Photochemistry of pyrimidin-2(1H)-ones: intermolecular hydrogen abstraction by an imino group nitrogen
作者:Takehiko Nishio、Yoshimori Omote
DOI:10.1039/p19880000957
日期:——
6-diarylpyrimidin-2(1H)-ones (1a–c) in the presence of hydrogen donors such as acyclic or cyclic ethers (2a–d), sulphides (2e–g), and xanthene (2h) gave the C–C bonded 1:1 adducts (3)–(16) of (1) and (2), via intermolecular hydrogen atom abstraction of the excited imino nitrogen of the starting pyrimidin-2(1H)-one (1). In contrast, irradiation of 1-aryl-4,6-dialkylpyrimidin-2(1H)-one (1d) in the presence
Irradiation of 1-methyl-4,6-diphenylpyrimidin-2(1H)-one (1a) in acyclic or cyclic ethers afforded the C–C bonded 1:1-adducts (2a–c) of 1a and ether via intermolecular hydrogen abstraction of the excited imino nitrogen of 1a, while irradiation of 1-phenyl-4-(3-ethoxypropyl)-6-methylpyrimidin-2 (1H)-one (1g) gave 1-phenyl-4,6-dimethylpyrimidin-2(1H)-one (1d) via intramolecular hydrogen abstraction of
The photochemicalreactions of 1-arylpyrimidin-2(1H)-ones have been examined. Irradiation of the 1-arylpyrimidin-2(1H)-ones (3a–f) in benzene–methanol gave 1-alkoxycarbonylamino-3-aryliminoprop-1-enes (4), (6), and (7), which were hydrolysed to give the corresponding 3-alkoxycarbonylaminoprop-2-enal (5), in 45–55% yield. The formation of the N-arylimine products (4), (6), and (7) was presumed to arise