In an embodiment, the compound of formula (III) or (IV) is an R- epimer at the 2' carbon center. In an embodiment, the compound of formula (III) or (IV) is an S- epimer at the 2' carbon center. In an embodiment, the reaction of compounds of formulas (III) and (IV) can take place in a solvent such as DCM, (CH₂CI₂), at a non- extreme temperature, suitably ambient temperature (around 20° - 25°C). Suitable acid catalysts include, but are not limited to, camphorsulphonic acid or p-toluenesulfonic acid or the like.

The protecting groups useful in the embodiments of the invention include any used for such reactions, for example those described in WO 2005/030150, WO 2007/075870, WO 2007/126893, WO 2007/073383 or US 2005/0148657.

Alternatively, the compounds of the formula (I) wherein A is a CH(OH)CH₂OH group can be prepared from the corresponding compound of the formula (VI) :

In which any hydroxylic groups of defined stereochemistry can be appropriately formed if desired, for example, by reaction of OSO4 under mild conditions. In an embodiment, the stereochemical configurations at 2' and 3' carbon centers of the compound of formula (VI) are selected from the group consisting of (2'S, 3'S), (2'S, 3'R), (2'R, 3'S), and (2'R, 3'R).

In an embodiment, the compound of formula (VI) is an R-epimer at the 3' carbon center.

In an embodiment, the compound of formula (VI) is an S-epimer at the 3' carbon center.

In an embodiment, the compound of formula (VI) is an R-epimer at the 2' carbon center.

In an embodiment, the compound of formula (VI) is an S-epimer at the 2' carbon center. Certain intermediates can be obtained by the methods of WO 2005/030150, WO 2007/075870, WO 2007/126893 or WO 2007/073383 or by methods analogous to those used in the art to prepare corresponding compounds containing a 9β and/or 10β configuration. The compound of formula (VI) can be obtained by the reaction of a compound of formula (III) with the compound (CH₃O)₂CH-CH=CH₂ or (CH₃CH₂O)2CH-CH=CH2 in the presence of a sulphonic acid or trifluoroacetic acid. The reaction conditions described for the conversion of the compound of formula 30 to that of formula 31 or formula 43 to that of formula 44 in WO 2005/03150 may be employed.

Also incorporated herein in their entirety are US Patent Applications serial numbers 11/691,024 (filed 26^th March 2007); PCT/US2008/055367 (filed28^th February 2008); 11/680,563 (filed 28^th February 2007); 11/743,849 (filed 3^rd May 2007); 11/834,489 (filed 6^th August 2007); 60/892,235 (filed 28^th February 2007) and PCT/US2008/055384 (filed 28^th February 2008).. The compound of the formula (VI) wherein a substituent on the 2'- position carbon atom in the form of a single optical isomer or a mixture of optical isomers, for example a diastereomeric mixture.

If such single optical isomers are reacted with a compound of the formula (V), the extent of racemization, if any, may be controlled, for example by using mild conditions. Compounds comprising optical isomers of the 7,9-bridge can also be obtained as single isomers by separating mixtures of isomers by chromatography to yield the desired mixture of isomers or separate single isomers. Chromatography using silica, especially spherical silica is apt. Normal phase purification at differing scales were carried out on various sizes of columns packed with YMC silica (Silica gel S-30-50pm 12θΑ) or Kromasil silica (100 A, 10pm Kromasil silica gel) and with solvents prepared from n- Heptane/walBAc (1% water and 1% acetic acid in Isobutyl acetate) or n-Heptane/waMTBE (1% water and 1% acetic acid in ethyl-i- butyl ether).

There is provided a method of producing a compound of the the invention, including, compounds of formulae (I) or (II) by the reaction of a compound of the formula:

wherein R³ and A are as defined in relation to formula (I) and (II) and in which any reactive groups other than the 13-OH group are optionally protected if desired, with a protected acylating derivative of the compound of the formula R₁CONHCH(R²)CH(OH)CO₂H, which is most aptly a compound of the formula (VIII) or (IX):

wherein R¹ and R² are as defined in relation to formula (I) and (II). In an embodiment, the compounds of formulae (VIII) and (IX) are respectively compounds of the formula (X) and (XI):

wherein R¹ and R² are as defined in relation to formula (I) and (II).

In an aspect of the invention, in the compounds of formulas (VIII), (IX), (X) and (XI), R ¹is t-BuO and R² is CHCH(CH₃)₂. In another aspect of the invention, in the compounds of formula (VII), R³ is COCH3.

In an embodiment of the invention, in the compound of formula (VII), the configuration of the 7-, 9- bridge is:

wherein A has the values referred to in relation to formula (I) and (II).

In an embodiment, the coupling of compound of the formula (VII) to a compound of the formula (VIII), (IX), (X) or (XI) can be performed under conditions similar to those employed for coupling side chains to the 13-OH group of optionally protected baccatin III or 10-deacetylbaccatin (III).

Protecting groups can be employed and later removed in conventional manner. In an embodiment, the compound of the formula (VII) can be obtained from the corresponding optionally protected compound of the formula (XII):

wherein R³ is as defined in relation to formulas (I) or (II) and any reactive groups are protected if desired, by reaction with a compound of the formula (V) as hereinbefore described.

In an embodiment, the compound of the formula (XII) can be prepared by the acid catalyzed isomerization of a compound of the formula (XIII) :

employing a sulfonic acid such as camphor sulphonic acid or p- toluene sulfonic acid or trifluoroacetic acid or an organic acid such as acetic acid in a protic solvent like ethanol, methanol etc. Alternatively, the compound of the formula (VII) can be obtained by the isomerisation of a compound of the formula (XIV) :

with a sulfonic acid such as camphor sulphonic acid or p-toluene sulfonic acid or trifluoroacetic acid or an organic acid such as acetic acid in a protic solvent like ethanol, methanol etc. Such isomerisation reactions can take place in a solvent such as dichloromethane or toluene or protic solvents such as methanol, ethanol, etc., at varying temperatures, for example ambient temperature, reflux etc.

The isomers of compounds of formulas (VII) and (XII) can be selected to provide the desired stereochemistry in the compounds of formulas (II) and (III). The acylating derivative of the compound of formula (VII) include those described in WO 2005/030150, WO 2007/075870 or WO 2007/126893. Similarly protecting groups and reaction conditions that can be employed include those described in WO 2005/030150, WO 2007/075870 or WO 2007/126893.

The compound of the formula (VII) can be prepared from an analogous 7,9-dihydroxy compound by reaction with an aldehyde of the formula (V) as set out herein before. Reaction conditions employed will be similar to those desired in the preparation of a compound of the formula (I) from a compound of formula (III). It is believed that separation into desired optical isomers may be performed chromatographically as described above.

In certain embodiments, compounds of the formula (I) may be preparable by treatment of a compound of the formula (II) wherein A is a CH=CH2 group with liver microsomal preparations. In an embodiment, metabolites of the compounds of the formula (I) are contemplated. Compounds of the formulas (I) and (II) can also be prepared by reaction of a corresponding compound wherein A is CH=CH₂ by hydrogenation (to prepare a compound wherein A is CH₂CH₃), reaction with a oxidizing agent such as a peroxyacid, for example m-chloroperbenzoic acid (to prepare a compound wherein A is

or

or

group); with AD mix a or AD mix β (to prepare a

compound wherein A is

respectively); reaction with 0s0₄, NMO (N-Methylmorpholine-N-Oxide) to form a

compound wherein A is

and subsequent reaction with NaI0₄ to form a compound wherein A is

. Reaction of a compound wherein A is

with sodiumborohydride and an amine forms a compound wherein A is

wherein i & R₂ are, independently, hydrogen, lower alkyl having from 1 to 8 carbon atoms, lower cycloalkyl having from 3 to 8 carbon atoms, lower alkenyl having from 2 to 8 carbon atoms, lower cycloalkenyl having from 3 to 8 carbon atoms, aryl or lower alkylaryl. Non-limiting examples of Ri and R₂ include groups such as methyl , ethyl, propyl, isopropyl, butyl, isobutyl, t-butyl, pentyl, iso-pentyl, hexyl, cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl, phenyl, tolyl, xylyl, and naphthyl.

Compounds of formula (I) and (II) wherein A is

may also be prepared by reaction of a corresponding compound wherein A is

with ammonium thiocyanate and thiourea under non-aqueous conditions in the presence of catalytic Bi(III) salts.

Compounds of formula (I) and (II) wherein A is

may also be prepared by reaction of a corresponding compound wherein A is CH=CH₂ by aziridination using N-iodo-/V-potassio- - toluenesulphonamide or chloramine-T etc. Reaction of a compound wherein A is

⁰ with vinylmagnesium halide or ethynylmagnesium halide forms a compound wherein A is

or

respectively.

The reactions set forth above can be executed in a solvent chosen from a group of halogenated solvents, like methylene chloride, chloroform, 1,2-dichloro ethane etc., ethers, like tetrahydrofuran (THF), methyl-t-butyl ether (MTBE), diisopropyl ether etc. The reactions can be conducted at temperatures ranging from -20°C to 50°C, preferably at ambient temperature. The other reactive functional groups in the molecule may be either protected or unprotected. The compounds of formula (I) and (II) wherein A is a

group may be employed as intermediates, for example to form compounds of the formula (I) and (II) wherein A is a -CH(OH)-CH₂OH group or a -CH(OH)-CH₂A² wherein A² is an amino or substituted amino group (within formulas (I) and (II)) by methods known in the art for such reactions.

In an embodiment, compounds analogous to those of formulae (I) and (II), wherein A is a CH=CH₂ group can be made as described in the above mentioned patents and applications.

In certain embodiments the invention provides a compound of the formula (I) or (II) in isolated form, and/or in solid form, and/or in crystalline form and/or in bulk form (i.e. greater than 2g, more suitably greater than 20 g and preferably greater than 200g). In another embodiment, compounds of the formula (I) or (II), wherein A is a CHO group may be used as intermediates in making, for example compounds wherein A is CH₂N e₂, CH₂OH and the like.

In another embodiment, compounds of the formula (I) or (II), wherein A is a CHO group may be used as intermediates in making, for example compounds wherein A is CH₂N(R^a)R^b, wherein R^a and R^b are, independently, lower alkyl radical having from 1 to 8 carbon atoms, lower alkenyl radical having from 2 to 8 carbon atoms, lower akynyl group having from 3 to 8 carbon atoms, lower cycloalkyl having from 3 to 8 carbon atoms, lower cycloalkenyl having from 3 to 8 carbon atoms, aryl or lower alkylaryl. The present invention also provides a pharmaceutical composition which comprises a compound of the invention and a pharmaceutically acceptable carrier.

Such carriers include cremophor, vitamin E, polyethylene glycols, polyoxysorbitan esters, such as polysorbate 20, 40, 60, polyoxyethylated vitamin E, glyceride mono, di and triesters for example with sterates or oleates, polyoxyethylated castor oil, and the like lipophilic carrier optionally in association with an ethanolic carrier and optionally together with some water.

In an aspect, the compositions of the invention comprise an effective anti-cancer amount of a composition of the invention and will be administered in an amount selected by a physician. By way of a non-limiting example, such amounts can be from about 100 mg/m² to 250mg/m², for example about 125 mg/m², 160 mg/m², or 185 mg/m². Such amounts can often be reflected in unit doses of about 200 mg to 400 mg, for example about 250 mg, 300 mg or 350 mg.

In an embodiment, the composition may be provided in a sealed vial or the like from which it may be taken diluted if desired with infusion fluids like D5W or the like.

Alternatively, the composition may be in the form of a tablet, capsule, pill or other shaped or unshaped unit dosage form suitable for oral administration.

In an aspect, the compounds and hence compositions of this invention possess an enhanced safety profile (for example, on the immune system or the blood) in comparison to marketed taxanes which offers the potential for enhanced or longer dosing schedules under the direction of the skilled physician than marketed taxanes.

Compositions for oral administration may contain at least 30 mg/m² of the compound of the invention per dose, more aptly at least 50, 80, 100, 150 mg/m² and more aptly less than 250 mg/m² per dose (the average area for a patient being assumed to be 2m for conversion to absolute weight). However, as will be understood by the skilled artisan when armed with the present disclosure, the dosage may be varied as directed by the physician in view of the individual patient's response.

