Selective demethylation of anthracycline derivatives
AssigneeSocieta' Farmaceutici Italia S.p.A.
InventorsLuigi Bernardi, Bianca Patelli
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Abstract
Anthracycline derivatives of the formula ##SPC1## Wherein R.sub.1, R.sub.2, R.sub. 3 and R.sub.4 are independently selected from the group consisting of hydrogen, chlorine, bromine and methoxy, with the proviso that at least one of the substituents is methoxy, and wherein R.sub.5 is selected from the group consisting of hydrogen, OH OR and OCOR; R being an alkyl group of 1 to 4 carbon atoms are prepared, in a single step, by selectively demethylating a compound of the formula: ##SPC2## Wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 are as defined above by treating same with an aluminum halide in the presence of a suitable solvent at a temperature of 0.degree. to 50.degree.C.
Claims4
A process for preparing an anthracycline derivative of the formula ##SPC6##
- wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are independently selected from the group consisting of hydrogen, chlorine, bromine and methoxy group, with the proviso that at least one of R.sub.1, R.sub.2, R.sub.3 and R.sub.4 is methoxy;
- and wherein R.sub.5 is selected from the group consisting of hydrogen, OH, OR and OCOR, in which R is an alkyl group of 1 to 4 carbon atoms;
- said process comprising reacting a compound of the formula ##SPC7##
- wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 are as defined above with an aluminum halide in the presence of a solvent selected from the group consisting of chlorobenzene, bromobenzene, and nitrobenzene, at a temperature of from 0.degree. to 50.degree.C., and isolating the demethylated product from the reaction mixture.
Dependencies are inferred from the claim text.