GB2125784A - Fluorinated pentene diamine derivatives - Google Patents

Abstract

Novel fluorinated alkylene diamine derivatives are inhibitors of decarboxylase enzymes involved in polyamine formation and have the following general Formula I:- <IMAGE> wherein:- Ra and Rb independently represent hydrogen, C2-C5 allylcarbonyl, phenylcarbonyl, phenyl-(C1-C4 alkyl) carbonyl, or an aminocarboxylic acid residue derived by removal of an hydroxy group from a carboxy moiety of an L-aminocarboxylic acid; and each p independently represents 1 or 2.

Description

SPECIFICATION Fluorinated diaminohexane derivatives Field of the invention The invention relates to novel pharmaceutically useful fluorinated alkylene diamine derivatives which in vivo are inhibitors of a decarboxylase enzyme involved in polyamine formation in organisms. The invention provides the compounds perse, pharmaceutical compositions comprising said compounds, methods of medical treatment using said compounds, and processes for preparing said compounds.

Background of the invention The decarboxylation of ornithine to putrescine, a reaction catalyzed by the enzyme ornithine decarboxylase (ODC), is the first step in the biosynthesis of the polyamines known as spermidine and spermine.

Spermidine is formed by the transfer of an activated aminopropyl moiety from S-adenosyl S-methyl homocysteamine to putrescine, while spermine is formed by the transfer of a second aminopropyl group to spermidine. S-Adenosyl S-methyl homocysteamine is formed by the decarboxylation of Sadenosylmethionine (SAM), a reaction catalyzed by the enzyme S-adenosylmethionine decarboxylase (SAM-DC).

The polyamines, which are found in animal tissues and microorganisms, are known to play an important role in cell growth and proliferation. The onset of cell growth and proliferation is associated with both a marked increase in ODC activity and an increase in the levels of putrescine and the polyamines. Although the exact mechanism of the role of the polyamines in cell growth and proliferation is not known, it appears that the polyamines may facilitate macromolecular processes such as DNA, RNA, or protein synthesis.

Polyamine levels are known to be high in embryonic tissue; in the testes, ventral prostrate, and thymus; in tumor tissue; in psoriatic skin lesions; and in other cells undergoing rapid growth or proliferation.

Since putrescine is the precursor of both spermidine and spermine, it is apparent that blockade of the conversion of ornithin to putrescine, such as by inhibition of ODC, should lower intercellular polyamine levels and should provide a wide range of useful physiological effects. Inhibitors of ODC should, thus, provide a means for treating infections caused by the proliferation of certain microorganisms in which the polyamines are essential for replication; and for treating certain animal diseases and disorders associated with rapid cell proliferation, such as malignent or non-malignent tumors, psoriasis, and prostatic hypertrophy.

It is apparent from the above that non-toxic inhibitors of ornithine decarboxylase would be useful pharmacological agents having a potentionally wide range of uses.

We have disclosed in U.K. Patent Specification No. 2003276A that interalia compounds of the following Formula A are inhibitors of lysine decarboxylase:

wherein: Ra and Rb independently represent hydrogen, C2-C5 alkylcarbonyl, C2-C5 alkoxycarbonyl, or -COCH(Re)NH2, where Re represents hydrogen, Cl-C4alkyl, benzyl orp-hydroxybenzyl; andp represents 1 or2.

Summary of the invention The compounds of the invention are represented by the following general Formula I:

wherein: Ra and Rb independently represent hydrogen, C2-C5 alkylcarbonyl, phenylcarbonyl, phenyl-(C1-C4 alkyl) carbonyl, or an aminocarboxylic acid residue derived by removal of an hydroxy group from a carboxy moiety of an L-aminocarboxylic acid; and p represents 1 or 2.

Pharmaceutically acceptable salts and individual optical isomers of the compounds of general Formula I are also within the scope of the invention.

The compounds of Formula I inhibit ornithine decarboxylase enzyme (ODC) in vivo, as evidenced by standard pharmacological test procedures performed in laboratory animals. As a consequence of ODC inhibition, the compounds can be used in general to decrease putrescine, spermidine, andlor spermine concentrations in cells undergoing rapid growth or proliferation. The administration of a compound of Formula I, therefore, provides a method for controlling undesirable cell growth or proliferation in mammals.

The compounds of Formula I are useful pharmacological agents for treating those diseases or conditions that are known in the art to be characterized by rapid growth or proliferation associated with high ODC activity. In particular, the compounds are useful systemically for controlling the growth of tumor tissues in mammals and for controlling the growth of pathogenic parasitic protozoa in infected domestic animals and humans.

