Chinese Academy of Sciences

Xinjiang Cui

Feng Shi

Youquan Deng

Hangkong Yuan

Yan Zhang

Xiaoguang Guo

Liujin Lu

Jian Li

Xiong Tian

Yubo Ma

Jianpeng Shang

Qinghua Zhang

Liguo L Wang

Xiangyuan Ma

Hongzhe Zhang

A process for producing N-methyl or N,N-dimethyl amines, which comprises using amine compound, nitro-containing compound or nitrile compound as a starting material, carbon dioxide as a methylating agent and hydrogen gas as a reducing agent, and allowing them to react in a sealed reactor for 6 to 48 h in a reaction medium at a reaction temperature of 80 to 180 &#xb0; C. in the presence of a composite catalyst, so as to provide N-methyl or N,N-dimethyl amines. The process of the present invention is simple and under relative mild reaction conditions. By means of the process of the invention, the target products can be prepared at low cost with a high yield. The catalysts used have a high catalytic activity and can be separated from the reaction system simply and reused. Furthermore, the whole process of the present invention is environmental-friendly and facilitates the cycling use of carbon dioxide.

Process for producing N-methyl or N,N-dimethyl amines

The invention relates to a method for producing a N-substituted amine compound by catalyzed alkylation. The method uses amine and alcohol or two kinds of amines as the reaction materials, employs composite metal oxides catalyst at a reaction temperature of 80-180&#xb0; C. to catalyze the reaction for 6-36 hours, so as to produce the N-substituted amine compound. The reaction condition of the method of the invention is relatively moderate, using a catalyst made of cheap non-noble metals, which is non-caustic and easy to be separated and reused. The reaction does not need any medium and has relatively high conversion rate and selectivity.

Method for producing N-substituted amine compounds through catalyzed alkylation

The present invention discloses a method for preparing isocyanates by liquid-phase catalytic thermal cracking. In this method, in a reaction-rectification thermal cracking reactor, using a catalyst composition comprising a superfine powder metal oxide catalyst and an ionic liquid, an alkyl or aryl dialkylurethane, or multialkylurethane being a reactant is liquid-phase thermal cracked for a reaction time of 0.5-3 h under a reaction temperature of 160-220&#xb0; C. and an absolute pressure of 1000-8000 Pa so as to prepare the corresponding isocyanate. The invention has the characteristics of low thermal cracking temperature, high yield of target products, relatively simple reaction apparatus and good universality for substrates (the yields of HDI, MDI, TDI, HMDI, NDI and IPDI or the like are all&#x3e;85%) and the like.

Method for preparing isocyanates by liquid-phase thermal cracking

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Lanzhou, China

Xinjiang Cui