A liquid composition will normally contain about 0.1 mg/ml to about 15 mg/ml for example about 0.5, 1, 2, 3, 5 or 10 mg/ml of the compound of the invention. A non-liquid composition may contain a higher proportion of the compound of the invention, for example 5% to 50%, such as 10, 20, 25 or 30% by weight. WO 1999/45918 and the international patent applications and US patent applications referred to above disclose compositions that may be considered for use with compounds of the invention. To prepare a pharmaceutical composition of the present application, a compound of the invention is admixed with a pharmaceutically acceptable carrier according to conventional pharmaceutical compounding techniques, wherein the carrier may take a wide variety of forms depending on the form of preparation desired for administration. Suitable pharmaceutically acceptable carriers are well known in the art. Descriptions of some pharmaceutically acceptable carriers may be found in The Handbook of Pharmaceutical Excipients Eds. Rowe et a/., American Pharmaceutical Association and the Pharmaceutical Society of Great Britain.

The pharmaceutical composition of the present application may be in the form of a tablet, pill, capsule, granule, powder, sterile parenteral solution or suspension, ointment, gel or cream, metered aerosol or liquid spray, or suppository, or a biodegradable resolvable medium, depending on the administration route.

As a solid dosage form, the pharmaceutical composition of the present application may comprise, in addition to a compound of the invention, at least one diluent, binder, adhesive, disintegrant, lubricant, antiadherent, and/or glidant. Additionally, sweeteners, flavorants, colorants and/or coatings may be added for specific purposes. As a liquid dosage form, the pharmaceutical composition of the present application may comprise, in addition to a compound of the invention and a liquid vehicle, at least one wetting agent, dispersant, flocculation agent, thickener, buffer, osmotic agent, coloring agent, flavor, fragrance, and/or preservative.

Such a possible liquid formulation includes a solution (sterile if for injection) containing 10 mg/mL of a compound of the invention in a 15:85 or 50:50 (w/v) polyoxyl 35 castor oil/dehydrated alcohol solution. An appropriate pharmaceutical grade polyoxyl 35 castor oil is Cremophor EL-P, which is a non-ionic solubilizer made by reacting castor oil with ethylene oxide in a molar ratio of 1 :35, followed by a purification process (BASF Pharma).

In an embodiment, the invention comprises the use of a compound of the formula (I) or (II) in the treatment of cancer, including cancers resistant to paclitaxel. IN another embodiment, the invention comprises the use of a compound of the formula (I) or (II) in the treatment of multiple drug resistant cancer.

Cancers which may be treated include breast cancer; ovarian cancer; prostate cancer; head and neck cancer; bladder cancer; brain cancer including neurosarcoma and glial cell cancer; cervical cancer; bone cancer; kidney cancer; liver cancer; skin cancer such as a melanoma; squamous cell carcinoma; and lung cancer. Brain cancers are particularly difficult to treat using taxanes so it is a further advantage of this invention that such treatment is possible.

Clinically used taxanes such as paclitaxel and docetaxel are administered intravenously. The compounds of this invention can be administered intravenously if desired, but it is one of the considerable advantages of such compounds that they may also be administered by other routes such as orally. Other modes of administration include sublingual, subcutaneous, rectal, intramuscular, intraspinal, intraperitoneal, vaginal, topical, transdermal and transmucosal.

The compound of the invention can be useful in the treatment of diseases when used alone or in combination with other therapies. For example, when used for the treatment of cancer, the compounds of the invention can be administered alone or in combination with radiotherapy, surgical removal, hormonal agents, antibodies, antiangiogenics, COX-2 inhibitors, and/or other chemotherapeutic agents such as taxanes, temozolomide, cisplatin, 5-fluorouracil, taxotere, gemcitabine, topoisomerase II inhibitor, topoisomerase I inhibitor, tubulin interacting agent, antibodies, antiangiogenics, COX-2 inhibitors, hormonal agent, thymidilate synthase inhibitor, anti-metabolite, alkylating agent, farnesyl protein transferase inhibitor, signal transduction inhibitor, EGFR kinase inhibitor, antibody to VEGFR, C-abl kinase inhibitor, hormonal therapy combination and aromatase combination.

The compound of the invention can be useful in the treatment of diseases when used alone or in combination with other chemotherapeutics. For example, when used for the treatment of cancer, the compounds of the invention may be administered alone or in combination with aromatase inhibitors, antiestrogen, anti- androgen, a gonadorelin agonists, topoisomerase 1 inhibitors, topoisomerase 2 inhibitors, microtubule active agents, alkylating agents, anthracyclines, corticosteroids, IMiDs, protease inhibitors, IGF-1 inhibitors, CD40 antibodies, Smac mimetics, FGF3 modulators, mTOR inhibitors, HDAC inhibitors, IKK inhibitors, P38MAPK inhibitors, HSP90 inhibitors, akt inhibitors, antineoplastic agents, antimetabolites, platinum containing compounds, lipid- or protein kinase-targeting agents, protein- or lipid phosphatase- targeting agents, anti-angiogentic agents, agents that induce cell differentiation, bradykinin 1 receptor antagonists, angiotensin II antagonists, cyclooxygenase inhibitors, heparanase inhibitors, lymphokine inhibitors, cytokine inhibitors, bisphosphanates, rapamycin derivatives, anti-apoptotic pathway inhibitors, apoptotic pathway agonists, PPAR agonists, inhibitors of Ras isoforms, telomerase inhibitors, protease inhibitors, metalloproteinase inhibitors, aminopeptidase inhibitors, thymidilate synthase inhibitors, a DNA cross linking agents, topoisomerase I or II inhibitors, DNA alkylating agents, ribonuclase reductase inhibitors, cytotoxic factors, and growth factor inhibitors.

The compound of the invention can be useful in the treatment of diseases when used alone or in combination with other chemotherapeutics. For example, when used for the treatment of cancer, the compounds of the invention may be administered alone or in combination with one or more pharmaceutically acceptable, inert or physiologically active diluents, adjuvants or chemotherapeutic agents selected from the group consisting of phomopsin, dolastatin, Avastin, steganacin, paclitaxel, taxotere, vinblastine, vincristine, vindesine, vinorelbine, navelbine, colchicine, maytansine, ansamitocin, Iressa, Tarceva, Herceptin, lapatinib, vandetanib, Sorafenib, BAY-57-9006, bevacizumab, cetuximab, gemtuzumab, panitumumab, rituximab, tositumomab, trastuzumab, apolizumab, oregovomab, mitumomab, alembuzumab, ibritumomab, vitaxin, SU-6668, semaxanib, sunitinib malate, SU- 14813, vandetanib, Recentin, CP-547632, CEP-7055, AG-013736, pazopanib, combretastatin, squalamine, combrestatin A4 phosphate, TNP-470, neovastat, dasatinib, imatinib, nilotinib, sorafenib, sunitinib, triethylenethiophosphoramine, alitretinoin, altretamine, arsenic trioxide, asparaginase, bexarotene, denileukin diftitox, hydroxycarbamide, masoprocol, mitotane, pegaspargase, tretinoin, raltitrexed, IL-10, IL-12, bortezomib, leuprolide, interferon β, pegylated interferons, atrasentan, melphalan, cyclophosphamide, chlormethine, chlorambucil, trofosfamide, ifosfamide, nitromin, busulfan, thiotepa, chlorambucil, CC-1065, temozolomide, pipobroman, dacarbazine, mechlorethamine, procarbazine, uramustine, RSU-1069, CB-1954, hexamethylmelamine, cisplatin, carboplatin, oxaliplatin, BBR3464, satrapiatin, tetrapiatin, iproplatin, amsacrine, netropsin, pibenzimol, mitomycin, duocarmycin, dactinomycin, distamycin, mithramycin, chromomycin, olivomycin, anthramycin, bleomycin, liblomycin, rifamycin, actinomycin, adramycin, trichostatin A, propamidine, stilbamidine, rhizoxin, nitroacridine, geldamycin, 17-AAG, 17- DMAG, plicamycin, deoxycoformycin, levamisole, daunorubicin, doxorubicin, epirubicin, idarubicin, mitroxantrone, valrubicin, carmustine, fotemustine, lomustine, streptozocin, gemcitabine, 5- fluorouracil (5-FU), fludarabine, cytarabine, capecitabine, mercaptopurine, cladribine, clofarabine, thioguanine, pentostatin, floxuridine, pentostatin, aminopterin, methotrexate, pemetrexed, camptothecin, irinotecan, topotecan, epipodophyllotoxin, etoposide, teniposide, aminogluthetimide, anastrozole, exemestane formestane, letrozole, fadrozole, aminoglutethimide, leuprorelin, buserelin, goserelin, triptorelin, abarelix, estramustine, megestrol, flutamide, casodex, anandron, cyproterone acetate, finasteride, bicalutamide, tamoxifen or its citrate salt, droloxifene, trioxifene, raloxifene or zindoxifene, a derivative of 17-3-estradiol such as ICI 164, ICI 384, ICI 182, ICI 780, testolactone, fulvestrant, toremifene, testosterone, fluoxymesterone, dexamethasone, triamcinolone, dromostanolone propionate, megestrol acetate, methyltestosterone, chlorotrianisene, hydroxyprogesterone, medroxyprogesterone acetate, reloxafine, etanercept, thalidomide, revimid (CC-5013), aziridoquinones, misonidazole, NLA-l, RB-6145, misonidazole, nimorazole, RSU-1069, SR-4233, porfimer, photofrin, verteporfin, merocyanin 540, tin etiopurpurin, PUVA, aminolevulinic acid, methyl aminolevulinate, minodronate, zoledronic acid, ibandronate sodium hydrate or clodronate disodium, misonidazole, misonidazole, amifostene, oblimersen, TIMP-1 or TIMP-2, marimastat, TLK-286 and mixtures thereof.

The practice of the invention is not limited to any particular mechanism of operation. In one embodiment of the present invention, the compounds and their analogues are used for stabilizing microtubule or inducing tubulin polymerization. In another embodiment, the compounds of the present invention are used in the treatment of diseases mediated by tubulin. Such diseases include cancers such as brain, hepatocellular, breast, renal, melonoma, colorectal, lung (small cell and non-small cell), prostate and pancreatic cancers, as well as sarcoma, leukemia, lymphoma, and other bone marrow dyscrasias.

In one an embodiment, brain cancer is treated with a composition comprising a compound of the invention and a second anti-cancer agent effective in the treatment of brain cancer. A non-limiting example of a scond anti-cancer agent is temozolomide.

In another aspect , the invention comprises the use of a compound of the formula (I) or (II) in the treatment of neurodegenerative diseases or tauopathies in a mammal, including a human. In an embodiment, the tauopathies include Alzheimer's disease (AD), Parkinson's disease (PiD), progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD).

