The chemistry of pyrrolic compounds. XLV. Haematoporphyrin derivative: haematoporphyrin diacetate as the main product of the reaction of haematoporphyrin with a mixture of acetic and sulfuric acids

A mixture of acetic and sulfuric acids converts haematoporphyrin into a complex mixture of porphyrins of which the main product has been characterized as the diacetate (1g). Other compounds identified in the reaction mixture were the known vinylporphyrins (1b-d), (1h) and (li) and the isomeric monoacetoxyethyl(monohydroxyethyl)porphyrins (11) and (1m). Analysis of the reaction mixture was complicated by the presence of 1'-ethoxyethyl derivatives (1e) or (1f), (1j) and (1k)which presumably arose by solvolysis of the corresponding acetate with ethanol present in the chloroform used for the chromatographic separation.