EP0278686A1 — Pyridopyrimidines methods for their preparation and pharmaceutical formulations thereof

USPTO Abstract

The present invention relates to compounds of the general formula (III) wherein R¹ is hydrogen when R² is methyl or R¹ is methyl when R² is hydrogen, and pharmaceutically acceptable salts thereof, i.e. the compounds 2,4-diamino-5-methyl-6-(2-hydroxy-5-methoxybenzyl)pyrido (2,3- d )pyrimidine and 2,4-diamino-5-methyl-6-(5-hydroxy-2-methoxybenzyl)­pyrido(2,3- d )pyrimidine and their pharmaceutically acceptable salts. The compounds have potent inhibitory activity against dihydrofolate reductase, and are useful in treating bacterial infections and in treating proliferative diseases, for example in mammals. Compounds of formula (III) may be prepared for example by debenzylation of the corresponding benzyloxy derivative.