The compounds of Formula I can also be employed to study the presence and physiological function of ODC inhibition in biological systems and its relationship to pathological processes.

The compounds of Formula I wherein Ra or Rb is a group other than hydrogen or do not inhibit ODC in vitro. In order to produce inhibition of ODC in vivo, said compounds must undergo biotransformation to the compounds of Formula I wherein Ra and Rb are both hydrogen which compounds are inhibitors of ODC both in vitro and in vivo. The ODC activity of the compounds can be determined in vitro by the method described by B. Metcalf et al. J. Am. Chem. Soc, 100, 2551(1978). The ODC activity of the compounds of Formula I can be determined in vivo by the method of C. Danzin, Biochemical Pharmacology, 28, 627 (1979).

Detailed description of the invention In the above general Formula I, Ra and Rb independently can be hydrogen, C2-C5 alkylcarbonyl, phenylcarbonyl, phenyl-(C1-C4 alkyl)carbonyl, or an aminocarboxylic acid residue derived by removal of an hydroxy group from the carboxy moiety of an L-aminocarboxylic acid. Preferably, Ra and Rb both represent hydrogen.

When Ra or Rb is an aminocarboxylic acid residue, it can be, for example, of the formula -COCH(R6)NH2 or -CO(CH2)nCH(NH2)-CO2H, wherein R6 is hydrogen, C1-C4 alkyl, aminopropyl, aminobutyl, benzyl or p-hydroxybenzyl and n is 1 or 2. Examples of said residues are those derived from glycine, alanine, leucine, lysine, isoleucine, phenylalanine, tyrosine, glutamic acid and aspartic acid.

References in this Specification, including the Claims, to an alkyl group or moiety mean a straight or branched chain alkyl group or moiety and, in the case of an alkyl group or moiety having structural isomers, includes all of those isomers and mixtures thereof unless a particular isomer is specified or clearly implied by the context.

Illustrative examples of straight or branched chain alkyl groups or moieties having 1 to 4 carbon atoms are methyl, ethyi, n-propyl, iso-propyl and n-butyl.

In the above general Formula I, each p independently represents 1 or 2. It will be appreciated that when both p represents 1, the compounds of the invention are monofluoromethyl derivatives, when both p represent 2 they are difluoromethyl derivatives, and when onep represents 1 and the other p represents 2, they are mixed mono- and di-fluoromethyl derivatives.

Illustrative examples of pharmaceutically acceptable salts of the compounds of this invention include non-toxic acid addition salts formed with inorganic acids, such as hydrochloric, hydrobromic, sulfuric and phosphoric acid, or with organic acids, such as, organic carboxylic acids, for example salicylic, maleic, malonic, tataric, citric and ascorbic acids, and organic sulfonic acids, for example methane sulfonic acids.

The salts are prepared by conventional means.

In one embodiment of the invention, there are provided compounds of the following general Formule IA:

wherein Ra and Rb are as defined in connection with Formula I; and pharmaceutically acceptable salts thereof.

In a second embodiment of the invention, there are provided compounds of the following general Formula IB:

wherein: wherein Ra and Rb are as defined in connection with Formula I; and pharmaceutically acceptable salts thereof.

In a third embodiment of the invention, there are provided compounds of the following general Formula lC:-

wherein Ra and Rb are as defined in connection with Formula The presently preferred compounds of the present invention are the following : 1,7-difluoro-2,6-diamino-heptane; 1,1 ,7-trifluoro-2,6-diamino-heptane; 1,1,7,7-tetrafluoro-2,6-diamino-heptane; As used herein, the term "tumor tissue" means both benign and malignent tumors or neoplasms, and includes leukemias, lymphomas, melanomas, and sarcomas. The term "controlling the growth of tumor tissue" as used herein means slowing, interrupting, arresting, or stopping the growth of a rapidly proliferating tumor in a warm blooded animal.It should be understood that the administration of a compound of the Formula I does not provide a "cure" for the tumor in the sense that the tumor tissue is destroyed or totally eliminated from the animal being treated.

For controlling the growth of tumor tissues, a compound of Formula I can be administered to the patient in conjunction with other therapeutic methods or in combination with cytotoxic drugs known in the art to be useful for cancer chemotherapy. For example, a compound of Formula I can be administered in conjunction with surgical excision of the tumor or with radiation therapy, hormonai treatment, immunotherapy, or local heat therapy. Moreover, in a preferred manner, a compound of Formula I can be administered to a patient in combination with a chemical cytotoxic agent known in the art to be useful for tumor chemotherapy. When such combination therapy is employed for the treatment of a tumor, the cancer chemotherapeutic agent may be administered at a dosage known in the art to be effective for treating the tumor.However, a compound of Formula I may produce an additive or synergistic effect with a chemotherapeutic agent against a particular tumor. Thus, when such combination antitumor therapy is used, the dosage of the chemotherapeutic agent administered may be less than that administered when the agent is used alone. In combination with a compound of Formula I, the chemotherapeutic agent may, therefore, be administered at a lower dosage level or at less frequent intervals as compared to the chemotherapeutic agent when used alone.

