Synthetic Technology Study Of2-Amino-N,3-Dimethyl-5-Cyano Benzamide

A new insecticide Cyantraniliprole with novel mechanism, high efficiency,low toxicity and low residue, was developed by Dupont Company which has apromising market. Cyantraniliprole was obtained from the intermediate M-9andM-5via one-pot amide. However, the material of the synthetic intermediate M-9is high cost and long route, results the high sales price of Cyantraniliprole.On the basis of original synthesis routes, this paper designs with a newsynthesis route of M-9, which is low cost, short route and more suitable forindustrialization. And economic analysis was given. The concrete researchcontents and results are as follows:1. Synthesis of2-amino-N,3-dimethyl-5-halo benzamide (M-X-8): thesynthesis of M-X-8from2-amino-3-methylbenzoic acid by the cyclization,aminolysis and halo three steps in one pot. And the influences of material ratio,reaction temperature, solvents on the reation were studied. The best reactioncondition is THF as the solvent, the molar ratio of2-amino-3-methyl benzoatewith BTC, haloimides is1:0.35:1(chlorinated is1:0.35:1.07), temperature is20-25℃including cyclization, aminolysis, bromide and iodide, expect thechloride which temperature is50℃, yield was85-90%.2. Synthesis of2-amino-N,3-dimethyl-5-cyano benzamide (M-9): M-9wassynthesized from M-X-8and cyanide reagent by aromatic nucleophilicsubstitution. And the influences of material, cyanide reagent, reaction solvents,catalysts, etc, on the reation were studied. It is found that reaction solvent is thevital factor affecting. When DMSO as the solvent, quinazolinone compound8-methyl-7-cyano-4-quinazoline was synthesized by condensation reactioninstead of cyano reaction; NMP as the solvent, the reaction time is short and no by-product formation. The best reaction conditions is NMP as the solvent, themolar ratio of M-Br-8with cuprous cyanide is1:1.1, cuprous iodide andN-methylimidazole as the catalyst. The product yield was80%by post-treatmentSoxhlet extraction and recrystallized.3. Economic analysis of M-9: Paper gives economic analysis about theoptimized process route, and the results showed that the establishment of anannual output of200tons M-9, a total investment of18million yuan, totalinternal rate of70.70%(tax later), payback period is2.56years (tax later), theinvestment can be recovered in the short term, with very good profitability andrisk-resisting ability, the project is economically viable.Starting with some simple materials, the synthetic method of M-9has beenstudied, as a result, improved synthetic route, and optimized the synthesis process.Meanwhile, it is a green, economical and efficient synthetic route, because thegentle reaction conditions, easy operation route, short reaction period, and lowercost, this route is more suitable for industrial production. This paper gaveanalysis of the economic on the synthesis of M-9, and provided the basic data forindustrialization.