太原理工大学 硕士学位论文 甘氨酸-亚磷酸二甲酯法合成草甘膦的研究 姓名：胡景焕 申请学位级别：硕士 专业：应用化学 指导教师：李福祥 20100501 太原理工大学硕士研究生学位论文 I 甘氨酸-亚磷酸二甲酯法合成草甘膦的研究 摘 要 草甘膦（PMG）是一种具有良好生物活性的芽后灭生性除草剂。它具 有高效、低毒等特点，属于氨基酸的衍生物。针对目前我国草甘膦行业和 甘氨酸行业的发展现状及其存在的问题，本课题提出采用一锅法以氯乙酸、 多聚甲醛、亚磷酸二甲酯为主要原料经加成、缩合、水解等反应直接合成 高纯度的草甘膦。此工艺可以简化氯乙酸甘氨酸草甘膦的合成过程， 实现两条生产链的整合；降低生产成本；有效提高氯乙酸的转化率；消除 甘氨酸合成过程中带来的环境污染。本论文通过对甘氨酸-亚磷酸二甲酯法 合成草甘膦进行研究分析，为进一步考察氯乙酸一锅法制备草甘膦工艺做 基础。 实验中通过对物料的配比、加料顺序、体系含水量、酯化液的冷却方 式及水解过程中的滴加顺序、酯化液的滴加时间、反应温度、常压及减压 蒸馏时间等因素进行分析，得出最佳工艺条件如下： （1）各物料的摩尔比为：多聚甲醛：甘氨酸：三乙胺：无水甲醇：亚 磷酸二甲酯：盐酸=1.95：1.0：0.85：7.0：1.26：3.0。 （2）在解聚和加成阶段，加料顺序为：先加无水甲醇、三乙胺、多聚 甲醛，然后再加甘氨酸。 （3）在反应中（尤其是酯化反应阶段）要尽可能的降低体系中的含水 太原理工大学硕士研究生学位论文 II 量。 （4）在水解的酸化阶段：将酯化液缓慢冷却至室温后，再滴加到盐酸 溶液中。控制滴加速度，使酯化液的滴加时间在 40min 以上；酸化温度控 制在 825之间。 （5）在水解的脱溶过程中，控制常压蒸馏时间在 3.5h 左右；在水解的 脱酸过程中，控制减压蒸馏时间在 1h 左右；水解温度控制在 115120范 围内。 在以上最佳实验条件下 PMG 的固体纯度可以超过 90%， 总产率可以达 到 81.87%。水解的结晶液加水后用 30%的 NaOH 溶液调 pH 值为 1.5 左右， 使草甘膦在结晶液中的溶解度最低，可以提高 PMG 的固体产率。 在以上优化的工艺条件下，又初步探讨了由氯乙酸制备甘氨酸过程中 产生的副产物盐酸三乙胺对 PMG 总产率的影响，结果发现： （1）盐酸三乙 胺的存在对 PMG 的生成极为不利。当加入 0.1mol 盐酸三乙胺时，PMG 的 总产率降至 32.59%。因此在一锅法制备草甘膦的过程中要尽可能降低或者 消除盐酸三乙胺对实验的影响。 （2）将含 0.1mol 盐酸三乙胺的酯化液冷冻 0.5h 后，过滤除去盐酸三乙胺，PMG 的总产率可提高到 67.06%。 关键词：草甘膦，甘氨酸，亚磷酸二甲酯，盐酸三乙胺 太原理工大学硕士研究生学位论文 III THE STUDY OF GLYCINEDIMETHYL PHOSPHITE SYNTHESIS OF GLYPHOSATE ABSTRACT N-phosphonomethylglycine(PMG) is one of broad-spectrum herbicides with good bioactivity such as low toxicity, high efficiency and other characteristics, which destroys the ruderal after in bud and derives from the amino acid. Acoording to the actuality and problem of glycine and glphosate industry, the topic proposed to use chloroacetic acid，paraformaldehyde and dimethyl phosphite as the main raw materials, after synthesis, condensation and hydrolysis directly synthesis high-purity glyphosate through one-pot method. This process simplified the synthesis process of chloracetic acid glycine glyphosate to achieve the integration of the two production chain and reduce production costs and effectively improve the conversion rate of chloroacetic acid and eliminate the synthesis of glycine on the environmental pollution. In this paper, our arm is to further examine chloroacetate one-pot preparation of glyphosate technology by studying and analysising the synthesis of glyphosate through glycine - dimethyl phosphate. Several factors were experimental analyzed, such as the ratio of the 太原理工大学硕士研究生学位论文 IV reactants, adding order, water content, cooling method of esterification liquid and hydrolysis process of dropping sequence, dropping time of the esterification, reaction temperature, atmospheric and vacuum distillation time and so on. The optimum process conditions are as follows: (1) The molar ratio of reactants：paraformaldehyde: glycine: triethylamine: anhydrous methanol: dimethyl phosphite: hydrochloric acid = 1.95: 1: 0.85: 7.0: 1.26: 3. (2) In the depolymerization and addition stages, adding order: first add anhydrous methanol, triethylamine and paraformaldehyde then plus glycine. (3) Reduce the water content in the reaction system as much as possible, especially in the eaterification stage. (4) In the hydrolysis process of acidification stage, esterification liquid should be cooled down to be room temperature slowly before dropping into hydrochloric acid solution. To make sure dropping time last 40min least, the dropping speed should be controlled. The reaction temperature was within 825. (5) In the hydrolysis process of desolventizing Stage, controlling the atmospheric distillation time around 3.5h；In the hydrolysis process of removal of hydrochloric acid, controlling the vacuum distillation time around 1h; the hydrolysis temperature in the range of 115120. At the preferred reaction conditions above, the solid purity of glyphosate can be more than 90%; the tatal yield can reach 81.87%. Add water to the crystal 太原理工大学硕士研究生学位论文 V Liquid of hydrolysis, thereafter adjust the pH value of the crystal liquid about 1.5 by using 30% NaOH solution, which makes the minimum solubility of glyphosate in the crystal solution and can improve the solid yield of glyphosate. In the optimized process conditions above, we also preliminarily discussed the impact of triethylamine hydrochloride which is generated in the preparation of glycine through chloroacetic acid on the total yield of glyphosate. Results show that: (1) Triethylamine hydrochloride is extremely adverse to the generation of glyphosate. When the amount of triethylamine hydrochloride was 0.1 mol, the total yield of glyphosate reduced to 32.59%. Therefore we should minimize or eliminate the impact of triethylamine hydrochloride on the experiment in the process of preparing glyphosate with one pot method. (2) Frozen the esterification liquid 0.5h which contains 0.1mol triethylamine hydrochloride acid，and then filtered to remove triethylamine hydrochloride， the total yield of PMG can be increased to 67.06%. KEY WORDS：glyphosate, glycine, dimethyl phosphite, triethylamine hydrochloride 太原理工大学硕士研究生学位论文 1 第一章 前言 1.1 草甘膦