Preparation method of modified molecular sieve catalyst and method for continuously synthesizing 3-methoxy-3-methyl butanol

Abstract

The invention provides preparation of a modified molecular sieve catalyst. The modified molecular sieve catalyst is a polyphosphate modified molecular sieve catalyst, bentonite is added into the molecular sieve catalyst, so that the catalyst changes acid site distribution and pore channel structure, and the modified molecular sieve prepared by the invention is used as a catalyst to prepare 3-methoxy-3-methyl butanol. The method overcomes the defects of many side reactions and short service life of the catalyst under the high temperature condition in the process of continuously preparing 3-methoxy-3-methyl butanol by taking 3-methyl-3-butylene-1-alcohol and methanol as raw materials, the conversion rate and selectivity of 3-methyl-3-butylene-1-alcohol are improved, and the yield of 3-methoxy-3-methyl butanol reaches 97% or above. The method has the advantages of high continuous operability, low cost and simple process.

Description

technical field [0001] The invention relates to a method for synthesizing 3-methoxy-3-methylbutanol, an important fine chemical raw material, and belongs to the technical field of organic chemical synthesis. Background technique [0002] 3-Methoxy-3-methylbutanol has good hydrophilicity, lipophilicity, low toxicity and biodegradability, and is widely used in cosmetics, printer inks, air fresheners, detergents, pesticides and insecticides It is an important fine chemical raw material. [0003] Regarding the preparation method of 3-methoxy-3-methylbutanol, CN102206142 adopts 3-methyl-3-butene-1-alcohol, methyl alcohol and heterogeneous catalyst to react in a closed reactor, and the reaction time is 1~ 12h, the reaction temperature is 50~200℃, the reaction pressure is 0.1~5MPa, and the heterogeneous catalyst is used in a closed reactor to obtain the highest yield of 95.2% of 3-methoxy-3-methylbutanol, but the reaction time needs 12h, and belongs to intermittent reaction; pate...

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Problems solved by technology

[0003] Regarding the preparation method of 3-methoxy-3-methylbutanol, CN102206142 adopts 3-methyl-3-butene-1-alcohol, methyl alcohol and heterogeneous catalyst to react in a closed reactor, and the reaction time is 1~ 12h, the reaction temperature is 50~200℃, the reaction pressure is 0.1~5MPa, and the heterogeneous catalyst is used in a closed reactor to obtain the highest yield of 95.2% of 3-methoxy-3-methylbutanol, but the reaction time needs 12h, and belongs to intermittent reaction; patent JP8176053 uses 4,4-dimethyl-1,3-dioxane to react with methanol under the catalysis of strong acid cationic resin, but 3-methoxy-3-methylbutanol is selected property ~ 40%, many by-products, and low atom economy; patent CN106966923A discloses a synthetic method for synthesizing 3-methoxy-N,N-dimethylpropionamide, which has a similar reaction and uses propylene Nitrile and anhydrous methanol are prepared in a closed reactor under the action of metal alkoxide, which is a batch reaction and does not have continuous operability

[0004] In summary, the currently disclosed technology uses 3-methyl-3-butene-1-alcohol as the technique for synthesizing 3-methoxyl-3-methylbutanol as a raw material, under high temperature and acidic catalyst conditions 3-Methyl-3-buten-1-ol is easy to generate too many low-boiling impurities, and at the same time, it is easy to cause coking and loss of the catalyst under high temperature conditions, which affects catalyst efficiency and life; while under low temperature conditions, the reaction rate is slow and the reaction long time problem

Moreover, the continuous operability is poor, and there is no technical advantage in terms of economy and industrial mass production.

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