CN1314337A

CN1314337A - Method for producing 3,4,5 trimethoxybenzoic acid

Info

Publication number: CN1314337A
Application number: CN 01106881
Authority: CN
Inventors: 罗伟
Original assignee: Individual
Current assignee: Individual
Priority date: 2001-02-21
Filing date: 2001-02-21
Publication date: 2001-09-26

Abstract

The present invention prdouces 3,4,5-trimethoxybenzoic acid by using gall powder as raw material and through once synthesis process including graded extraction in 6-10 times of water at 60-100 deg.c for 2-10 hr, vacuum concentration to 10 Baume degree, freezing, filtering and methylation with dimethyl sulfate. The present invention has high product quality, low power consumption, low cost, high yield and stable technological process.

Description

3, the production method of 4,5 trimethoxybenzoic acids

The present invention relates to a kind of be used to produce antibiotic synergist trimethoprim, the production method of synthetic intermediate 3,4,5 trimethoxybenzoic acids of anxiolytic Sedoxazin etc.

3, the conventional production methods of 4,5 trimethoxybenzoic acids (TMBA) is to methylate and get with Weibull or gallic acid and dimethyl sulfate, mainly may further comprise the steps: the hydrolysis of (1) raw material: the hydrolysis under water and liquid caustic soda condition of raw material Weibull or gallic acid; (2) dimethyl sulfate methylates (comprise hydrolyzing methylization, alkaline condition heating is steamed water, regulates PH8.5-9, added the liquid caustic soda vacuum hydrolysis down, the acidifying suction filtration gets crude product, activated carbon decolorizing under alkaline condition).The subject matter of this method is: owing to will be concentrated to 30 ° of Be, can cause the partly oxidation of component like this in the process of concentrate drying, the purity of product is not high; The pigment height; The gac that energy consumption is many on the other hand, drying plant is many, when decolouring uses is many, cause the production cost height; The rate of recovery is not high yet.

The object of the present invention is to provide a kind of can reducing production costs, improve the quality of products, improve the production method that the rate of recovery, process stabilizing are produced 3,4,5 trimethoxybenzoic acids reliably.

Method of the present invention is to adopt one step of raw material gallnut extract directly synthetic.It is characterized in that may further comprise the steps:

(1). the lixiviate of raw material gallnut extract: gallnut extract adds 6-10 times of water, temperature 60-100 ℃, gradation lixiviate 2-10 hour; Vacuum concentration to 10 ° Be filters;

(2) dimethyl sulfate hydrolyzing methylization: A) by Turkey-galls: 40% liquid caustic soda=1: 1.2-1.6 adds liquid caustic soda hydrolysis 20 minutes, again by Turkey-galls: dimethyl sulfate=1: 1.6-1.9 temperature 70-90 ℃, be incubated 30-60 minute and be hydrolyzed and methylate; B) heating was steamed water 2 hours under alkaline condition, C) regulated PH to 8.5-9, added the liquid caustic soda vacuum hydrolysis 8 hours; D) the acidifying suction filtration gets crude product; E) with water dissolution, under alkaline condition with activated carbon decolorizing, refining elaboration.

The product of producing with the present invention only needs to be concentrated into 10 ° of Be owing to vat liquor, the oxidation of product can not take place, and because vat liquor is at concentrated after-filtration, further removed impurity, so the purity of product improves greatly, pigment obviously reduces, and the fusing point of the important parameter of its explanation quality product can reach 170-171 ℃, and the fusing point of former method product is less than 170 ℃; And because vat liquor only needs to be concentrated into 10 ° of Be,, saved drying plant, reduced the activated carbon dosage of decolouring, thereby greatly reduced production cost so reduced energy consumption; Also reduced the absorption of gac, thereby the rate of recovery of product improves to product.And process stabilizing is reliable.

Embodiment 1:

(1) lixiviate of raw material gallnut extract: gallnut extract 350 gram, at every turn add 500 gram water, temperature 60-100 ℃ lixiviate 3 times, each 2 hours; At 90 ℃ of vacuum concentration to 10 ° Be, vacuum filtration;

(2) dimethyl sulfate hydrolyzing methylization: A) get above-mentioned filtrate and add in the three-necked flask, add 280 milliliter of 40% liquid caustic soda, hydrolysis 20 minutes, add 290 milliliters of dimethyl sulfates, in 40 minutes hydrolyzing methylizations of 90 ℃ of insulations of temperature; B) liquid caustic soda of adding 40% is 130 milliliters, and heating was steamed water 2 hours, (C) adds two formicesters and a spot of liquid caustic soda and regulates PH to 8.5-9, is incubated 0.5 hour; Added the liquid caustic soda vacuum hydrolysis 8 hours; D) acidifying, vacuum filtration get crude product 220 grams; E) crude product adds 10 times of water dissolution, uses activated carbon decolorizing 30 minutes under alkaline condition; The cooling of suction filtration, filtrate, add sulfuric acid acidation, vacuum filtration, washing, promptly get elaboration; Vacuum-drying 5 hours gets finished product 170 grams.Recording content is 99.5%, 171 ℃ of fusing points.Pigment is less than 50f.

Embodiment 2:

(1) lixiviate of raw material gallnut extract: 300 kilograms of gallnut extracts drop in the lixiviate pond, add 600 kg of water 80 ℃ of adverse current lixiviates 5 times, each 2 hours at every turn; Total vat liquor concentration is about 5 ° of Be, at 90 ℃ of vacuum concentration to 10 ° Be, vacuum filtration;

(2) dimethyl sulfate hydrolyzing methylization: A) get above-mentioned filtrate and add 250 kilogram of 40% liquid caustic soda, hydrolysis 20 minutes, add 260 kilograms of dimethyl sulfates, in 40 minutes hydrolyzing methylizations of 90 ℃ of insulations of temperature, B) liquid caustic soda of adding 40% is 110 kilograms, heating was steamed water 2 hours, (C) add two formicesters and a spot of liquid caustic soda and regulate PH to 8.5-9, be incubated 0.5 hour; Added the liquid caustic soda vacuum hydrolysis 8 hours; D) the acidifying vacuum filtration gets 225 kilograms of crude products; E) crude product adds 10 times of water dissolution, uses activated carbon decolorizing 30 minutes under alkaline condition; The cooling of suction filtration, filtrate, add sulfuric acid acidation, vacuum filtration, washing, promptly get elaboration; Vacuum-drying got 175 kilograms of finished products in 7 hours.Recording content is 99.3%, and fusing point is 171 ℃.Pigment is less than 50f.

Claims

1. one kind 3,4, the production method of 5 trimethoxybenzoic acids (TMBA) is characterized in that may further comprise the steps:

(1). the lixiviate of raw material gallnut extract: gallnut extract adds 6-10 times of water, temperature 60-100 ℃, gradation lixiviate 2-10 hour; Vacuum concentration to 10 ° Be,, filter;

(2) dimethyl sulfate hydrolyzing methylization: A) by Turkey-galls: 40% liquid caustic soda (weight ratio)=1: 1.2-1.6 adds liquid caustic soda hydrolysis 20 minutes, again by Turkey-galls: dimethyl sulfate (weight ratio)=1: 1.6-1.9 temperature 70-90 ℃, be incubated 30-60 minute and be hydrolyzed and methylate; B) heating was steamed water 2 hours under alkaline condition, C) regulated PH to 8.5-9, added the liquid caustic soda vacuum hydrolysis 8 hours; D) the acidifying suction filtration gets crude product; E) with water dissolution, under alkaline condition with activated carbon decolorizing, refining elaboration.