Catalyst for continuously preparing N-isopropyl-4-fluoroanilines, and preparation method and application of catalyst

Abstract

The invention discloses a catalyst for continuously preparing N-isopropyl-4-fluoroanilines. The catalyst comprises an activated carbon carrier, Pt, metal M1 and metal M2, wherein the Pt, metal M1 and metal M2 are loaded on the activated carbon carrier; the Pt accounts for 0.3-1.0wt% of the catalyst; the metal M1 accounts for 0.05-0.5wt% of the catalyst; the metal M2 accounts for 0.05-0.5wt% of the catalyst; the metal M1 is selected from Fe, Cu or Sn; the metal M2 is selected from K, Ce, or Ag. In addition, the invention also discloses a preparation method and application of the catalyst. The catalyst disclosed by the invention has the characteristics of being high in activity, high in selectivity and high in stability and can be used for preparing N-isopropyl-4-fluoroanilines in a high-efficiency catalyzing manner; the conversion ratio of a raw material, namely 4-fluoronitrobenzene, is 98% or more, the yield of a product, namely N-isopropyl-4-fluoroanilines, is 95% or more, and the yield of dehydrogenation by-products is not more than 0.1%.

Description

technical field [0001] The invention belongs to the technical field of catalytic hydrogenation anti-dehalogenation and ketone-amine condensation process, and specifically relates to a catalyst for continuously preparing N-isopropyl-4-fluoroaniline, a preparation method and application thereof. Background technique [0002] N-isopropyl-4-fluoroaniline is mainly used in the synthesis of pharmaceutical intermediates, the pesticide herbicide flufenacet, etc. Among them, flufenacet is a new type of aryloxyacetamide herbicide developed and listed by German Bayer company in 1998 , compared with difenacet, it has higher activity and is suitable for controlling weeds in more crops. The market of flufenacet is developing rapidly. It is currently one of the top 50 pesticides in the world, but there is no mature technology in my country And large-scale production, so the market prospect of N-isopropyl-4-fluoroaniline is very broad. [0003] At present, there are two synthetic methods of ...

AI Technical Summary

Problems solved by technology

This method is relatively mature, but the price of p-fluoroaniline is expensive, the yield is low, the production cycle is long, the cost is high, and the product quality is poor; the equipment is severely corroded, and the amount of three wastes is large, and post-processing is difficult, which does not meet the requirements of modern clean production

[0005] 2) Use p-fluoronitrobenzene, acetone, and hydrogen as raw materials to catalyze the alkylation process. The catalysts include copper chromite, modified zeolite, and loaded noble metal catalysts. Copper chromite and modified zeolite are used as catalysts. The reaction temperature is 300 ℃, the pressure is above 5MPa, the conversion rate is lower than 70%, the selectivity is 80%, the reaction requirements are high, the production cost is high, and it does not have market competitiveness in terms of technology and economy

[0006] Using p-fluoronitrobenzene, acetone, and hydrogen as raw materials to catalyze the alkylation process, using 5% to 10% Pt / C as the catalyst, catalytic hydrogenation and alkylation reactions at 100°C to 150°C and a pressure of 2MPa to 6MPa And get, conversion rate 97%, selectivity 95%, the reaction conversion rate of this synthesis method and selectivity are better, three wastes are few, meet the requirement of modernized clean production, but catalyst is expensive, and easily poisoned, reasonable use catalyst is this. The key to realize the industrialization of the route. The process uses an autoclave reactor and is carried out intermittently. This is the main production process at present, but there are problems such as high production costs, high personnel requirements, and unstable product quality.

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