Recently, axonal transport has been identified as a common theme in neurodegenerative diseases, including Alzheimer's disease, frontotemporal dementias, Parkinson's disease, and polyglutamine diseases (S. Roy et al., "Axonal Transport Defects: A Common Theme In Neurodegenerative Diseases," Acta Neuropathol. 2005, 109, 5-13). Other neurodegenerative diseases and disorders such as sporadic and familial Alzheimer's disease, including the prodromal phase of Alzheimer' s disease known as mild cognitive impairment, Down's syndrome, Lewy body variant of Alzheimer's disease, as well as sporadic or hereditary neurodegenerative diseases known collectively as tauopathies (e.g. Pick's disease, corticobasal degeneration, progressive supranuclear palsy, frontotemporal dementia with Parkinsonism linked to chromosome 17 or FTDP-17), various forms of motor neuron disease (e.g. Lou Gehrig's disease or sporadic or hereditary amyotrophic lateral sclerosis), polyglutamine or or trinucleotide repeat diseases (including Huntington's disease), sporadic and familial synucleinopathies (including dementia with Lewy bodies, Parkinson's disease, multiple system atrophy, neurodegeneration with brain iron accumulation), neuronal intranuclear inclusion disease, hereditary spastic paraplegias, Charcot- Marie-Tooth disease, sporadic or hereditary prion disease, in addition to traumatic brain injury, and the like, may be associated with impaired microtubule structure, or function, or associated disruption of axonal transport. These and other diseases, disorders, and/or conditions that may be associated with impaired microtubule structure, or function, or associated disruption of axonal transport can benefit from therapeutic interventions with compounds of the present invention that stabilize microtubules thereby maintaining axonal and other forms of intraneuronal transport. Dementia refers to a group of symptoms that are caused by changes in the way the brain functions. Senile dementia refers to the onset of these symptoms in older people. While dementia can strike anyone at any age, the most common conditions with dementia as a symptom include Alzheimer's disease and vascular disease, both of which are specific to older individuals. Individuals suffering from senile dementia have impaired memory as well as changes in other areas of cognition, such as language, vision, and abstract thinking, that prevent them from functioning properiy on a daily basis (D.S. Knopman et al. "Practice Parameter: Diagnosis of dementia (an evidence-based review)" Report of the Quality Standards Subcommittee of the American Academy of Neurology. Neurology 56 (2001), 1143-53). In certain embodiments, the compounds or pharmaceutically acceptable salts can be used for dementia's prophylaxis or for the therapeutic treatment of pre-existing symptoms of the dementia.

Alzheimer's disease (AD) is the most common form of dementia, accounting for 50-60% of all cases. The prevalence of dementia is below 1% in persons aged 60-64 years, but shows an almost exponential increase with age, such that in people aged 85 years or older the prevalence is between 24% and 33% in the western world (CP. Ferri et al., "Global Prevalence Of Dementia: A Delphi Consensus Study," Lancet, 2005. 366(9503), 2112-7). Besides age, epidemiological studies have suggested several potential risk factors for the disease. Some are related with a decreased reserve capacity of the brain including education (R. Mayeux, "Epidemiology Of Neurodegeneration," Annu Rev. NeuroscL, 2003, 26, 81-104; J. A. Mortimer, "Head Circumference, Education And Risk Of Dementia: Findings From The Nun Study," J. Clin. Exp. Neuropsychol., 2003, 25(5), 671-9), others with head injury and repair (K.A. Jellinger, "Head Injury And Dementia," Curr. Opin. Neurol., 2004, 17(6), 719-23), or vascular pathology including, hypertension, coronary heart disease, atherosclerosis, smoking, hypercholesterolemia, obesity and diabetes ( . ayeux, "Epidemiology Of Neurodegeneration," Annu Rev. Neurosci., 2003, 26, 81-104).

In certain embodiments of the present invention, the compounds of the present invention or pharmaceutically acceptable salts thereof can be used to treat, or to reverse dementia or pre-existing symptoms of dementia. In one embodiment, a compound is used to prevent, treat or reverse Alzheimer's disease or symptoms of pre-existing Alzheimer's disease. While some types of dementia, such as that caused by Alzheimer's disease, often cause a steady and progressive decline in patients, other types of dementia can be prevented, treated, or reversed by addressing the underlying conditions. Vascular dementia (VD) is another common type of dementia besides AD. Vascular problems in the brain or body (most commonly strokes) are the main causes of VD. VD generally occurs suddenly, frequently after a stroke. In general VD does not progress steadily, however, like AD-related dementia. Those afflicted with VD may have long periods of stability or even improvement, but quickly develop new symptoms if more strokes occur.

Pseudodementia refers to severe depression in some elderly who suffer anxiety and fear that their mental abilities and memory are declining. Cognitive changes, memory loss, and slowed motor movements are typical of this condition. This type of depression may also trigger other symptoms, like those of senile dementia, including apathy, inability to answer simple questions correctly, poor eye contact, or little spontaneous movement. Treatment of the underlying depression will cause the dementia like symptoms to disappear. In an embodiment, a compound of the invention is used to prevent, treat, or reverse vascular dementia or pre-existing symptoms of vascular dementia. In another emdodiment, a compound of the invention is used in combination with a second compound to prevent, treat, or reverse vascular dementia or pre-existing symptoms of vascular dementia.

In another embodiment, a compound of the invention is used to prevent, treat, or reverse pseudodementia or pre-existing symptoms of pseudodementia. In another embodiment, the compound is used alone or in combination with another pharmaceutical agent effective in the treatment of dementia.

The compound of the invention is also useful in the treatment of diseases when used alone or in combination with other chemotherapeutics. For example, when used for the treatment of cancer, the compounds of the invention may be administered alone or in combination with one or more pharmaceutically acceptable, inert or physiologically active diluents, adjuvants or chemotherapeutic agents selected from the group consisting of phomopsin, dolastatin, Avastin, steganacin, paclitaxel, taxotere, vinblastine, vincristine, vindesine, vinorelbine, navelbine, colchicine, maytansine, ansamitocin, Iressa, Tarceva, Herceptin, lapatinib, vandetanib, Sorafenib, BAY-57-9006, bevacizumab, cetuximab, gemtuzumab, panitumumab, rituximab, tositumomab, trastuzumab, apolizumab, oregovomab, mitumomab, alembuzumab, ibritumomab, vitaxin, SU-6668, semaxanib, sunitinib malate, SU- 14813, vandetanib, ecentin, CP-547632, CEP-7055, AG-013736, pazopanib, combretastatin, squalamine, combrestatin A4 phosphate, TNP-470, neovastat, dasatinib, imatinib, nilotinib, sorafenib, sum^'tinib, triethylenethiophosphoramine, alitretinoin, altretamine, arsenic trioxide, asparaginase, bexarotene, denileukin diftitox, hydroxycarbamide, masoprocol, mitotane, pegaspargase, tretinoin, raltitrexed, IL-10, IL-12, bortezomib, leuprolide, interferon β, pegylated interferons, atrasentan, melphalan, cyclophosphamide, chlormethine, chlorambucil, trofosfamide, ifosfamide, nitromin, busulfan, thiotepa, chlorambucil, CC-1065, temozolomide, pipobroman, dacarbazine, mechlorethamine, procarbazine, uramustine, RSU-1069, CB-1954, hexamethylmelamine, cisplatin, carboplatin, oxaliplatin, BBR3464, satraplatin, tetraplatin, iproplatin, amsacrine, netropsin, pibenzimol, mitomycin, duocarmycin, dactinomycin, distamycin, mithramycin, chromomycin, olivomycin, anthramycin, bleomycin, liblomycin, rifamycin, actinomycin, adramycin, trichostatin A, propamidine, stilbamidine, rhizoxin, nitroacridine, geldamycin, 17-AAG, 17- DMAG, plicamycin, deoxycoformycin, levamisole, daunorubicin, doxorubicin, epirubicin, idarubicin, mitroxantrone, valrubicin, carmustine, fotemustine, lomustine, streptozocin, gemcitabine, 5- fluorouracil (5-FU), fludarabine, cytarabine, capecitabine, mercaptopurine, cladribine, clofarabine, thioguanine, pentostatin, floxuridine, pentostatin, aminopterin, methotrexate, pemetrexed, camptothecin, irinotecan, topotecan, epipodophyllotoxin, etoposide, teniposide, aminogluthetimide, anastrozole, exemestane formestane, letrozole, fadrozole, aminoglutethimide, leuprorelin, buserelin, goserelin, triptorelin, abarelix, estramustine, megestrol, flutamide, casodex, anandron, cyproterone acetate, finasteride, bicalutamide, tamoxifen or its citrate salt, droloxifene, trioxifene, raloxifene or zindoxifene, a derivative of 17-p-estradiol such as ICI 164, ICI 384, ICI 182, ICI 780, testolactone, fulvestrant, toremifene, testosterone, fluoxymesterone, dexamethasone, triamcinolone, dromostanolone propionate, megestrol acetate, methyltestosterone, chlorotrianisene, hydroxy progesterone, medroxyprogesterone acetate, reloxafine, etanercept, thalidomide, revimid (CC-5013), aziridoquinones, misonidazole, NLA-1, RB-6145, misonidazole, nimorazole, RSU-1069, SR-4233, porfimer, photofrin, verteporfin, merocyanin 540, tin etiopurpurin, PUVA, aminolevulinic acid, methyl aminolevulinate, minodronate, zoledronic acid, ibandronate sodium hydrate or clodronate disodium, misonidazole, misonidazole, amifostene, oblimersen, TI P-1 or TIMP-2, marimastat, TLK-286 and mixtures thereof.

The following examples illustrate the invention. As will be understood by the skilled worker, these examples are representative and not limiting and the skilled worker will be able to modify the content in accordance with common knowledge according to the disclosure set forth herein.

In the Examples, the compounds referred to are of the structure:

wherein A is :

Example 1

Preparation of compound of formula El

The compound of formula El can be prepared as exemplified by the methods described in Fig-1 or Fig-2.

Experimental details for preparation of compound of formula El by method described in Fig-1 : I. Oxidation of 10 DAB III 1:

A 4 L reaction flask, rinsed with dried EtOAc (300 mL) and held under N₂, was charged with dried EtOAc (1250 mL). Agitation was begun and dried 1 (100 g, 0.184 mol) was added. The addition of USP EtOH (800 mL) followed and the reaction mixture was cooled to -1.3 °C (internal temperature). Anhydrous CuC (86.4 g, 3.5 eq) was added and solids from the sides of the flask were washed into the mixture with anhydrous EtOH (450 mL). The reaction mixture was cooled to ≤ -13 °C and anhydrous TEA (90 mL, 3.5 eq) was added slowly. The reaction was monitored by HPLC /TLC. At 1 h the reaction was judged complete (< 5% 1).

TFA (36 mL) was added to quench the reaction and stirring continued for 15 min. The reaction mixture was transferred to a 10 L rotovap flask. EtOAc (500 mL) and EtOH (300 mL) were added to the reaction flask, stirred for 2 min and the rinse added to the contents of the rotovap flask, which was evaporated on the rotovap at 40 °C until no further distillation occurred (80 min). Acidified ethanol (300 mL) was added to the residue and the resulting slurry was transferred to a 2 L rotovap flask. The first rotovap flask was rinsed into the second with acidified EtOH (400 mL). Again, the mixture was evaporated on the rotovap at 40 °C until no further distillation occurred (1 h).

Acidified ethanol (305 mL) was added to the rotovap flask and the mixture was stirred on the rotovap at 40 °C for 10 min. The contents of the flask were then cooled to 5 °C and filtered. The rotovap flask was rinsed (2X) with cold (2 °C) acidified ethanol (300 mL) and the rinse was transferred completely to the filter to wash the solids. The solids were dried in the vacuum oven overnight at 45 °C to give 2a. HPLC Area % = 91.3%. Yield = 96.72 g.

