Preparation method for 3, 3-dimethylbutyraldehyde

Abstract

The invention discloses a preparation method for 3, 3-dimethylbutyraldehyde. The method includes: taking tert-butyl alcohol and vinyl chloride as raw materials and dichloromethane as the reaction solvent to conduct catalytic synthesis of 1-hydroxy-3, 3-dimethyl butyl chloride, then under the action of a catalyst, controlling the temperature at 40DEG C-60DEG C, conducting hydrolysis disproportionation on 1-hydroxy-3, 3-dimethyl butyl chloride to prepare a hydrolysis disproportionation reaction mixture containing 3, 3-dimethylbutyraldehyde; and finally subjecting the hydrolysis disproportionation reaction mixture containing 3, 3-dimethylbutyraldehyde to rectification purification, thus obtaining 3, 3-dimethylbutyraldehyde. Compared with the prior art, the raw materials used by the method are low in price, the production cost can be reduced, the temperature needed by the reaction process is low, wherein the disproportionation temperature is 40DEG C-60DEG C, and compared with the 100DEG C-110DEG C disproportionation temperature in the prior art, the preparation method provided by the invention has the characteristics of milder reaction conditions, no need for high temperature, no special requirement for production equipment, high production safety, higher product purity, and yield up to over 97%.

Description

technical field [0001] The invention belongs to the technical field of chemical synthesis, and in particular relates to a new preparation method of 3,3-dimethylbutyraldehyde. Background technique [0002] Neotame N-[N-(3,3-dimethylbutyl)-L-α-aspartyl]-L-phenylalanine 1-methyl ester is a high-intensity sweetener developed by NutraSweet Company in the United States. Flavoring agent, it has advantages such as high sweetness, low calorie, high stability, no cariogenicity, has huge market potential; And 3,3-dimethyl butyraldehyde is the important intermediate of synthetic neotame (disclosed in Patents US5480668 and US5510508), its market price is expensive, so it is necessary to find an economical and specific method for preparing this intermediate. [0003] In the prior art, there are many preparation methods for 3,3-dimethylbutyraldehyde, such as some foreign preparation methods such as patent US4175204, which discloses the use of sodium bromide and allyl chloride, and the sub...

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Problems solved by technology

[0003] In the prior art, there are many preparation methods for 3,3-dimethylbutyraldehyde, such as some foreign preparation methods such as patent US4175204, which discloses the use of sodium bromide and allyl chloride, and the substituted allyl chloride is used in the catalyst In the presence of a certain amount of sodium bromide, it is oxidized to the corresponding aldehyde with N,N-dimethylsulfoxide; in the patent US5994593, it is disclosed that it is prepared by hydrolysis of 1,1-dichloro-3,3-dimethylbutane; US In 5905175, the preparation of 3,3-dimethylbutanal by oxidation of 1-chloro 3,3-dimethylbutane is disclosed; in the patent US6825384 and the World Intellectual Property Organization WO2005082825, the use of 3.3-dimethylbutanol is disclosed Oxidation to prepare 3,3-dimethylbutyraldehyde; in EP0391652 and EP0374952, 3,3-dimethylbutyraldehyde is obtained by 3,3-dimethylbutyraldehyde in methylene chloride solution with oxalyl chloride, dimethyl When sulfoxide and triethylamine exist, it is prepared by oxidation. This method is the well-known Swern oxidation method, which will produce a foul-smelling dimethyl sulfide by-product, which is not conducive to industrialization

[0004] In addition, there are currently many domestic patents publishing methods for preparing 3,3-dimethylbutyraldehyde, such as the use of 1-chloro-3,3-dimethylbutane in CN200910029947 to hydrolyze alcohol, which is expensive to use Silver oxide and other precious metal oxidation catalysis to prepare, in the above-mentioned method, all exist efficiency low, cost is high, pollution is big, reproducibility is poor, the deficiency that is difficult to realize industrialized production; As CN102295541A discloses a kind of 3,3-di The preparation method of methyl butyraldehyde comprises the following steps: taking tert-butyl chloride and vinyl acetate as raw materials, and catalytically preparing 1-chloro-3,3-dimethylbutyl acetate, tert-butyl chloride and acetic acid The weight ratio of vinyl ester is 1:0.84-0.93. Under the action of a catalyst, 1-chloro-3,3-dimethylbutyl acetate is hydrolyzed and disproportionated under the action of a catalyst to prepare 3,3-dimethylbutyraldehyde-containing Hydrolyze the disproportionation reaction mixture, carry out rectification and purification to obtain 3,3-dimethylbutyraldehyde, the catalyst is aluminum trichloride or p-toluenesulfonic acid or ferric chloride, and the hydrolysis and disproportionation temperature is 100°C-110°C

The hydrolysis gasification temperature recorded in this patent is 100°C-110°C, the reaction energy consumption is high, and the cost of reactants is high, which affects the overall industrial cost.

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