1,8-Diazabicyclo(5.4.0)undec-7-ene → 1-Cyclopropyl-7-(3-amino-1-pyrrolidinyl)-6-fluoro-8-methyl-1,4-dihydro-4-oxoquinoline-3-carboxylic acid

Participants

Reaction Steps

A mixture of 1-cyclopropyl-6,7-difluoro-1,4-dihydro-8-methyl-4-oxo-3-quinolinecarboxylic acid (200 mg), 3-t-butoxycarbonylaminopyrrolidine (200 mg), 1,8-diazabicyclo[5,4,0]-7-undecene (110 mg, DBU) and anhydrous acetonitrile (2 ml) was refluxed for 18 hours. The reacting mixture was concentrated under reduced pressure. The resulting residue was dissolved in chloroform (20 ml), washed with 10% aqueous citric acid solution and saturated aqueous sodium chloride solution successively, dried over anhydrous sodium sulfate and concentrated under reduced pressure. To the solution of the resulting residue in methanol (2 ml) was added concentrated hydrochloric acid (2 ml) and stirred at room temperature for 15 minutes. After the reacting mixture was neutralized with concentrated aqueous ammonia, the mixture was concentrated under reduced pressure. The resulting residue was purified by silica gel chromatography eluting chloroform-methanol-concentrated aqueous ammonia (10:10:3) and recrystallized from dichloromethane-methanol further to give the title compound (30 mg) as yellow powder, mp 187°-190° C.

Provenance & Evidence