IT8909564A1 - 8-FLUORO-ANTHRACYCLIN, RELATED MANUFACTURING PROCEDURES AND THEIR USE. - Google Patents

Description

Description of the Industrial Invention entitled: 8-FLUORO-ANTHRACYCLIN, RELATED MANUFACTURING PROCEDURES AND THEIR USE "

SUMMARY

8-fluoro-anthracyclines of general formula:

where X = H or OH and where: R1 = H and R2 = OH; or R1 = OH and R2 = H; or R1 = H and R2 = H; as well? their manufacturing processes and use as novel anticancer agents

DESCRIPTION

The invention refers to new derivatives of 2? -Acetyl-2?, 4?, 5, 12-tetrahydroxy-3? -Fluoro-1,2,3,4-tetrahydro-6, 11-naphtacendione, to pharmaceutical preparations containing said products and the methods for producing and using these derivatives.

Anthracyclines are known to be important antitumor agents with clinical efficacy against many types of human cancer. However their therapeutic use? limited by side effects, particularly cardiotoxicity? dose-related (see for example F. Arcamone, DOXORUBICIN, ANTITUMOR ANTIBIOTICS, Pergamon Press, New York, 1981; or J.W.Lown (ED.) ANTHRACYCLINE AND ANTHRACENEDIONE-BASED ANTICANCER AGENTS, Elsevier, 1988).

It has now been surprisingly discovered that the introduction of a fluorine atom in place of a hydrogen atom in the 3p position of the aglycone of the anticancer anthracyclines increases the activity. antitumor and selectivity? of action of such compounds. The result is therefore some compounds that surprisingly - and presumably in connection with a different reactivity? of hydroxyl in 2? or for reasons not foreseeable by those skilled in the art - they have advantages over the drugs currently used in the therapy of human tumors.

The present invention therefore refers to new fluorine derivatives of anthracycline of general formula

where X = H or OH e

The invention also claims a new synthesis method useful for obtaining the aglycone of the formula:

as well? the said aglycone.

The synthesis to obtain the aglycone? shown in the following diagram:

The invention also relates to intermediate products

III to IX above

Compound I? obtained according to F A.J. Kerdesky, R.D. Ardecky, M. V. Lakshmikantham and M.P. Quarry, J. AM.

CHEM. SOC. 1981, 103, 1992-1996; or according to R.J. Ardecky, D. Dominguer and M.P. Quarry, J. ORG. CHEM. 1982, 47, 409-412.

To obtain the intermediate compound III, a variant fc is used as reported by Kerdesky et al. (F.A.J.

Kerdesky, R.D. Ardecky, M.V. Lakshmikantham and M.P.Cava, J. AM. CHEM. SOC. 1981, 103, 1992-1996): cyclization occurs by reaction of 3-butin-2-one with 1,4-dimethoxy-2,3-bis (bromomethyl) anthraquinone which in the reaction conditions formally behaves as a diene. The naphthcendione is then oxidized on the double bond 2,3 (intermediate compound IV) with a peroxyacid in a suitable solvent.

To obtain the intermediate compound V, the oxirane ring is opened with a nucleophilic fluorine, such as for example Olah's reagent.

The demethylation of the phenolic hydroxyls, in order to obtain the intermediate compound VI, is carried out, in yield almost? quantitative, with a suitable Lewis acid, such as boron trichloride.

Before brominating position 4? it is preferable to protect the acetyl chain, for example with ethylene glycol (intermediate compound VII). The subsequent bromination in position 4 is carried out with a suitable brominating agent, such as for example bromine or N-bromosuccinimide, in a suitable solvent, in the presence or not of radical initiators such as light or azo-bis-isobutyronitrile. The bromine derivative obtained easily undergoes substitution with a hydroxyl to give the intermediate VIII. The latter is deprotected in an acidic environment, thus obtaining? 20-acetyl-2?, 4?, 5,12-tetrahydroxy-3? -fluoro-1,2,3,4-tetrahydro - 6,11-naphthycendione (intermediate IX).

