Study on a new synthesis approach of glyphosate.
On the basis of glycine-dimethyl phosphite synthesis of glyphosate, a new synthesis approach of glyphosate, without using triethylamine and the establishment of triethylamine recovery equipment, was designed in the laboratory. The environmental pollutants were reduced. The influences of reactant amount (mol), reaction temperature (°C), and reaction time (min) on the glyphosate yield and purity were investigated. The results showed that the glyphosate yield and purity could be 80.12 and 86.31 wt %, respectively, under the optimum scheme for glyphosate yield (glycine consumption, 0.1 mol; dimethyl phosphite consumption, 0.12 mol; condensation reaction temperature, 50 °C; hydrochloric acid consumption in hydrolysis reaction, 0.35 mol; temperature of acidification with hydrochloric acid, 10 °C; adjusting hydrolysis product pH value, 1.0; time of dropping esterifying liquid into hydrochloric acid in hydrolysis reaction, 80 min; hydrolysis reaction temperature, 120 °C; and vacuum distillation time, 90 min), and the glyphosate yield and purity could be 77.92 and 94.94 wt %, respectively, under the optimum scheme for glyphosate purity (glycine consumption, 0.1 mol; dimethyl phosphite consumption, 0.1 mol; condensation reaction temperature, 50 °C; hydrochloric acid consumption in hydrolysis reaction, 0.35 mol; temperature of acidification with hydrochloric acid, 10 °C; adjusting hydrolysis product pH value, 1.5; time of dropping esterifying liquid into hydrochloric acid in hydrolysis reaction, 60 min; hydrolysis reaction temperature, 110 °C; and vacuum distillation time, 90 min). The product structures under the two schemes were confirmed by means of FTIR (Fourier transform infrared spectroscopy) and (1)H NMR ((1)H nuclear magnetic resonance spectroscopy).
Experimental Teaching Center of Environment and Cleaner Production in Chemical Industry, Key Laboratory for Green Chemical Process of Ministry of Education, School of Chemical Engineering & Pharmacy, Wuhan Institute of Technology , No. 693, Xiongchu Street, Hongshan District, Wuhan 430073, China. georchun@163.com
Ji
J
Zhou
Jian
J
Li
Ran
R
An
Hua
H
Yuan
Faquan
F
Yu
D060326:Chemistry Techniques, Synthetic / Q000379:methods*; D005998:Glycine / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry; D006540:Herbicides / Q000138:chemical synthesis* / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D017550:Spectroscopy, Fourier Transform Infrared; D013696:Temperature; D000097797:Glyphosate
D005998:Glycine; D006540:Herbicides; D000097797:Glyphosate