申请人:SHANDONG RAINBOW BIOTECH CO., LTD.
公开号:US11040933B2
公开(公告)日:2021-06-22
Disclosed is a preparation method of phenoxycarboxylic acid herbicides. The preparation method comprises the following steps. S1: mixing an anhydrous phenol and a basic substance with a chloro-substituted carboxylic acid ester and performing a one-pot condensation reaction in an anhydrous system to obtain a phenoxycarboxylic acid ester. The chloro-substituted carboxylic acid ester is represented by the formula ClR1COOR, in which R1 is a C1-3 alkanediyl or alkylidene group, R is a C1-10 alkyl group or a C3-10 cycloalkyl group; S2: the phenoxycarboxylic acid ester undergoes selective chlorination with a chlorinating agent in the presence of a first catalyst and a second catalyst to obtain a chloro-substituted phenoxycarboxylic acid ester; and S3: the chloro-substituted phenoxycarboxylic acid ester undergoes an acid hydrolysis reaction to obtain a phenoxycarboxylic acid herbicide represented by formula I, in which R3 is H, Cl or CH3.
本发明公开了一种苯氧羧酸除草剂的制备方法。该制备方法包括以下步骤。S1:将无水苯酚和碱性物质与氯代羧酸酯混合,在无水体系中进行一锅缩合反应,得到苯氧羧酸酯。氯代羧酸酯由式 ClR1COOR 表示,其中 R1 是 C1-3 烷二基或亚烷基,R 是 C1-10 烷基或 C3-10 环烷基;S2:苯氧羧酸酯在第一催化剂和第二催化剂存在下与氯化剂进行选择性氯化反应,得到氯代苯氧羧酸酯;以及 S3:氯代苯氧羧酸酯进行酸水解反应,得到由式 I 表示的苯氧羧酸除草剂,其中 R3 为 H、Cl 或 CH3。