Question

What happens when (Write chemical equation only):
(i) Silver propionate reacts with Br$_2$ in CCl$_4$:
(ii) Bromobenzene reacts with Mg in the presence of dry ether:
(iii) Methyl bromide reacts with KCN (alc.):
(iv) Ethyl bromide is heated with sodium ethoxide:
(v) Ethyl bromide reacts with silver acetate:

Hint:

- Hunsdiecker reaction: silver salt of acid + halogen → alkyl halide + CO$_2$.
- Grignard reagent: ArX + Mg (dry ether) → ArMgX.
- $KCN$ gives alkyl cyanides; $AgCN$ would give isocyanides.
- $NaOEt$ (alc.) promotes $\beta$-elimination to form alkenes.
- Silver acetate replaces halogen with $-OCOCH_3$ group.

Answer 1

(i) Silver propionate reacts with Br$_2$ in CCl$_4$:
(Hunsdiecker reaction)
\[ C_2H_5COOAg + Br_2 \xrightarrow{CCl_4,\;\Delta} C_2H_5Br + CO_2 + AgBr \]
(ii) Bromobenzene reacts with Mg in the presence of dry ether:
(Grignard reagent formation)
\[ C_6H_5Br + Mg \xrightarrow{dry\ ether} C_6H_5MgBr \]
(iii) Methyl bromide reacts with KCN (alc.):
\[ CH_3Br + KCN \longrightarrow CH_3CN + KBr \]
(iv) Ethyl bromide is heated with sodium ethoxide:
(Dehydrohalogenation – elimination, gives ethene)
\[ CH_3CH_2Br + C_2H_5ONa \xrightarrow{\Delta} CH_2=CH_2 + NaBr + C_2H_5OH \]
(v) Ethyl bromide reacts with silver acetate:
\[ CH_3CH_2Br + CH_3COOAg \longrightarrow CH_3CH_2OCOCH_3 + AgBr \]
(Product: ethyl acetate)