反应详情

To a solution of N-benzyl-p-toluenesulphonamide (21 g, 80 mmol) and acetic acid (100 ml) in acetic anhydride (400 ml) was added solid sodium nitrite (120 g, 1.7 mol) in portions over a period of 12 hours at 5° C. The temperature was kept below 10° C. all the time. After the addition was finished the reaction mixture was stirred at room temperature for 18 hours. The reaction mixture was poured over an excess of ice water and stirred for 1 hour. The pale yellow precipitate was filtered and washed several times with water. The crude product was recrystallized from ethanol to give the title compound as a tiny yellow needles (19.1 g, 82% yield, m.p. 92°-93° C., (Lit.1 89°-90° C.). δH (CDCl3): 7.80(2H,m); 7.25(7H,m); 4.95(2H,s); 2.40(3H,s)ppm.

1. customwas kept below 10° C.
2. additionAfter the addition
3. stirringstirred for 1 hour
4. filtrationThe pale yellow precipitate was filtered
5. washwashed several times with water
6. customThe crude product was recrystallized from ethanol