Thioglycolic Acid → 2-(4-(N-(tert-butoxycarbonyl)methylsulfonamido)-3-(cyclopropylmethoxy)benzoylthio)acetic acid

Participants

Reaction Steps

To a solution of 4-(N-(tert-butoxycarbonyl)methylsulfonamido)-3-(cyclopropylmethoxy)benzoic acid (for reference procedure see Example 18, WO2010/089107, which is incorporated herein by reference in its entirety) (0.2 g, 0.519 mmol), in dry DMF (6 ml), HATU (0.198 g, 0.521 mmol) and 4-methylmorpholine (0.057 ml, 0.521 mmol) were added and the mixture was stirred at RT until the complete conversion of the carboxylic acid into the activated ester occurred. 2-mercaptoacetic acid (0.030 ml, 0.434 mmol) was then added drop-wise, and the reaction mixture was stirred in the same conditions overnight. DMF was removed under reduced pressure and the crude was partitioned between EtOAc and HCl 1N; the organic layer was dried over Na2SO4, and the resulting crude was purified by trituration with Et2O affording 2-(4-(N-(tert-butoxycarbonyl)methylsulfonamido)-3-(cyclopropylmethoxy)benzoylthio)acetic acid as an off-white solid containing some impurities (0.253 g, yield supposed to be quantitative, MS/ESI+ 459.7 [MH]+). The product was used for the next step without any further purification.

Provenance & Evidence