Method for preparing amide using nonhomogeneous phase oximation rearrangement

Abstract

The present invention discloses oximation and rearrangement process of preparing amide with aliphatic and / or cyclic aliphatic ketone as material. The preparation process includes catalytic reaction of ketone, hydrogen peroxide solution and ammonia inside inert solvent to produce ketoxime solution, Beckmann rearrangement of the oil phase product under the action of fuming sulfuric acid, and hydrolysis to neutralize and produce amide. The present invention has shortened technological process, lowered cyclohexyl ketoxime rearranging reaction temperature, lowered sulfuric acid consumption and reduced side product.

Description

technical field [0001] The invention relates to a method for preparing amides, and further illustrates that the amides are prepared by heterogeneous ammoximation and heterogeneous Beckmann rearrangement using ketones as raw materials. Background technique [0002] Amides are a class of compounds in which the hydroxyl groups in carboxylic acid molecules are replaced by amino or amino groups, and can also be regarded as acyl derivatives of ammonia, primary or secondary amines. Most of the amides with the general formula RCONH2 are crystalline at room temperature, have good water solubility, and are excellent solvents and polymer raw materials. The preparation of amides usually includes amine acylation, carboxylate ammonium salt dehydration, nitrile partial hydrolysis and ketoxime rearrangement and other methods. [0003] Aliphatic ketones or aromatic ketones can condense with ammonia derivatives such as hydroxylamine to generate corresponding ketoximes. Using acidic substanc...

AI Technical Summary

Problems solved by technology

[0010] (1) The technological process is complicated and the energy consumption is large;

[0011] (2) Both distillation and extraction are carried out at relatively high temperatures, and the stability of the oxime solution is relatively poor, and trace impurities are generated in the subsequent rearrangement, which brings difficulties to the refining process;

[0012] (3) The material that enters the subsequent rearrangement is molten oxime. During production, the pipeline needs heat preservation and heat tracing, which is easy to block, which brings inconvenience to start-up and production operations.

[0016] (1) The decline of multi-stage rearrangement by-products is small. Under the conditions of low acid content and low temperature, the viscosity of the material is high, which is unfavorable for mass transfer and reaction

[0017] (2) Ammonium salt metathesis and sulfuric acid cycle process consume a lot of energy and cost, so they are not economical