SolutionsPreparation
1. Reagents
Give the reagent to obtain from benzoic acid: a) benzoyl chloride; b) benzoyl bromide. What is the advantage of SOCl2?
- SOCl2 (also PCl5 or oxalyl chloride).
- PBr3.
With SOCl2 the by-products, SO2 and HCl, are gases and leave the reaction mixture by themselves.
2. Fluorides
How is an acid fluoride prepared, and why is it not made directly from the acid?
By exchange, treating the acid chloride (or an anhydride) with HF. Fluoride is a poor leaving group and F− does not displace the OH of the acid.