A kind of preparation method of diethyl malonate

Abstract

The invention provides a preparation method of diethyl malonate. Ethyl chloroacetate, alcohol and magnetic silica support metal complex and ammonium hydroxide are mixed to be uniform in a reaction vessel, carbon monoxide is used for replacing air in the reaction vessel for 3-6 times, the carbon monoxide is introduced, the pressure is maintained at 0.5-3 MPa, stirring is performed, a mixture inside the reaction vessel is heated to 30-70 DEG C to be subjected to a reaction for 1-6 h, diethyl malonate can be prepared, cooling and filtering are performed, and separation and rectification are performed to obtain the product diethyl malonate. The functional magnetic silica support metal complex material is adopted as the catalyst, reaction raw materials are simple, and operation is convenient; the catalyst is high in activity and small in consumption; the catalyst is good in stability and can be conveniently recycled; the preparation method is simple, the product yield is high, reaction conditions are mild, the preparation method of diethyl malonate is efficient and environmentally friendly, and large-scale industrial production is promoted.

Description

Technical field [0001] The invention relates to a new method for preparing diethyl malonate cleanly and catalyzed by a functionalized magnetic silica gel immobilized metal complex, and belongs to the chemical technical field. Background technique [0002] Diethyl malonate is an important fine chemical raw material. Because the methylene hydrogen in its molecule is easily replaced by a variety of groups, it generates a variety of important derivatives and is widely used in various chemical production. Fields, including food, medicine, pesticides, industrial dyes, liquid crystal materials and other industries. In recent years, with the further development and application of downstream products of diethyl malonate at home and abroad, the demand for diethyl malonate has increased sharply, and the domestic demand for diethyl malonate is relatively large. At present, domestic manufacturers use the sodium cyanide method for production (CN101525290A). This method has a long process flow...

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Problems solved by technology

Catalysts for the synthesis of diethyl malonate by catalytic carbonylation usually use complexes or compounds of transition metals such as Fe, Co, Ni, Rh, Ru, Pt, Ir as catalysts (Journal of Chemical Engineering of Universities, 2002, 16 (1) : 41; CN1237572A; CN102442904A), but there are some disadvantages more or less in the above-mentioned method, such as expensive raw material, long reaction time, low yield, difficult product separation, difficult recycling of catalyst, serious corrosion of equipment, complicated operation process, etc.

Cobalt carbonyl is a very important homogeneous complex catalyst for the carbonylation reaction of organic compounds. Diethyl malonate can be synthesized by cobalt carbonyl catalyzed carbonylation. This method has high conversion rate and mild reaction conditions, but there is a process flow Problems such as long time, high cost, unstable catalyst and easy decomposition, and environmental pollution

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