Acid-Catalyzed Photoreaction of 6-Chloro-1, 3-Dimethyluracil and Mesitylene: Formation of Photocycloadducts and Their Characterization¹⁾

Abstract

In contrast to the previously reported short time required (1 h) for photolysis of 6-chloro-1, 3-dimethyluracil (6-CIDMU) and mesitylene, in the presence of TFA, resulting in two major products: 1, 3, 6, 8, 10-pentamethyl-cyclooctapyrimidine derivative (1d), and diazapentacyclo[6.4.0.0^{1, 3}.0^{2, 5}.0^{4, 8}]dodecane (2c), prolonged irradiation (18 h) of this same mixture yields novel pentalenopyrimidine derivatives, including diazapentacyclo[6.4.0.0^{1, 3}.0^{2, 6}.0^{4, 8}]dodecane (3c).