Catalyst for preparing salicylonitrile as well as preparation method and application thereof

Abstract

The present invention relates to a catalyst for preparing salicylonitrile, a preparation method and an application thereof, the catalyst comprises a carrier and an active component, the composition general formula of the active component is P1.0 AlaBbXcYdOm, and X is any one or a combination of at least two selected from lithium, sodium, potassium or cesium, Y is selected from any one or a combination of at least two of calcium, magnesium, barium, manganese, iron, cobalt, nickel, lead, molybdenum, tungsten or rare earth elements; wherein a is 0.5-2, b is 0.05-0.8, c is 0.01-0.7, d is 0.01-0.2, and m is the number of oxygen atoms required for meeting element valence balance in the active component; the catalyst provided by the invention has excellent catalytic performance and selectivity to salicylonitrile, the conversion rate of catalyzing conversion of methyl salicylate is greater than 98%, and the selectivity to salicylonitrile is greater than 94%.

Description

technical field [0001] The invention belongs to the field of catalysis, and relates to a catalyst for preparing salicylonitrile, a preparation method and application thereof. Background technique [0002] Salicylonitrile, also known as o-hydroxybenzonitrile, is slightly soluble in water and unstable to strong alkalis or strong oxidants. As a pharmaceutical intermediate, salicylonitrile is mainly used to produce Bunirolol hydrochloride, and as a pesticide intermediate, it is mainly used to produce the methoxyacrylate fungicide azoxystrobin. Salicylonitrile can also be used as an intermediate for some perfumes and liquid crystal materials. [0003] At present, the processes for synthesizing salicylonitrile mainly include the following three types. The first one is to generate salicylonitrile by one-step dehydration of salicylamide. The selection of dehydrating agent has become the biggest problem in the industrial production of this process. At present, triphosgene and Thion...

AI Technical Summary

Problems solved by technology

The biggest problem in the industrialization of this process is the need to use a large amount of solvents such as N-methylpyrrolidone and N,N-dimethylformamide (N,N-Dimethylformamide, DMF), which leads to a large amount of organic waste water, high production costs, and high pressure on environmental protection.

The third method is to use o-cresol as a raw material through etherification and ammoxidation, the process is complicated and the yield is low

[0005] Disclosed in CN108816256A is a preparation method for a catalyst for synthesizing salicylonitrile, comprising the following steps: (1) at 30°C-70°C, adding a phosphorus source into water to stir and dissolve, and sieving the calcium source in batches Add it; after filtering and washing, dry at 90°C-150°C, pulverize and sieve to obtain the precursor powder; (2) add the auxiliary agent to the sieved precursor powder and mix evenly, then add deionized water, Extrude to obtain a shaped catalyst precursor, dry to constant weight; (3) put the shaped catalyst precursor in a muffle furnace, and raise the temperature to 500°C-600°C at a heating rate of 2°C-5°C / min and keep it warm for 3 -7h, the catalyst for the synthesis of salicylonitrile, the catalyst described in this scheme is only suitable for the catalytic process of using salicylic acid as a raw material to synthesize salicylonitrile, and it is used to catalyze methyl salicylate as a raw material to prepare salicylonitrile. process, the catalytic activity is low

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