In combination with a compound of Formula I, any cancer chemotherapeutic agent may be employed.

Drugs commonly used for cancer chemotherapy are described in The Medical Letter, Vol. 22, No. 24 (Issue 571), November28, 1980, Published bytheMedical Letter, Inc., NewRochalle, N.Y., 10801. Illustrative examples of cytotoxic chemotherapeutic agents are cyclophosphamide, methotrexate, prednisone, 6-mercaptopurine, procarbozine, daunorubicin, vincristine, vindesine, vinblastine, chlorambucil, cytosine arabinoside, 6-thioguanine, thio TEPA, 5-fluorouracil, 5-fluoro-2-deoxyuridine, 5-azacytidine, nitrogen mustard, 1 ,3-bis(2-chloroethyl)-1 -nitrosourea (BCNU), ),1 -(2-chloroethyl)-3-cyclohexyl-1 -nitrosourea (CCNU), busulfan, adriamycin, bleomycin, cycloleucine or methylglyoxal bis (guanylhydrazone) (MGBG).Other cancer chemotherapeutic agents will be apparent to those skilled in the art.

The effect of the compounds of Formula I for the control of the growth rate of rapidly proliferating tumor tissue can be assessed in standard animal tumor models after oral or parenteral administration. For example, the antitumor effects can be demonstrated in the following models: (a) L1210 leukemia in mice, (b) EMT 6 tumor in Balb/C mice, (c) 7,1 2-dimethylbenzanthracene-induced (DMBA-induced) mammary tumor in rats, or (D) Morris 7288 C or 5123 hepatoma in Buffalo rats. In addition, the antitumor effects of the compounds in combination with chemotherapeutic agents can be demonstrated in animal models.

In general in animal tumor models, the compounds of Formula I effectively reduce tumor growth rate systematically at a daily dose of from about 20 mg/kg to about 400 mg/kg (body weight). As will be apparent to those skilled in the art, the effective dosage will vary depending on the compound employed, the nature and severity of the particular neoplasm being treated, the route of administration, and the species being treated. Treatment should be initiated at lower doses, the dosage thereafter being increased until the desired effect on tumor growth is achieved.

When, in the treatment of malignent neoplastic disease, a compound of Formula I is administered in combination with a chemotherapeutic agent, the therapeutic effect of the chemotherapeutic agent may be potentiated in that the remission produced by the chemotherapeutic agent may be enhanced and regrowth of the tumor tissue may be slowed or prevented. Use of such combination therapy therefor allows smaller doses or fewer individual doses of the chemotherapeutic agent to be employed. Thus, the detrimental and/or debilitating side effects of the chemotherapeutic agent are minimized while, at the same time, the antitumor effects are enhanced.The term "combination therapy" contemplates the administration of a compound of Formula I immediately prior to the beginning of chemotherapy, concomittantlywith chemotherapy, or during the period of time immediately following cessation or discontinuance of chemotherapy. Preferably, the patient is treated with a compound of Formula I for about 1 to 14 days, preferably 4 to 14 days, prior to the beginning of chemotherapy, and, thereafter, on a daily basis during the course of such therapy. Daily treatment with the compound of Formula I can be continued for a period after the last dose of the chemotherapeutic agent is administered.

When chemotherapy results in remission of the tumor and all tumor cells are not destroyed, regrowth of the tumor may be prevented or slowed indefinitely by continued treatment with a compound of Formula I.

Thus, a compound of Formula I can be administered to stop or slow the growth of the tumor during the periods when chemotherapy using a cytotoxic agent may be temporarly discontinued.

A preferred cytotoxic agent for combination therapy with a compound of Formula I is methylglyoxal bis(guanylhydrazone), herein referred to as MGBG, which is also an inhibitor of S-adenosyl methionine decarboxylase. The activity of MGBG as a chemotherapeutic agent in the treatment of neoplastic diseases is well documented. For example, W.A. Knight metal. Cancer Treat.Rep., 43, 1933, (1979) have reported that a dose of MGBG administered intravenously once or twice week to patients in the advanced stages of carcinoma of the bladder, esophagus, lung, pancreas, colon, kidney, breast and prostate, oat cell carcinoma, adenocarcinoma, lymphoma, hepatoma, melanoma, leukemia, or Edwing's sarcoma produced measurable regression of the tumor in many of the patients treated and complete disappearance of the disease in two of the 65 treated patients.

