The Improvement On The Synthesis Of Glyphosate

Glyphosate is a kind of herbicide which has the high effect, low toxicity andgood bioactivity, destroy the ruderal after in bud,and derives from the aminoacid.:Asone kind of the extensive weed killer, glyphosate is one of the biggest global outputagricultural chemical.This paper is to study the synthesis of glyphosate by using iminodiaceticacid(IDA) as the raw material,it has three steps:preparing iminodiacetic acid,preparing N-phosphonomethyliminodiacetic acid(PMIDA)and preparing glyphosateby catalytic oxidation.In the synthesis of IDA,we choose the two common used routes to synthesize it:diethanolamine catalysis dehydrogenation and iminodiacetonitrile alkalinehydrolysis,The results show that the yield of IDA can reach98.5%by usingdiethanolamine as the raw material, and the yield of IDA can reach96.5%by usingiminodiacetonitrile as the raw material.Both methods have their advantages anddisadvantages,the yield of diethanolamine routes is higher,but it need higher pressureand catalyst, higher equipment requirements. the diethanolamine routes has mildreaction conditions and low equipment requirements,no need of catalyst, there aregreat industrial value.The yield of two routes are higher than domestic literature.In preparing PIDA, Influences of the mole ratio of reactants, reaction time,reaction temperature,dosage of catalyst on yield are discussed. The experimentalresults show that in the appropriate reaction conditions, the quality of content can upto98%PIDA, Solid yield of95%, and the reaction process is smooth, easy to operate.In the processof preparing glyphosate,oxidation of PMIDA with hydrogenperoxide and air are all improved.Experimental results show that the optimal reactionconditions, Solid yield of79.6%, total yield of89.4%by using hydrogen peroxide,Solid yield of92.6%, total yield of95.5%by using air oxidation.In addition,In preparing glyphosate, a new technique for the preparation ofglyphosate formulations was developed,which has the merit of the two oxidationmethods.The newly developed one-step technique makes30%glyphosate, and thereaction process is stable, easy to operate. This new method also readuces the cost ofproduction,it does not produce any waste. The method was first used in domestic production. Experimental results show that in the optimal reaction conditions, theyield of glyphosate formulations can reach96%.The yield of the process as a wholehas reached the leading level in domestic.