A process for the production of 2-aryl-4-acyl-1.3.4-oxdiazolones-(5), in which an aromatic carboxylic acid hydrazide is reacted at a pH value of from 1.8 to 3.0 with phosgene in a mixture consisting of water and acetone at a temperature of from 0.degree. C. to 50.degree. C., subsequently the pH is increased to from 9.5 to 11.0, then about 100 mol % of a carboxylic acid chloride or about 50 mol % of a dicarboxylic acid chloride (based on mols of carboxylic acid hydrazide) is added and optionally from 10.sup.-4 to 1.0 mol % (based on mols of carboxylic acid hydrazide) of a tertiary amine or phosphine is added as a catalyst and the reaction is completed at a temperature from 0.degree. C. to 50.degree. C.
生产2-芳基-4-酰基-1.3.4-
噁二唑酮-(5)的过程中,芳香族
羧酸酰
肼在pH值为1.8至3.0的条件下与
光气在由
水和
丙酮组成的混合物中,在0°C至50°C的温度下反应,随后将pH值增加至9.5至11.0,然后加入约100摩尔%的
羧酸氯化物或约50摩尔%的二
羧酸氯化物(基于
羧酸酰
肼的摩尔数),并可选择性地加入约10^-4至1.0摩尔%(基于
羧酸酰
肼的摩尔数)的三级胺或膦作为催化剂,反应在0°C至50°C的温度下完成。