The amount of MGBG to be administered may be the same as the amount known in the art to be effective for tumor therapy. Effective and non-toxic dosages are determined by the physician in each case, taking into account the condition of the individual patient. For example, a dosage of 250-500 mg per meter2 of body surface area may be infused once or twice weekly in 100ml of aqueous 5% dextrose solution over a 30 min period. Combination therapy with a compound of Formula I improves the response of the tumor tissue to the cytotoxic effect of MGBG and permits the use of a smaller individual dose of MGBG and a shorter course of treatment than would be required with the use of MGBG alone.

Suitable dosages of the compounds of Formula I for use in combination therapy with MGBG or other cancer chemotherapeutic agents can be any amount effective in inhibiting polyamine biosynthesis sufficiently to control the tumor growth rate or to achieve a heightened response to the cytotoxic agent administered in conjunction therewith.

The term "controlling the growth of pathogenic parasitic protozoa", as used herein, means slowing, interruting, arresting, or stopping the replication of the protozoa in an infected host. The compounds of Formula I are particularly useful against T.b. brucei (which causes trypanosomiasis in cattle), T.b.

rhodesiense, (which causes human sleeping sigk-sickness), the coccidia, for example, Eimeria tenella (which causes intestinal coccidiosis in fowl (e.g. chickens, turkeys, and ducks)) and the exoerythocytic form of plasmodia, for example, plasmodium falciparum (which causes human malaria).

The antiprotazoal activity of the compounds of Formula I can be demonstrated in vivo or in vitro in standard microbiological test procedures. For example, the activity of the compounds against Tb. brucei, and T.b. rhodesiense can be determined in infected mice by administering the test compound at lib daily (3 to 15 days post infection) as a solution in the drinking water at a concentration of 0.5 to 2%. Activity is indicated by an increase in survival time (as compared to untreated controls) or by the absence of parasites in the blood.The activity of the compounds against the coccidia can be determined in infected chickens, for example those infected with E. tenella by administering the test compound daily adlib (from one day pre injection to five days post infection) as a solution in the drinking water at a concentration of 0.5 to 2%. The cecal lesions are evaluated by a standard lesion scoring procedure. (see Reid. Am. J. VetRes., 30, 447 (1969) and Avian Coccidiosis, P. Long. Editor, British Poultry Science, Ltd., Edinburgh). The activity of the compounds against malaria (p. faleiparum) can be determined by a standard in vitro plate culture test (see K.

Rieckmann et al, Lancet, 1, 22 (1978)). Antimalarial activity can also be determined in special strains of mice infected with the exoerythrocitic form of p. berghei. In this test, the compound is administered adlib in drinking water at a concentration of from 0.2 to 1.0% starting two days pre-infection and continuing 28 days post-infection. Activity is measured by a significant decrease in deaths as compared to controls or by a significant increase in survival time.

Compounds of Formula I may have one or more additional uses, for example to treat epidermal hyperplasia (e.g. psoriasis) or prostatic hypertrophy.

The compounds of this invention can be administered in various manners to achieve the desired effect.

The compounds can be administered alone or in the form of pharmaceutical preparations either orally or parenterally, for example, subcutaneously, intravenously or interperitoneally. The amount of novel compound administered will vary and can be any effective amount. Depending upon the patient, the condition being treated and the mode of administration, the effective dosage of the compound administered may vary from about 5 mg/kg to about 100 mg/kg, of body weight of the patient per day. Unit doses of these compounds can contain, for example, from about 10 mg to 300 mg of the compounds and may be administered, for example, from 1 to 4 times daily.

The term "unit dosage form" is used herein to mean a single or multiple dose form containing a quantity of the active ingredient in admixture with or otherwise in association with the diluent or carrier, said quantity being such that one or more predetermined units are normally required for a single therapeutic administration. In the case of multiple dose forms such as iiquids or scored tablets, said predetermined unit will be one fraction, such as a 5 ml (teaspoon) quantity of a liquid or a half or quarter of a scored tablet, of the multiple dose form.

In the composition aspect of the invention there are provided pharmaceutical formulations in which form the active compounds of the invention will normally be utilized. Such formulations are prepared in a manner well known perse in the pharmaceutical art and usually comprise at least one active compound of the invention in admixture or otherwise in association with a pharmaceutically acceptable carrier or diluent therefor. For making these formulations the active ingredient will usually be mixed with a carrier, or diluted by a diluent, or enclosed or encapsulated in a capsule, sachet, cachet, paper or other container. A carrier or diluent may be solid, semi-solid or liquid material which serves as a vehicle, excipient or medium for the active ingredient. Suitable carriers or diluents are well known per se.

