General procedure for the synthesis of cyclohexylsulfonamides from cyclohexylmagnesium chloride: 18.5 mL (37.0 mmol) of an ether solution of 2M cyclohexylmagnesium chloride (TCI Americas) was added slowly and dropwise to 3.0 mL (37.0 mmol) of freshly distilled sulfonyl chloride dissolved in a cooled solution of 100 mL of hexanes at -78 °C. The reaction mixture was gradually warmed to 0°C over a period of 1 hr, followed by careful concentration under vacuum. The concentrate was redissolved in 200 mL of ether, washed once with 200 mL of ice water, dried over anhydrous magnesium sulfate, filtered and again carefully concentrated. The resulting mixture was dissolved in 35 mL of tetrahydrofuran (THF) and slowly added dropwise to 500 mL of THF solution saturated with ammonia and stirred overnight. After completion of the reaction, the mixture was concentrated under vacuum to give a crude yellow solid. The crude product was purified by column chromatography on 50 g silica gel, using 70% ethyl acetate-hexane as eluent, and the target fraction was collected and concentrated. The concentrate was recrystallized from a hexane solution containing a small amount of dichloromethane and 1-2 drops of methanol to give 1.66 g (30% yield) of cyclohexylsulfonamide as a final white solid. The product was analyzed by 1H NMR (CDCl3) δ 1.11-1.37 (m, 3H), 1.43-1.56 (m, 2H), 1.67-1.76 (m, 1H), 1.86-1.96 (m, 2H), 2.18-2.28 (m, 2H), 2.91 (tt, J = 12, 3.5 Hz, 1H), 4.70 (br s, 2H ); 13C NMR (CDCl3) δ 25.04, 25.04, 26.56, 62.74; mass spectrum m/e 162 (M-1)-confirms the structure.
