On Some p-Substituted Benzoic Anhydrides

Abstract

Some p-substituted benzoic anhydrides were prepared from corresponding p-substituted benzoic acid and acetic anhydride by the ordinary method. p-Chlorobenzoic anhydride (mp 190 -2°C)was obtained in almost quantitative yield and p-nitrobenzoic anhydride (mp 191 -2°C)， in 71% yield. p-Acetoxybenzoic anhydride (mp 78 -80°C) which has not been reported in the literature，was also synthesized as the above，by the reaction of p-acetoxybenzoic acid or p-oxybenzoic acid with acetic anhydride，but recrystalisation of the product was difficult. In order to confirm the formation of p-acetoxybenzoic anhydride accordingly， it was converted into p-oxybenzamide by warming with 28% aqueous ammonia or into p-acetoxybenzoic acid methyl ester by heating with methanol