A kind of preparation method of 3-bromo-4-hydroxybenzoic acid methyl ester
A technology of methyl hydroxybenzoate and glacial acetic acid, which is applied to the preparation of carboxylic acid esters, the preparation of organic compounds, chemical instruments and methods, etc., can solve the problems of high solvent toxicity, low reaction yield, and complicated operation, and achieve solvent The effect of less dosage, simple operation and high yield
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Problems solved by technology
Method used
Image
Examples
Embodiment 1
[0028] Add glacial acetic acid (90ml, 0.155mol, 1.1eq) to methyl p-hydroxybenzoate (21.42g, 0.148mol, 1eq) in dichloromethane (300ml), stir until completely dissolved, cool to below 5°C in an ice bath, Liquid bromine (8.0ml, 0.155mol, 1.1eq) was slowly added dropwise to the reaction mixture, and the temperature was controlled at 0-5°C during the dropwise addition. After the dropwise addition was completed, the reaction was carried out at room temperature for 32 hours, and the HBr tail gas was received during the reaction. After the reaction, Na was added to the reaction solution 2 S 2 o 3 Aqueous solution (35.2g, 264ml), stirred for 1h, then added methanol (200ml), extracted, several layers were washed twice with water, washed once with saturated sodium chloride, dried over anhydrous sodium sulfate, concentrated in vacuo to obtain a white solid, used Toluene (4:1) was recrystallized to obtain 20.4 g of white solid with a yield of 78.2%. Melting point: 105.8 ~ 106.7, MS (ESI...
Embodiment 2
[0030] Add glacial acetic acid (5ml, 7.88mmol, 1.1eq) to methyl p-hydroxybenzoate (1.19g, 7.8mmol, 1eq) in dichloromethane (45ml), stir until completely dissolved, cool to below 5°C in an ice bath, Liquid bromine (0.4ml, 7.88mmol, 1.1eq) was slowly added dropwise to the reaction mixture, and the temperature was controlled at 0-5°C during the dropwise addition. After the dropwise addition was completed, the reaction was carried out at room temperature for 35h, and the HBr tail gas was received during the reaction. After the reaction, Na was added to the reaction solution 2 S 2 o 3 (2.32g, 40ml) in aqueous solution (2.32g, 40ml), stirred for 1h, then added methanol (20ml), extracted, several layers were washed twice with water, once with saturated sodium chloride, dried over anhydrous sodium sulfate, concentrated in vacuo to obtain white or light yellow The solid was recrystallized from toluene (4:1) to obtain 1.24 g of a white solid with a yield of 77.5%. Melting point: 105....
Embodiment 3
[0032] Add glacial acetic acid (30ml, 0.0515mol, 1.1eq) into dichloromethane (180ml) of methyl p-hydroxybenzoate (7.14g, 0.0468mol, 1eq), stir until completely dissolved, cool to below 5°C in an ice bath, Liquid bromine (2.6ml, 0.0515mol, 1.1eq) was slowly added dropwise to the reaction mixture, and the temperature was controlled at 0-5°C during the dropwise addition. After the dropwise addition was completed, the reaction was carried out at room temperature for 24 hours, and the HBr tail gas was received during the reaction. After the reaction, Na was added to the reaction solution 2 S 2 o 3 Aqueous solution (27.8g, 264ml), stirred for 1h, then added methanol (120ml), extracted, several layers were washed twice with water, once with saturated sodium chloride, dried over anhydrous sodium sulfate, concentrated in vacuo to obtain white, washed with toluene (4:1) recrystallized to obtain 7.36 g of white solid, yield 73.4%. Melting point: 105.8~106.7, HPLC: 98.7%
PUM
Login to View More Abstract
Description
Claims
Application Information
Login to View More