1: With oxygen; 5,15,10,20-tetraphenylporphyrin in dichloromethane T=-60°C; 3 h; Irradiation; 2: With 4-phenyl-3,5-dioxo-1,2,4-triazolidine in dichloromethane T=20°C;

oxygen; 5,15,10,20-tetraphenylporphyrin in dichloromethane T=-60°C; 3 h; Irradiation; Further byproducts given. Title compound not separated from byproducts;

oxygen Irradiation;