ChemicalBook CAS DataBase List 2-Hydroxyphenylboronic acid

2-Hydroxyphenylboronic acid synthesis

15synthesis methods

Product Name:2-Hydroxyphenylboronic acid
CAS Number:89466-08-0
Molecular formula:C6H7BO3
Molecular Weight:137.93

1034050-50-4

89466-08-0

General procedure for the synthesis of 2-hydroxyphenylboronic acid from 2-methoxyphenylboronic acid: 1.5 kg of 2-methoxyphenylboronic acid was added to a 30 L glass reactor under nitrogen protection, followed by 18 L of anisole and 1.56 kg of acetyl chloride. After the addition was completed, the reaction mixture was cooled to -10 to 0 °C and stirred at this temperature for 1 hour. Then, 133 g of anhydrous aluminum trichloride was added in batches. After the addition was completed, the reaction mixture was allowed to warm up naturally to room temperature and stirred continuously until the TLC detection showed that the reaction of the raw material was complete, a process that usually takes 8 to 10 hours. During the reaction, the solids in the reaction mixture were first gradually dissolved, followed by gradual precipitation of solids. Upon completion of the reaction, the reaction was quenched with 5 M aqueous potassium hydroxide and the pH was adjusted to 11 to 12. The organic layer was separated and discarded. The pH was adjusted to 2~3 by adding 6 M aqueous hydrochloric acid to the aqueous layer and then extracted twice with 12 L ethyl acetate, the organic layers were combined and washed with saturated brine. The organic layer was rotary evaporated to dryness and finally pulped with acetone/n-heptane to give 1.06 kg of 2-hydroxyphenylboronic acid in 77% yield and 98.6% HPLC purity.

5720-06-9 Synthesis

5720-06-9
361 suppliers
$5.00/1g

89466-08-0
329 suppliers
$5.00/1g

Yield:89466-08-0 92%

Reaction Conditions:

Stage #1:2-Methoxyphenylboronic acid with aluminum (III) chloride;acetyl chloride in toluene at 10 - 100; for 3.75 h;Large scale;
Stage #2: with hydrogenchloride in water; pH=4Large scale;

Steps:

3; 2
Use a vacuum pump to vacuum the reactor to -0.1Mpa, lower the temperature of the reactor to 10, add 1.52kg (10mol) o-methoxyphenylboronic acid, 1.57kg (20mol) acetyl chloride, and 12L toluene into the reactor and mix Stir until it is uniform, then add 2mol aluminum chloride, increase the temperature by 10 every 15 minutes during the reaction, until the temperature reaches 100, and then react at a constant temperature for 1.5h (the methyl chloride gas generated during the reaction is removed to the recovery system by vacuum ) To obtain the intermediate compound, add sodium carbonate solution to adjust the pH of the system to 10 to obtain an aqueous layer, continue to use hydrochloric acid to adjust the aqueous layer to pH 4, extract with ethyl acetate, collect the organic layer, concentrate, and re-weight with n-hexane Crystallized to obtain 1.27 kg of o-hydroxyphenylboronic acid, with a yield of 92% and a purity of 99.3%.

References:

Business Hezhiji New Materials Technology Center;Lu Zhengxiang CN112047970, 2020, A Location in patent:Paragraph 0042-0043; 0048-0049

FullText

213211-69-9 Synthesis