Ethanethiol → 4-Amino-5-chloro-2-hydroxybenzoic acid

Participants

Reaction Steps

A cooled (5° C.) suspension of 60% sodium hydride/oil dispersion (20 g, 0.5 mole) in anhydrous dimethylformamide (300 ml) under nitrogen was treated dropwise with ethyl mercaptan (18.7 g, 0.3 mole) while maintaining a temperature below 15° C., then stirred at room temperature for 15 minutes, cooled (5° C.), and treated in portions with 4-amino-5-chloro-2-methoxybenzoic acid (40.33 g, 0.2 mole). The mixture was heated to 105°±5° C. for 4 hours, cooled, and concentrated in vacuo to remove most of the dimethylformamide, then poured into water (500 ml). The aqueous solution was extracted with methylene chloride (2×150 ml), and ether (150 ml), acidified with concentrated HCl (55 ml), filtered, and the filter cake washed with water and dried in vacuo to provide 35.7 g of crude product. Crystallization of the product from tetrahydrofuran/hexane yielded 31.3 g (83%) of a white solid, mp 192° C.

Provenance & Evidence