Synthesis technology of benthiavalicarb isopropyl

Abstract

The invention discloses a new synthesis technology of benthiavalicarb isopropyl, and belongs to the field of pesticide chemistry. A method for implementing the synthesis technology comprises the steps as follows: fluorocyclohexanone is used as a raw material and catalyzed by iodine to generate 2-amino-6-fluorobenzothiazole through oxidative cyclization, and after hydrolysis and acidification, 2-amino-5-fluorothiophenol is prepared; meanwhile, D-alanine is used as a raw material and reacts with triphosgene to generate (R)-4-methyl-oxazolidine-2, 5-diketone, and an intermediate reacts with 2-amino-5-fluorothiophenol to prepare chiral (R)-1-(6-fluorine-benzothiazole-2-) ethylamine; and L-valine is used as a raw material and reacts with isopropyl chlorocarbonate to prepare N- Isopropoxy carbonyl-L-valine, carboxyl activation is performed simultaneously, and finally, the raw materials and (R)-1-(6-fluorine-benzothiazole-2-) ethylamine perform a one-pot reaction to directly generate benthiavalicarb isopropyl. The synthesis technology has short process route and high total yield, and purity degree is higher than 95%.

Description

technical field [0001] The invention relates to an amino acid carbamate fungicide-benthiocarbamide, specifically relates to a new synthesis process thereof, and belongs to the field of pesticide chemistry. Background technique [0002] Throughout the world's pesticide market, with the rapid development of genetically modified crops, chemical pesticides have continued to decline in recent years, but agricultural fungicides have grown steadily in today's sluggish pesticide market, which is mainly due to the advent of new fungicides. The fungicides used before the 1970s were basically traditional protective fungicides. Most of the protective fungicides have strong bactericidal effect, multiple action sites, and are not easy to cause drug resistance of pathogenic bacteria. However, with the With the development and large-scale application of selective and efficient modern fungicides, the resistance of fungicides is becoming more and more serious, which often leads to the failure...

AI Technical Summary

Problems solved by technology

The fungicides used before the 1970s were basically traditional protective fungicides. Most of the protective fungicides have strong bactericidal effect, multiple action sites, and are not easy to cause drug resistance of pathogenic bacteria. However, with the With the development and large-scale application of selective and efficient modern fungicides, the resistance of fungicides is becoming more and more serious, which often leads to the failure of plant disease control, and the agricultural fungicides themselves are toxic to human activities and other organisms, while residual parts pollute the environment

The existing literature methods usually use p-fluoroaniline as a raw material to generate 2-amino-6-fluorobenzothiazole (compound 1) through addition, bromination, and cyclization, and then obtain 2-amino-5- Metal salts of fluorothiophenol (compound 2) (M= Zn, K, Mg, Ca, Ni, Cu, etc.), then (R)-4-methylazolidine-2,5 (R)-1-(6-fluoro-benzothiazole)ethylamine or its p-toluenesulfonate hydrochloride obtained by cyclization of diketone (compound 3) under acidic conditions , this method needs to be protected under nitrogen and react for a long time at low temperature, and produces wastewater containing heavy metal ions, which is difficult to treat and is not conducive to environmental protection

[0007] In addition, the synthesis of (R)-4-methylazolidine-2,5-dione (compound 3) in the literature The classic method is to prepare by the reaction of alanine and phosgene or diphosgene. This method has high requirements for water and because phosgene is highly toxic, the process is not easy to operate and control

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