Hydrochloric Acid → HCID 86629875, compound

Participants

Reaction Steps

A mixture of L-proline methylester hydrochloride (15 mmol), 2-acetylamino-thiazole-5-sulfonyl chloride (12 mmol) (prepared as described in J. Am. Chem. Soc 69, 2063, 1947), DIPEA (35 mmol) in DCM (50 mL) was stirred at room temperature over night. Addition of water and 1N HCl to pH 2. Isolation of the organic phase which was washed with water and brine, dried and concentrated to give (S)-1-(2-acetylamino-thiazole-5-sulfonyl)-pyrrolidine-2-carboxylic acid methyl ester as brown crystals. These were suspended in EtOH (15 mL) and added 4N HCl in dioxane (15 mL) and heated for 3H at 80° C. and then cooled to room temperature. Addition of aqueous NaHCO3 to neutral pH. The organic phase was isolated and the aqueous phase was extracted with CH2Cl2, and the combined organic phases were dried and concentrated in vacuo to give (S)-1-(2-amino-thiazole-5-sulfonyl)-pyrrolidine-2-carboxylic acid methyl ester as colourless crystals.

Provenance & Evidence