A newtype drug-nitazoxanide (2-Acetyloxy-N-(5-nitro-2-thiazolyl)benzamide) was synthesized through amidation from acetylsalicylic acid and 2-Amino-5-nitrothiazole in the presence of P2O5 as dehydrant. The effects of the amount of acetylsalicylic acid, 2-Amino-5-nitrothiazole and P2O5, the temperature and time of amidation on the yield were investigated. The optimal conditions were as follows: n (acetylsalicylic acid): n (2-Amino-5-nitrothiazole): n (P2O5): 1.2: 1.0: 2.5, in DMF at 90℃ for 2.0h, the yield can be higher than 75%.