Ethyl 1-cyclopropyl-6,7-difluoro-8-methyl-5-nitro-4-oxo-1,4-dihydroquinoline-3-carboxylate → Ethyl 5-amino-1-cyclopropyl-6,7-difluoro-8-methyl-4-oxo-1,4-dihydroquinoline-3-carboxylate

Participants

Reaction Steps

A suspension containing 18.5 g of ethyl 1-cyclopropyl-6,7-difluoro-1,4-dihydro-8-methyl-5-nitro-4-oxoquinoline-3-carboxylate, 10 ml of Raney nickel, and 300 ml of acetic acid was hydrogenated at room temperature for 1.5 hours under atmospheric pressure. The catalyst was filtered off and the filtrate was concentrated. The resulting residue was added with 150 ml of 10% aqueous potassium carbonate, and then the mixture was extracted with methylene chloride. The organic layer was dried and concentrated to give 14.8 g of pale yellow crystals. The crystals were recrystallized from acetonitrile to give pale yellow needles, m.p. 182.5°-185.5° C.

Provenance & Evidence