Hydrochloric Acid → (3S)-methyl 3-aminocyclopentanecarboxylate

Participants

Reaction Steps

Hydrogen chloride gas was bubbled through a solution of (1R,3S)-3-aminocyclopentanecarboxylic acid (5.00 g, 38.7 mmol, Peptech) in MeOH (100 mL) for about 15 min to give a tan solution, and the reaction mixture was stirred at ambient temperature for about 24 h. The solvent was removed under reduced pressure to give (3S)-methyl 3-aminocyclopentanecarboxylate (5.5 g, 25.5 mmol, 66%) which was dissolved in DMF (100 mL) and then K2CO3 (17.6 g, 127 mmol) and (bromomethyl)benzene (6.05 mL, 50.9 mmol) were added. The reaction mixture was stirred overnight at ambient temperature. The solid was collected by filtration and washed with DMF (100 mL). The filtrate was concentrated under high vacuum and the crude material was purified by silica gel chromatography eluting with 10% EtOAc in heptane to give (3S)-methyl 3-(dibenzylamino)cyclopentanecarboxylate (7.3 g, 89%) as a yellow oil: LC/MS (Table 2, Method a) Rt=2.97 min; MS m/z: 324 (M+H)+.

Provenance & Evidence