新型除草剂苯嘧磺草胺的合成研究

Study of Synthetic Process of Novel Herbicide Saflufenacil

以2-氯-4-氟苯甲酸为起始原料,经硫酸和硝酸硝化,氯化亚砜酰化后与N-甲基-N-异丙基磺酰胺反应得到化合物N-(2-氯-4-氟-5-硝基苯甲酰)-N′-异丙基-N′-甲基磺酰胺;制得N-(2-氯-4-氟-5-硝基苯甲酰)-N′-异丙基-N′-甲基磺酰胺经钯碳加氢硝基还原,然后与氯甲酸乙酯反应得到化合物N-[2-氯-4-氟-5-{(乙氧基羰基)氨基}苯甲酰]-N′-异丙基-N′-甲基磺酰胺;N-[2-氯-4-氟-5-{(乙氧基羰基)氨基}苯甲酰]-N′-异丙基-N′-甲基磺酰胺与3-甲基氨基-4,4,4-三氟丁烯酸乙酯进行环化,得到目的产物苯嘧磺草胺。总收率68.0%(以2-氯-4-氟苯甲酸计)。经核磁谱图分析,所得化合物与目的产物苯嘧磺草胺结构一致。

2-Chloro-4-fluorobenzoic acid was nilrated by salflufenacil acid and nitric acid, acylated by thionyl chloride, then reacted with N-methyl-N-（1-methylethyl）sulfamoylamide to give the compound of N-（2-chloro-4-fluoro-5- nitrobenzoyl）-N＇-isopropyl-N＇-methylsulfamide. The compound latter was hydrogenated by palladium carbon, then reacted with ethyl chloroformate to give the N-[2-chloro-4-fluoro-5-{（ethoxycarbonyl）-amino}benzoyl]-N＇-isopropyl-N＇- methylsulfamide. The purposed compound of saflufenacil was obtained by the reaction of ethyl 4,4,4-trifluoro-3- （methylamino）-2-butenoic with N-[2-chloro-4-fluoro-5-{（ethoxycarbonyl）-amino}benzoyl]-N＇-isopropyl- N＇-methylsulfamide. The total yield is over 68.0% （Calculated as 2-chloro-4-fluorobenzoic acid）. Through the analysis of nuclear magnetic resonance （1HNMR）, the structure of the purposed compound is consistent with saflufenacil.