Acetic anhydride

The thiol acetic acid and acetic anhydride both has been used for nucleophilic acyl substitution of phenols in two different methods. Both methods are simple and inexpensive by using aqueous NaOH base with acetic anhydride and no catalyst required for thiol acetic acid reaction. This can be a key method for identification of phenolic functional groups.

Ring acylations of aromatic substances are very difficult to achieve to a great extent. Nencki reaction has attempted on mono to poly hydroxy and substituted phenols have good results. Reactions are using solely acetic acid, acetic anhydride and adipic acid or mixture of acid and anhydride resulting complete consumption of phenols. The use Lewis acid freshly fused ZnCl2 is best suitable catalyst compare to others. The essential data on phenols acylation has been studied and described as below.