Preparation and after-treatment method of p-tert-butylbenzoic acid

A technology of tert-butylbenzoic acid and p-tert-butyltoluene, which is applied in the field of its preparation and post-processing, can solve the problems of severe reaction heat release, high consumption of raw materials, and large amount of phthalic acid

Active Publication Date: 2018-09-14
SUQIAN COSMOS CHEM
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AI Technical Summary

Problems solved by technology

[0002] In traditional production methods, the synthesis of p-tert-butylbenzoic acid is mostly oxidized with oxygen. The oxidation kettle is always within the explosion limit range, and the attached safety protection technology and equipment and facilities are strictly required; The tail gas discharged is almost pure oxygen (carrying a trace amount of organic gas), so it is afraid to carry out incineration disposal, which will pollute the environment; the amount of by-product terephthalic acid is large, resulting in high consumption of raw materials and affecting the purity of the product
[0003] Moreover, there are deficiencies such as high preparation temperature and low yield in the method disclosed in the prior art

Method used

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  • Preparation and after-treatment method of p-tert-butylbenzoic acid

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preparation example Construction

[0037] The invention provides a kind of preparation and aftertreatment method of p-tert-butylbenzoic acid, described method comprises the following steps:

[0038] Step 1, utilizing toluene, isobutylene and concentrated sulfuric acid to prepare p-tert-butyltoluene, and then utilizing the obtained p-tert-butyltoluene to carry out oxidation reaction;

[0039] Step 2, carry out crystallization treatment after the oxidation reaction finishes, then centrifuge and wash to obtain the wet product of the crystallization mother liquor and the first batch of p-tert-butylbenzoic acid respectively, preferably the first batch of p-tert-butylbenzoic acid obtained The wet product is dried;

[0040] Step 3, adding aqueous sodium hydroxide solution to the crystallization mother liquor obtained in step 2, extracting to obtain the water phase, then adding concentrated sulfuric acid to the water phase, the residual p-tert-butylbenzoic acid in step 2 is precipitated, and filtered to obtain the seco...

Embodiment approach

[0045] According to a preferred embodiment of the present invention, step 1 includes the following sub-steps:

[0046] Step 1-1, mixing toluene and concentrated sulfuric acid, passing through isobutylene for alkylation reaction, removing acid after the reaction, adding alkaline water for extraction to obtain an aqueous phase and an organic phase, and performing rectification on the organic phase to obtain p-tert-butyltoluene;

[0047] Step 1-2, transfer the p-tert-butyltoluene obtained in step 1-1 into an oxidation kettle, add a catalyst, and feed air to carry out oxidation reaction.

[0048] According to a preferred embodiment of the present invention, in step 1-1, the alkylation reaction is carried out as follows: react at 6-14° C. for 8-15 hours.

[0049] In a further preferred embodiment, in step 1-1, the alkylation reaction is carried out as follows: react at 8-10° C. for 10.5-11.5 hours.

[0050] According to a preferred embodiment of the present invention, in step 1-1...

Embodiment 1

[0110] (1) 340g of toluene and 20g of concentrated sulfuric acid are added to the reactor, and 170g of isobutylene is introduced into the reaction kettle at 8° C. for alkylation for 11 hours. After the reaction, the acid is removed, and a 30% sodium carbonate aqueous solution is added to adjust the pH to neutral. Extract the water phase and the oil phase; then carry out rectification on the oil phase to obtain p-tert-butyltoluene.

[0111] Transfer the obtained p-tert-butyltoluene into an oxidation kettle, add 0.968g of cobalt acetate and 0.032g of manganese acetate into the kettle, raise the temperature to 125°C, and feed air at a rate of 2200mL / min to carry out the oxidation reaction. During the oxidation reaction process, control the produced water to 24-26g.

[0112] Among them, after the oxidation starts, the heat release in the oxidation process is stable. Although the reaction is stable, the temperature must be lowered, but the temperature reduction is easy to control, ...

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Abstract

The invention discloses a preparation and after-treatment method of p-tert-butylbenzoic acid. The preparation method of the p-tert-butylbenzoic acid includes the steps: firstly, performing tert-butylation on toluene to obtain p-tert-butyl toluene; secondly, oxidizing the p-tert-butyl toluene; finally, performing crystallization to obtain the p-tert-butylbenzoic acid. Crystallization mother liquidis retreated after crystallization, p-tert-butylbenzoic acid remained in the mother liquid is further acquired, the yield of the p-tert-butylbenzoic acid is improved, waste sodium sulfate in the mother liquid is after-treated to obtain industrial-grade sodium sulfate, waste emission in the preparation process is reduced, the waste sodium sulfate is converted into recyclable industrial-grade sodiumsulfate, a certain economic benefit is achieved, and environment-friendly significance is remarkable.

Description

technical field [0001] The invention relates to the field of p-tert-butylbenzoic acid, in particular to its preparation and post-treatment methods. Background technique [0002] In the traditional production method, the synthesis of p-tert-butylbenzoic acid is mostly oxidized with oxygen. The oxidation kettle is always within the explosion limit range, and the attached safety protection technology and equipment and facilities are strictly required; The tail gas discharged is almost pure oxygen (carrying a trace amount of organic gas), so it is afraid to carry out incineration disposal, which pollutes the environment; the amount of by-product terephthalic acid is large, which causes high raw material consumption and affects the purity of the product. [0003] Moreover, the methods disclosed in the prior art have disadvantages such as relatively high preparation temperature and low yield. Contents of the invention [0004] In order to solve the above problems, the present i...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C51/265C07C51/43C07C51/487C07C63/04C07C2/70C07C15/02C01D5/00
CPCC01D5/00C07C2/70C07C51/265C07C51/43C07C51/487C07C63/04C07C15/02
Inventor 王宁宁汪佳斌马瑞唐梁平
Owner SUQIAN COSMOS CHEM
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