Dichloromethane → Pazufloxacin

Participants

Reaction Steps

In 100 ml of acetic acid was dissolved 10 g of ethyl (S)-10-(1-benzyloxycarbonylaminocyclopropyl)-9-fluoro-3-methyl-7-oxo-2,3-dihydro-7H-pyrido[1,2,3-de][1,4]benzoxazine-6-carboxylate. To the resulting solution was added 2 g of 5% palladium-carbon. The resulting mixture was stirred at room temperature for 2 hours at atmospheric pressure in a hydrogen stream. The reaction mixture was filtered. The filtrate was concentrated to dryness under reduced pressure. To the residue obtained were added 200 ml of methylene chloride and 200 ml of water in this order. The resulting mixture was adjusted to pH 7.7 with a saturated aqueous sodium hydrogen-carbonate solution. The organic layer was separated, washed with water and a saturated aqueous sodium chloride solution in this order, and dried over anhydrous magnesium sulfate. The solvent was removed by distillation under reduced pressure. Diethyl ether was added to the residue obtained. The resulting crystals were collected by filtration to obtain 6.43 g (yield: 89.2%) of ethyl (S)-10-(1-aminocyclopropyl)-9-fluoro-3-methyl- 7-oxo-2,3-dihydro-7H-pyrido[1,2,3-de][1,4]benzoxazine-6-carboxylate.

Provenance & Evidence