74684-38-1

74-88-4

1620-98-0

74684-38-1

General procedure for the synthesis of 3,5-di-tert-butyl-4-hydroxybenzaldehyde from 3,5-di-tert-butyl-4-methoxybenzaldehyde and iodomethane: (1) Sodium hydride (NaH, 1.27 g, 53 mmol) was slowly added to a solution of 3,5-di-tert-butyl-4-hydroxybenzaldehyde (5 g, 21 mmol) dissolved in anhydrous tetrahydrofuran (THF, 22.5 ml) under the protection of nitrogen gas, keeping the reaction temperature at 0 °C. After the reaction mixture was removed from the cooling bath, stirring was continued for 30 minutes. (2) Subsequently, methyl iodide (CH3I, 5.2 ml, 84 mmol) dissolved in anhydrous THF (9 ml) was added to the reaction mixture and the mixture was refluxed for 12 hours. (3) After completion of the reaction, the reaction was quenched with methanol (MeOH) and then extracted with dichloromethane (CH2Cl2). (4) The organic layers were combined, concentrated and purified by column chromatography using ethyl acetate: hexane = 1:7 as eluent. (5) The final yellow liquid product 3,5-di-tert-butyl-4-methoxybenzaldehyde (4.5 g, 87% yield) was obtained. 1H NMR (CDCl3,400MHz) δ 9.91 (s, 1H), 7.79 (s, 2H), 3.73 (s, 3H), 1.46 (s, 18H).