从两方面研究了苯并噁嗪酮环上N-甲基化反应:首先,研究了不同甲基化试剂对甲基化反应的影响,综合安全环保和成本等因素筛选得到碳酸二甲酯甲基化试剂。其次,研究了碳酸二甲酯作为甲基化试剂的反应温度等工艺条件。结果表明适宜反应温度为75℃。优化条件下,以碳酸二甲酯作为苯并噁嗪酮环上N甲基化的反应收率达到90%以上,产物纯度大于98%。 We studied the N-methylation of benzoxazinone rings in two aspects: Firstly, the effects of different methylating agents on the methylation reaction were studied, and dimethyl formamide (A) was screened based on the factors of safety, environmental protection and cost Base reagent. Secondly, the reaction conditions such as the reaction temperature of dimethyl carbonate as a methylating reagent were studied. The results show that the optimum reaction temperature is 75 ℃. Under the optimized conditions, the yield of N-methylation of benzoxazinones with dimethyl carbonate reached more than 90%, and the product purity was more than 98%.