Methanesulfonic Acid → Garenoxacin Mesylate

Participants

Reaction Conditions

Reaction Steps

In 192 ml of 50% ethanol is suspended 24 g of (R)-1-cyclopropyl-8-difluoromethoxy-7-(1-methyl-2,3-dihydro-1H-5-isoindolyl)-4-oxo-1,4-dihydro-3-quinoline-carboxylic acid monohydrate, and the suspension is warmed to 40° C., after which 5.71 g of methanesulfonic acid is added to form a uniform solution. Subsequently, 2.4 g of activated carbon is added and the resulting mixture is stirred at the same temperature for 10 minutes, after which the insolubles are removed by filtration. The filtrate is concentrated and the crystals deposited are collected by filtration to obtain 26.64 g of (R)-1-cyclopropyl-8-difluoromethoxy-7-(1-methyl-2,3-dihydro-1H-5-isoindolyl)-4-oxo-1,4-dihydro-3-quinolinecarboxylic acid methanesulfonate monohydrate.

Provenance & Evidence