The formulations of the invention may be adapted for enteral or parenteral use and may be administered to the patient in the form of tablets, capsules, suppositories, solutions, suspensions or the like.

In the specific examples included hereinbelow illustrative examples of suitable pharmaceutical formulations are described.

Methods of preparing the compounds of Formula I will now be described. If in any of the reaction steps described an amino group of a reactant would be involved in an unwanted reaction under the relevant reaction conditions, the amino group will be protected in manner known perse by introduction of an appropriate protecting group. The protecting group will be chosen having regard to the nature of the relevant reaction and ease of removal to free the amino group. The protecting group can be selected from, for example, acyl, for example, lower alkanoyl, e.g. acetyl, propionyl, trifluoroacetyl, and the like; aroyl, e.g.

benzoyl, toluoyl and the like; lower alkoxycarbonyl, for example methoxycarbonyl, ethoxycarbonyl, tert-butoxycarbonyl and the like; carbobenzoxy, benzenesulfonyl and tosyl. Both amino hydrogen atoms can be substituted by a single protecting group such as, for example phthalyl. The protecting groups are introduced in manner known perse by, for example, reaction of the amine with a lower alkanoyl or aroyl chloride, anhydride, sulfonylchloride, tert-butoxycarbonyloxyimino-2-phenyl-acetonitrile (BOC-ON), of di-tert-butyl dicarbonate ((BOC)2O).

Removal of the protecting group after the required reaction has been completed can be carried out in manner known perse for the relevant protecting group. Usually, said removal will be by hydrolytic cleavage using a strong organic or mineral acid such as, for example, trifluoroacetic acid, hydrochloric acid and the like acids; or by hydrogen chloride gas under anhydrous conditions. The use of conditions which will reduce the olefinic double bond or of reactants, such as hydrobromic acid, which will react with the olefinic double bond must be avoided. Solvents used will be chosen dependent upon the conditions of protecting group removal. For example, ethers such as, for example, diethylether can be used for cleavage using hydrogen chloride gas.

The compounds of Formula I in which Ra and Rb both represent hydrogen can be prepared in manner known perse from the corresponding hydroxyamino of the following general Formula ll:-

wherein p is as defined in connection with Formula I.

Suitably, the reaction can proceed via the corresponding tosyioxy (i.e. toluene-p-sulfonyloxy) or mesyloxy (i.e. methanesulfonyloxy) derivative and then the corresponding phthalimido, isocyanato or urotropino derivative as described below.

The amino group in the compound of Formula II will be protected in manner known perse during the reaction by a suitable subsequently removable protecting group or groups. The protecting group preferably is phthaloyl or tert.butoxycarbonyl. When proceeding via the phthalimido or isocyanate derivative when p is 1, it is desirable to use a protecting group which does not leave any hydrogen atom on the amino group.

Usually, the protecting group will be selected so that it is removed during the final step in the conversion of the compound of Formula II into the corresponding compound of Formula I.

The compounds of Formula II or the amino-protected derivatives thereof can be treated in the presence of a base such as pyridine with tosyl or mesyl chloride to form the tosyloxy or mesyloxy derivative. Said derivative can be treated with an alkali metal phthalimide, especially sodium or potassium phthalimide, in a polar organic solvent, such as for example, dimethylformamide, dimethylsulfoxide or hexamethylphosphoric triamide, to form the corresponding phthalimido derivative. Conveniently one to three equivalents of the phthalimide salt are used per equivalent of compound of Formula II at a temperature of 25 to 200"C for a period of 0.5 to 3 hours.

The phthalimido derivative can be converted into the required compound of Formula I by heating with a reactant such as hydrazine or methylamine in a polar organic solvent, such as, for example, an alkanol, preferably ethanol. Preferably hydrazine hydrate is used in an amount of about 2 equivalents per equivalent of phthalimido derivative. Suitably, the conversion is performed at 50 to 100 C, preferably under reflux conditions, for a period of 3 to 24 hours.

The phthalimido derivative of Formula II also can be converted into the required compound of Formula I by heating with a strong mineral acid such as hydrochloric acid or sulfuric acid. Preferably a mixture of hydrochloric and acetic acid is used at a temperature of about 95"C for about 24 hours.

In an alternative process, the tosyloxy or mesyloxy derivative of the compound of Formula II is treated with an alkali metal isocyanate, especially sodium or potassium isocyanate, and the resultant isocyanato derivative subsequently hydrolysed to the required compound of Formula I. The reaction conditions can be the same as those discussed above with reference to conversion of a compound of Formula II to a compound of Formula I via the phthalimido derivative in which the phthaloyl group is removed by acid hydrolysis.

