PROTONATION OF THE ELECTRON ADDUCTS OF PYRIMIDINE-DERIVATIVES

被引:0
作者
OHKURA, K [1 ]
SEKI, K [1 ]
机构
[1] HLTH SCI UNIV HOKKAIDO, FAC PHARMACEUT SCI, ISHIKARI, HOKKAIDO 06102, JAPAN
关键词
ACID-CATALYZED PHOTOREACTION; 5-SUBSTITUTED 1,3-DIMETHYLURACIL; ELECTRON ADDUCT; O(4)-PROTONATION; C(6)-PROTONATION;
D O I
暂无
中图分类号
R914 [药物化学];
学科分类号
100701 ;
摘要
Photolyses of 5-substituted 1,3-dimethyluracils (1a-e: a, R = F; b, R = Cl; c, R = H; d, R = CH3; e, R =p-xylyl) in p-xylene in the presence of trifluoroacetic acid (TFA) afforded 5,6-dihydro-1,3-dimethyl-6-p-methylbenzyluracils (3a-d), 5,6-dihydro-1,3-dimethyl-5-p-methylbenzyluracils (4a-e), and 5,6-dihydro-1,3-dimethyluracils (5a-e) in varying ratios. It is suggested that the 6-isomers (3) are derived from the O(4)-protonated electron adducts of 1, while 4 and 5 are the products from the C(6)-protonated electron adducts. The ratio of(4+5),Is. 3 depends on the ionization potentials of the O(4)-protonated intermediates. The formation of 4+5 increases with increasing concentration of TFA.
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页码:1024 / 1027
页数:4
相关论文
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