Question

What happens when (Give chemical equations only): (i) n-butyl chloride reacts with alcoholic KOH?
(ii) Methyl iodide reacts with magnesium in presence of dry ether?
(iii) Methyl bromide reacts with sodium in presence of dry ether?
(iv) Methyl iodide reacts with KCN solution?
(v) Chlorobenzene reacts with aqueous NaOH?

Hint:

Alc. KOH causes elimination, Mg in ether gives Grignard reagents, Na gives Wurtz products, KCN gives nitriles, and chlorobenzene needs drastic conditions for nucleophilic substitution.

Answer 1

(i) n-Butyl chloride + alc. KOH.
Dehydrohalogenation occurs, giving 1-butene: \[ C_4H_9Cl + alc. KOH \rightarrow C_4H_8 + HCl \] (ii) Methyl iodide + Mg (dry ether).
Grignard reagent formation: \[ CH_3I + Mg \rightarrow CH_3MgI \] (iii) Methyl bromide + Na (dry ether).
Wurtz reaction gives ethane: \[ 2CH_3Br + 2Na \rightarrow C_2H_6 + 2NaBr \] (iv) Methyl iodide + KCN.
Forms methyl cyanide: \[ CH_3I + KCN \rightarrow CH_3CN + KI \] (v) Chlorobenzene + aq. NaOH.
At high temp. and pressure forms phenol: \[ C_6H_5Cl + NaOH \, (300^\circ C, 200 \, atm) \rightarrow C_6H_5OH + NaCl \]