In another alternative process, the tosyloxy or mesoyloxy derivative of the compound of Formula II is treated with hexamethylenetetramine in an organic solvent, such as a C1-C4 alkanol or chloroform, to form the corresponding urotropine (i.e. hexamethylenetratammonium) salt. Conveniently, the reaction can be carried out at about ambient temperature for a period of 0.5 to 24 hours. The urotropine salt can be converted into the required compound of Formula I by heating with an aqueous acid, such as hydrochloric acid, preferably under reflux conditions and preferably under an inert atmosphere, for example nitrogen or argon.

Compounds of Formula II can be obtained in manner known perse from the corresponding amino-protected benzyl ether by, for example, treatment with hydrogen in the presence of palladium or cleavage using boron tribromide or a trialkylsilyliodide. As usual, the amino-protecting group will be chosen having regard to the reaction conditions. It is preferred to use tert.butoxycarbonyl for said reduction and phthaloyl for said cleavage.

The benzyl ester can be prepared from the corresponding compound of the following general Formula II by reduction with a reducing agent, such as a borohydride, which selectively reduces the imino group: especially ammonium chloride.

wherein: Z represents

p is as defined in connection with Formula II.

Compounds of Formula Ill can be obtained by treatment of the corresponding Grignard reactant of the following general Formula IV with the corresponding fluorinated acetonitrile of the following general Formula V: Z-MgBr Formula IV wherein Z is as defined in connection with Formula III; CFpH3 p - CN Formula V wherein p represents 1 or 2.

The Grignard reactants of Formula IV can be prepared in manner known perse from, the corresponding bromides of the following general Formula IV and magnesium turnings in an appropriate solvent for Grignard type reactions.

Z-Br Formula VI wherein Z is as defined in connection with Formula IV.

The compounds of Formula VI can be obtained from a pent-4-enyl halide (1) by the following sequence of reaction steps known per se: (a) reaction with magnesium turnings to form a Grignard compound (2); (b) reaction with mono- or di-fluoroacetonitrile to form a ketimine magnesium halide (3); (c) acid hydrolysis to form a ketone (4); (d) reduction with, for example, sodium borohydride, to form an alcohol (5); (e) etherification with benzoylchloride to form a benzyl ether (6); (f) oxidation of the olefinic double bond with, for example, ozone to form an acid (7); (g) reduction of the acid group with, for example, lithium aluminium hydride or diborane to form an alcohol (8); and (h) bromination by, for example treatment with phosphorus tribromide to form the bromide of Formula Vl (9); The reaction sequence is represented below in Scheme A.

CH2 = CH - CH2 - CH2 X (1) (a) CH2 = CH - CH2 - CH2Mg X (2) (b) l CH2 = CH - CH2 - CH2 - C(CFpH) p) = NMg X (3) (c) I CH2 = CH - CH2 - CH2 - CO - CFpH3.p (4) (d) CH2 = CH - CH2 - CH2 - CH(CFpH3p)OH (5) (e) | CH2 CH - CH2 - CH2 - CH(CFpHs) OCH2Ph (6) (f) | HO2C - CH2 - CH2 - CH(CFpH3.p) OCH2Ph (7) (g) I HOCH2 - CH2 - CH2 - CH(CFpH3) OCH2 Ph (8) (h) Br CH2 - CH2 - CH2 - CH(CFpH3p) OCH2Ph (9) It will be appreciated that the order of some of the reaction steps in the process routes described above can be changed.

The amides of Formula I derived from one of the amino groups can be prepared directly or indirectly in manner known perse from the corresponding diamines of Formula I. In some circumstances, it may be necessary to protect the non-reacting amino group prior to the reaction. Conveniently, the protected reactant can be obtained by selective hydrolysis of a derivative in which the amino group required for reaction is protected in the form of a urotropine salt and the other amino group is protected in the form a phthalimido group. Said derivatives readily can be prepared by appropriate choice of reaction sequence from those discussed above for the general preparation of compounds of Formula I.

The amides of Formula I wherein Ra or Rb is alkylcarbonyl can be obtained in manner known perse by treatment of the corresponding compounds of Formula I wherein Ra or Rb is hydrogen with the corresponding acid halide, especially acid chloride, or acid anhydride in water in the presence of a base.

The amides of Formula I wherein Ra or Rb is an aminocarboxylic acid residue can pe prepared in manner known perse by treating the corresponding compound of Formula I wherein Ra or Rb is hydrogen with the corresponding aminocarboxylic acid in an anhydrous organic solvent in the presence of a dehydrating agent, followed by acid or base hydrolysis.

