Synthesis method of dinotefuran

Abstract

The invention discloses a synthesis method of dinotefuran. The synthesis method includes: using gamma-butyrolactone as a raw material, and preparing 3-hydroxymethyltetrahydrofuran through two-step reaction of Aldol condensation and reduction; synthesizing 3-tetrahydrofuran methylamine through a Gabriel method; using dimethyl carbonate (DMC) as a methylation reagent to synthesize with urea to obtain O-methylisourea; performing nitration to synthesize O-methyl-N-nitroisourea; reacting with methylamine to synthesize 1, 3-dimethyl-2-nitroisourea; subjecting 3-tetrahydrofuran methylamine and 1, 3-dimethyl-2-nitroisourea to a one-step process to synthesize dinotefuran through SN2dimolecular nucleophilic substitution. Dimethyl carbonate which is nontoxic is adopted as the methylation agent, methylation reaction yield is greater than or equal to 95%, O-methylisourea content is greater than or equal to 96%, byproducts are carbon dioxide and methanol, the process is environment-friendly, and total yield of dinotefuran is greater than or equal to 50%. The synthesis method can lower production cost, has the advantages of little three wastes, simple aftertreatment and environment friendliness, is suitable for industrial production and can bring about remarkable economic benefit.

Description

technical field [0001] The invention belongs to the technical field of neonicotinoid insecticide synthesis and relates to a synthesis method of dinotefuran. Background technique [0002] Dinotefuran is a new neonicotinoid insecticide developed by Mitsui East Asia Chemical Co., Ltd., Japan. It has been introduced to the market in many countries around the world, and is used to control aphids, leafhoppers and their resistant strains in various crops such as rice. [0003] There are mainly 5 synthetic routes of dinotefuran reported in the literature at present: [0004] Route 1: Use diethyl malonate as raw material to react with ethyl chloroacetate to prepare ethane-1,1,2-tricarboxylic acid ethyl ester, and react with sodium borohydride to prepare 2-hydroxymethyl-1,4- Butanediol, and then prepare 3-tetrahydrofuran methanol under the action of p-toluenesulfonic acid, and further react to prepare 3-tetrahydrofuryl methyl methanesulfonate. 1,5-Dimethyl-2-(nitroimino)-hexahydro-1...

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Problems solved by technology

[0017] Route 4 has two catalytic hydrogenation reactions, high reaction pressure, nitrogen protection is required, and there are safety risks; the reaction conditions are strict and difficult to control; the steps are complicated, the reaction selectivity is not high, and the total yield is low; a large amount of waste water is generated in the reaction Difficult to handle, severely corroded equipment

[0018] Route 5 is a chemical reaction for the synthesis of dinotefuran, with low atom utilization and low atom economy; the methylating reagent dimethyl sulfate is highly toxic

[0019] Based on the above five routes, there are problems such as high cost and serious environmental pollution. Therefore, it is urgent to further improve the synthesis process of dinotefuran to meet the requirements of green environmental protection and further reduce costs.

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