3-Hydroxypiperidine → 8-Fluoro-9-(3-hydroxy-1-piperidyl)-2-methyl-1,2-dihydro-6-oxo-pyrrolo[3,2,1-ij]quinoline-5-carboxylic acid

Participants

Reaction Steps

8,9-Difluoro-2-methyl-1,2-dihydro-6-oxo-pyrrolo[3,2,1-ij]quinoline-5-carboxylic acid (5 g) and a solution of 7.5 g of 3-hydroxypiperidine in 50 ml of hexamethylphosphoric triamide were reacted with heating at 120° to 130° C. for 7 hours with stirring. After completion of reaction, hexamethylphosphoric triamide and unreacted 3-hydroxypiperidine were distilled off under reduced pressure. Recrystallization of the residue from dimethylformamide gave 2.5 g of 8-fluoro-9-(3-hydroxy-1-piperidyl)-2-methyl-1,2-dihydro-6-oxo-pyrrolo[3,2,1-ij]quinoline-5-carboxylic acid. m.p. 251°-253° C.

Provenance & Evidence