Process for preparing derivatives of 5,11-dihydro-6h-pyrido[2,3-b][1,4]-benzodiazepin-6-one, and the final derivatives and synthesis intermediates obtained thereby

Abstract

This invention relates to a process for preparing derivatives of 5,11-dihydro-6H-pyrido[2,3-b][1,4]-benzodiazepin-6-one of general formula (I) ##STR1## in which R is hydrogen, halogen or methyl; R.sub.1 and R.sub.2 are linear or branched C.sub.2 -C.sub.4 alkyl groups, which alternatively may be joined together to give a piperazine cycle which can be substituted in position 4 with a methyl, ethyl or benzyl group, and their salts with organic and inorganic acids, characterised by comprising the following stages: (a) reacting a compound of general formula (X), ##STR2## in which R has the meaning heretofore defined, with 2-cloro-3-amino-pyridine of formula (III) ##STR3## in the presence of polyphosphoric acid, to give an intermediate of general formula (II) ##STR4## (b) reacting said intermediate with a compound of general formula (XI) ##STR5## in which R.sub.1 and R.sub.2 have the meaning heretofore defined and R.sub.3 is a hydroxyl or halogen, in an inert solvent at a maximum temperature equal to the solvent boiling point, to give said derivatives of general formula (I). The invention also relates to the final compounds thus obtained, and the synthesis intermediates obtained during the course of said process. The final products of formula (I) are of great interest in the pharmaceutical field.

Dependencies are inferred from the claim text.