1-Phenethylamine, (+)- → (1S,2R,4S)-4-(dibenzylamino)-2-methylcyclopentanecarboxylate.(R)-1-phenylethanamine

Participants

Reaction Steps

To a solution of 4-(dibenzylamino)-2-methylcyclopentanecarboxylic acid (1240 g, 1499 mmol, prepared using X with Example #24 Step H and dibenzylamine and TT) in THF (8.0 L) was added (R)-(+)-1-phenylethylamine (0.193 L, 1499 mmol). The mixture was warmed to reflux to dissolve the solids, and was then cooled to ambient temperature. After about 15 h, the reaction mixture was filtered, washed THF (800 mL) and dried in a vacuum oven to afford (1S,2R,4S)-4-(dibenzylamino)-2-methylcyclopentanecarboxylate•(R)-1-phenylethanamine (565 g, 85%, 97.5% ee): LC/MS (Table 2, Method 70) Rt=8.49 min. The mother liquor was concd. The residue was dissolved in THF (1 L), heated to dissolve the solids, and cooled to ambient temperature. After about 15 h, the reaction mixture was filtered, washed THF (800 mL) and dried in a vacuum oven to afford additional (1S,2R,4S)-4-(dibenzylamino)-2-methylcyclopentanecarboxylate•(R)-1-phenylethanamine (78.5 g, 12%, 95.2% ee): HPLC (Table 2, Method 70) Rt=8.57 min

Provenance & Evidence