1,1'-Carbonyldiimidazole → (3aR,4S,7aR)-7,7-diphenyl-2-[(S)-2-(2-methoxyphenyl)propionyl]-4-perhydroisoindolol

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Reaction Steps

0.37 g of carbonyldiimidazole is added to a solution, cooled to +4° C., of 0.41 g of (S)-2-(2-methoxyphenyl)propionic acid in 15 cm3 of dry dichloromethane. The mixture is stirred for one hour at +4° C. and then a solution of 0.75 g of (3aR,4S,7aR)-7,7-diphenyl-4-perhydroisoindolol hydrochloride is added. The reaction mixture is stirred at room temperature for 20 hours and then then washed twice with 10 cm3 of water, dried over magnesium sulphate, filtered and 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 3.6 cm, height 37 cm), eluting under a nitrogen pressure of 0.5 bar with an ethyl acetate and cyclohexane mixture (50/50 by volume) and collecting fractions of 50 cm3. Fractions 21 to 41 are pooled and concentrated to dryness under reduced pressure (2.7 kPa). The residue is triturated in isopropyl oxide and then dried. 0.3 g of (3aR,4S,7aR)-7,7-diphenyl-2-[(S)-2-(2-methoxyphenyl)propionyl]-4-perhydroisoindolol is obtained in the form of a white meringue.

Provenance & Evidence