Chlorosulfonic acid → HCID 21883492, compound

Participants

Reaction Conditions

Reaction Steps

To chlorosulfonic acid (50.0 mL) chilled to −15° C. was added 2-(trifluoromethyl)-2H-1-benzopyran-3-carboxylic acid (Example 10) (4.0 g, 16.7 mmol). After stirring at −15° C. for 1 hour, the solution was warmed to room temperature and stirred for 16 hours. The resulting solution was added dropwise over ice (100 mL) with two diethyl ether(2×75 mL) extractions. The diethyl ether layers were combined, washed with water (2×75 mL), and brine (2×75 mL, dried over sodium sulfate and concentrated in vacuo. The resulting solids were triturated with hexane-ethyl acetate (9:1, 100 mL). The 6-chlorosulfonyl-2-trifluoromethyl-2H-1-benzopyran-3-carboxylic acid was isolated as a white solid: mp 169–174. 1H NMR (CD3OD/300 MHz) 8.18 (d, 1H, J=2.7 Hz), 8.06 (dd, 1H, J=8.7, 2.7 Hz), 7.93 (s, 1H), 7.28 (d, 1H, J=8.7 Hz), 6.00 (q, 1H, J=6.6 Hz). EIHRMS m/z 324.9977 (M+, Calcd 324.9994).

Provenance & Evidence