II. Tesylation of 2a to form 3; To 2 . (96.72 g, 0.1783 mmol) in a 10 L rotovap flask was

added ethyl acetate (3000 mL, 30 mL/g). The solution was evaporated on the rotovap at 40 °C to approximately half the original volume (distilled volume = 1680 mL). Toluene (1000 mL, 10 mL/g) was added to the remaining solution and it was

evaporated on the rotovap at 40 °C until solids were obtained (45 min). The solids were suspended in toluene (1000 mL, 10 mL/g) and the suspension was evaporated on the rotovap at 40 °C (~1 h) to dry solids. The solids were transferred to a 2 L flask equipped with a mechanical stirrer, thermocouple, addition funnel and N₂ stream (previously purged for 5 min). The solids in the rotovap flask were rinsed into the reaction flask with anhydrous pyridine (292 mL, 3 mL/g) and agitation was begun. Upon dissolution, agitation was continued and the contents of the flask were cooled to -20 °C. Triethylsilyl trifluoromethanesulfonate (120.9 mL, 3.0 eq) was slowly added to the reaction mixture to maintain the internal temperature of the reaction at <-10 °C. After the addition of TES- OTf was complete, the reaction mixture was allowed to warm to - 5.8 °C and agitation continued. Thirty minutes after the addition of TES-OTf, sampling was begun and continued at thirty-minute intervals for HPLC/TLC. The reaction was judged complete at 2 h when HPLC/TLC indicated < 2% mono-TES derivative remaining. The reaction mixture was cooled to -17.5 °C. Methanol (19.3 mL, 0.2 mL/g) was added to quench the reaction and the reaction mixture was stirred for 5 min. While allowing the mixture to warm to ambient temperature, TBE (500 ml_) was slowly added with stirring and the mixture was transferred to a separator funnel. Residues remaining in the reaction flask were washed into the separator/ funnel with additional MTBE (200 ml_, 2 mL/g), then water (250 ml_, 2.5 mL/g) and saturated NH₄CI solution (250 mL, 2.5 mL/g) were added. The mixture was agitated and the layers were separated. The organic layer was transferred to a clean container. MTBE (250 mL, 2 mL/g) was added to the aqueous layer. It was agitated and the layers were separated. The second organic layer was washed into the first organic layer with MTBE (100 mL) and water (200 mL, 2 mL/g) was added to the combined layers. This mixture was agitated and the layers were separated. The organic layer was transferred to a 2 L rotovap flask and evaporated to a residue at 40 °C. n-Heptane (500 mL, 5 mL/g) was added to this residue and the solution was again evaporated to a residue at 40 °C. n-Heptane (1000 mL, ~10 mL/g) was added again and the solution was evaporated to one-half of its volume (distilled volume = 375 mL). n-Heptane (300 mL, ~2.5 mL/g) was added and the solution was stirred for 35 min on the rotovap at 40 °C. The solution was then cooled to -15.7 °C while stirring was continued for ~2.5 h. The solution was filtered. The solids remaining in the flask were rinsed into the filtration funnel with cold (<5 °C) n-heptane (100 mL) and all the solids were collected and dried overnight in the vacuum oven to give 111.2 g 3. HPLC Area % purity = 93.4%.

III. Reduction of 3 to prepare 4:

To a stirred solution of THF (560 mL, 5 mL/g) under N₂ in a 4 L reaction flask, was added 3 (111 g, 0.144 mol,) followed by

anhydrous ethanol (560 mL, 5 mL/g). The mixture was stirred to dissolve the solids and then cooled to -12 °C. 2 M LiBH₄ in THF (72 mL) was added slowly to control the reaction temperature (temp = - 11.9 to -9.7 °C). The reaction mixture was stirred and sampled for HPLC / TLC at 30 min intervals. Additional 2 M LiBH₄ in THF was introduced slowly (72 mL, 1.0 eq) to the reaction flask (temp = -9.6 °C to -7.1 °C) and agitation continued for 30 min. A third addition of 2 M LiBH₄ in THF (36 mL, 0.5 eq) was made in the same manner as the previous additions (temp = -7.6 °C to -6.7 °C), but with the bath temperature adjusted to 15 °C following the addition of the L1BH4 solution and to 12.5 °C ten minutes later. At 1 h following the final L1BH4 addition, the reaction was judged complete (mono reduced product <3% relative to 4).

The reaction mixture was cooled to -10.8 °C and 10% ammonium acetate in EtOH (560 mL) was added slowly and cautiously to allow the foam to settle and to control the temperature of the solution < -3 °C. The reaction mixture was transferred to a 2 L rotovap flask and any residues in the reaction flask were rinsed into the rotovap flask with EtOH (250 mL) and the contents of the rotovap flask were evaporated on the rotovap at 40 °C to an oil. Methanol (560 mL) was added to the residue. Water (1700 mL) was added to a 5 L flask equipped with an addition funnel and mechanical stirrer and was vigorously agitated. To precipitate the product, the methanol solution of the reaction mixture (748 mL) was slowly added to the flask containing water. The resulting mixture was filtered and the solids were washed with water (650 mL). A portion of the water was used to wash solids remaining in the precipitation flask into the filtration funnel. The solids were placed in the vacuum oven overnight at 45 °C to give 139.5 g of slightly wet non-homogeneous product, 4.

HPLC area % purity = 92.8%.

IV. Acetylation/Deprotection of 4_to prepare §1 Acetylation: To 4 (138 g, 0.178 mol) in a 2 L rotovap flask was added IPAc (1400 mL, 10 mL/g). The solution was evaporated on the rotovap at 40 °C to an oil. The procedure was repeated. Dried IPAc (550 mL) was then added to the residual oil and the contents of the rotovap flask were transferred to a 1 L reaction flask, equipped with a mechanical stirrer, addition funnel, thermocouple and a N₂ stream. The rotovap flask was washed into the reaction flask with IPAc (140 mL). DMAP (8.72 g, 0.4 eq), anhydrous TEA (170 mL, 7 eq) and acetic anhydride (100.6 mL, 6 eq) were added to the contents of the reaction flask and the mixture was stirred and heated to 35 °C. While continuing agitation and heating to 35 °C, the reaction was monitored by HPLC /TLC at 1-hour intervals.

Upon completion of the reaction, as indicated by the absence of 4 (3 h total time), the reaction mixture was cooled to 19.7 °C and saturated ammonium chloride solution (552 mL) was added. After stirring for 15 min, the mixture was transferred to a separatory funnel, the layers were separated and the aqueous layer was removed. Water (280 mL) was added to the organic layer and the mixture was stirred for 4 min. The layers were again separated and the aqueous layer was removed. The organic layer was transferred to a 2 L rotovap flask and the remaining content of the separatory funnel was washed into the rotovap flask with IPAc (200 mL). The mixture was evaporated to dryness on the rotovap at 40 °C to give ~124 g 5 as pale yellow oily foam.

Deprotection: To the rotovap flask containing 5 (124 g) was added methanol (970 mL, 7 mL/g). Sampling for HPLC/TLC was begun and continued at 1-hour intervals. The 5 /methanol solution was transferred to a 3 L reaction flask and agitation was begun. The remaining content of the rotovap flask was washed into the reaction flask with methanol (400 mL). Acetic acid (410 mL, 3 mL/g) and water (275 mL, 2 mL/g) were added and the reaction mixture was heated to 50 °C and stirred. With the temperature maintained between 50 °C and 55 °C, the reaction was monitored by HPLC / TLC at 1-hour intervals for the disappearance of the starting material, formation and disappearance of the mono-TES intermediate and formation of the product, 6.

Upon completion (~9 h), the reaction mixture was cooled to rt and transferred to

a 10 L rotovap flask. Solvent exchanges to n-heptane (2 X 1370 mL,

1 X 1000 mL) and IPAc (2 X 1370 mL, 1 X 1500 mL) were performed. IPAc (280 mL, 2 mL/g) and silica (140 g, 1 g/g) were added to the rotovap flask and the contents were evaporated on the rotovap at 40 °C until no further distillation occurred and free flowing solids were obtained. The dry silica mixture was loaded onto a silica pad (7 cm column, 280 g silica), conditioned with 2: 1 n-heptane/IPAc (500 mL,

2 mL/g silica) and washed (4X) with 2: 1 n-heptane/IPAc, 2 mL/g silica, 3400 mL total) and (4X) with 1: 1 n-heptane/IPAc (3020 mL total, 2 mL/g silica) until all impurities were removed as indicated by TLC. Each wash (~840 mL) was collected as a separate fraction and analyzed by TLC. The silica pad was then washed (5X) with waEtOAc (1% water, 1% AcOH in EtOAc) (3950 mL total, 2 mL/g silica) and with 1 : 1 MeOH/EtOAc and each wash (~840 mL) was collected as a separate fraction. The product eluted with fractions 11-15. The fractions containing 6 as indicated by HPLC/TLC were combined, transferred to a rotovap flask and evaporated to dryness on the rotovap at 40 °C. The residue in the flask was dissolved and

evaporated to dryness: first with IPAc (1055 mL) and n-heptane (550 mL) and a second time with IPAc (830 mL) and n-heptane (410 mL). IPAc (500 mL) was then added to the residue, the solution was transferred to a 2 L round bottom flask and n-heptane (140 mL) was added. The resulting solution was evaporated on the rotovap and dried in the vacuum oven at 40 °C to give 6 as foam. To dissolve the foam, IPAc (160 mL) was added to the flask followed by toluene (800 mL). The solution was evaporated on the rotovap under vacuum at 50 °C until half of the solvent was removed and solids were forming. The contents of the flask were stirred and cooled to 21 °C for 1.5 h. The solids were filtered in a 90cm filtration funnel on #54 Whatman filter paper and were washed with toluene (165 mL), transferred to the vacuum oven and dried at 40 °C to give 62.6 g of 6. H PLC area % = 96.9%

VI. Acetal Formation: 6 to 7 To a 3 L reaction flask containing 6 (25 g, 42.4 mmol) was added toluene (375 mL) and the reaction mixture was cooled to ~ -15 °C. TFA (9.8 mL, 3.0 eq) was slowly added. This was followed by the addition of acrolein diethyl acetal (8.7g) and the reaction was monitored by HPLC until <3% of 6 remained.

Hydrated silica was prepared by mixing silica (25 g) and water (25%) and a "basified silica" mixture was prepared by mixing a solution of K₂C0₃ (17.6 g, 3.0 eq) in water (1 mL/g 6) with 50 g silica.

Upon reaction completion, the hydrated silica was added to the reaction mixture and it was stirred for 30-45 min while maintaining the temperature <5 °C. The basified silica was then added to the mixture while continuing to maintain the temperature <5 °C and the pH >5. After stirring for ~15 min, the mixture was filtered. The silica was washed with ~20 mL/g toluene and the filtrates were combined and concentrated. The residue was digested with 1 mL/g toluene for ~4 h. The resultant solids were filtered and washed with 80:20 toluene/heptane to give 25 g of 7. HPLC area % = 98%. Mass yield = 66%.

VII. Preparation of Compound 10 from 7i

To THF (300 mL, 8 mL/g) stirring in a 1 L reaction flask (rinsed with THF (500 mL)) was added 7_(35.7 g, 0.0570 mol). Purified 8a (30.9 g, 1.25 eq) was added to the reaction mixture followed by the addition of NMM (11.5 mL, 1.8 eq), DMAP (2.77 g, 0.4 eq) and THF (75 mL, 2 mL/g). The mixture was stirred while l\l₂ was bubbled from the bottom of the flask to mix and dissolve the solids. Pivaloyl chloride (11.5 mL, 1.6 eq) was then added slowly to the reaction mixture. The reaction mixture was warmed and the temperature maintained at 38 °C ± 4 °C while stirring continued and N₂ continued to be bubbled from the bottom of the flask. The reaction mixture was analyzed by HPLC/TLC for consumption of starting material and formation of the coupled ester, 9a, at 30 min intervals beginning 30 min after the addition of the pivaloyl chloride.

After 1 h the reaction was judged complete and the reaction mixture was cooled to 2 °C. 0.5 N HCI in MeOH (280 mL, ~20 mL/mL NMM) was added to maintain the pH of the reaction mixture = 1.5-1.9. The reaction mixture was stirred at 2 °C ± 2 °C and monitored by

HPLC/TLC at 30 min intervals for consumption of 9a and formation of 10 and the acrolein acetal hydrolyzed by-product. Upon completion at 2 h the reaction was quenched with 5% aqueous sodium

bicarbonate (300 mL) and IPAc (185 mL, 5 mL/g) was added. The reaction mixture was transferred to a 2 L rotovap flask and the reaction flask rinsed into the rotovap flask 2X with 60 mL IPAc. The mixture was evaporated under vacuum at 40 °C until a mixture of oil and water was obtained. IPAc (200mL) was added to the oil and water mixture and the contents of the flask were transferred to a separatory funnel. The reaction flask was rinsed into the separatory funnel with IPAc (100 mL) and the contents of the separatory funnel were agitated and the layers were separated. The aqueous layer was removed. Water (70 mL) was added to the organic layer and, after agitation, the layers were separated and the aqueous layer was removed. The organic layer was transferred to a rotovap flask and evaporated under vacuum at 40 °C to a foam, which was dried in the vacuum oven to give 64.8 g crude 10. HPLC area % = 45.5%. VIII. Purification Procedures:

Normal Phase Chromatography: The 6" Varian DAC column was packed with Kromasil (5 Kg, lOpm, 100 Λ normal phase silica gel). The 50-cm bed length provided a 9 L empty column volume (eCV). The column had been regenerated (1 eCV 80:20 waMTBE:MeOH) and re-equilibrated(l eCV waMTBE, 1 eCV 65:35 n-heptane:waMTBE). The crude 10 (64.70 g), was dissolved in MTBE (180 ml_) and heated to ~ 40 °C. n-Heptane (280 mL) was slowly added to the solution. This load solution was pumped onto the column using a FMI "Q" pump. The column was then eluted with 65:35 n-heptane:waMTBE at 800 mL/min. A 34 L forerun (~3.8eCV) was collected followed by 24 fractions (500 mL each). Fractions 1 through 23 were combined and concentrated to dryness on a rotovapor. The residue was dried in the vacuum oven overnight to provide 41.74 g 10. HPLC area % = 99.4%.