The synthesis proceeds as follows - to reach the final product XIII - with a glycosidation for example with:

to continue with the removal of the protections and obtain:

XIII

The glycosidation of compound IX to give the compounds of general formula object of the present invention with X = H takes place through the reaction of compound IX with a glucidic derivative suitably protected and having, in position 1, a chemical function capable of originating, under suitable conditions, a sufficiently stabilized carbocation capable of giving rise to a condensation with the benzyl hydroxyl of compound IX and the formation of a glucosidic bond. Typical examples of glucose reagents are 3-N-trifluoroacetyl-1,4-bis (0-p-nitrobenzoyl) -daunosamine (X), 3-N-trifluoroacetyl-1,4-bis (O-p-nitrobenzoyl) -acosamine (XI), 3-N-trifluoroacetyl-1-O-p - nitrobenzoyl-4-deoxy-daunosamine (XII), or 3,4-di-triflaoroacetyl-1-chlorodaunosamine, 3,4-di-trifluoroacetyl-1-chloroacosamine, or the corresponding 4-deoxy derivative.

Which protective group of the alcoholic function of sugar can? also be used the derivative trimethylsilyl, while the position 1 of the same can? also be activated as 1-bromo, 1-fluoro, 1-trimethylsilyloxy, 1-acetoxy, or as 1,2-glycol.

Condensing agents in the reaction between glucose reactive and intermediate IX can be salts such as silver triflate or silver perchlorate, mixtures of mercuric oxide and bromide, trimethylsilyl triflate, or acids such as p-toluenesulfonic acid, or Lewis acids such as a boron trihalide, tin tetrachloride or chemical compounds with properties equivalents. The solvents used are generally chlorinated solvents such as methylene chloride, hydrocarbons, such as benzene or toluene, ethers, such as tetrahydrofuran, or mixtures of these with each other and / or with other solvents such as dimethylformamide, in the presence or absence of organic bases such as pyridine , collidina or equivalent.

The protective groups on the glucose residue are removed with suitable basic reagents, according to procedures known in the literature.

Compounds with X = OH are obtained starting from the hydrochlorides or other suitable salts of the corresponding compounds with X = H by treatment with bromine in a mixture of solvents, preferably methyl alcohol and dioxane, even if the nature of the solvents once that they were compatible with the reaction conditions, can not? limit the meaning of the present invention. The 14-bromine derivative obtained is then substituted with hydroxyl through a reaction with aqueous solutions of an inorganic base, such as an alkaline hydrate, or organic, such as an amine, or of a salt such as an alkaline salt of a weak mineral acid. or an organic acid, for example sodium bicarbonate or sodium formate.

A possible synthesis reaction starting from products I and II is now described.

III (2-acetyl-5, 12-dimethoxy-1,4-dihydro-6,11-naftscendione)

In a mixture consisting of 50 ml of dimethylacetamide and 10 ml of dioxane, 29 g (193 mmoles) of Nal are dissolved under nitrogen. The dissolution? exothermic: when the temperature? dropped to 40 ° C, 6.6 g (97 mmoles) of butinone II are added in a single portion. The temperature of the mixture is brought to 65 ° C and a solution composed of 5 g (11 mmoles) of I and 100 ml of dimethylacetamide is dropped into it in one hour, keeping the temperature close to the initial value. At the end of the addition it is left under stirring at 65-70 ° C for a further hour, then it is cooled and poured into 600 ml of water. The solid obtained is filtered, washed well with water and dried under vacuum over PO to give 83.85 of III. P.f .:

IV (2-acetyl-2,3-epoxy-5,12-dimethoxy-I, 2,3,4-tetra! -Dro-6,11-naphtacendione)

In 400 ml of chloroform, 3.0 g (8.3 mmoles) of III and 18 g of 55% mCPBA (57 mmoles) are refluxed for 7 hours under nitrogen. The reaction mixture, cooled to room temperature, is treated with 10% sodium bisulfite solution (2x100 ml), then with 5% sodium bicarbonate (3x100 ml), finally with water. The organic phase is dried over sodium sulphate and the solvent evaporated. The raw reaction product is purified by suspending it in boiling carbon tetrachloride, it is cooled, filtered and the solid washed well with the same solvent to give 850 mg of IV at 90% purity (yield: 30%). P.f .: 241-245? C (dee.)

