尿酸及びXanthine誘導体のMurexide反応

概要

論文の詳細を見る
The murexide reactions of uric acid and other xanthine derivatives were investigated to clarify the pathways of the coloration. From the reaction mixture of uric acid with nitric acid, alloxan (3) and parabanic acid (4) were isolated. Alloxan was found to be a key intermediate, since it was converted to a purple colored murexide by treatment with conc. ammonia. From the murexide reaction of theophylline, 3-hydroxy-4,6-dimetyloxazolo[4,5-d]pyrimidine-2,5,7(3H, 4H, 6H)-trione (1) and 1,3-dimethylalloxan (2) were isolated, and these compounds were converted to the purple colored murexoin with conc. ammonia. From the murexide reactions of theobromine and xanthine, 5[(hexahydro-1-methyl-2,4,6-trioxo-5-pyrimidinyl)imino]-1-methyl-2,4,6(1H, 3H, 5H)-pyrimidinetrione monoammonium salt (5) and murexide were obtained as colored substances, respectively, but an attempt to isolate intermediates was unsuccessful. Murexide and 5 were found to occur in the anion delocalized structure in solution from the nuclear magnetic resonance spectral data.
1988-09-25