Final Purification: The normal phase pool was dissolved in USP EtOH (6 mL/g) and concentrated to dryness three times. The resultant residue was dissolved in USP EtOH (2 mL/g). This ethanolic solution was slowly added drop-wise to water (deionized, 20 mL/g) with vigorous stirring. The resultant solids were vacuum filtered and washed with cold DI water. The solids were dried in the vacuum oven at 40 °C overnight to give 38.85 g 10. HPLC area % = 99.5%.

IX. Separation of diastereoisomers of formula 10 by Normal Phase Chromatography

The compound of formula 10, (570mg) which comprises a mixture of diasteroisomers is dissolved in 35:65 MTBE/n-heptane. The solution is loaded onto a flash chromatography column packed with spherical silica (YMC-1701, 56 g), which has been conditioned with 35:65 MTBE/n-heptane. The column is eluted with 35:65 TBE/n- heptane and fractions (25mL) collected. Fractions containing the pure product as indicated by visual spotting (to identify the elution of UV active material) and by TLC analysis (50:50 MTBE/n-heptane) are collected, pooled and concentrated to the diastereoisomer of formula El as a white solid.

The compound El was characterized by IMMR, including ¹H, ¹³C, HMBC, HSQC, NOESY, COSY and gHSQMBC. The compound of formula El was also analyzed by β-tubulin binding modeling studies.

Examples 2 and 3

Preparation of E2 and E3 (Epoxides)

Metachloroperoxybenzoic acid (0.789 g, 4.2816 mmol) was added to a solution of the compound of formula El (2.98 g, 3.425 mmol) in anhydrous CH2CI2, equipped with a magnetic stir bar and held under nitrogen at 0°C. The solution was stirred and allowed to gradually come to room temperature. The progress of the reaction (over several days) was monitored by LC-MS. On completion, the reaction mixture was then diluted with CH₂CI₂ and quenched with NaHCO3 at 0°C. The organic layer was washed with NaHCO3, water, brine and dried over anhydrous a2SO₄. The solvent was evaporated and the crude product purified by normal phase column chromatography to afford the crude epoxides mixture E2 and E3 as white solids (1.79 g).

The crude epoxide mixture was loaded on a Kromasil normal phase column (packed with 100A, lOpm media) and eluted with 55:45 n- heptane:waIBAc (wet acidified isobutyl acetate) to provide the two separated epoxides as white solids (0.345g and 0.218g respectively and each about 98% pure by HPLC area percent). Alternative preparation of Compounds E2 and E3:

Alternatively, the compounds E2 and E3 can by the method prepared as described in Fig-3.

(a) Preparation of the compound 11 :

mCPBA (0.689g, 2.995 mmol, 75%mCPBA) was added to an ice- cold solution of compound 7a (1.5g, 2.396 mmol) in anhydrous CH2CI2 under nitrogen atmosphere and stirred. The reaction was judged complete at ~3h by LC-MS and quenched by addition of satd. NaHC0₃ solution at 0°C. The organic layer was separated, washed with water, brine, and dried (Na₂S0₄). Evaporation of the organic layer and subsequent drying at 40°C in the vacuum oven provided 1.2 g of the epoxide 11.

(b) Preparation of the compound 12:

PivaloyI chloride (0.08mL, 0.6681mmol) was added to a solution of the epoxide 11 (0.240g, 0.5568 mmol), 8fe_(0.238g, 0.3712 mmol), NMM (N-Methylmorpholine-N-oxide) (0.08mL, 0.7424 mmol) and DMAP (4-Dimethylamino pyiridine) (18mg, 0.1484 mmol) in anhydrous THF (lOmL) at room temperature under nitrogen atmosphere and stirred. The reaction was quenched by addition of satd. NH₄CI solution when judged complete. The solvents were evaporated and the residue suspended in IPAc. The IPAc layer was washed with satd. NH₄CI solution, water and concentrated to provide the coupled epoxide 12.(0.682 g) as a solid.

(c) Preparation of the compound E2&E3.

0.5 N HCI in MeOH (2 mL) was added to an ice-cold solution of the compound 12 above (0.650 g, 0.6292 mmol) in methanol (5 mL) to adjust the pH of the reaction mixture to about 1.5. The reaction mixture was stirred at ~ 0°C and monitored by HPLC/TLC for the formation of the product. Upon completion at 3 h, the reaction was quenched with 5% aqueous sodium bicarbonate (5 mL). The solvents were removed under reduced pressure and the residue suspended in IPAc. The mixture was washed with water and the organic layer was rotostripped to give the desired epoxides E2 and E3 as a foam (0.4g). The product was characterized by HPLC and LC-MS.

Example 4

Preparation of E4 fS-DioO

A 25 mL round bottom flask, equipped with a magnetic stir bar, was charged with EtOAc (6 mL) and the compound of formula El (500 mg 0.575mmol) at room temperature. Water (6 mL) was then added followed by the dihydroxylating reagent, AD-mix-β (500 mg) (Aldrich) (Reagent for Sharpless Asymmetric Dihydroxylation, contains chiral ligand containing dihydroquinidine (DHQD)₂PHAL), potassium ferricyanide, potassium carbonate and potassium osmate) and stirred for a couple of days, monitoring the reaction progress periodically by LC-MS. Additional quantities of the reagent AD-mix-β were added, and the reaction continued to be monitored periodically. The reaction was judged complete after a week and was quenched with sodium sulfite (3.2 g), water (10 mL), and EtOAc (10 mL). After stirring for about half an hour, the organic layer was separated and washed with saturated NaHC.03 solution. The solution was then dried over anhydrous sodium sulfate and evaporated to provide the crude product. The crude product was purified by normal phase chromatography using a Kromasil column (lOOA, 10μιη media) and 15:85 n-heptane;waMTBE (wet acidified methyl-rert-butyl ether) as the mobile phase to afford the purified compound E4 as a white solid (0.232g, ~99% by HPLC area percent). The product was characterized by HPLC/LC-MS and NMR.

Example 5

Preparation of E5 (R-dioD

A 25 mL pear shaped flask, equipped with a magnetic stir bar, was charged with EtOAc (5 mL), water (5 mL) and AD-mix-a (300 mg) (Reagent for Sharpless Asymmetric Dihydroxylation, contains chiral ligand containing dihydroquinine (DHQ)₂PHAL), potassium ferricyanide, potassium carbonate and potassium osmate). The compound of formula El (300mg, 0.345mmol) was then added and the reaction stirred at room temperature, monitoring the progress periodicall by LC-MS. More AD-mix-a (300 mg) was added after a couple of days and the reaction continued to stir.. The reaction was judged complete after two weeks (by LC-MS) and quenched by the addition of sodium sulfite (3 g), water (10 mL), and EtOAc (10 mL). The EtOAc layer was separated and washed with saturated NaHCO₃ solution (10 mL), dried with Na₂SO₄ and concentrated. The crude compound was purified by normal column chromatography using a Kromasil column (ΙΟθΑ, ΙΟμηι media) and 15:85 n- heptane:waMTBE (wet acidified methyl-tert-butyl ether) as the mobile phase to afford the purified compound E5 as a white solid (0.192g, ~98% by HPLC area percent). The product was characterized by HPLC/LC-MS and NMR.

Example 6

Preparation of E6 A round bottomed flask was charged with the compound of formula El (0.320 g, 0.3583 mmol) in THF (10 mL) at room temperature. Pd/C (0.170 g) was added to the solution and a Hydrogen balloon was fitted to the flask and stirred. The reaction, sampled by HPLC/LC-MS, showed completion after 1.5 hours. The mixture was filtered through celite and washed with THF (Tetrahydrofuran) (15 mL). The filtrate was then concentrated to an oil and dissolved in a minimum amount of MTBE (Methyl-f-butyl ether). The TBE solution was added to a flak containing excess n-Heptane to precipitate the product as white solids which was dried in a vacuum oven for two hours to affored ~ 0.310 g of crude product. A second, identical reaction was done and crude product was combined (total 0.55 g) for purification by normal phase column chromatography using a Kromasil column (ΙΟθΑ, lOpm media) and 65:35 n-heptane:waMTBE (wet acidified methyl-te/t-butyl ether) as the mobile phase to afford the purified compound E6 as a white solid (0.333g, ~99% by HPLC area percent). The product was characterized by HPLC/LC-MS.

Example 7

Preparation of E7 A 50 mL round bottom flask, equipped with a magnetic stir bar, was charged with the compound of formula El (1.0 g) in THF (16 mL) at room temperature. Water (10 mL), followed by OSO4 (250 pL) solution in tert-butanol (Molarity?) and NMO (N-Methylmorpholine- N-oxide) (0.210 g) were added to the reaction mixture and stirred for three days, at which time LC-MS indicated that the reaction had gone to completion. Sodium sulfite (400 mg) was added, followed by florosil (2.2 g) and stirred for 10 minutes. The solution was filtered by Buchner funnel and washed with about 75 mL of EtOAc. The organic layer was then concentrated and the crude dihydroxylated product used as such in the next step. This intermediate has the structure in which A is

A 50 mL pearshaped flask, equipped with a magnetic stir bar, was charged with the intermediate from previous reaction and THF (5 mL) at room temperature. Water (5 mL) was then added followed by NaIO₄ (0.568 g, 2.68 mmol). Stirring continued and after about 2.5 hours LC-MS analysis showed evidence of the formation of the aldehyde and the reaction was transferred to a 100 mL round bottom flask. The solvent evaporated and the precipitate was washed with EtOAc (50 mL) and filtered to remove inorganic salts, washing twice with EtOAc (20 mL). The filtrate was then concentrated. Toluene (15 mL) and EtOAc (5 mL) were added and the solution left to stand for two days. MTBE (Methyl-t-butyl ether) (20 mL) was added and layers separated in a separatory funnel. The organic layer was separated, dried over Na2SO₄ and concentrated to provide the product E7 (1.03 g) as foam which was characterized by HPLC and LC-MS.

Example 8

Preparation of E8

A 5 mL pearshaped flask, equipped with a magnetic stir bar, was charged with the compound of formula E7 (0.1 g, 0.115 mmol) and EtOH (0.8 mL) and stirred at room temperature. HNMe₂ (0.25 mL) added to reaction and allowed to stir for 20 minutes at which time AcOH (35 microL) and NaCNBH₃ (0.25 mg) were added. The stirring was continued for two hours at which time LC-MS indicated the reaction had gone to completion. A second reaction was done on 0.5g of E7 and crude products were combined and purified by normal phase column chromatography using a Kromasil column (lOOA, ΙΟμηη media) and eluting initially with 80:20 waEtOAc: MeOH i.e wet acidified ethyl acetate ; methanol and subsequently with 50:50 waEtOAC : MeOH as the mobile phase to afford the purified compound E8 as a white solid (0.410g, ~98% by HPLC area percent). The product was characterized by HPLC/LC-MS.

Example 9

Preparation of deuterated analogs:

a) Preparation of Reagents

1. Preparation of Compound 15

The preparation of deuterium labeled BOC-p-N0₂ phenyl carbonate (compound 15) is shown in FIG. 4.

Compound 13 (9.96 g, 118 mmol) was placed in a 200 mL round bottom flask and pyridine (48 mL) was added as solvent.

