Synthesis of 2-amino-5-(4-methoxyphenyl)-1,3,4-oxadiazoles

2-Amino-5-(4-methoxyphenyl)-1,3,4-oxadiazoles was synthesized from p-anisaldehyde by hydrazone reaction and intramolecular cyclization.The effects of time,temperature and reactants ratio on the yield were discussed.The results indicate that the molar ratio of p-anisaldehyde and semicarbazide hydrochloride is 1.2∶1,hydrazone reaction temperature 65 ℃,hydrazone reaction time 1.5 h,intramolecular cyclization time 16 h,n(Br2)∶n(4-methoxybenzaldehyde semicarbazone)=1.2∶1.The total yield was 68.5% and the structure of product was confirmed by IR,1HNMR and MS.