Triethylamine → (3aRS,7aRS)-2-[(2-dimethylamino-6-fluorophenyl)acetyl]-7,7-diphenyl-4-perhydroisoindolone

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Reaction Steps

N,N'-Carbonyldiimidazole (1.62 g) is added to a solution of (2-dimethylamino-6-fluorophenyl)acetic acid (1.97 g) in dry dichloromethane (50 cc), cooled to +5° C. The mixture is stirred for 90 minutes at +5° C. and a solution of (3aRS,7aRS)-7,7-diphenyl-4-perhydroisoindolone hydrochloride (3.27 g) and triethylamine (2.8 cc) in dichloromethane (50 cc) is then added. The reaction mixture is stirred at 20° C. for 16 hours, then washed with water (2×100 cc), dried over magnesium sulphate and filtered and the filtrate is concentrated to dryness under reduced pressure (2.7 kPa). The residue is chromatographed on a silica gel column (particle size 0.04-0.06 mm, diameter 4 cm, height 25 cm), eluting under a nitrogen pressure of 0.5 bar with a mixture of cyclohexane and ethyl acetate (70/30 by volume) and collecting 50 cc fractions. Fractions 6 to 19 are combined and concentrated to dryness under reduced pressure. The residue is triturated in ethyl ether. The crystals are drained and dried. (3aRS,7aRS)-2-[(2-dimethylamino-6-fluorophenyl)acetyl]-7,7-diphenyl-4-perhydroisoindolone (3.6 g) is obtained in the form of white crystals melting at 210° C.

Provenance & Evidence