(2S)-2-methyl-3-sulfanylpropanoic acid

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 3 g of 2(S)-methyl-3-mercaptopropionic acid is added to a mixture of 3.5 g of potassium carbonate, 60 ml of water and 30 ml of ether with stirring atroom temperature under a nitrogen atmosphere whereupon 6.3 g of 4-chloro-3-sulfamoylbenzoyl chloride is added, and the resulting mixture is stirred at room temperature for 5.5 hours. The aqueous layer is then collected and made acidic with dilute hydrochloric acid, and the separatedoil is extracted with ethyl acetate. The extract is washed with water, dried over anhydrous magnesium sulfate, and concentrated under reduced pressure. Isopropyl ether is added to the residual oil. The crystals thus obtained are recrystallized from a mixture of ethyl acetate and hexane to give 3-(4-chloro-3-sulfamoylbenzoylthio)-2(S)-methylpropionic acid as white crystalline powder, melting at 152°-153° C. (sinteringat 145° C.). is added The aqueous layer is then collected the separatedoil is extracted with ethyl acetate The extract is washed with water dried over anhydrous magnesium sulfate concentrated under reduced pressure Isopropyl ether is added to the residual oil The crystals thus obtained are recrystallized from a mixture of ethyl acetate and hexane

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 3 g of 2(S)-methyl-3-mercaptopropionic acid is added to a mixture of 3.5 g of potassium carbonate, 60 ml of water and 30 ml of ether with stirring atroom temperature under a nitrogen atmosphere whereupon 6.3 g of 4-chloro-3-sulfamoylbenzoyl chloride is added, and the resulting mixture is stirred at room temperature for 5.5 hours. The aqueous layer is then collected and made acidic with dilute hydrochloric acid, and the separatedoil is extracted with ethyl acetate. The extract is washed with water, dried over anhydrous magnesium sulfate, and concentrated under reduced pressure. Isopropyl ether is added to the residual oil. The crystals thus obtained are recrystallized from a mixture of ethyl acetate and hexane to give 3-(4-chloro-3-sulfamoylbenzoylthio)-2(S)-methylpropionic acid as white crystalline powder, melting at 152°-153° C. (sinteringat 145° C.). is added The aqueous layer is then collected the separatedoil is extracted with ethyl acetate The extract is washed with water dried over anhydrous magnesium sulfate concentrated under reduced pressure Isopropyl ether is added to the residual oil The crystals thus obtained are recrystallized from a mixture of ethyl acetate and hexane