THE PREPARATION OF N-ACYLPYRAZOLES AND THEIR BEHAVIOR TOWARD ALCOHOLS

According to four different methods, various types of N-acylpyrazoles were prepared from the corresponding pyrazoles and carboxylic acids or their acid chlorides. Although N-acylpyrazoles were inert to alcohols under neutral or weakly basic conditions, the alcoholysis was dramati cally accelerated by the action of strong acid or base. On the basis o f these chemical properties, the regioselective synthesis of methyl be nzyl 2,2-dimethylglutarate was achieved by selective protection and fu nctionalization of a carboxylic acid derivative using N-acylpyrazoles.