Freidal Crafts Alkylation Reaction

Friedel Crafts Alkylation Reaction

Introduction: In the experiment we will create 1,4-Di-t-Butyl-2,5-Dimethoxybenzene by performing a Friedel-Crafts reaction on 1,4-Dimethoxybenzene. In the reaction a t-butyl carbocation will be added on to the 1,4-Dimethoxybenzene. The t-butyl carbocation will be formed by a reaction of t-butyl alcohol with sulfuric acid. To perform the reaction we will create a mixture of the 1,4-Dimethoxybenzene, t-butyl alcohol with acetic acid. To this mixture we will add sulfuric acid dropwise through a separation funnel. We will then add this mixture to some crushed ice and water to precipitate the product. We will then filter the product, recrystallize the product, and then filter it again. After we have a product, we will record the weight and the melting point.

Table of Reagents: Mol. Wt. Mp. density

1,4-Dimethoxybenzene 138.17 g 57 °C

t-Butyl alcohol 74.12 g .79 g/ml

Sulfuric Acid 98.08 g 1.84 g/ml

Methanol 32.05 g

Ethanol 46.08 g

1,4-Di-t-butyl-2,5-dimethyloxybenzene 250.37 g 104-105 °C

Safety Information:

Use caution with the sulfuric acid as it is corrosive and can cause severe burns. Keep heat and flames away from the methanol and ethanol, as both are flammable. Dispose of all wastes in the proper containers. Dispose of all broken glass in the broken glass container. Wear gloves and goggles the entire time in the lab for safety.

Procedure:

1. Obtain 3 g of 1,4-dimethoxybenzene, 5 mL of t-butyl alcohol, and 10 ml of acetic acid and place all in a 125 ml flask, and cool the