Boron Trichloride → HCID 19736745, compound

Participants

Reaction Steps

Ethyl 2-{(8-chloro-5-methoxy-3,4-dihydro-4-oxospiro[2H-1-benzopyran-2,1'-cyclohexan ]-7-yl)oxy}acetate (65-3, prepared in Preparation 65) (0.575 g, 1.50 mmol) is dissolved in dry dichloromethane (3 ml). To the solution is added dropwise a 2M boron trichloride solution in dichloromethane (1.5 ml, 3.0 mmol) at -75° to -70° C. After stirring at -70° to -50° C. for 1.5 hours, ice-cold water is added thereto and the mixture is extracted with dichloromethane. Organic layer is separated, washed with aqueous sodium bicarbonate, dried, and concentrated. The residue is applied to a silica gel column and eluted with a mixture of acetonitrile and dichloromethane (1:9) to yield the title compound as a crystalline solid (0.428 g, yield 77.4%). Recrystallization from diethyl ether gives a product having a melting point of 110°-111° C.

Provenance & Evidence