Identify the reaction that converts CH_3CN to CH_3-CH_2-NH_2 .

The conversion of an alkyl cyanide (nitrile) to a primary amine by reduction is known as the Mendius reduction.

$\text{CH}_3\text{CN} + 4[\text{H}] \xrightarrow{\text{Na/C}_2\text{H}_5\text{OH}} \text{CH}_3\text{CH}_2\text{NH}_2$

Hoffmann reduction is used for converting amides to primary amines with one less carbon atom.

Clemmensen reduction is used for reducing aldehydes and ketones to alkanes.

Rosenmund reduction is used for reducing acid chlorides to aldehydes.

Answer: Mendius reduction