Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D319/00—Heterocyclic compounds containing six-membered rings having two oxygen atoms as the only ring hetero atoms
  • C07D319/04—1,3-Dioxanes; Hydrogenated 1,3-dioxanes
  • C07D319/06—1,3-Dioxanes; Hydrogenated 1,3-dioxanes not condensed with other rings

Definitions

• the invention relates to protected 5,7-dihydroxy-4,4-dimethyl-3-oxoheptanoic acid esters and 5,7-dihydroxy-2-alkyl-4,4-dimethyl-3-oxoheptanoic acid esters for the synthesis of epothilones and derivatives and processes for Production of these esters, i.e. new intermediates and processes for their production and use.
• the process for the production of new intermediates is based on inexpensive starting materials, supplies the intermediates in high enantiomeric purities, in high chemical purity, in good yields and allows large-scale production.
• the invention is used in the synthesis of the C1-C6 segment required for the production of natural and synthetically modified epothilones or derivatives.
• the natural epothilones are 16-membered macrolide rings isolated from cultures of the Myxobacte around Sorangium Cellosum and represent a class of promising antitumor agents that have been tested to be effective against a range of cancer lines.
• R represents a C1-C4-alkyl radical, such as the methyl, ethyl, n- or i-propyl, n-butyl or tert-butyl radical or a C2-C4-alkenyl radical, such as the vinyl or allyl radical, PGi and PG 2 are known to a person skilled in the art for a hydroxy function
• Protecting groups such as, for example, methoxymethyl, methoxyethyl, ethoxyethyl, tetrahydropyranyl, tetrahydrofuranyl, trimethylsilyl, triethylsilyl, tert.butyldimethylsilyl, tert.butyldiphenylsilyl, tribenzylsilyl, triisopropyl, triisopropyl Butyl, benzy
• a preparation of the epothilone C1-C6 segment of the formula III is described in patent applications WO 03/04063 and WO 03/015068.
• the starting compounds of type Ila or type IIb are converted in an organometallic reaction with an alkyl metal to a compound of the formula III.
• R 6 alkyl, alkenyl, alkynyl, etc., see description
• the conversion of the dialkylamide group in IIIa or the nitrile group in IIb can be achieved in a smooth reaction in a synthesis step to III. After hydrolysis of the reaction mixture, the product of formula III is obtained in a high yield.
• the direct reaction of an organometal with an alkyl ester function -CO 2 R a is not selective, since the intermediate ketone continues to react. In the case of the primary adducts from Ila or IIb, these are stabilized and do not react further to the carbinol in question as a side reaction.
• organolithium and organometallic compounds are limited. It would therefore be advantageous if standard lithium organyles could be used, which are commercially available or can be produced in a simple manner. With these, a further alkyl radical should be introduced in a subsequent alkylation step via ⁇ -alkylation of the methyl ketone of the formula purple. This would be particularly advantageous if the alkyl or alkenyl halide on which the organometallic compound is based is quite expensive or is not available, as is the case with the C4-C6 alkenyl halides, for example. For example, in the case of a homoallyl residue to be introduced, the underlying homoallyl bromide is very expensive.
• but-3-en-1-lithium lithium also causes technical problems.
• the conversion of 1-bromobut-3-en to but-3-en-1-lithium is accompanied by the elimination to buta-1, 3-diene.
• the alkylation is carried out with a suitable alkylating agent in the presence of a base to give a compound of the form IVa.
• a suitable alkylating agent in the presence of a base to give a compound of the form IVa.
• the bisalkylation product of formula IVb is definitely undesirable.
• bisalkylation product IVb is also generally formed, and the conversion is often incomplete, so that starting material also remains.
• condensation reactions can also occur in the alkylation reaction.
• the reaction products such as monoalkylation product IVa, bisalkylation product IVb and starting material of the formula purple can generally only be separated with difficulty.
• the problem of bisalkylation has been discussed by A. Streitwieser et al. in Org. Lett., 2001, 3, 2599-2601.
• a problem with purification is that the reaction mixture consisting of starting material, monoalkylation product and bisalkylation product has to be separated.
• the present invention was intended to provide a process which allows only the monoalkylation product to IV a to be obtained in a simple manner in the alkylation of lilac.
• a ⁇ -keto ester of the general form V is prepared from a compound of the general formula purple.
• Keto esters of the general formula V provide access to compounds of the general formula VI which, after saponification to VII and decarboxylation of the ester group, gives a product of the formula IVa.
• the compounds of the general formula V can be prepared by known methods from a compound of the general formula purple and an ester of carbonic acid, preferably dimethyl or diethyl carbonate.
• an ester of carbonic acid preferably dimethyl or diethyl carbonate.
• sodium methylate, sodium ethanolate, potassium tert-butoxide or sodium hydride is used as the base.
• the carbonate itself can also serve as the solvent.
• keto esters of the formula V can be alkylated well to give compounds of the general formula VI.
• bases are metal hydroxides such as sodium, lithium, potassium or calcium hydroxide, metal hydrides such as sodium or lithium hydride, amine bases such as LDA (lithium diisopropylamide), sodium amide, LiHMDS (lithium hexamethyldisilazane), metal alkoxides such as, for.
• LDA lithium diisopropylamide
• sodium amide lithium amide
• LiHMDS lithium hexamethyldisilazane
• metal alkoxides such as, for.
• R 6 in R 6 X and thus in the general formulas IIIa, IVa, VI and VII has the meaning of C- ⁇ -C 6 alkyl, C 2 -C 6 alkenyl or C 2 -C 6 alkynyl.
