Hydrochloric Acid → Hydrochloric Acid

Participants

Reaction Conditions

Reaction Steps

Concentrated hydrochloric acid is added to (2R*,4S*)-4-acetylamino-2-(4-nitro-benzyl)-piperidine-1-carboxylic acid benzyl ester (2.65 g, 6.45 mmol) and the mixture is heated at 55° C. for 2 hours, the evolution of gas occurring. The reaction mixture is washed twice with hexane and concentrated by evaporation under reduced pressure using a rotary evaporator. The title compound is obtained as a hydrochloride in the form of white crystals containing 3 molecules of water of crystallisation. M.p.: >250° C. TLC: methylene chloride/methanol/conc. ammonia (90:9:1) Rf =0.29. 1H-NMR (200 MHz, D2O): δ 8.26 (d, 2H), 7.59 (d, 2H), 4.26-4.17 (m,1H), 3.90-3.72 (m, 1H), 3.40-3.02(m, 4H), 1.99 (s, 3H), 2.06-1.75 (m, 4H).

Provenance & Evidence