Sodium hydride → Ethyl 10-(1-t-butoxycarbonyl-3-pyrrolidinyloxy)-9-fluoro-2,3-dihydro-3-methyl-7-oxo-7H-pyrido[1,2,3de][1,4]-benzoxazine-6-carboxylate

Participants

Reaction Steps

To a mixture of 263 mg of ethyl 9,10-difluoro-2,3-dihydro-3-methyl-7-oxo-7H-pyrido[1,2,3-de][1,4]-benzoxazine6-carboxylate, 318 mg of 1-t-butoxycarbonyl-3-hydroxypyrrolidine, 194 mg of DBU and 3 ml of DMSO was added 74 mg of 55% sodium hydride while the former was stirred at room temperature for 2.5 hours. After the resultant mixture was stirred at room temperature, the reaction mixture was diluted with chloroform and then successively washed with 10% citric acid and saturated saline. The organic layer was dried over anhydrous sodium sulfate and then concentrated to dryness. The residue was purified by chromatography on silica gel (chloroform/methanol: 100/1), whereby 220 mg of ethyl 10-(1-t-butoxycarbonyl-3-pyrrolidinyloxy)-9-fluoro2,3-dihydro-3-methyl-7-oxo-7H-pyrido[1,2,3-de][1,4]-benzoxazine-6-carboxylate was obtained.

Provenance & Evidence