Question

Draw the structures of major products: (a) Chlorobenzene + $CH_3Cl$ / Na, dry ether
(b) p-Hydroxyphenethyl alcohol + HBr

Hint:

Wurtz-Fittig: ArX + RX + 2Na ? Ar-R + 2NaX. In (b), alcoholic $-$OH reacts with HBr but phenolic $-$OH does not under mild conditions.

Answer 1

Step 1: Concept
(a) This is the Wurtz-Fittig reaction, used for synthesis of alkylbenzenes. (b) HBr reacts with the $-$OH group of the primary alcohol.

Step 2: Analysis (a)
Chlorobenzene reacts with $CH_3Cl$ in the presence of sodium metal and dry ether. The aryl halide and alkyl halide couple together by losing both halogen atoms (as NaCl). The aryl carbon and alkyl carbon are joined directly. Product: Toluene ($C_6H_5-CH_3$).

Step 3: Analysis (b)
p-Hydroxyphenethyl alcohol is $HO-C_6H_4-CH_2CH_2OH$. When treated with HBr, the alcoholic primary $-$OH undergoes substitution (the phenolic $-$OH does not react under these mild conditions since phenols are less reactive toward HBr). Product: p-Hydroxyphenethyl bromide, i.e., $HO-C_6H_4-CH_2CH_2Br$.

Final Answer:
(a) Toluene: $C_6H_5-CH_3$
(b) p-Hydroxyphenethyl bromide: $HO-C_6H_4-CH_2CH_2Br$