Compound 14 (24.0 g, 118 mmol) was added and the mixture stirred under nitrogen for 4 hours. MTBE (50 mL) was added and the suspension was filtered to remove solids. The solids were washed with MTBE (50 mL). The combined filtrate was washed with water (20 mL) and the water wash back extracted with MTBE (25 mL). The combined organic layer was washed with IN HCI (50 mL x 5), NaHC0₃ (10%, 50 mL x 2), Na₂C0₃ (50 mL), NaHC0₃ (50 mL X 2), water (50 mL) and brine (50 mL). The organic layer was dried with Na₂S0₄. The solvent was removed and the residue was dissolved in ethanol (82 mL). Water (93 mL) was slowly added to precipitate solids. The suspension was placed in the refrigerator to cool overnight. The suspension was filtered and the solid collected and washed with a solution of ethanol (82 mL)/water (93 mL). The washed solid was placed in a vacuum at room temperature for two days to give 13.8 g of compound 15 (46.9% of theory). HPLC area % = 88.4%, m/e = 248. 2. Preparation of die-di-tert-Butyl dicarbonate: 18 Compound 18, was prepared as shown in FIG. 5 following a similar procedure described for di-tert-butyl dicarbonate in Organic

Synthesis, Coll. Vol. 6, 1988, 418; and Vol. 57, 1977: 45.

In general, the preparation of compound 18 may be performed by the carboxylation of compound 13 to form a metal carboxylate, such as the potassium carboxylate compound 16. Carbonylation of compound 16 with a carbonylation reagent, such as phosgene or a phosgene equivalent, such as triphosgene (CCI3OCOOCCI₃, Aldrich), afford the tricarboxylate diester compound 17. Compound 17 may be decarboxylated with a base, such as an amine base, such as DBU in an organic solvent such as CCI₄ to form compound 18.

2a. Preparation of Compound 17 To a solution of compound 13. (10.0 g, 119 mmol) in THF (30 ml_), in an oven dried flask fit with a reflux condenser and held under N_2/ were added THF (50 ml_) and potassium (5.8 g, 1" pieces in heptane). The reaction was stirred at room temperature for 5 h and then stirred overnight at 55 °C. The following morning the reaction mixture was cooled to room temperature and then to -5 °C in an ice-salt water bath. C0₂ gas was bubbled through the reaction mixture for 45 min. The bubbler was removed and replaced with a septum through which 20% phosgene/toluene (35 ml_) was added over ~15 min. Stirring continued for 45 min when the reaction mixture was flushed with N₂ for 1 h to remove the excess phosgene. Stirring was discontinued and the solvent was evaporated on the rota vapor at ~ 0 °C using the ice-water bath. The concentrate was placed in the freezer overnight at ~ -20 °C. The following morning the flask was removed from the freezer and pentane (~300 ml_, stored in freezer) was added to the reaction mixture. Celite (~50 cc) was added and the resulting slurry was filtered over a Buchner funnel. The solids were washed with pentane (~150 mL), concentrated and stored in the freezer (solidified within 10 min). The following morning the filtrate was dissolved in pentane (300 mL) at room temperature and the clear solution was placed in the freezer for 1 h. Crystals formed. After removing ~100 mL pentane on the rotavapor, the mixture was filtered to give 4.2 g of white crystalline solid 17. The mother liquor was concentrated to ~15 mL and was stored in the freezer.

2b. Preparation of 18 by Decarboxylation of 17

To a stirred solution of 17 (2.7 g) held at rt in carbon tetrachloride (20 mL) was added, with vigorous stirring, Dabco™ (25 mg). The immediate vigorous evolution of CO₂ was noted. IR analysis after 2 h showed no tricarbonate remaining. The carbon tetrachloride was removed and DCM (25 mL) was added. This was followed by the addition of cold (in the freezer 15 min) 0.5 N NaOH (20 mL). After stirring the reaction solution for 20 min, the layers were separated. The organic layer was washed with 10% citric acid, 5%

NaHCO₃/brine (1: 1), dried over Na₂SO₄ and concentrated to give ~2.0 g 18 as an oil. b) Preparation of deuterated compounds

Method to Prepare Compound 22b from Compound 19

An exemplary preparation of a deuterium labeled taxane analog, 22b is outlined in FIG. 6. This process generally includes removal of the t-BOC protecting group from the side chain nitrogen of the advanced taxane intermediate, acylating the side chain nitrogen with an appropriate stable isotope labeled acylating agent and forming the acrolein acetal bridge on the taxane backbone. 1. Synthesis of Compound 20: BOC Deprotection:

To a solution of 19 (1.5 g, 1.8 mmoi) in DCM (30 mL) in a 250 mL Camile® reactor cooled to -3 °C was added water (1 mL) followed by the dropwise addition of TFA (4 mL) over 2 min. At ~16 h

LC/MS analysis indicated more than 60% conversion of the starting material. The reaction mixture was poured into a cold flask and the reactor was rinsed into the reaction flask with coid DCM. The mixture was poured onto a 25 g silica plug conditioned with heptane and eluted with heptane (100 mL), 50:50 EtOAc/heptane (250 mL), 75:25 EtOAc/heptane (250 mL), EtOAc (500 mL) and finally 12% MeOH/DCM/1% AcOH (~1.5 L). The fractions containing the amine, which eluted with the middle 1200 mL, were collected and

concentrated on the rotavapor (with evaporation of most of the AcOH) to give 2.2 g of crude 20. for use in the next step.

2. Synthesis of Compound 21: Addition of d₁₈-BOC

anhydride

To a solution of 20 (700 mg) in DCM (7 mL) at room temperature water (3 mL) and TEA (~1 mL) were added with stirring. After 5 min, a solution of 7 (250 mg) in DCM (1 mL) was added to the reaction mixture and the mixture continued stirring for 1 h when LC/MS analysis indicated that most of the starting material had been converted to 21. Following the introduction of additional TEA (1 mL), the remainder of the compound 20 pool (1.5 g) in DCM was added to the reaction mixture. Compound 7 (900 mg) was added and the mixture stirred overnight, after which the layers of the solution were separated. The organic layer was collected and evaporated. The crude concentrated solution was loaded onto a column and eluted with 40% EtOAc/heptane to give 200 mg of 21. 3. Synthesis of Compound 22b: Acrolein Dimethyl Acetal Condensation To a solution of 21 (200 mg, 0.24 mmol) in DCM (5 mL), stirred under N₂ at room temperature, were added 3,3-dimethoxyprop-l- ene (0.15 g, 1.5 mmol) and CSA (0.006 g, 0.1 eq). The reaction mixture was stirred and monitored by LC/MS. After 2 h, LC/MS analysis indicated >80% conversion of starting material to 22b. After 3 h, LC/MS indicated the presence of < 10% starting material with later impurities beginning to develop. 5% NaHC03 (25 mL) was added. This was followed by the addition, with stirring, of DCM (25 mL). The layers were separated and the aqueous layer was extracted with additional DCM (25 mL). The organic layers were combined, washed with brine (50 mL), dried over Na₂S0₄, concentrated and dried under vacuum for 30 min to give 250 mg of crude 22b, which was submitted for purification. c) Alternative method to prepare compound 22b:

Preparation of deuterated side chain:

An exemplary preparation of a deuterium labeled side chain analog, 29 is outlined in FIG. 7. This process generally includes protecting the free acid as an ester, removal of the N-O-acetal protecting group and the t-BOC protecting group from the side chain, acylating the side chain nitrogen with an appropriate stable isotope labeled acylating agent, reprotecting the nitrogen and oxygen, preferably as an Ν,Ο-acetal and hydrolyzing the ester to the free acid or a stable salt.

1. Synthesis of Compound 23: Methyl ester formation Pivaloyl chloride (Piv-CI, 8.5mL, 69.6mmol, 1.5 equiv) was added dropwise to a solution of compound 8 (20g, 46.4mmol), methanol (MeOH, 4.5mL, 139mmol, 3 equiv), N-methylmorpholine (NMM, 15.3mL, 139mmoI, 3 equiv) and Ν,Ν-dimethylamino pyridine (DMAP, 2.26g, 18.56mmol, 0.4 equiv) in anhydrous tetrahydrofuran (THF, lOOmL) at room temperature and stirred. The reaction was judged complete by HPLC analysis at 15 minutes. The reaction mixture was cooled to 0°C with an ice-water bath and quenched by the addition of water. The solvents were rotostripped and the residue was suspended in isopropyl acetate (IPAc). The contents were transferred to a separatory funnel and the IPAc layer was washed with water, satd. NH₄CI solution, NaHC0₃ solution, water and brine. Evaporation of the organic layer under vacuum afforded the crude product which was dried overnight in the vacuum oven to provide 23g of compound 23.

2. Synthesis of Compound 24: Deprotection of Ν,Ο acetal

To a cold solution of compound 23 (21g) in methanol (lOOmL) was added a solution of 0.5N aq. HCI in methanol (20mL, till pH reached ~2). The reaction was gradually allowed to warm up to room temperature and the progress monitored periodically by TLC (10% methanol in dichloromethane) and judged complete at about 60 minutes. The reaction mixture was then cooled to 0°C and quenched by the addition of aq, NaHC0₃ solution. The solvents were rotostripped and the residue was suspended in dichloromethane (150mL). 10% aq. sodium metabisulfite solution (80mL) was added and the mixture stirred vigorously for about 30 minutes. The contents were transferred to a separatory funnel and the organic layer was washed with brine and rotorstipped to provide the crude product which was purified by normal phase chromatography to afford 8.7g of pure compound 24. 3. Synthesis of Compound 25; Deprotection of Boc group

To a solution of compound 24 (6.6g), at room temperature in dichloromethane (60ml_) and water (1.5mL) was added trifluoroacetic acid (60ml_) over a period of one minute and stirred. The reaction was judged complete at about 60 minutes by LC-MS analysis. The reaction mixture was then rotostripped and azeotroped twice with isopropyl acetate (50mL each time) to provide the trifluoroacetate salt, compound 25 (7.4g) to be used as such in the next transformation step.

4. Synthesis of Compound 26: Deuterated Boc protection To a solution of compound 25 (7.4g) in tetrahydrofuran (60mL) and water (lOmL) was added Ν,Ν-dimethylaminopyridine (DMAP, 7.5g) followed by compound 15 (7.5g) and stirred overnight at room temperature. Monitored progress of the reaction by TLC (5% methanol, 1% acetic acid in dichloromethane). An additional quantity of 3.5g each of DMAP and 15 was added and stirring continued. The reaction was quenched after several hours by addition of satd. NH₄CI solution (80mL). The organic solvent was rotostripped and isopropyl acetate (60ml_) was added to the mixture. The mixture was shaken in a separatory funnel and the IPAc layer was separated. The aqueous layer was re-extracted twice with IPac (60mL each time). The combined IPAc layers were concentrated the crude residue purified by normal phase chromatography to afford 4.2g of pure compound 26 as a solid. 5. Synthesis of Compound 28: N,0 acetal protection To a solution of compound 26 (4g) in anhydrous dichloromethane (25mL) was added a solution of compound 27 (4.47g, 1.5 equiv) in dichloromethane (15mL) followed by camphorsulphonic acid (CSA, 0.163g, 0.05 equiv) and stirred overnight at room temperature, under nitrogen atmosphere. The reaction was then quenched by the addition of satd. NaHC0₃ solution (80mL). The organic layer was separated and washed with water, 15% aq. sodium metabisulfite solution, water and brine. The organic layer was rotostripped to provide the crude product which was purified by normal phase chromatography to afford 3.07g of pure compound 28 as a solid.

6. Synthesis of Compound 29: Hydrolysis of methyl ester To a solution of compound 28 (3.07g) in tetrahydrofuran (30mL) and water (30ml_) was added sodium hydroxide pellets (0.312g) and stirred at room temperature. The reaction was judged complete by LC-MS analysis at 60 minutes. The mixture was rotostripped and extracted with isopropyl acetate thrice. Evaporation of the IPAc layer provided the compound 29 (3g) as a pale yellow solid.

