Triethylamine → 364069-14-7

Participants

Reaction Steps

(7S)-7-Amino-5-azaspiro[2.4]heptane dihydrochloride (61.4 g; 0.332 mol) was dissolved in dimethylsulfoxide (800 ml), and triethylamine (138 ml; 0.994 mol) was added to the resultant solution under a nitrogen atmosphere at room temperature, followed by stirring for 10 hours. 6,7-Difluoro-1-[(1R, 2S)-2-fluoro-1-cyclopropyl]-1,4-dihydro-8-methoxy-4-oxo-3-quinolinecarboxylic acid difluoroboron chelate (100 g; 0.276 mol) in powder form was slowly added to the reaction mixture, followed by stirring for 40 hours at room temperature. The reaction mixture was concentrated under reduced pressure, and ethanol (90%: 1000 ml) and triethylamine (20 ml) were added thereto, followed by refluxing for 2.5 hours. The reaction mixture was left to cool, and crystals that precipitated were collected by filtration. The crystals were sequentially washed with ethanol and ether, followed by drying under reduced pressure at 70° C. for 16 hours, to thereby yield 72.5 g of the title compound (as 0.5 hydrate) as a pale yellow powder (yield: 61.4%). Solvents were removed from the filtrate under reduced pressure, and water (2000 ml) was added to the residue. An aqueous sodium hydroxide solution (3N) was added to the mixture so as to adjust the pH value to 10.0 while being stirred under ice cooling. Subsequently, an aqueous hydrochloric acid solution (3N) was added to the mixture so as to adjust the pH to 7.4, followed by stirring for 16 hours at room temperature. Crystals that precipitated were collected by filtration, washed with water, and dried under reduced pressure at 70° C., to thereby yield 19.2 g of the title compound (as 0.5 hydrate) as a pale yellow powder (yield: 33.6%).

Provenance & Evidence