Determination of organic hydroxyl and amino compounds with o-sulphobenzoic anhydride

The determination of alcoholic hydroxyl groups by acylation with o-sulphobenzoic anhydride in dioxane medium is proposed. Quantitative esterification was generally obtained by refluxing for 2–3 h. No interferences were found from water, aldehydes, ketoncs, ethers, esters and phenols ; the reagent appeared to be of the phthalic anhydride type. Results for 26 hydroxyl and some amino compounds by the proposed reagent are given.