IT9009357A1 - 8-FLUORO-4-METOSSI-ANTRACICLINE, RELATED MANUFACTURING PROCEDURES AND THEIR USE. - Google Patents

Description

"NEW 8- FLU0R0-4-METQS SI -ANTRACI CLINE, RELATIVE PRO-

MANUFACTURING RELEASES AND THEIR USE "

SUMMARY

New 8-fluoro-4-methoxy-anthracyclines of general formula:

where X = H or OH and where Ri = H and R2 = OH; or Ri = OH and R2 = H; or Ri = H and R2 = H; as well as their manufacturing processes and use as novel anticancer agents.

DESCRIPTION

The invention relates to new derivatives of 2p-acetyl-2a, 4a, 5,12-tetrahydroxy-3pfluoro-7-methoxy-1,1,3,4-tetrahydro-6, 11-naphtacendione, to pharmaceutical preparations containing said products and methods to produce and use these derivatives.

Anthracyclincs are known to be important antitumor agents with clinical efficacy against many types of human cancer. However, their therapeutic use is limited by side effects, particularly dose-related chaidiotoxicity (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 3β position of the antitumor anthracycline aglycone increases the antitumor activity and the selectivity of action of these compounds. Consequently, compounds result which surprisingly, and presumably in connection with a different reactivity of the hydroxyl in 2α or for reasons also not foreseeable by those skilled in the art, have advantages with respect to the drugs currently in use 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 as the said aglycone.

The synthesis to obtain the aglycone is shown in the following scheme:

The invention also relates to the aforementioned intermediate products ΙΠ to IX.

Compound I is 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 RJ. Ardecky, D. Dominguer and M.P. Quarry, J. Org. Chem. 1982, 47, 409-412.

To obtain the intermediate compound III a variant is used to what 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 ri, 4,5- trimethoxy-2,3-bis- (bromomethyl) anthraquinone which under the reaction conditions behaves formally 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, to obtain the intermediate compound VI, is carried out, in an almost quantitative yield, with a suitable Lewis acid, such as for example 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 e.g. 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 Γ intermediate VIII. The latter is deprotected in an acid environment, thus obtaining 2β-3οεή1-2α, 4α, 5,12-ΐεη ^ ίΐΓθ58Ϊ-3β-ίΙυοΓθ-7-Γηεΐθ85Ϊ-l, 2,3,4-tetrahydro-6, l 1 -naftacendione (intermediate IX).

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

to continue with the removal of the protections and obtain:

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 carbocation sufficiently stabilized and capable of giving rise to a condensation with the benzyl hydroxyl of IX and 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 (0-p-nitrobenzoyl) -acosamine (XI), 3-N-trifluoroacetyl-1-0-p-nitrobenzoyl-4-deoxy-daunosamine (XII), or 3,4-di-trifluoroacetyl-1-chlorodaunosamine, 3,4-di trifluoroacetyl -1-chloroacosamine, or the corresponding 4-deoxy derivative.

The trimethylsilyl derivative can also be used as the protective group of the alcoholic function of the sugar, while position 1 of the same can also be activated as 1-bromine, 1-fluorine, 1-trimethylsilyloxy, 1-acetoxy, or as 1,2-glycal .

Condensing agents in the reaction between glucose reactive and intermediate IX can be salts such as silver trillate or silver perchlorate, mixtures of mercuric oxide and bromide, trimethylsilyl trriflate, or acids such as p-toluene sulfonic acid, or Lewis acids such as a boron trihalide, tin tetrachloride or chemical compounds with equivalent properties. 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, collidine or equivalent.

The protective groups on the legal 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, cannot 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 the products I and Π is now described.

ΠΙ (2-acetyl-5, 7, 12-trimethoxy-1,4-dihydro-6, 11-naphtacendione)

In a mixture consisting of 50 ml of dimethylacetamide and 10 ml of dioxane, 29 g (193 mmoles) of NaI are dissolved under nitrogen. Dissolution is exothermic: when the temperature has dropped to 40 ° C, 6.6 g (97 mmoles) of Π butinone are added in a single portion. The temperature of the mixture is brought to 65 ° C and a solution consisting of 5.3 g (11 mmoles) of I and 100 ml of dimethylacetamide is dropped into it in an hour, maintaining the temperature close to the initial value. At the end of the addition it is left under stirring at 65-70 ° C for another 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 P2O5 to give 3.9 g of crude oil. The ΠΙ product is separated by chromatography on a silica column, eluting with n-hexane / THF 2: 1. 1.9 g of pure product are obtained. Ms, m / z (%): 392 (M +, 100).

TLC: n-Hexane / THF 2: l Rf = 0.3.

IV {2-acetyl-2, 3-epoxy-5, 7, 12-trimethoxy-1, 2, 3, 4-tetrahydro-6, 11 -naphtacendione)

In 250 ml of chloroform, 1.9 g (4 mmoles) of ΙΠ and 8.7 g of 55% m-CPBA (27.5 mmoles) are refluxed for 7 hours under nitrogen. The reaction mixture, cooled to room temperature, is treated with 10% sodium bisulfite solution (2x 100 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 600 mg of IV at 90% purity.

MS, m / z (%): 408 (M +, 80).