Preparation of Compound 22b: An exemplary preparation of a deuterium labeled taxane analog

22b is outlined in FIG. 8. This process generally includes coupling the advanced taxane intermediate with the side chain and removal of the N-O-acetal protecting group. Synthesis of Compound 30: Coupling Reaction Piva!oyl chloride (Piv-CI, 1.12mL, 9.11mmol, 1.5 equiv) was added dropwise to a solution of compound 7a (3.80g, 6.07mmol), compound 29 (2.67g, 6.07mmol, 1 equiv), N-methylmorpholine (NMM, 1.7mL, 15.18mmol, 2.5 equiv) and N,N-dimethylamino pyridine (DMAP, 0.3g, 2.43mmol, 0.4 equiv) in anhydrous tetrahydrofuran at room temperature and stirred. The reaction was judged complete by HPLC/LC-MS analysis at about 3.5h and quenched by the addition of satd. NH₄CI solution. The contents were transferred to a separatory funnel and extracted with IPAc, washed with water, satd. NH₄CI solution, water and brine. Evaporation of the organic layer under vacuum afforded the crude product which was dried overnight in the vacuum oven to provide 7.74g of compound 30 as a solid. Synthesis of Compound 22b: Deprotection of Ν,Ο acetal

To a cold solution of compound 30 (7.5g) in methanol (80mL) was added a solution of 0.5N aq. HCI in methanol (4mL, pH 1.6) and stirred. The reaction progress monitored periodically by HPLC/LC- MS and judged complete at about 3.5h. The reaction mixture was then quenched at 0°C by the addition of satd. aq. NaHC0₃ solution. Methanol was rotostripped and the residue was extracted with IPAc. The IPAc layer was washed with water, 15% sodium metabisulfite solution, water and rotostripped to provide the crude which was purified by normal phase chromatography to afford 2.28g of pure compound 22b. cH Preparation of deuterated E4 fS-Pioi. compound 31) fFia- 91

A 25 mL round bottom flask, equipped with a magnetic stir bar, was charged with EtOAc (6 mL) and compound 22b (406 mg) at room temperature. Water (6 mL) was then added followed by the dihydroxylating reagent, AD-mix-β (668 mg) (Aldrich) (Reagent for Sharpless Asymmetric Dihydroxylation, contains chiral ligand containing dihydroquinidine (DHQD)₂PHAL), potassium ferricyanide, potassium carbonate and potassium osmate) and stirred for a couple of days, monitoring the reaction progress periodically by LC- MS. Additional quantities of the reagent AD-mix-β were added, and the reaction continued to be monitored periodically. Upon completion, the reaction was quenched with sodium sulfite (7.2 g) and water (50 mL). IPAc (50mL was added and the mixture was stirred for about half an hour. The organic layer was separated and and the aqueous layer was re-extracted with IPAc twice. The combined IPAc layer was washed with saturated NaHC0₃ solution and evaporated to provide the crude product. The crude product was purified by normal phase chromatography using a Kromasil column (ΙΟθΑ, lOpm media) and 15:85 n-heptane:waMTBE (wet acidified methyl-tert-butyl ether) as the mobile phase to afford the purified compound deuterated E4 (31)as a white solid (0.221g, 99.8% by HPLC area percent). The product was characterized by HPLC/LC-MS.

Preparation of deuterated E2 and E3 (32, 331 (Fiq-9)

Metachloroperoxybenzoic acid (0.160 g, 0.713 mmol) was added to a solution of the compound of formula 22b (0.502g, 0.571 mmol) in anhydrous CH₂CI₂ (15mL) at 0°C and stirred. The solution was allowed to gradually come to room temperature and stirring continued. The progress of the reaction (over several days) was monitored by LC-MS. On completion, the reaction mixture was then diluted with CH2CI2 and quenched with NaHCO₃ at 0°C. The organic layer was washed with NaHCO₃, water, brine and dried over anhydrous a2SO₄. The solvent was evaporated and the crude product purified by normal phase column chromatography to afford the purified deuterated epoxides deuterated E2 (67mg) and deuterated E3 (66mg) as white solids.

Example 10

The MTS proliferation assay

Day 1: Cells were plated in appropriate growth medium at 5xl0³ per well in 100 μΙ_ in 96 well tissue culture plates, Falcon, one plate for each drug to be tested. Column 1 was blank; it contained medium, but no cells. The plates were incubated overnight at 37°C in 5% CO2 to allow attachment. Day 2: Drug diluted in culture media was added to the cells at a concentration of 0.005 nM to 10 nM, in quadruplicate. After 48-72 hours of drug exposure, the MTS agent was added to all wells and incubated 1-6 hours (37°C, 5% CO2), depending on cell type, as per CellTiter 96^® AQueous IMon-Radioactive Cell Proliferation Assay (MTS), Promega. Plates were processed using a Bio-Tek Synergy HT Multi-detection microtiter plate reader at 490 nanometer wavelength and data were processed with KC4V.3 software. Data plots of drug concentration vs. absorbance were plotted and IC5₀ values were extrapolated for each of the tested compounds.

As summarized in Table 2, the IC₅₀ value for each tested compound in each of the various cell lines was determined. The clinical comparator drug, paclitaxel, was included in the experiment to allow comparison of the results of the candidate compounds to a clinically relevant standard in the taxane class. The results of all the compounds tested gave a wide range of IC₅₀ values, some of which were extrapolated from outside the actual range of drug tested and are thus represented as <0.002 nM. The MDR negative cell lines KB, SKNAS, DU145, MDAMB435s, and the HT29 are all cell lines sensitive to paclitaxel with IC50 <0.002 nM, while the MDR positive cell lines, KBV, MV522/Mdrl, MESSA/DOX are much less sensitive to paclitaxel and have IC₅₀ values of 500 nM and higher. These results are consistent with published studies where paclitaxel has been shown to be a good substrate for the MDR1 drug efflux pump, thus requiring significantly higher drug levels to reach equivalent cell cytotoxicity in MDR positive cell lines as compared to MDR- cell lines. Example 11

DETAILS OF XENOGRAFT ASSAY METHOD

Xenograft Methods Female CD-I nu/nu mice (NxGen Biosciences) were implanted with harvested tumor cells in a single subcutaneous site on the flank of the mice in the axillary region. Tumors were allowed to grow to 200 + 50 mm³, at which time the animals were sorted into

treatment groups of 8 animals per group based on weight (± 1 g body weight) and tattooed on the tail for permanent identification. Tumor volumes and body weights were determined twice weekly. The tumor volume was determined by measuring in two directions with vernier calipers and calculated using the formula: Tumor volume = (length x width²)/2. The data were plotted as the % change in mean values of tumor volume and body weight for each group. The tumor growth inhibition (%TGI) was determined as %TGI = lOO(l-Wt-Wc) : where W_t is the median tumor volume of the treated group at time x and W_c is the median tumor volume of the control group at time x. The log cell kill (LCK) was determined using the formula: LCK = (T-C)/3.32xT_d; where T = the time in days for the treated group to reach a terminal end point defined as % tumor volume; C = the time in days for the control group to achieve the same tumor volume; and T_< is the tumor doubling time in days for the control group. Cures were excluded from all tumor volume calculations.

Animals were dosed via i.v. bolus to the lateral tail vein. Treated animals were monitored daily for signs of morbidity and mortality. Animals with non-measurable tumors following treatment were monitored for at least twice as long as the control group took to reach their terminal endpoint, at which time they were designated as durable cures.

The results of this test are shown in Figure 10 (Efficacy on H526 sclc Xenografts) and Figure 11 (Efficacy on H526 sclc Xenografts). All compounds were employed at 18 mg/kg. Example 12

Cytototoxicity assay in example 10.

The data are shown in Figure 12.

Example 13

Compounds were evaluated for microsomal assay according to the descriptions by Di LI, Kerns EH, Hong Y, Kleintop TA, McConnell OJ, Huryn DM., J. Biomol. Screen. 8(4) :453-462, (2003) and Obach RS., Drug Metab. Dispos. 27: 1350-1359, (1999), both of which are incorporated herein in their entirity.

The microsomal stability data of the compounds are shown in Figure 13.

Example 14

PROTEIN ASSEMBLY ASSAY In one embodiment, the protein assembly assay was conducted according to the procedures as described by Mathew AE, Mejillano MR, Nath JP, Himes RH, Stella VJ, "Synthesis and Evaluation of Some Water-Soluble Prodrugs and Derivatives of Taxol with Antitumor Activity" J. Med. Chem. , 35, 145-151 (1992) and Georg GI, Cheruvallath ZS, Himes RH, Mejillano MR, Burke CT, "Synthesis of Biologically Active Taxol Analogues with Modified Phenylisoserine Side Chains" J. Med. Chem., 35, 4230 (1992). Both references are incorporated herein in their entirity.

Example 15

Neuronal Cell Cultures Deposition of β-amyloid peptide (Αβ) and hyperphosphorylation of the τ protein are associated with neuronal dysfunction and cell death in Alzheimer's disease (Michel Goedert et al., "A Century of Alzheimer's Disease," Science 2006, 314 (5800), 777-781). Extracellular deposition of β-amyloid peptide (Αβ) aggregates in the brain and/or hyperphosphorylation of the τ protein represent two defining pathological features of many neurodegenerative diseases or disorders for which the compounds of the present can be useful for treating, curing, preventing, ameliorating the symptoms of, or slowing or stopping the progression of. Αβ is derived from proteolytic cleavage of APP, a type I transmembrane glycoprotein that belongs to a family of proteins that includes APP-like protein (APLP) 1 and 2. Presumably, APP phosphorylation can facilitate the generation of Αβ, and can lead to the generation and/or progression of AD and symptoms associated therewith. Therefore, compounds the can proctect against Αβ-induced toxicity of neurons have the potential to be therapeutically useful for treating, curing, preventing, ameliorating the symptoms of, or slowing or stopping the progression of many degerateive disorders.

To determine whether the compounds of the present invention can protect neurons against Αβ-induced toxicity, primary cortical neurons were cultured at a density of 500,000 per 35 mm² cutout culture dishes and then exposed to 10μΜ of Αβ in presence or absence of Ei (TPI-287) , E₂ (ΤΡΪ-510), E₃ (TPI-511), E₅ (TPI-512) or E₄ (TPI-513) using the procedures described previously by Michaelis et al. ^ β-Amyioid-Induced Neurodegeneration and Protection by Structurally Diverse Microtubule-Stabilizing Agents" 2005, 312 (2), 659-668). Varying concentrations of TPI-287 and metabolites: TPI-510, TPI-511, TPI-512 or TPI-513, were tested. The effects of the Αβ peptide and E₁-E5 and E₈ were determined by monitoring neuronal cell survival using the Live/Dead assay as previously described by Michaelis et al. ("Protection Against Beta- Amyloid Toxicity in Primary Neurons by Paclitaxel" 1998, J. Neurochem., 70, 1623-1627). After 48 h of exposure to Αβ and/or E₁-E5 and E₈, cells were labelled with 20 uM propidium iodide and 150 nM calcein acetoxy-methylester for 30 minutes at 37 °C. After incubation with the dyes, the dishes were rinsed with phosphate- buffered saline and placed on the stage of a Nikon inverted microscope (Nikon Eclipse TE200) with filters for fluorescein isothiocyanate and Texas Red. Digital images were captured with a Dage Camera and the percent of surviving neurons determined by cell counting.

The data obtained from the experiment are shown on FIGS. 15-16. FIG. 15 illustrates dose-dependent effects of Ei alone on neuronal viability. The graph shows percent neuronal cell survival for concentrations 10 nM, 50 nM; 100 nM, 200 nM, 1 μΜ and 10 μΜ. There was no statistically significant cell death observed following exposure to Ei at concentrations up to 200 nM. However, some citotoxicity was observed at concentrations of 1 μΜ and 10 μΜ. The differences in observed cell death between control and Ei-treated neuronal samples treated with El at 1 μΜ and 10 μΜ were statistically significant at **p< 0.005 for Ei at both 1 μΜ and 10 μΜ concentrations.

