METHOD FOR PREPARING BENZO b]NAPHTHYRIDINES.

摘要

Process for the preparation of benzo[b]naphthyridines of general formula: in which R is a carboxyl, alkyloxycarbonyl, cyano, carbamoyl, alkylcarbamoyl, benzylcarbamoyl, hydroxyethylcarbamoyl or dialkylaminoethylcarbamoyl radical or a dialkylcarbamoyl radical in which the alkyl parts may optionally form, with the nitrogen atom to which they are attached, a 5- or 6-membered heterocycle optionally containing another heteroatom chosen from oxygen, sulphur or nitrogen and optionally substituted on the nitrogen by an alkyl radical, R' is H, alkyl, fluoroalkyl, carboxyalkyl, (3 to 6 C)cycloalkyl, fluorophenyl, difluorophenyl, alkyloxy or alkylamino, and Hal is halogen, and their salts, where such exist, characterised in that: 1) an amine of general formula: R'-NH-CH2-CH2-R'' in which R'' is alkyloxycarbonyl, cyano, carbamoyl, alkylcarbamoyl, benzylcarbamoyl, hydroxyethylcarbamoyl, dialkylaminoethylcarbamoyl or dialkylcarbamoyl in which the alkyl parts may optionally form, with the nitrogen atom to which they are attached, a 5- or 6-membered heterocycle optionally containing another hetero atom chosen from oxygen, sulphur or nitrogen and optionally substituted on the nitrogen by an alkyl radical, is condensed with a chlorofluoroquinoline of general formula: in which R1 is an alkyl radical, the alkyl radicals mentioned above have 1 to 4 C and are straight or branched, 2) the fluoroquinoline of general formula: in which R1 is defined as above in 1), is cyclised, 3) the 1,2,3,4-tetrahydrobenzo[b][1,8]naphthyridine of general formula: is oxidised and the ester obtained is then optionally converted to an acid and optionally converted to a salt.