24677-78-9

light yellow to beige-greenish cryst. powder

2,3-disubstituted benzaldehyde.

ChEBI: 2,3-dihydroxybenzaldehyde is a dihydroxybenzaldehyde.

The general procedure for the synthesis of 2,3-dihydroxybenzaldehyde from o-vanillin was as follows: acetonitrile (40 ml) was added to a 100 ml aubergine flask, followed by sequential addition of aluminum trichloride (0.752 g, 5.64 mmol, 1.1 equiv), sodium iodide (2.305 g, 15.38 mmol, 3.0 equiv) and o-vanillin (0.780 g, 5.13 mmol). The reaction mixture was heated to 80 °C and the reaction was stirred for 18 hours. After completion of the reaction, the heating was stopped and cooled to room temperature. The reaction solution was acidified with 2 mol/L dilute hydrochloric acid (10 ml) and subsequently extracted with ethyl acetate (50 ml x 3). The organic phases were combined and washed sequentially with saturated aqueous sodium thiosulfate (10 ml) and saturated brine (10 ml). The organic phase was dried with anhydrous magnesium sulfate, filtered and concentrated under reduced pressure. Purification by column chromatography afforded 2,3-dihydroxybenzaldehyde (0.620 g, yellow solid, 87% yield).

Crystallise the aldehyde from water. [Beilstein 8 III 1979.]

[1] Patent: CN108821955, 2018, A. Location in patent: Paragraph 0021; 0022; 0025; 0026
[2] Patent: CN108178753, 2018, A. Location in patent: Paragraph 0023-0025
[3] Journal of the American Chemical Society, 2007, vol. 129, # 45, p. 13808 - 13809
[4] Patent: CN106699722, 2017, A. Location in patent: Paragraph 0050-0052
[5] Patent: CN107840845, 2018, A. Location in patent: Paragraph 0179; 0180; 0181; 0182