dibenzoyl-L(+)tartaric acid → (+)-2-(4-Chlorobenzyl)-1-methylpyrrolidine dibenzoyl tartrate

Participants

Reaction Steps

Add a solution of 27 g of dibenzoyl-L-tartaric acid in 200 ml of acetone to 15 g of 2-(4-chlorobenzyl)-1-methylpyrrolidine dissolved in 100 ml of acetone. Allow the resulting mixture to stand for 6 hours at room temperature and for 4 days at 0°. Filter off the precipitated crystals (8.5 g). Concentrate the filtrate somewhat and then allow the mixture to stand for a further 12 hours at 0°. Collect the further-precipitated crystals (4.53 g). Recrystallize the collected crystalline products from 100 ml of acetone and filter to obtain a total yield of 9.9 g of (+)-2-(4-chlorobenzyl)-1-methylpyrrolidine dibenzoyl tartrate, m.p. 117° to 120°, [α]58920 =-64° (25 mg/ml in methanol). Shake 9.4 g of this salt with diethyl ether/sodium hydroxide solution until solution is complete. Dry the ether phase, evaporate off the solvent and distill the residue to obtain 2.73 g of the base, the title compound, b.p. 70° at 0.005 mm of Hg, [α]58920 =+78.9° (25 mg/ml in methanol).

Provenance & Evidence