Prof. Dr. Helmut Quasit and Dipl.-Chem. Andreas Fuss
The photolysis of 1-pyrazolines of type(1) holds numerous surprises. Thus, irradiation of (1), X = O, in deuterated benzene, cyclohexane or acctonitrile (1a) gave without filter the products (3) and (4), whose ratio depends on the conditions. (2a) could be trapped with CD3OD. When X = S in (1), only (5) is formed.