When necessary in the preparation of compounds of Formula I separation of cis/trans isomers or intermediates or final products can be carried out by chromatographic techniques.

The compounds of Formula I exist as stereoisomers. Methods of separating the stereoisomers of a particular compound will be apparent to those skilled in the art.

The compounds produced by the foregoing processes may be isolated either per se or as acid addition salts thereof.

The acid addition salts are preferably the pharmaceutically acceptable, non-toxic addition salts with suitable acids such as those previously referred to in this Specification. Apart from pharmaceutically acceptable acid addition salts, other salts are also included within the scope of acid addition salts, such as for example, those with picric or oxalic acid; they may serve as intermediates in the purification of the compounds or in the preparation of other, for example, pharmaceutically acceptable, acid addition salts, or are useful for identification or characterisation of the bases.

A resulting acid addition salt may be converted into the free compound according to known methods, for example, by treating it with an alkali or alkaline earth metal hydroxide or alkoxide; with an alkali metal or an alkaiine earth metal carbonate or hydrogen carbonate; with trialkylamine; or with an anion exchange resin.

A resulting acid addition salt may also be converted into another acid addition salt according to known methods; for example, a salt with an inorganic acid may be treated with a sodium, barium or silver salt of an acid in a suitable diluent, in which a resulting inorganic salt is insoluble and is thus removed from the reaction medium. An acid addition salt may also be converted into another acid addition salt by treatment with an anion exchange preparation.

The invention is illustrated by the following non-limiting Examples. All NMR measurements are given on the delta scale (i.e. tetramethylsilane = 0).

In the following Examples relating to pharmaceutical compositions, the term "active compound" is used to indicate the compound 1,7-difluoro-2,6-diamino-heptane. This compound may be replaced in these compositions by any other compound of the invention, for example by 1,1 ,7-trifluoro-2,6-diamino-heptane.

Adjustments in the amount of medicament may be necessary or desirable depending upon the degree of activity of the medicament as is well known in the art.

Example I An illustrative composition for hard gelatin capsules is as follows: (a) active compound 20 mg (b) talc 5 mg (c) lactose 90 mg The formulation is prepared by passing the dry powders of (a) and (b) through a fine mesh screen and mixing them well. The powder is then filled into hard gelatine capsules at a net fill of 115 mg per capsule.

Example II An illustrative composition for tablets is as follows: (a) active compound 20 mg (b) starch 43 mg (c) lactose 45 mg (d) magnesium stearate 2 mg The granulation obtained upon mixing the lactose with the compound (a) and part of the starch and granulated with starch paste is dried, screened, and mixed with the magnesium stearate. The mixture is compressed into tablets weighing 110 mg each.

Example Ill An illustrative composition for an injectable suspension is the following 1 ml ampul for an intramuscular injection: weight per cent (a) active compound 1.0 (b) polyvinylpyrrolidone 0.5 (c) lecithin 0.25 (d) water for injection to make 100.0 The materials (a)-(d) are mixed, homogenized, and filled into 1 ml ampuls which are sealed and autoclaved 20 minutes at 121"C. Each ampul contains 10 mg per ml of novel compound (a).

Example IV mgisuppository Active Compound 50 Oil of Theobroma 950 The medicament is powdered and passed through a B.S. No. 100 sieve and triturated with molten oil of Theobroma at 45"C to form a smooth suspension. The mixture is well stirred and poured into moulds each of nominal 1 G capacity, to produce suppositories.

Example V The ODC inhibitory activity of the compounds of Formula I can be demonstrated in vivo according to the following procedure: Male rats of the Sprague-Dawley strain (200-220 g body weight), purchased from Charles River, are given food and water adlibitum under a constant 12 hr light-12 hr dark lighting schedule. Drugs are injected intraperitoneally (dissolved in 0.9 % saline) or are given by gavage (dissolved in water). Rats given saline or water serve as control. Five to six hours after drug administration, the animals are killed by decapitation and the ventral prostate and thymus are excised rapidly and immediately processed.The tissues are homogenized with three volumes of 30 mM sodium phosphate buffer (pH 7.1) containing 0.1 mM EDTA, 0.25 M sucrose, 0.1 mM pyridoxal phosphate and 5 mM dithiothreitol. Ornithine decarboxylase activities are determined on a 1000 g supernatant of prostate homogenate and on a whole thymus homogenate, essentially as described by Ono et (Biochem. Biophys. Acta, 284, 285 (1972)).

