Clean production technology of methyl anthranilate

Abstract

A clean production technology of methyl anthranilate is characterized in that the solubilities of methyl ester, sodium carbonate and sodium chloride in water are different, no other solvents or reagents are introduced, and a solution obtained after esterification and hydrolysis is successively cooled to obtain methyl ester and sodium carbonate decahydrate (called scale for short). The technology shortens the technologic route and reduces impurities in a recovered material, so the quality of the obtained recovered product is high; the technology effectively reduces a large amount of technologic water and recovers reaction byproducts to realize conversion of industrial wastes as a secondary raw material and reinforce recycling of the wastes; the technology realizes comprehensive utilization of energy and reduces total consumption of energy, so the product production cost is greatly reduced; and the technology uses change of physical properties to obtain the methyl ester, and does not use a chemical solvent to extract the methyl ester residual in a mother liquor, so the generation of new pollutants is effectively avoided, and the whole production process is clean and environmentally friendly.

Description

technical field [0001] The invention relates to a production process of methyl anthranilate, in particular to a clean production process of methyl anthranilate. Background technique [0002] Methyl anthranilate is a synthetic organic intermediate and a valuable fragrance, which has a wide range of uses. There are two ways to prepare methyl anthranilate: one is to prepare from phthalic anhydride, whether it is phthalic anhydride, ammonia water, liquid alkali reaction, or phthalic anhydride, urea, liquid alkali reaction, or phthalic anhydride and other ammoniation In the end, sodium o-carboxamide benzoate solution (abbreviated as amidation solution) will be generated in the end of the reagent reaction, and then sodium hypochlorite and methanol are added to the amidation solution to make methyl anthranilate (abbreviated as methyl ester). The other is to prepare from anthranilic acid, anthranilic acid and methanol react under the action of an acidic catalyst, and finally genera...

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Problems solved by technology

[0014] 1. The sodium carbonate produced by the reaction was discarded into the raffinate because it could not be recycled, resulting in waste of materials. The salinity of the raffinate was too high, reaching more than 8%, and it was difficult to treat environmentally friendly sewage

[0015] 2. Using organic solvents such as benzene or toluene or other solvents to recover the residual methyl ester in the mother liquor, not only the process route is long, the material recovery contains many impurities, the quality of methyl anthranilate is not high, and the organic solvent is consumed, resulting in the organic solvent Benzene or toluene or other solvents remain in the mother liquor, increasing the difficulty of subsequent treatment

[0016] 3. In order to ensure the separation of methyl ester from the esterification reaction solution, a large amount of hot water needs to be added, resulting in the need for a large number of storage tanks in the post-treatment process, and the process takes a long time; the by-product sodium carbonate cannot be recycled and used; when recovering methanol, the presence of sodium carbonate leads to distillation The methanol recovery heater is often blocked, the packing of the distillation tower is fouled, and it needs to be stopped for cleaning, resulting in a waste of manpower and material resources; adding a large amount of hot water will result in a large amount of mother liquor and low methanol content, resulting in thermal energy loss when recovering methanol

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