HCID 20286060, compound → HCID 54371081, compound

Participants

Reaction Steps

A mixture of 3 gm (8 mmol) of 3-(2',3',5',6'-tetrafluoro-4'-methoxyphenacyl)phthalide in 40 ml of glacial acetic acid was heated and stirred at 55°-60° C., and 3 gm of molecular bromine in 20 ml of glacial acetic acid was added dropwise. The colorless solution of the α-brominated starting material was thereafter added to 260 ml of ice cold water with vigorous stirring. The white precipitate was filtered and dried, dissolved in 150 ml of methylene chloride and refluxed for 2 hours in the presence of 3 ml of triethylamine. Dilute acid washing, followed by concentration and recrystallization from ethanol gave 1.1 gm (45%) of 3-(2',3',5',6'-tetrafluoro-4'-methoxyphenacylidene)phthalide, mp 199°-200° C.

Provenance & Evidence