8,9-Difluoro-3-methyl-6-oxo-2,3-dihydro-6H-1-oxa-3a-aza-phenalene-5-carboxylic acid → 10-(cis-3-t-Butoxycarbonylamino-4-methyl-1-pyrrolidinyl)-9-fluoro-2,3-dihydro-3-methyl-7-oxo-7H-pyrido[1,2,3-de][1,4]benzoxazine-6-carboxylic acid

Participants

Reaction Steps

A mixture of 9,10-difluoro-2,3-dihydro-3-methyl-7-oxo-7H-pyrido[1,2,3-de][1,4]benzoxazine-6-carboxylic acid (0.5 g), anhydrous dimethyl sulfoxide (10 ml) and cis-3-t-butoxycarbonylamino-4-methylpyrrolidine (0.54 g) was stirred for 2 hours at 90°-100° C. and then concentrated. To the residue was added methanol and the resulting precipitate was collected by filtration and then washed with cold methanol to give the title compound (0.58 g) as yellowish powder, mp 219°-220° C.

Provenance & Evidence