136738-87-9Relevant academic research and scientific papers
Protonation of the electron adducts of pyrimidine derivatives
Ohkura,Seki
, p. 1024 - 1027 (2007/10/03)
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) vs. 3 depends on the ionization potentials of the O(4)-protonated intermediates. The formation of 4 + 5 increases with increasing concentration of TFA.
ACID CATALYZED PHOTOREACTION OF 5-CHLORO-1,3-DIMETHYLURACIL WITH SUBSTITUTED BENZENES
Ohkura, Kazue,Matsuda, Kohki,Seki, Koh-ichi
, p. 1371 - 1376 (2007/10/02)
The photo-induced substitution of 5-chloro-1,3-dimethyluracil with substituted benzenes, affording the corresponding 5-aryl-1,3-dimethyl-uracils in appreciable yields, was significantly promoted by the addition of trifluoroacetic acid to the reaction mixture.
