Methanesulfonic Acid → 1433857-41-0

Participants

Reaction Conditions

Reaction Steps

3.36 L of acetone was added to 178 g of 7-{(3S,4S)-3-[(cyclopropylamino)methyl]-4-fluoropyrrolidine-1-yl}-6-fluoro-1-(2-fluoroethyl)-8-methoxy-4-oxo-1,4-dihydroquinoline-3-carboxylic acid synthesized according to Reference Example 3, and the mixture was heated for dissolution. 0.48 L of an acetone solution of 59.1 g of methanesulfonic acid was added dropwise to the solution at an internal temperature of around 40° C. (the solution obtained is hereinafter referred to as a solution mixture). The solution mixture was stirred at an internal temperature of around 40° C. for 0.5 hours. The solution mixture was cooled and stirred at an internal temperature of 10° C. or less for 0.5 hours. Precipitated crystals were separated by filtration, washed with 1.44 L of acetone, and dried at 50° C. under reduced pressure for 2 hours to obtain 198 g of crude 7-{(3S,4S)-3-[(cyclopropylamino)methyl]-4-fluoropyrrolidine-1-yl}-6-fluoro-1-(2-fluoroethyl)-8-methoxy-4-oxo-1,4-dihydroquinoline-3-carboxylic acid methanesulfonate salt.

Provenance & Evidence