1,8-Diazabicyclo(5.4.0)undec-7-ene → Ethyl 6,8-difluoro-1-methyl-4-oxo-7-((S)-3-trifluoroacetylamino-1-pyrrolidinyl)-1H,4H-[1,3]thiazeto[3,2-a]quinoline-3-carboxylate

Participants

Reaction Steps

A mixture of 1.34 g of ethyl 6,7,8-trifluoro-1-methyl-4-oxo-1H,4H-[1,3]thiazeto[3,2-a]quinoline-3-carboxylate, 2.66 g of (S)-3-trifluoroacetylaminopyrrolidine hydrochloride [[α]D20 -28.6° (c=1, MeOH)], 1.80 g of 1.8-diazabicyclo[5,4,0]-7-undecene and 30 ml of N,N-dimethylformamide was stirred at room temperature for 5 hours. The reaction mixture was concentrated in vacuo, and water was added to the residue. The precipitate was collected by filtration and was chromatographed on silica gel using chloroform-methanol (8:2) to give the desired compound, which was recrystallized from methanol to give 0.80 g of pale yellow needles, m.p. 219°-224° C.

Provenance & Evidence