Synthesis technology of oxadiazon

The invention discloses a synthesis technology of oxadiazon. The synthesis technology comprises following steps: (A). carrying out a reaction between 2,4-dichloro-5-isopropoxylbenzhydrazide and methyl chloroformate in an organic solvent to obtain hydrazide methyl ester; (B). enabling the hydrazide methyl ester to be subjected to a cyclization reaction under the effect of a catalyst to obtain the oxadiazon. During the synthesis technology of the oxadiazon, the oxadiazon is synthesized with 2,4-dichloro-5-isopropoxylbenzhydrazide and methyl chloroformate being raw materials, wherein the methyl chloroformate is employed, instead of phosgene or triphosgene, as a carbonylation ring-closing reagent, so that safety potential risk during a conventional phosgene technology is avoided, which enables the synthesis technology of the oxadiazon to be high in safety. In addition, yield of the oxadiazon is high in the invention. An experimental result proves that the yield of the oxadiazon is higher than 97%.