2-Methoxyphenylacetic acid → (3aRS,7aRS)-7,7-Bis(3-fluorophenyl)-2-(phenylacetyl)perhydro-4-isoindolone

Participants

Reaction Conditions

Reaction Steps

A solution of (2-methoxyphenyl)acetic acid (0.46 g) in dry dichloromethane (15 cc) is cooled to 0° C., then treated with N,N'-carbonyldiimidazole (0.45 g) and stirred for 1 hour at 0° C. A solution of 7,7-bis(3-fluorophenyl)perhydro-4-isoindolone hydrochloride (1 g) and triethylamine (0.76 cc) in dichloromethane (20 cc) is added dropwise. The reaction mixture is stirred for 3 hours at 25° C. and then washed with water (2×50 cc) and with saturated sodium chloride solution (50 cc). The organic phase is dried over magnesium sulphate, filtered and concentrated to dryness under reduced pressure (2.7 kPa). The residue is chromatographed on a column of silica gel (particle size 0.04-0.063 mm, diameter 2.2 cm, height 23 cm), eluting under a nitrogen pressure of 0.5 bar with a mixture of cyclohexane and ethyl acetate (70:30 by volume) and collecting 15-cc fractions. Fractions 4 to 9 are combined and concentrated to dryness under reduced pressure (2.7 kPa), and the product obtained is recrystallized in acetonitrile. The crystals are drained, washed with isopropyl ether and dried. (3aRS,7aRS)-7,7-Bis(3-fluorophenyl)-2-(phenylacetyl)perhydro-4-isoindolone (0.76 g) is obtained. M.p. 194° C.

Provenance & Evidence