Hydrochloric Acid → Moxifloxacin hydrochloride

Participants

Reaction Conditions

Reaction Steps

1-cyclopropyl-6,7-difluoro-8-methoxy-4-oxo-1,4-dihydro-3-quinoline carboxylic acid-O3,O4 bis(propyloxy-O)borate (100.0 g) was suspended in acetonitrile (445.0 ml). (S,S)-2,8-diazabicyclo(4,3,0)nonane (29.0 g) diluted with 50.0 ml acetonitrile was slowly added at 10-15° C. followed by triethyl amine (25.0 g). The contents were heated to reflux temperature for 2 hours. Cooled to 25-30° C. Methanol (200.0 ml) was added and pH was adjusted to 1.0-2.0 using hydrochloric acid and stirred at 10-15° C. for 2 hours. After the completion of reaction, the reaction mass was concentrated to residue. Purified water 500.0 ml was added and pH was adjusted to 7.5-9.0 using liquour ammonia under stirring. The contents were heated to 70-75° C. and ammonia is expelled off by purging Nitrogen gas to the reaction mass. The reaction mass was cooled to 25-30° C. and stirred for 1 hour. The resulting solid was filtered and washed with purified water and dried under vacuum at 55-60° C. to obtain 75.0 g moxifloxacin base. 70.0 g of moxifloxacin base was stirred with 350.0 ml of methanol at 25-30°. The pH was adjusted to 1.0-2.0 using methanolic hydrochloric acid and contents were chilled to 0-5° C. and stirred for 1 hour at the same temperature. The solid was filtered and dried under vacuum at 85-90° C. to yield 78.0 g (77%) of moxifloxacin hydrochloride.

Provenance & Evidence