V (2? -Acetyl-20i-hydroxl-3? -Fluoro-5,12-dimethoxy - 1,2,3,4-tetrahydro-6,11-naphtacendione)

In a polyethylene flask, 1.4 g (3.7 mmoles) of IV and 50 ml of 70% HF / pyridine are reacted for 24 hours at room temperature, in a nitrogen atmosphere. The reaction mixture is poured into 600 g of ice, stirring well, then the solid obtained is filtered and washed repeatedly with water. This crude is dried under vacuum over PO and suspended in 100 ml of boiling acetone; it is allowed to cool and filtered, washing the solid with a little acetone to give 880 mg of V. M.p. 241-245? C dee. (yield: 60%).

VI (2? -Acetyl-2?, 5,12-trihydroxy-3? -Fluoro-1,2,3,4-tetrahydro-6,11-naphtacendione)

In 15 ml of anhydrous methylene chloride, 82 mg (0.21 mmoles) of V are suspended under nitrogen and, after having brought the temperature to -65 ° C with an acetone and dry ice bath, add in 5 'ml 3 of a 1M solution of Boron trichloride (3 mmoles) in methylene chloride. The mixture is left under stirring for 30 'at -65 ° C before slowly adding 4 ml of methanol and allowing the reaction mixture to return to room temperature. Finally, by evaporation of the solvent 79 mg (100%) of VI are obtained. P.f .: 247-253? C.

VII (20- [2-methyl-1,3-dioxolanyl-2-yl] 2? 5,12-trihydroxy-3? -Fluoro-1, 2,3,4-tetrahydro-6,11-naphtacendione) In a 250 ml flask equipped with a Dean Stark device, 320 mg (0.86 mmol) of VII e are reacted in a nitrogen atmosphere. 7.77 (ml 7, 124 mmoles) of ethylene glycol at reflux in 100 ml of benzene, in the presence of 70 mg (0.4 mmoles) of p-toluenesulfonic acid, eliminating from the reaction environment the azeotrope which gradually distills. At the end the solvent is concentrated to a small volume and the solid obtained is filtered by washing it subsequently with a little benzene, ethanol, water, aqueous solution of sodium bicarbonate at 5% and again with water. Finally, it is dried under vacuum at 80 ° C to give 283 mg (0.68 mmoles) of VII: Pf.

237-240? C. (Yield 79.1%). P.f. 239-241? C (toluene).

TLC: CCl4 / AcOEt 2: 1 R = 0.54

VIII (2? - [2-methyl-1,3-dioasolanyl-2-yl] -2?, 4?, 5,12-tetrahydroxy-3? -Fluoro-1,3,4-tetrahydro-6, 11-naphtacendione)

880 mg of VII are suspended in 200 ml of carbon tetrachloride, under nitrogen, together with 880 mg of potassium carbonate. A solution of 500 mg of bromine in 20 ml of carbon tetrachloride is added. It is irradiated with a 500W lamp bringing the mixture to a slight ebb. After about 5 'the product is dissolved. The reaction is stopped after 1 hour. It is diluted with 200 ml of chloroform and washed with bicarbonate and then with water. It is dried on sodium sulphate and the solvent is evaporated. The residue is chromatographed on silica, first eluting with carbon tetrachloride / ethyl acetate 3: 1 to eliminate the residual starting product and by-products. It is then eluted with ethyl acetate until 300 mg of VIII is obtained.

IX (20-acetyl-2?, 4?, 5,12-tetrahydroxy-3? -Fluoro - 1,2,3,4-tetrahydro-6, 11-naphthycendione)

In 5 ml of anhydrous CH2C12, 82 mg (0.19 mmoles) of VIII are solubilized under nitrogen and the solution obtained is cooled to 0 ° C. Then 5 ml (5 mmoles) of a 1M solution of BC1 in CH Cl are added and the ice bath is removed. It is left under stirring at room temperature for 2 days, then 15 ml of water and s? Are carefully added. wash, after having diluted with 20 ml of CH Cl2 with water (3x20 ml). The organic phase is dried on sodium sulfate, yes? the solvent is evaporated and the crude is purified by chromatography on a silica column (eluent: CHCl / acetone 4: 1). 40 mg of IX are obtained. (Yield 50?).

