Preparation method of o-ethoxybenzoic acid

A technology of o-ethoxybenzoic acid and salicylic acid, which is applied in the field of preparation of o-ethoxybenzoic acid, can solve problems such as difficulty in realizing large-scale industrial production, uneasy control of reaction conditions, unfavorable industrial production, etc., and facilitates industrialization The effect of low production, low cost and convenient operation
CN103553908AActive Publication Date: 2014-02-05苏州诚和医药化学有限公司
1 Cites 9 Cited by

Patent Information

Authority / Receiving Office
CN · China
Current Assignee / Owner
苏州诚和医药化学有限公司
Publication Date
2014-02-05

Smart Images

  • Figure 1
    Figure 1
Patent Text Reader

Abstract

The invention relates to a preparation method of o-ethoxybenzoic acid, which comprises the following steps: adding salicylic acid, acetone and potassium hydroxide into a reaction bulb, dropwisely adding bromoethane while stirring at room temperature, heating under reflux for 9-15 hours, recovering the acetone under reduced pressure, adding water and liquid alkali, heating under reflux for 2-4 hours, cooling to room temperature, regulating the pH value to 3-4 with glacial acetic acid, cooling to 1-15 DEG C, separating by vacuum filtration, washing with water, and carrying out vacuum drying to obtain the o-ethoxybenzoic acid, wherein the salicylic acid:potassium hydroxide:bromoethane:liquid alkali mol ratio is 1:(2.0-2.5):(2.1-2.5):1.4. The method has the advantages of simple technique, low raw material cost, high yield and good quality, and is convenient to operate and convenient for industrial production.
Need to check novelty before this filing date? Find Prior Art

Description

technical field

[0001] The invention relates to the technical field of pharmaceutical intermediates, in particular to a preparation method of o-ethoxybenzoic acid. Background technique

[0002] O-ethoxybenzoic acid is an important intermediate for the synthesis of ED drugs (Viagra). There are many related reports on the synthesis of this intermediate at home and abroad. The following two types are typical, one is etherified with o-chlorobenzoic acid, The raw material cost of this method is high, and it is difficult to operate under high temperature and high pressure, which is not conducive to industrial production. Another method first esterifies salicylic acid and then undergoes etherification and alkali hydrolysis to obtain the product. This method has high synthesis cost and reaction conditions Difficult to control, difficult to realize large-scale industrial production. Contents of the invention

[0003] The purpose of the present invention is to provide a kind of pro...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More