Preparation method of p-methoxybenzaldehyde

Abstract

The invention discloses a preparation method of p-methoxybenzaldehyde, wherein the preparation method includes following steps: (A) with p-hydroxybenzaldehyde and dimethyl carbonate as raw materials, immobilized TEBA as a catalyst and chloroform as a solvent, adding sodium carbonate and performing a reaction under a microwave / ultrasonic combination condition; (B) adding 1-2 mol of p-hydroxybenzaldehyde, 1.5-3 mol of dimethyl carbonate, 3-5 mol of chloroform to dissolve the raw materials, adding 0.05-2 mol of the immobilized TEBA and 0.1-0.5 mole of sodium carbonate, and performing a reflux reaction under a microwave and ultrasonic condition; (C) when the solution is boiled and reflux liquid begins to drop from a condenser, regulating a heat source to enable reflux speed to be normal; (D) when the reaction is finished, cooling the liquid to room temperature, performing filtration to recycle the sodium carbonate, moving a filtrate to a distillation flask, performing pressure-reduced fractionation to remove the top layer liquid, and performing pressure-reduced distillation to collect the fraction in the range of -0.098 MPa - 0.1 MPa and 100-120 DEG C to obtain p-methoxybenzaldehyde. The method is simple in operations and is less in by-product. The catalyst is low in cost, is easy to obtain and is less in pollution. The method is low in requirement on production equipment and is suitable for being carried out in large-scale production.

Description

Technical field [0001] The invention belongs to the field of food additives, and specifically relates to a preparation method of p-anisaldehyde. Background technique [0002] With the development of the national economy, people's lives have gradually changed from food and clothing to well-off, which provides a broad market for the development of perfume industry products, especially natural spices are favored. However, natural animal and plant spices are often restricted by natural conditions and processing factors, which have a certain impact on the number of varieties and product quality. The innovation and quality improvement of flavors are increasingly dependent on new synthetic flavors. Because synthetic spices are not restricted by natural conditions, the quality is stable, the scale of production can be arranged by people themselves, and the price of the products is much cheaper than natural sources. Therefore, the research and development of new synthetic fragrances are...

AI Technical Summary

Problems solved by technology

However, because natural animal and plant spices are often limited by natural conditions and processing factors, the number of varieties and product quality are affected to a certain extent.