Question

These question are for the Friedel Crafts Alkylation of 1,4-Dimethoxybenzene organic chem lab

1. Why is 1,4-di-t-butyl-2,5-dimethoxybenzene the preferred product of this reaction? Why is neither 1,2-di-t-butyl-3,6-dimethoxybenzene nor 1,3-di-t-butyl-3,6-dimethoxybenzene formed as side products? OCH3 OCH3 OCH3 OCH3 1,2-di-t-butyl-3,6-dimethoxybenzene 1,3-di-t-butyl-3,6-dimethoxybenzene 2. 3. 4. Why was the product washed with water? Why was the product washed with methanol? We used t-butyl alcohol to generate t-butyl cation. Suggest two other compounds that could be used to generate the t-butyl cation.

Answer 1

1. Methoxy group is an activating ortho para director. This will result in the formation of only 1,4-di-t-butyl-2,5-dimethoxybenzene.

2. Washing with water helps in removal of sulfuric acid, acetic acid and t-butanol present in the product.

3. Washing with methanol helps in removal od any organic matter present in the product along with excess water.