反应详情

To 61.29 g (270 mmol) of the material of Example I dissolved in 1300 ml of anhydrous N,N-dimethylformamide ("DMF") (Aldrich; Cat. No. 22, 70506), was added 28 ml (296 mmol) of acetic anhydride (Aldrich; Cat. No. 11,004-3), and the resulting mixture was stirred at room temperature for 20 hrs. DMF was removed under reduced pressure, and the resulting residue was treated with the excess of 100 ml dimethyl ether; 71.4 g (98% yield) of a crystalline product was obtained and collected by filtration, washed thoroughly with dimethyl ether, and dried over P2O5 for 3 hrs. This product had a melting point of 150°-170° C.; the published melting point for this product 154°-176° C.

1. customDMF was removed under reduced pressure
2. additionthe resulting residue was treated with the excess of 100 ml dimethyl ether