Synthesis of Mesodiphenylhelianthrene from 1-Aminoanthraquinone and the Structural Elucidation of Its Endoperoxide Species after Irradiation.

A safe, five-step synthetic route to yield the reliable chemical actinometer, mesodiphenylhelianthrene ( MDH ), is reported from a commercially available compound. Full characterization of the intermediates of the synthetic route and the final product MDH are presented together with four crystal structures of intermediates and MDH . The usage of the actinometer is described, and finally, the structure of the endoperoxide species ( MDHPO ), which is formed after irradiation of MDH , has been elucidated experimentally and theoretically.