反应详情

A flask containing DCM (90 mL) and methylamine in water (40 wt %, 7.5 mmol) is chilled in an ice water bath with magnetic stirring. 3-Cyano-benzenesulfonyl chloride (5 g, 2.49 mmol) is added along with DCM (10 mL) to wash down the sides of the flask. After 30 min, concentrated HCl in water is added at 0° C., until the reaction is acidic (pH<4). Water (50 mL) is added and DCM is removed in vacuo. The residue is filtered to afford 3-cyano-N-methyl-benzenesulfonamide as a solid (99%). MS: 195 (M+H); 1H NMR (300 MHz, CDCl3): δ 2.76 (d, 3H), 4.48 (broad-s, N—H), 7.7 (t, 1H), 7.9 (d, 1H), 8.13 (d, 1H), 8.19 (s, 1H).

1. temperatureis chilled in an ice water bath with magnetic stirring
2. washto wash down the sides of the flask
3. additionconcentrated HCl in water is added at 0° C., until the reaction
4. additionWater (50 mL) is added
5. customDCM is removed in vacuo
6. filtrationThe residue is filtered