Hydrochloric Acid → 1-(4-Toluenesulfonyl)-4-hydroxy-L-proline

Participants

Reaction Steps

To a solution of 100 g (763 mmol) of 4-hydroxy-L-proline in 750 ml of water was added 169.9 g (1602 mmol) of sodium carbonate at 0° C. along with 174.5 g (916 mmol) of 4-toluenesulfonyl chloride (added in 3 portions over a period of 1 hour). The slurry was then warmed to room temperature and allowed to stir for 48 hours. The reaction was acidified with concentrated hydrogen chloride solution to pH 2 and the product was isolated via filtration. The filter cake was washed with pH 2 buffer and dried in a vacuum oven at 60° C. for 16 hours to obtain 215.3 g of the product as a white crystalline solid in 99% yield. M.P.=149°-151° C.

Provenance & Evidence