Question

Question: Draw the products formed when benzoyl anhydride is treated with each nucleophile: (a)H₂O , pyridine; (b) . CH₃OH ; (c) NH₃ (excess); (d) (CH₃)₂NH (excess).

Short answer

Answer

a. H₂O

b. CH₃OH

c. NH₃ excess

d. (CH₃)₂NH

Step-by-step solution

Step-by-Step Solution Step 1: Acid anhydrides

• Acid anhydride has the general formula: $\mathbf{RC}\left(=O\right)\mathbf{OC}\left(=O\right)\mathbf{R}$ .

• The molecule contains two carbonyl groups; one carbonyl group is attacked by the nucleophile and the second carbonyl becomes a part of the leaving group.

Reaction of benzoic anhydride with the nucleophile

a. H₂O

Anhydride undergoes hydrolysis to form carboxylic acids in the presence of water.

b. CH₃OH

Benzoic anhydride reacts with to form an ester and carboxylic acid.

c. NH₃ excess

Benzoic acid reacts with (excess) to form an amide with an ammonium salt as a byproduct.

d. (CH₃)₂NH

Benzoic acid reacts with (excess) to form an amide with an ammonium salt as a byproduct