Synthesis
General procedure: Alkylation reaction of 2,3,5-trimethylphenol using dimethyl carbonate. The specific operation was as follows: 3 mmol of Mn2(CO)10, W(CO)6 or Co2(CO)8 catalyst, 100 mmol of 2,3,5-trimethylphenol, and 300 mmol of dimethyl carbonate were sequentially added to a 17 mL stainless steel high-pressure micro reactor. After sealing the reactor, it was heated at 180°C for 1 hour. Upon completion of the reaction, the reactor was cooled to room temperature and opened, and the reaction mixture was filtered through an alumina layer. Subsequently, the unreacted dimethyl carbonate was removed by distillation, and the residue was distilled under atmospheric or reduced pressure conditions or recrystallized using ethanol to give 1-methoxy-2,3,5-trimethylbenzene. The compound was obtained in 99% yield with a boiling point of 84.5-85 °C (7 mmHg).13C NMR data were as follows (δC, ppm): 11.60, 20.03, 21.38 (CH3); 110.52 (C6), 119.95 (C2), 124.92 (C4), 137.32 (C3), 137.54 (C5). 157.43 (C1). Elemental analysis results: measured value (%): C 79.87; H 9.35. Calculated value (%) for molecular formula C10H14O: C 79.96; H 9.39.
References
[1] Russian Journal of Organic Chemistry, 2015, vol. 51, # 3, p. 330 - 334
[2] Methylation of Phenol and Its Derivatives with Dimethyl Carbonate in the Presence of Mn2(CO)10, W(CO)6, and Co2(CO)8, 2015, vol. 51, # 3, p. 330 - 334,5
