Photoinitiators with functional groups 9: New derivatives of covalently benzophenone-amine based photoinitiators

摘要

This paper describes the synthesis of a number of benzophenone derivatives in which the 4 position carries a chain linking the ketone to an aromatic amino acid or one of its derivatives. In a typical synthetic route, 4-bromomethylbenzophenone was reacted with N-phenylglycine, and the ethyl ester of N-phenyl glycine to yield a substituted amino acid derivative. In the case of the amino acid, it was anticipated, on the basis of earlier work, that excitation of the benzophenone would bring about electron transfer between the amino acid and the ketone leading to decarboxylation, which in turn produces a carbon-centred radical (an aminomethyl radical) capable of initiating polymerisation.