Synthesis
E. Synthesis of 3-bromo-6-methylanisole. 5.00 g (30.1 mmol) of 3-methoxy-4-methylbenzoic acid was dissolved in 40 mL of thionyl chloride and the reaction was stirred at room temperature for 3.5 days. After completion of the reaction, the solution was evaporated to dryness under vacuum. Using benzene as the azeotropic solvent, azeotropic distillation was performed to remove the residual thionyl chloride. Subsequently, the crude 3-methoxy-4-methylbenzoyl chloride obtained was dried under high vacuum for 4 hours. In another reaction flask, 4.80 g (33.1 mmol) of 1-hydroxypyridine-2-thione sodium salt was suspended in 180 mL of bromotrichloromethane, 5.56 g (33.1 mmol) of the above-dried crude 3-methoxy-4-methylbenzoyl chloride and about 500 mg of AIBN were added and dissolved in 120 mL of bromotrichloromethane. The reaction mixture was heated to reflux and stirred for 2 hours. At the end of the reaction, the mixture was filtered and the solids were washed with dichloromethane. The filtrate was concentrated under vacuum to give the crude product. The crude product was purified by fast column chromatography (silica gel, hexane solution of 6% ethyl acetate as eluent) to give 2.86 g (14.2 mmol, 47% yield) of 3-bromo-6-methyl anisole as a yellow oil.FDMS showed molecular ion peak m/z 200 (M+). Elemental analysis results (C8H9BrO): calculated value C 47.79, H 4.51; measured value C 47.50, H 4.36.
