Question

Acetaminophen was reacted with K2CO3 and iodoethane to yield phenacetin. Would a similar reaction take place if cyclohexanol, K2CO3, and iodoethane were mixed together? Explain.

Answer 1

If cyclohexanol were used, no reaction (or very little reaction) will take place.

In acetominophen, the -OH group is a phenol, that is, it is directly attached to a benzene ring.

In cyclohexanol, the -OH group is just a simple alcohol.

Due to the presence of the benzene ring, the conjugate base of a phenol is resonance stabilized, so that a phenol is roughly a million times stronger acid than an ordinary alcohol.

In this reaction, we need to deprotonate the alcohol or phenol in order to alkylate it. However, potassium carbonate is NOT a strong enough base to deprotonate a typical alcohol. Of course, due to the increased reactivity of phenols, K2CO3 IS strong enough, so the reaction works with acetominophen.

Answer 2