Propose a mechanism for the hydrolysis of N,N-dimethylacetamide (a) under basic conditions.

Verified step by step guidance

1. Step 1: Deprotonation of water by the base to form hydroxide ion (OH⁻).
2. Step 2: Nucleophilic attack of the hydroxide ion on the carbonyl carbon of N,N-dimethylacetamide, forming a tetrahedral intermediate.
3. Step 3: Collapse of the tetrahedral intermediate, leading to the expulsion of the dimethylamine group (NMe₂).
4. Step 4: Protonation of the expelled dimethylamine group by water, forming dimethylamine (NMe₂H).
5. Step 5: Formation of acetic acid (CH₃COOH) as the final product after the intermediate collapses.

Key Concepts

Hydrolysis Mechanism

Hydrolysis is a chemical reaction involving the breaking of a bond in a molecule using water. In the case of amides like N,N-dimethylacetamide, hydrolysis typically involves the nucleophilic attack of water on the carbonyl carbon, leading to the formation of a carboxylic acid and an amine. Understanding the mechanism is crucial for predicting the products and the steps involved in the reaction.

Basic Conditions

Basic conditions refer to an environment where a base, such as hydroxide ions (OH-), is present. In the hydrolysis of amides under basic conditions, the base can deprotonate water to generate hydroxide ions, which act as strong nucleophiles. This enhances the nucleophilic attack on the carbonyl carbon, facilitating the hydrolysis process more efficiently than under neutral or acidic conditions.

Nucleophilic Attack

Nucleophilic attack is a fundamental concept in organic chemistry where a nucleophile, a species with a pair of electrons, attacks an electrophile, a positively polarized atom. In the hydrolysis of N,N-dimethylacetamide, the hydroxide ion acts as the nucleophile, attacking the electrophilic carbonyl carbon. This step is critical in forming the tetrahedral intermediate, which eventually leads to the cleavage of the C-N bond and the formation of the hydrolysis products.