1-Fluoro:phenyl-1,8-naphthyridine-3-carboxylic acid derivs. prodn.

摘要

Prodn. of naphthyridine derivs. of formula (I) or their salts comprises reacting nicotinoyl-acetic acid cpds. (II) with formamide acetal (II), opt. in the presence of an acoid anhydirde, and if required removal of protecting gps. or conversion to a salt or ester. In the formulae, R1 = H or protecting gp. R2 = halo, OH, N3 or (all opt. substd.) alkoxy, alkylthio, arylthio, alkane- or arene-sulphinyl or -sulphonyl, di(alkoxy or aryloxy) phosphinyloxy, or (both opt. N-protected) 3-aminopyrrolidino or piperazino; X = H or F; R1a = protecting gp. R3 and R4 = alkyl or cycloalkyl or together are alkylene complating the -CH(O)-O- ring; R5 and R6 = alkyl, or together complete a heterocycle. (I) are new cpds. where R2 is other than halo or opt. protected 3-aminopyrrolidino or piperazino. Also new are intermediates (II) and their percursors of formula (IV).