What will be the product of the following reaction:
C6H5ONa + C2H5Cl → ?
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → C6H5OC2H5
This is the Williamson synthesis: an alkyl halide reacts with a sodium alkoxide or phenoxide. The phenoxide ion attacks the ethyl carbon (SN2) and displaces chloride:
\( \displaystyle \ce{C6H5ONa + C2H5Cl -> C6H5OC2H5 + NaCl} \)
The product is ethoxybenzene (phenetole), an aryl alkyl ether.
Why the other options are incorrect
Option (1) C6H5COC2H5 — Incorrect. Propiophenone, a ketone; making it needs a C–C bond (Friedel–Crafts acylation), not an O–C bond.
Option (3) C6H5OC2H4Cl — Incorrect. Chlorine leaves as NaCl and does not stay in the product.
Option (4) C2H5OC2H5 — Incorrect. Diethyl ether needs sodium ethoxide; here the oxygen comes from phenoxide, so the phenyl group stays in the ether.
NCERT (2026-27 edition):
Williamson Synthesis – “It is an important laboratory method for the preparation of symmetrical and unsymmetrical ethers. In this method, an alkyl halide is allowed to react with sodium alkoxide.”
\( \displaystyle \ce{R-X + R'-ONa -> R-O-R' + NaX} \)
“… Phenols are also converted to ethers by this method. In this, phenol is used as the phenoxide moiety.”