1,8-Diazabicyclo(5.4.0)undec-7-ene → 7-(cis-3-Amino-4-methyl-1-pyrrolidinyl)-1-ethyl-6,8-difluoro-1,4-dihydro-4-oxo-3-quinolinecarboxylic acid

Participants

Reaction Steps

A mixture of 1-ethyl-6,7,8-trifluoro-1,4-dihydro-4-oxo-3-quinolinecarboxylic acid (1.0 g), cis-3-t-butoxycarbonylamino-4-methylpyrrolidine (0.89 g), DBU (0.62 g) and anhydrous acetonitrile (30 ml) was refluxed for 2 hours and then concentrated. The resulting residue was dissolved in chloroform (50 ml), washed with 10% aqueous citric acid solution and water successively, dried over anhydrous sodium sulfate and concentrated. To the resulting residue was added hot methanol to crystallize and then cooled. The resulting precipitate was collected by filtration, added to the mixture of concentrated hydrochloric acid-methanol (1:1, 18 ml) and stirred at room temperature for an hour. The reacting mixture was neutralized with concentrated aqueous ammonia and the resulting precipitate was collected by filtration, washed with ice-water sufficiently and recrystallized from dichloromethane-methanol (1:1) to give the title compound (0.41 g) as colorless prisms, mp 232°-234° C. (decompd.).

Provenance & Evidence