Question

At high temprature phenyl Acetate on reaction
with Alcl3 gives ortho. acyl Phenol as a mejor
product explain.​

Answer 1

At high temprature phenyl Acetate on reaction

At high temprature phenyl Acetate on reactionwith Alcl3 gives ortho acyl Phenol as a major

ves ortho acyl Phenol as a major product -

• This reaction can be explained by the fries rearrangement.

• In the first step, the Lewis acid AlCl3 will attack on the carbonyl oxygen atom of the acetate grp as it more electron rich oxygen than that of phenolic group.

• Due to this there is polarization is developed between the bonds of acyl residue and phenolic oxygen atom , so the AlCl3 rearranges to the phenolic group and thus , creates acylium carbocation .

• This generated acylium carbocation then show the electrophilic substitution reaction with the aromatic ring.

• Now, at the high temperature (>370K) ortho product will be major due to ortho product form stable bidentate complex with the Aluminium , aslo it formation favours in case of non polar solvents , as polarity increases the para product ratio.