Technology of synthesizing 2-hydroxybenzonitrile through one-step method

Abstract

The invention provides a technology of synthesizing 2-hydroxybenzonitrile through a one-step method. The technology comprises the following steps that 1, a vanadium oxide loaded catalyst is placed into a fixed bed reactor, and by conducting vacuuming through a double-row pipe and sweeping through inert gas, water and air are removed; 2, a certain amount of salicylamide is converted to gas at a certain temperature through a vaporization furnace; 3, the gaseous salicylamide enters the fixed bed reactor, wherein the bed height of the catalyst is 2-3 cm; 4, a product condenses through a temperature control pipe and flows into a receiving tank in a liquid mode. The 2-hydroxybenzonitrile prepared through the method is high in yield, the technology process is simple, the cost is low, and the technology is clean and efficient.

Description

technical field [0001] The invention relates to the field of synthesis of pesticides and pharmaceutical intermediates, in particular to a process for synthesizing 2-hydroxybenzonitrile by one-step method, especially a process for preparing 2-hydroxybenzonitrile by one-step gas-solid phase reaction. Background technique [0002] 2-Hydroxybenzonitrile is an intermediate in the synthesis of pesticides and medicines. It is often used as an intermediate in the organic synthesis of bunilol and the fungicide azoxystrobin. There are several common synthetic methods of 2-hydroxybenzonitrile: [0003] (1) First, salicylaldehyde and hydroxylamine hydrochloride generate salicylaldoxime, and then dehydrate in the dehydrating agent acetic anhydride or thionyl chloride to obtain 2-hydroxybenzonitrile. (2) Salicylamide can obtain 2-hydroxybenzonitrile under the action of dehydrating agent phosgene (or diphosgene, triphosgene, etc.), thionyl chloride, and phosphorus oxychloride. [0004] A...

AI Technical Summary

Problems solved by technology

Although homogeneous catalysis has the characteristics of fast reaction speed and high conversion rate, the separation of products, solvents and catalysts in homogeneous catalysis is complicated, the process is complicated, and the industrial cost is increased; moreover, a large amount of waste liquid will be generated in the production process, resulting in waste of resources. ; At the same time, a large amount of waste liquid pollutes the environment, which does not conform to the principles of green chemistry proposed by the international community.

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