Chlorosulfonic acid → 3-chloro-4-[[(2R)-3,3,3-trifluoro-2-hydroxy-2-methyl-propanoyl]amino]benzenesulfonyl chloride

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Reaction Conditions

Reaction Steps

(R)-N-(2-Chlorophenyl)-2-hydroxy-2-methyl-3,3,3-trifluoropropanamide (Method 74) (13.8 g, 52 mmol) was added in portions to a cooled (0° C.) solution of chlorosulphonic acid (25 ml) over 15 mins and then the mixture was heated to 85° C. After 4.5 h the reaction mixture was cooled in an ice bath and then poured very slowly onto a stirred ice-water mixture. After stirring for 15 mins. the mixture was extracted with ethyl acetate (2×100 ml) and the combined organic layer washed with brine, dried and concentrated to yield a brown oil. This oil was purified by flash column chromatography using 10:1, iso-hexane: ethyl acetate to yield the title compound as a pale yellow solid (11 g, 30 mmol). NMR: 1.6 (s, 3H), 7.55 (dd, 1H), 7.6 (d, 1H), 7.95 (d, 1H), 9.7 (brs, 1H); MS: 364.

Provenance & Evidence