last updated Thursday, February 16, 2006

Meeting #13

General Announcements

1. The next quiz will be administered on Thursday February 23, 2006 at 12 pm. It will cover esterification and electrophilic substitutions and drying of solvents.

2. Please look start lookin for a partner for the last project. Your partner should be in a different time slot than yourself e.g. if you are in T/R morning section, your partner should be in section in the T/R afternoon section or in the W/F afternoon section.

3. If possible both reactions (esterification and nitration) should be carried out in this lab. This will give you more time to recrystallize the final product and get better quality crystals.

Homework questions

1. Referring to the esterification part of the project

a. why is it important to dry the benzoic acid thoroughly prior using it in this step?

b. why is the reaction mixture refluxed?

c. why is water added after the reaction mixture cooled to room temperature?

d. why is sodium bicarbonate used in the work-up process? Show pertinent equations.

2. When performing electrophilic aromatic substitution reactions, the groups that are attached to the benzene play a very important role in the reaction in terms of directing effect and rate of the reaction. Classify the following groups accordingly and explain briefly.

a. ethoxy group

b. bromo

c. imine function via the carbon atom

d. neopentyl group