Example VI The activity of the compounds of Formula las inhibitors of ornithine decarboxylase (ODC) can be demonstrated in vitro according to the following procedure: Ornithine decarboxylase (ODC) is prepared from the livers of rats which have been injected with thioacetamide (150 mg/kg of body weight) 18 hrs before sacrifice, and is purified about ten fold by acid treatment at pH 4.6 as described by Ono etal(Biochem. Biophys. Acta 284,285(1972)). The stock solution of ODC is comprised of protein (16 mg/mL), sodium phosphate buffer (30 mM, pH 7.1), dithiothreitol (5mM) and pyridoxal phosphate (0.1 mM). The specific activity of this stock solution is 0.12 nmol of CO2/min per mg of protein.For a typical experiment 320 1 of this stock solution are mixed at time 0 with 80 1 of a solution of the inhibitor in water and incubated at 37 . At different times 50 1 aliquots are transferred into a 1 -mL assay medium containing sodium phosphate (30 mM, pH 7.1), dithiothreitol (5 mM), pyridoxal phosphate (0.1 mM), L-ornithine (0.081 mol), and DL-[1-14C) ornithine (0.043 mol, 58 Ci/mol, Amersham) in a closed vessel in which a filter paper moistered with 50 1 hyamine hydroxide (1 M) is fitted. The reaction is allowed to proceed for 60 min at 37 C and then terminated by addition of 0.5 ml of 40% trichloroacetic acid. After an additional 30 min the CO2 absorbed on the filter paper is counted in a standard scintillation cocktail. Kl (apparent dissociation constant) and 50 (half-life, at infinite concentration of inhibitor are calculated according to the method of Kitz and Wilson (J. Biol. Chem., 237,3245(1962)).

Example Vll The anti-neoplastic effects of the compounds of Formula I can be demonstrated in vivo in C57BL (BD2F) mice inoculated i.p. with L 1210 leukemia (106 cells) or in BALBC mice inoculated s.c. with EMT6 solid sarcona (105 cells).

Claims (15)

1. Afluorinated alkylene diamine derivative of the following general Formula I:

wherein: Ra and Rb independently represent hydrogen, C2-C5 alkylcarbonyl, phenylcarbonyl, phenyl-(C1-C4 alkyl) carbonyl, or an aminocarboxylic acid residue derived by removal of an hydroxy group from the carboxy moiety of an L-aminocarboxylic acid; and each p independently represents 1 or 2 and pharmaceutically acceptable salts thereof.

2. A compound as claimed in Claim 1 and having the following general Formula IA:

wherein Ra and Rb are as defined in Claim 1; and pharmaceutically acceptable salts thereof.

3. A compound as claimed in Claim 1 and having the following general Formula IB:

wherein Ra and Rb are as defined in Claim 1; and pharmaceutically acceptable salts thereof.

4. A compound as claimed in Claim 1 and having the following general Formula IC:

wherein Ra and Rb are as defined in Claim 1.

5. A compound as claimed in any one of Claims 1 to 4 wherein Ra and Rb both represent hydrogen.

6. 1 ,7-Dif(uoro-2,6-diamino-heptane and pharmaceutically accSeptable salts thereof.

7. 1,1 ,7-Trifluoro-2,6-diamino-heptane and pharmaceutically acceptable salts thereof.

8. 1,1,7,7-Tetrafluoro-2,6-diamino-heptane and pharmaceutically acceptable salts thereof.

9. A compound as claimed in any one of the preceding Claims for use in a method of treatment of the human or animal body by therapy or of diagnosis practiced on the human or animal body.

10. A compound as claimed in any one of the preceding Claims for use in the inhibition in the human or animal body of ornithine decarboxylase.

11. Pharmaceutical compositions comprising a compound as claimed in any one of the preceding Claims in admixture or otherwise in association with a pharmaceutically acceptable carrier or diluent therefor.

12. Pharmaceutical compositions as claimed in Claim 11 in unit dosage form containing 10 mg to 300 mg of said compound per unit dose.

13. A method of preparing a compound as claimed in Claim 1 which comprises treating a hydroxyamine of the following general Formula ll:-

wherein p is as defined in Claim 1; in the form of a derivative thereof in which the amino group is protected by a subsequently removable blocking group or groups, in manner known perse to convert the hydroxy group into an amino group and, if necessary, subsequently removing the blocking group or groups.

14. A method as claimed in Claim 13 wherein the said hydroxyamine is treated with tosyl or mesyl chloride to form the corresponding tosyloxy or mesyloxy derivative, which is subsequently treated with an alkali metal phthalimide to form the corresponding phthalimido derivative, which is hydrolytically cleaved using a strong mineral acid or reaction with hydrazine or methylamine.

15. A compound as claimed in any one of Claims 1 to 10 whenever prepared by a method as claimed in Claim 13 or Claim 14.