Alkylation Of 1 4-Dimethoxybenzene Lab Report

The alkylation of 1,4-dimethoxybenzene is very favorable because of the presence of two methoxy groups. The groups act as activators to electrophilic aromatic substitution because of their ability to donate electrons through resonance. This enhanced activation helps favor the initial substitution. After this, the ring has two methoxy groups and an alkyl group attached to it. The addition of the alkyl group further activate the ring for another electrophilic aromatic substitution. The addition of a second alkyl group must attach on the opposite side of the ring from the other alkyl group. This results in the less sterically hindered product possible. Although more substitutions maybe be theoretically possible, they will not occur because the possible attachment sites are too streakily hindered1.
This indicates the presence of impurities in the solid product. These impurities could be leftover reagents that never reacted or leftover methanol that was not dried out. The presence of these molecule most likely lowered and broadened the melting point range. Similarly, the percent yield of 49.4% is not a very high and productive value. The mediocre yield could have resulted from many mistakes made during the procedure. For example, some solid was not removed from the Erlenmeyer flask because it was impossible to reach with a stir rod. Also, some product stuck to the stir rod and was not rinsed into the funnel. If the stir rod was rinsed and more product retrieved from the Erlenmeyer, the percent yield would have been much