XIII (4-demethoxy-8-fluoro-daunomycin)

142 mg of (?) - 3-N-trifluoroacetyl - 1,4-bis (O-p-nitrobenzoyl) -1-daunosamine are suspended in a solution of 45 mg of IX in 8.3 ml of anhydrous methylene chloride and 7 ml of anhydrous ether, under nitrogen, in the presence of 600 mg of 4A molecular sieves in grains. It is cooled to 0 ° C and 0.08 ml of trimethylsilyl triflate are added. After three hours the reaction mixture is treated with 50 ml of ethyl acetate and 100 ml of saturated sodium bicarbonate solution. then washing the organic phase with sodium chloride solution. It is dried, the solvent is evaporated and the residue is purified by chromatography on silica, eluting with 4: 1 chloroform / acetone. 80 mg of product are obtained, which are solubilized in 0.6 ml of methylene chloride and 37 ml of methanol. It is cold at 0 ° C and in a nitrogen atmosphere, 1.2 ml of 0.1 M sodium hydroxide are added. The solution is stirred for 30 minutes, then glacial acetic acid is added until the color of the solution is light orange. It is then treated with 60 ml of ethyl acetate and 60 ml of sodium chloride solution. The organic phase is washed twice more with sodium chloride solution, then anhydrified and evaporated. The residue is solubilized in 15 ml of 0.1 M sodium hydroxide at 0 ° C and is stirred for 20 minutes, in a nitrogen atmosphere. The pH of the solution is brought to 8 with 5 M HCl, then it is extracted repeatedly with chloroform. The organic phase is washed with water, dried and concentrated under vacuum. The residue is solubilized in a little chloroform and methanol (9: 1), HCl is added in 0.25 M methanol up to pH 3.5, then ether is added until the XIII hydrochloride precipitates.

TLC: (free base) r = 0.52 (CHC1 / MeOH / H O 13: 6: 1).

ACTIVITIES? ' BIOLOGICAL

The compounds object of the present invention were evaluated in cultures of human tumor cells "in vitro" and "in vivo" against transplantable mouse tumors according to the methods described in CANCER CHEMIOTHERAPY REPORTS, Part.3, Vol.3, pp.9 ( 1972).

Did the compounds show activity? higher than that of daunorubicin and doxorubicin used as comparator products.

Claims (20)

CLAIMS 1. A compound of formula: where X H or OH 2. A compound according to claim 1, where X? hydrogen. A compound according to claim 1, wherein X? a hydroxyl. 4. A compound according to claim 1, wherein X? H or OH and R1 = H, R2 = OH. 5. A compound according to claim 1, wherein X? H or OH and R1 = OH and R = H. 1 2 6. A compound according to claim 1, wherein X? H or OH and R, = R_ = H. 1 2 7. An aglycone having the formula: 8. An intermediate product of formula (III) for the production of an aglycone. 9. An intermediate product of formula (IV): for the production of an aglycone. 10. An intermediate product of formula (V) for the production of an aglycone. 11. An intermediate product of formula (VI) for the production of an aglycone. 12. An intermediate product of formula (VII) for the production of an aglycone. 13. An intermediate product of formula (VIII) for the production of an aglycone. 14. An intermediate product of formula (IX) for the production of an aglycone. 15. A pharmaceutical composition comprising an amount? therapeutically effective of a compound according to claim 1 in combination with a suitable excipient. 16. A method for inhibiting the growth of transplanted lymphatic leukemia P388, which involves the administration of a compound according to claim 1? 2, or 3, o, f or 5, or 6. 17. Use of the compound of one of claims 1 to 6, to produce a pharmaceutical composition for inhibiting the growth of transplanted lymphatic leukemia P388. 18. A process for preparing compounds according to claim 1, which provides: cyclization of 1,4 - dimethoxy-2, 3-bis (bromomethyl) anthraquinone with 3-butin-2-one; epoxidation with a peroxyacid; opening the oxirane ring with a nucleophilic fluorine; demethylation of phenolic hydroxyls; then protection of the acetyl chain and bromination in position 4 of the naphthacendione; subsequent replacement with a hydroxyl; and finally deprotection of the acetyl group 19. Process of claim 18, in which the glycosidation is carried out with a glucidic derivative suitably protected in the presence of condensing agents. 20. Process of claim 18, in which the deprotection of the glycosidate derivative is carried out - in a known way - with basic agents to obtain compounds with a hydroxyl in position 14 of the anthracycline, first introducing a bromine atom in said position, then replacing it with a hydroxyl both by direct hydrolysis of the bromoderivative and by hydrolysis of a suitable ester, such as for example formiate, obtained from the same by an exchange reaction.