3-bromo-4-chloro-2-hydroxybenzaldehyde synthesis

Yield:872274-09-4 97%

Reaction Conditions:

with triethylamine;magnesium chloride in tetrahydrofuran at 90; for 12 h;Temperature;

Steps:

1.1 (1) Preparation of 3-bromo-4-chloro-2-hydroxybenzaldehyde

To a 500 mL three-necked flask was added tetrahydrofuran (250 mL), and anhydrous MgCl2 (9.2 g) was added under stirring.(96 mmol, 2 eq) and paraformaldehyde (4.3 g, 144 mmol, 3 eq), then triethylamine (9.7 g, 96 mmol, 2 eq) was added dropwise to the mixed suspension, and the mixture was stirred at room temperature for half an hour. To this was added 2-bromo-3-chlorophenol (10.0 g, 48 mmol, leq), and the temperature was raised to 90 °C. After stirring for 12 hours, the reaction solution was cooled to room temperature and diluted with 200 mL of water. Methyl tert-butyl ether was used for dilution. (100 mL) was extracted 3 times, and the layers were separated, and the organic layers were combined, washed once with 1 mol/L diluted hydrochloric acid, saturated sodium bicarbonate, and saturated brine, dried over anhydrous sodium sulfate, filtered, and concentrated to give 11 g of a yellow solid. Yield 97%, HPLC purity 98%.

References:

CN107011280,2017,A Location in patent:Paragraph 0017; 0018; 0028; 0036