FIG. 16 illustrates the dose-dependent effects of Ei on neuronal viabiity in samples that were exposed to 10 μΜ of Ab peptide 2 hours following the pretreatment with the indicated concentrations of Ei. Concentrations of Ei, well below even 100 nM were very potent in protecting the neurons. Thus, there is not likely to be a need to achieve brain concentrations of Ei above 100 nM. Moreover, this concentration of Ei would avoid the toxicity that can be induced with the considerably higher concentrations of either Ei or E₂-E₅ and E₈. The observed difference in cell death between control and Ap-only treated neuronal cell cultures was statistically significant at p< 0.001. The observed differences in neuronal cell death between Ab-only treated samples and Ει+Αβ treated samples were statistically significant at p< 0.005 for concentrations of Ei ranging froml nM, 5 nM to 100 nM. Half maximal effective concentration (EC₅₀), the concentration of Ei for which 50% of its maximal protective effect on neurons was observed, was estimated to be about 10 nM.

FIG. 17 illustrates the dose-dependent effects of E₂ on neuronal cell viability. No statistically significant cell death observed between E₂- treated neuronal cultures and the control neuronal culture for concentrations of E₂ up to 400 nM. A statistically significant difference in cell death (p < 0.001) between control and E₂-treated neuronal cultures was only observed at concentrations higher than 400 nM. FIG. 18 illustrates the dose-dependent effects of E₃ on neuronal cell viability. No statistically significant cell death observed between E₃- treated neuronal cultures and the control neuronal culture for concentrations of E₂ up to 400 nM. A statistically significant difference in cell death between control and E₃-treated neuronal cultures was observed at concentrations of E₃ of 600 and 800 nM with P < 0.01 and at concentration of E₃ ΙμΜ with P≤ 0.001. FIG. 19 illustrates the dose-depent effects of E₅ on neuronal cell viability. No statistically significant cell death observed between control and Es-treated neuronal cultures at up to 800 nM of E₅. A statistically significant difference in cell death between control and E₅-treated neuronal cultures was only observed at 1 μΜ (P ≤ 0.001).

FIG. 20 illustrates the dose-depent effects of E₄ on neuronal cell viability. No statistically significant cell death observed between control and E₄-treated neuronal cultures at up to 600 nM of E₄. A statistically significant difference in cell death between control and E₄-treated neuronal cultures was only observed at concentrations of greater than 600 nM (P≤ 0.001).

The data in FIGS. 16-17 provide evidence that compounds of the present invention are effective at blocking Αβ-induced apoptosis in neurons. FIGS. 16-20 demonstrate that no statistically significant difference in neuronal cell death between control and the compounds of the present invention even at concentrations up to 800 nM. Example 16

Toxicity Tests E2, E3, E5 and E5 whose chemical structures are shown on the pages immediately preceding Example 1, were tested for possible toxicity at 1 nM, 20 nM, 50 nM, 100 nM, 200 nM, 400 nM, 600 nM, 800 nM and 1 μΜ. the indicated concentrations in primary neuronal cultures. 48 h after addition of the drug to the neuronal culture, the % of surviving neurons was determined using the Live/Dead assay as described in Example 15. The data obtained are presented in Figures 17-20. The data represent the mean (± SEM) % of surviving neurons in 6 fields/well from duplicate wells (~200 cells/field). Moreover, the data were obtained from 3 separate primary neuronal preparations. The significance of differences between control and TPI-510-treated neurons is indicated as * = P < 0.001. The significance of differences between control and TPI- 512-treated neurons is indicated: * = P < 0.001. The significance of differences between control and TPI-513-treated neurons is indicated: * = P < 0.001.

Each of the references cited within is expressly incorporated herein in its entirety. Although the invention has been described with references to the examples provided above, modifications can be made without departing from the spirit of the invention.

Claims

WHAT IS CLAIMED:

1. A compound of formula (I):

wherein ¹ is hydrogen, lower alkyi, aryl, loweralkylaryl, lower alkenyl or hydroxyloweralkyl, lower alkoxy or aryloxy; R² is hydrogen, lower alkyi, aryl, lower alkyi aryl, lower alkenyl or hydroxyloweralkyl; R³ is hydrogen, lower alkyi, aryl, loweralkylaryl, lower alkenyl, hydroxyloweralkyl or COR⁴ where R⁴ is hydrogen, lower alkyi, aryl, loweralkylaryl, lower akenyl or hydroxyloweralkyl; and A is a group having at least two atoms which are not hydrogen atoms and is of the formula -(CHA^n-AZ wherein n is 0 or 1; and A² is -CH₂A²⁰, -CH=CH₂, -C≡CH or CHO and A¹ and A²⁰ are independently selected for each occurrence from hydrogen, hydroxyl, amino, lower alkyi amino, dilower alkyi amino, or dilower alkyi amino in which the alkyi groups are joined to form a 4, 5, 6 or 7 membered ring, or a -N-linked morpholino group; or A¹ and A²⁰ jointly represent an oxygen atom a sulphur atom or a -NH- moiety; and esters especially pro-drugs thereof wherein one or more of the hydroxyl groups is esterified to form an in-vivo hydrolysable ester group; or pharmaceutically acceptable salts thereof.

2. The compound of claim l, having the structure of formula

wherein A and R¹, R² and R³ are as defined in relation to formula (I)- 3. The compound of any one of claims 1 to 2 wherein R³ is hydrogen or COCH₃.

4. The compound of any one of claims 1 to 3 wherein R² is phenyl or sec-butyl.

5. The compound of any one of claims 1 to 4 wherein R¹ is phenyl or tert-butyloxy.

6. The compound of any one of claims 1 to 5 wherein A is a CH=CH₂ group.

7. The compound of any one of claims 1 to 5 wherein A is a group. . The compound of any one of claims 1 to 5 wherein A is a group.

9. The compound of any one of claims 1 to 5 wherein A is a group.

10. The compound of any one of claims of 1 to 5 wherein A is a -CH₂-N(CH₃)2 group.

11. The compound of any one of claims 1 to 5 wherein A is a CH(OH)CH₂OH group.

12. The compound of claim 11 wherein A is a

group.

The compound of claim 11 wherein A is a

group. 14. The compound of any one of claims 1 to 13 wherein R¹ is 0- C(CH₃)₃, R² is CH₂CH(CH₃)₂ and R³ is COCH₃.

15. The compound of any one of claims 1 to 13 wherein R¹ is 0- C(CD₃)₃.

16. The compound of any one of claims 1 to 15 wherein R¹ is O- C(CD₃)₃, R² is CH₂CH(CH₃)₂ and R³ is COCH₃.

17. A compound of formula (XV);

wherein R² is hydrogen, lower alkyi, aryl, lower alkyi aryl, lower aikenyl or hydroxyloweralkyi; R³ is hydrogen, lower alkyi, aryl, loweralkylaryl, lower aikenyl, hydroxyloweralkyi or COR⁴ where R⁴ is hydrogen, lower alkyi, aryl, loweralkylaryl, lower akenyl or hydroxyloweralkyi; and A is a group having at least two atoms which are not hydrogen atoms and is of the formula -(CHA^-nA² wherein n is 0 or 1; and A² is -CH₂A²⁰, -CH=CH₂, -C≡CH or CHO and A¹ and A²⁰ are independently selected for each occurrence from hydrogen, hydroxyl, amino, lower alkyi amino, dilower alkyi amino, or dilower alkyi amino in which the alkyi groups are joined to form a 4, 5, 6 or 7 membered ring, or a -N-linked morpholino group; or A¹ and A²⁰ jointly represent an oxygen atom a sulphur atom or a -NH- moiety; and esters especially pro-drugs thereof wherein one or more of the hydroxyl groups is esterified to form an in-vivo hydrolysable ester group; or pharmaceutically acceptable salts thereof. 18. The compound of claim 17, having the formula:

19. The compound of claim 17, having the formula:

21. A pharmaceutical composition which comprises an anticancer effective amount of a compound as claimed in any one of claims 1 to 20 and a pharmaceutically acceptable carrier therefore.

22. The composition of claim any one of claims 1-20 in a form suitable for oral administration.

23. The composition of claim 21 further comprising a second anticancer agent . 24. The composition of claim 23 wherein the second anti-cancer agent is temozolomide.

25. A method of treating cancer in a patient, comprising administering an effective amount of the compound of any one of claims 1 to 20. 26. The use of the compound of any one of claims 1 to 20 in the manufacture of a medicament for the treatment of cancer.

27. The use of the compound of anyone of claims 1-20 for the treatment of cancer, wherein the cancer is selected from the group consisting of brain cancer, pancreatic cancer, breast cancer, ovarian cancer, prostate cancer, lung cancer, kidney cancer, liver cancer, bone cancer, cancer of the neck or head, and skin cancer.

28. The use of the compound of any one of claims 1-20 for treatment of cancer, wherein the cancer is a neuroblastoma or glial cell cancer.

29. A compound of the formula 29a

wherein M is H, or alkali metal.

30. A method of treating a neurodegenerative disease or tauopathy in a mammal, said method comprising administering to said mammal suffering from or susceptible to said neurodegenerative disease or tauopathy an effective amount of a compound of claim 1.

31. A method of treating or reversing the progression of neurodegenerative diseases or tauopathies in a mammal in need thereof, said method comprising administering to said mammal an effective amount of a compound of claim 2.

32. The method of any one of claims 30-31 wherein the neurodegenerative diseases or tauopathies are selected from the group comprising sporadic and familial Alzheimer's disease, mild cognitive impairment, Down's syndrome, Lewy body variant of Alzheimer's disease, Pick's disease, corticobasal degeneration, progressive supranuclear palsy, frontotemporal dementia with Parkinsonism linked to chromosome 17 or FTDP-17, Lou Gehrig's disease, sporadic or hereditary amyotrophic lateral sclerosis, polyglutamine or trinucleotide repeat diseases, Huntington's disease, sporadic and familial synucleinopathies, dementia with Lewy bodies, Parkinson's disease, multiple system atrophy, neurodegeneration with brain iron accumulation, neuronal intranuclear inclusion disease, hereditary spastic paraplegias, Charcot-Marie-Tooth disease, and sporadic or hereditary prion disease.

33. A method of treating a mammal suffering from or susceptible to post-surgical neurological deficits or neurological deficits associated with cardiac arrest, comprising administering to said mammal a therapeutically effective amount of the compound of claim 1.

34. A method of treating a mammal suffering from or susceptible to post-surgical neurological deficits or neurological deficits associated with cardiac arrest, comprising administering to said mammal a therapeutically effective amount of the compound of claim 2.

35. A method of preventing age-associated cognitive decline or symptoms thereof in a mammal, including a human, comprising administering to said mammal, including a human, an effective amount of a compound of the compound of claim 2.

36. The method according to claim 32, wherein the age-related cognitive decline is age-reiated short term memory deficit or short- term memory related task performance.

37. A method of treating a neurodegenerative disease in a patient in need thereof which comprises administering to said patient an effective amount of a compound of claim 1.

38. The method of claim 32 wherein the neurodegenerative disease is selected from senile cognitive decline, Alzheimer's disease, myasthenia gravis, tardive dyskinesia, and dementia associated with Down's syndrome or Parkinson's disease.

39. A method of treating a cognitive memory disorder which comprises administering a therapeutically effective amount of the compound or salt according to claim 1 to a patient in need thereof, wherein the cognitive memory disorder is selected from age related cognitive decline, mild cognitive impairment, and cognitive deficits in schizophrenia.

40. A method for treating a disorder or condition selected from stroke, traumatic brain injury, obsessive-compulsive disorder, psychosis, Huntington's chorea, tardive dyskinesia, hyperkinesia, dyslexia, schizophrenia, multi-infarct dementia, age-related cognitive decline, senile dementia of the Alzheimer's type, 7

Parkinson's disease, attention deficit hyperactivity disorder and Tourette's Syndrome in a mammal, comprising administering to a mammal in need of such treatment an effective amount of a compound according to claim 1.

41. A process of making a compound of Formula 29a according to the following synthetic scheme:

wherein: M is H, or alkali metal, R is lower alkyl, aryl, lower

alkylaryl or lower alkenyl, and Ar represents aryl.

42. A process of making compounds of Formula E2 and E3

according to the following synthetic scheme:

43. A process of making compounds of Formula 30 and 22b according to the following synthetic scheme: