Chlorosulfonic acid → HCID 20227234, compound

Participants

Reaction Conditions

Reaction Steps

A suspension of ethyl 9-fluoro-10-phenyl-3-methyl-7-oxo-2,3-dihydro-(7H)-pyrido-(1,2,3-de)-1,4-benzoxazine-6-carboxylate (0.4 g, 1.2 mmol) in dichloromethane (15 ml) was cooled to 0° C. with stirring. Chlorosulfonic acid (5 ml) was added dropwise over 5 minutes. The dark solution was stirred at 0° C. for 15 minutes, then it was warmed gradually to room temperature over 1.5 hour. The reaction mixture was poured onto ice water with stirring. Three extractions with chloroform, drying the combined organic layers over magnesium sulfate, filtration and removal of solvent in vacuo gave a yellow oil (0.5 g) which was used without further purification.

Provenance & Evidence