24623-65-2

light yellow liquid

3-tert-Butyl-2-hydroxybenzaldehyde is used in preparation of coumarin derivative.

Triethylamine (8.35 mL, 60 mmol) was added dropwise to a stirred suspension of 2-tert-butylphenol (4.55 g, 30 mmol), magnesium chloride (5.71 g, 60 mmol) and paraformaldehyde (2.08 g, 66 mmol) in THF (120 mL) at room temperature. The reaction mixture was heated to reflux with continuous stirring for 3 h. An orange-colored suspension was obtained upon completion of the reaction. The crude product was extracted with EtOAc (3 x 50 mL). If a permanent emulsion is formed, a small amount of diluted HCl is added to break the emulsion. The organic layers were combined, dried with anhydrous MgSO4, filtered and concentrated under reduced pressure to give a light yellow oily product which did not require further purification. The product may gradually change to dark green color during storage. Yield: 90%. The product was a light yellow oil.1H-NMR (CDCl3, 300 MHz) δH: 1.44 (9H, s, 3×CH3), 6.97 (1H, t, J = 7.5 Hz, HAr), 7.41 (1H, dd, J = 1.5 Hz, J = 7.5 Hz, HAr), 7.54 (1H, dd, J = 1.2 Hz, J = 7.5 Hz, HAr), 9.88 (1H, s, CHO), 11.82 (1H, s, OH).

[1] Journal of Medicinal Chemistry, 2007, vol. 50, # 7, p. 1658 - 1667
[2] Advanced Synthesis and Catalysis, 2017, vol. 359, # 22, p. 3990 - 4001
[3] Patent: WO2008/132474, 2008, A1. Location in patent: Page/Page column 31
[4] Advanced Synthesis and Catalysis, 2009, vol. 351, # 9, p. 1325 - 1332
[5] Patent: WO2009/109765, 2009, A1. Location in patent: Page/Page column 27; 28