• C 1 -C 6 alkyl can be straight-chain or branched, R 6 can also be an alkoxyalkyl, alkoxyalkenyl, alkoxyalkynyl and also.
• Aryl-alkyl mean in which alkyl in the alkoxy part is a C 1 -C 6 -alkyl radical and aryl is a phenyl or naphthyl radical and - Alkyl, alkenyl, alkynyl are a CC 6 alkyl, C 2 -C 6 alkenyl or C 2 -C 6 alkynyl radical.
• R 6 represents the radical allyl, crotyl or benzyl.
• the alkylation is carried out with the corresponding alkyl halides, allyl halides, benzyl halides, tosylates and the radical R 6
• Alkyl sulfur ester derivatives of the formula R 6 X can be carried out.
• Alkyl chlorides, bromides, iodides and alkyl esters of sulfuric acid and alkyl esters of alkyl sulfonic acids or aryl sulfonic acids are preferably used as alkylating agents.
• the inventive method has the advantage that no expensive complexing agents such as B. DMPU (dimethylpropyleneurea) are required. Also, no low temperature conditions are required for the alkylation. The alkylation can be carried out in a temperature range between 0 ° C and 50 ° C. The reactions are also robust and not very sensitive to moisture and air presence. If the conversion is incomplete, the base and alkylation agents can be added. Condensation products due to self-condensation do not occur.
• B. DMPU dimethylpropyleneurea
• Acidification is preferably carried out with phosphoric acid or ammonium chloride solution, acidification takes place under pH control.
• the compounds of the general formula IVa are surprisingly stable in the alkaline range.
• the compounds of general formula VII can be reacted at a temperature up to 100 ° C for decarboxylation. It has been found that the decarboxylation can be carried out at a pH of 4-9. The pH is crucial for the stability of the protective groups during decarboxalation.
• the compounds of the formula II, Iva, V and VI can be reacted further in solution without intermediate isolation.
• An advantage is the quality of the product produced by this process, which contains less than 1 percent of the educt purple and less than 1 percent of the bisalkylated compound IVb.
• the compounds of the general formula VI can also be converted directly to the compounds of the general formula IVa by reacting the compounds of the general formula VI with lithium carbonate in DMF
• the compounds of the formula VI can also be prepared from a compound of the general formula IIb and a bromoester of the general formula VIII in a Reformatsky-type reaction with zinc under the action of ultrasound (K. Nakunan, B.-J. Uang, Synthesis 1989 , 571.
• R1 and R6 in the compounds of the general formulas VI and VIII have the meanings given previously in the general formula VI.
• the allyl ester of the formula IX can be used for the synthesis.
• IX One method for the synthesis of IX is the reaction of a compound of the general purple by reaction with diallyl carbonate in the presence of a base.
• the allyl ketoesters of the formula IX can also be obtained, for example, by transesterification of an alkyl ester of the general formula V.
• allyl keto ester of the general formula IX can also be used in a
• Rearrangement reaction can be converted into the product of the general formula X.
• This rearrangement is favored in the presence of bases and can be carried out at milder temperatures (see J.Org. Chem., 1987, 52, 2988-2995).
• an aluminum alkoxide such as z. B. AI (OiPr) 3 (aluminum tri-isopropylate) can be used.
• This reaction from IX to X can also be carried out by transesterifying an alkyl ester of the general formula V in the presence of a base, the subsequent reaction taking place with decarboxylation in the presence of aluminum alkoxides according to route A) and migration of the allyl group.
• Such palladium-catalyzed decarboxylations / allylations have been described by J. Tsuji et al. in J. Org. Chem., 1987, 52, 2988-2995.
• allyl esters of the general formula IX can be converted into a homoallyl ketone of the general formula X with decarboxylation and simultaneous allylation.
• R in the general formulas IX, X and XI can mean hydrogen or a straight-chain or branched-chain C 6 -C 6 alkyl radical, such as. B. have a methyl, ethyl or propyl radical.
• the double bond in compounds of the general formula X can be converted to the saturated form of the compounds of the general formula XI using hydrogen using a palladium or platinum catalyst.
• the process according to the invention permits the selective monoalkylation of alkyl ketones. It is possible to introduce different alkyl radicals which are not available or are difficult to access as an organometallic compound.
• the problem for the synthesis of homoallyl ketones of the formula X was solved.
• the present invention is illustrated by the following examples:
• S-3- (2,2-dimethyl- [1,3] dioxan-4-yl) -4-methyl-3-oxopentanoic acid ethyl ester is prepared from the compound Example 1 and diethyl carbonate.
• S-3- (2,2-dimethyl- [1,3] dioxan-4-yl) -4-methyl-5-oxopentanoic acid allyl ester can be prepared from the compound Example 1 and diallyl carbonate.
• reaction is mixed with 25 ml of 2N NaOH and stirred at 40 ° C for 2 h. After the saponification, neutralization is carried out with phosphoric acid (85%) (pH 7) and the solution is heated to 80 ° C. for 30 min with evolution of CO2
• the mixture is neutralized with phosphoric acid (85%) (pH 7) and the solution is heated to 80 ° C. for 30 minutes (CO 2 evolution). After cooling, the mixture is extracted with methyl tert-methyl ether and the product is chromatographed on silica gel. 5.64 g (97% of theory) of product are obtained.

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• 2003
  • 2003-06-07 DE DE10326195A patent/DE10326195A1/de not_active Withdrawn
• 2004
  • 2004-06-05 JP JP2006508280A patent/JP2006527180A/ja active Pending
  • 2004-06-05 EP EP04739609A patent/EP1631563A1/de not_active Withdrawn
  • 2004-06-05 US US10/559,389 patent/US7595418B2/en not_active Expired - Fee Related
  • 2004-06-05 WO PCT/EP2004/006057 patent/WO2004108697A1/de active Application Filing

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