Method for preparing N-methylpyrrolidine through catalysis

Abstract

The invention discloses a method for preparing N-methylpyrrolidine through catalysis. According to the method, 1,4-butanediol and a methylamine water solution which are used as raw materials react inan H2 reduction atmosphere at the reaction temperature of 230-330 DEG C and under the pressure of 4-10 Mpa for 1-8 h with a supported bimetal oxide as a catalyst to produce N-methylpyrrolidine. A supporter of the catalyst is an Al2O3, SiO2 or ZSM-5 molecular sieve, and active components are CuO and NiO. The method has the advantages that the reaction time is short, the catalyst is low in cost andreusable, the product yield is high and the like.

Description

technical field [0001] The invention relates to a method for preparing N-methylpyrrolidine from an aqueous solution of 1,4-butanediol and methylamine in the presence of a supported double metal oxide catalyst. Background technique [0002] N-Methylpyrrolidine is a cyclic secondary amine, which is mainly used for the preparation of broad-spectrum antibiotics cefepime and acetidine, and can also be used as a dye stabilizer, preservative, and ionic liquid. The existing N-methylpyrrolidine preparation methods mainly include: US4892959 adopts N-methylpyrrolidone and hydrogen to catalytic hydrogenation under the conditions of Cu-Al or Cu-Cr catalyst, the conversion rate is 85%, and the selectivity is 85%. The reaction pressure is as high as 150atm-280atm, which requires strict equipment and requires a large investment. CN1810787 adopts 1,4-dichlorobutane and monomethylamine to prepare N-methylpyrrolidine in a reactor, the reaction temperature is 50-180 ℃, and the reaction pressur...

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Problems solved by technology

Chen Yongsheng introduced in "Chemical Intermediates", 2008, 08: (19-21), using H-13X molecular sieves to catalyze tetrahydropyrrole and methanol to synthesize N-methylpyrrolidine. The reaction temperature of this method is 300 ° C, tetrahydropyrrole : Methanol=1:3, the yield of N-methylpyrrolidine is 83.8%, the raw material tetrahydropyrrole of this reaction is expensive, resulting in high cost and increased difficulty in industrialization

CN104276957 and CN106316866 reported that CO 2 As a methylation reagent, react with tetrahydropyrrole under hydrogen atmosphere to synthesize N-methylpyrrolidine, the highest yield of this reaction can reach 99%, but the raw material tetrahydropyrrole used in the reaction is expensive, and the catalyst is Precious metals, which limit their industrial application