1,3,5-Trimethoxybenzene can be prepared from 1,3,5-tribromide benzene and sodium methanol in reactions catalyzed by cuprous chloride and methyl formate. It reacts with N-bromosuccinimide in carbon tetrachloride to give 2-bromo-1,3,5-trimethoxybenzene. It can be used as an internal standard of the NMR hydrogen spectrum.
One of synthetic method of 1,3,5-trimethoxybenzene as bellow:
1、 Mix 95% ethanol and benzene with 2,4,6-tribromobenzene, heat and dissolve; gradually add concentrated sulfuric acid for 1-2 hours, stir, maintain the temperature at 50-60 degrees Celsius; then add NaNO2 in batches, boil for 2-3 hours; cool, filter, wash to neutral, dry to get solid 1,3,5-tribromobenzene.
2、mix 10g sodium metal and 80ml methanol sodium methanol solution, then add 80ml dimethylformamide, 2gCu2I2 and 20g1,3,5-tribromobenzene, heating to 90 degrees Celsius, stirring reflux reaction for 3 hours, filtration, filtrate pressure steam methanol and dimethyl formamide, steam with steam distillation, the distillation cooling crystallization, filtration, drying, namely 1,3,5-trimethoxybenzene.
