Question

An alkyl halide reacted with a metal cyanide to give an alkanenitrile. The metal cyanide is

• A. $AgCN$
• B. $KCN$
• C. $C{u}_2(CN{)}_2$
• D. All of the above

Answer 1

The correct option is B $KCN$

Cyanide ion $\left(C{N}^{-}\right)$ is the ambident nucleophile and can form different product with same substrate.

$RX+KCN\to \underset{nitrile}{RCN}+KX$

Here, $KCN$ is predominantly ionic and exist as free ions in solution. C site is more nucleophilic than N site and available to attack the alkyl halide​. Hence, the major product will be nitrile.