Abstract Irradiation of the 2 (1H)-pyrimidinones 1 in alcohols such as 2-propanol and ethanol afforded the 1-(alkoxycarbonylamino)-3-(arylimino)-1-propenes 4a–c, h and 2- (alkoxycarbonylamino)-4-(arylimino)-2-pentenes 4d–g. These photoproducts are formed by trapping the isocyanate intermediates 2, generated initially by the Norrish-type I cleavage of the ArN—CO bond of the 2 (1H)-pyrimidinones, with the alcohol.
![isopropyl [4-(phenylimino)-2-pentenyl]carbamate Structure](https://image.chemsrc.com/caspic/434/136984-72-0.png)
![4,6-dimethyl-3-phenyl-1,3-diazabicyclo[2.2.0]hex-5-en-2-one Structure](https://image.chemsrc.com/caspic/423/68230-25-1.png)