V (2p-acetyl-2a-hydroxy-3P-fluoro-5,7,12-trimethoxy-1,2,3,4-tetrahydro -6,11 -naphtacendione)

In a polyethylene flask, 1 g (2.5 mmoles) of IV and 30 ml of 70% HF / pyridine are reacted for 24 hours at room temperature, in a nitrogen atmosphere. The reaction mixture is poured into 300 g of ice, stirring well, then the solid obtained is filtered and washed repeatedly with water. This crude is dried under vacuum over P2O5 and suspended in 50 ml of boiling acetone; it is allowed to cool and filtered, washing the solid with a little acetone to give 600 mg of V.

MS, m / z (%): 428 (M +, 100).

VI (2 β-αοείΐΙ-2 a, 5, 12-trihydroxy-3 P-fluoro-7-methoxy-1, 2, 3, 4-tetrahydro-6,11-naphtacendione)

In 15 ml of anhydrous methylene chloride, 90 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. It is left under stirring for 30 'at -65 ° C before slowly adding 4 ml of methanol and letting the reaction mixture return to room temperature. Finally, by evaporation of the solvent 84 mg (100%) of VI are obtained.

MS, m / z (%): 400 (M +, 35).

VII (2β- [2-ηΐ € ίίΙ-1,3-άίθ3 $ οΙαηΐΙ-2-ίΙ] 2α, 5,12-ΐΓαάΓθ55ί-3β- / ΙιιοΓθ-7-methoxy-1, 2, 3, 4-tetrahydro- 6, 11 -naftacendione)

In a 250 ml conical flask equipped with a Dean Stark apparatus, 350 mg (0.88 mmol) of VII and 7.77 g (7.24 mmol) of ethylene glycol are reacted in a nitrogen atmosphere in 100 ml of benzene, in the presence of 70 mg (0.4 mmoles) of ptoluenesulfonic acid, eliminating from the reaction environment Γ azeotrope which gradually distils. 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. It is finally dried under vacuum at 80 ° C to give 310 mg of VII.

TLC: CCWAcOEt 2: 1 Rf = 0.5.

VIII (2β- [2-ηιβΜ-1) 3- <αο88θΙαηίΙ · 2-ίΙ] -2α, 4α., 5,12-ίΘίΓαί <ΐΓθ5ςί-3β -fluoro-7 -methoxy-1, 2, 3, 4- tetrahydro-6, 11 -naphtacendione)

900 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 330 mg of VIII is obtained.

IX (2 p-acetyl'2a, 4a, 5,12-tetrahydroxy-3P-fluorO'7-methoxy-1, 2,3,4 -tetrahydro-6, 11-naphthacendione)

In 5 ml of anhydrous CH2CI2, 88 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 BCI3 in CH2CI2 are added and the ice bath is removed. It is left under stirring at room temperature for 2 days, then 15 ml of water are carefully added and washed, after diluting with 20 ml of CH2C12, with water (3x20 ml) The organic phase is dried on sodium sulphate, the solvent is evaporated and the crude is purified by chromatography on a silica column (eluent: CHCiyacetone 4: 1). 50 mg of IX are obtained.

MS, m / z (%): 462 (M +, 100).

XIII (8 -fluoro-daunomycin)

142 mg of (-) - 3-N-trifluoroacetyl-1,4-bis (0-p-nitrobenzoyl) -ldaunosamine are suspended in a solution of 48 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 molecular sieves 4A 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. 85 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 1.2 ml of 0.1 M sodium hydroxide are added in a nitrogen atmosphere. 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 stirred for 20 minutes, in a nitrogen atmosphere. The pH of the solution is brought to 8 with HC15 M, 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 precipitation of the XHL hydrochloride

TLC: (free base) Rf = 0.49 (CHCl3 / Me0H / H20 '13: 6: 1).

BIOLOGICAL ACTIVITY *

The compounds object of the present patent 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, Pari. 3, Vol. 3, pp. 9 (1972).

The compounds showed an activity superior to that of daunorubicin and doxorubicin used as comparator products.

Claims (7)

CLAIMS 1. A compound of formula: 2. A compound according to claim 1, where X is hydrogen. A compound according to claim 1, wherein X is a hydroxyl. A compound according to claim 1, wherein X is H or OH and Ri = H, R2 = OH. A compound according to claim 1, wherein X is H or OH and Ri = OH and R2 = H. A compound according to claim 1, wherein X is H or OH and Ri = R2 = H. 7. An aglycone having the formula: for the production of the aglicone of claim 7. 11. An intermediate product of formula (VI): for the production of the aglicone of claim 7. A pharmaceutical composition comprising a therapeutically effective amount of a compound according to claim 1 in combination with a suitable excipient. 15. A method for inhibiting the growth of transplanted lymphatic leukemia P388 which involves the administration of a compound according to claim 1 or 2, or 3, or 4, or 5, or 6. 16. Use of the compound in one of claims 1 to 6, to produce a pharmaceutical composition for inhibiting the growth of transplanted lymphatic leukemia P388. 17. A process for preparing compounds according to claim 1, which provides: cyclization of 1, 4,5-trimethoxy-2,3-bis (bromomethyl) anirakinone with 3-butin-2-one; epoxidation with a peroxyacid; opening of 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. 18. Process of claim 17, in which the glycosidation is carried out with a glucidic derivative suitably protected in the presence of condensing agents. 19. Process of claim 17, 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 formate, obtained from the same by an exchange reaction.