Vinyl chloroformate → (3aRS,7aRS)-7,7-bis(3-chlorophenyl)-2-vinyloxycarbonylperhydro-4-isoindolone

Participants

Reaction Steps

A solution of (3aRS,7aRS)-2-benzyl-7,7-bis(3-chlorophenyl)perhydro-4-isoindolone (11.5 g) in 1,2-dichloroethane (250 cc) is treated with vinyl chloroformate (2.8 cc) and heated to reflux for 16 hours, then concentrated under reduced pressure (2.7 kPa). The residue is chromatographed on a column of silica gel (particle size 0.04-0.063 mm, diameter 6 cm, height 32 cm), eluting under a nitrogen pressure of 0.5 bar with a mixture of cyclohexane and ethyl acetate (80:20) and collecting 25-cc fractions. Fractions 19 to 27 are combined and concentrated to dryness under reduced pressure (2.7 kPa). The meringue-like product obtained is solidified in isopropyl ether and the precipitate is drained, washed with isopropyl ether and dried to give (3aRS,7aRS)-7,7-bis(3-chlorophenyl)-2-vinyloxycarbonylperhydro-4-isoindolone (6.7 g) in the form of a white solid.

Provenance & Evidence