Hydrochloric Acid → HCID 68620921, compound

Participants

Reaction Conditions

Reaction Steps

In a 6 L 4-neck flask, was added a solution containing a compound of general structure (V) (Intermediate 6, 60 g g, 150.18 mmol), e.g., tert-butyl (2S)-2-({[(R)-phenyl(pyridin-2-yl)methyl]amino}carbonyl)-1,3-thiazolidine-3-carboxylate, in DCM under argon atmosphere (1250 ml). At −30° C., a solution of HCl conc. (627 mL, 7509 mmol) was added slowly during a period of 40 minutes. The reaction mixture was stirred at −30° C. for 3 h 30. The reaction was kept at −30° C. and a solution of 1 L of NAOH 1M was added followed by 1250 mL of NaOH 5M so that to obtain pH=5. The last 50 mL of 5M NaOH solution were added at −10° C. due to formation if ice in the flask. The slurry was extracted with DCM (5×500 mL) and dried over MgSO4 and evaporated to almost dryness. The desired product, e.g., (2S)—N—[(R)-phenyl(pyridin-2-yl)methyl]-1,3-thiazolidine-2-carboxamide hydrochloride, was isolated and used for the next step without further purification and shows no trace of racemisation.

Provenance & Evidence