GUANINE, HYPOXANTHINE, AND XANTHINE ANALOGS - SYNTHESIS OF IMIDAZO[1,5-A]-1,3,5-TRIAZINONES VIA REARRANGEMENT

Syntheses of substituted imidazo[l, 5-α]-l, 3, 5-triazinones, which are analogues of N(9)-substituted guanines, hypoxanthines, and xanthines, have been accomplished by cyclization-rearrangement. Condensation of ethyl 2-cyano-2-formamidopropionate and ethyl 2-acetamido-2-cyanopropionate with urea, thiourea, guanidine, and N, N-dimethylguanidine yielded substituted 4, 5-dihydro-5-methylpyridin-4-ones. Treatment of these 4, 5-dihydro-5-methylpyrimidin-4-ones with chlorotrimethylsilane and hexamethyldisilazane in pyridine gave the correspondingly substituted imidazo[l, 5-α]-l, 3, 5-triazinones. Structures were established in this series on the basis of precursors and routes of synthesis, and 13C NMR spectra, and mass spectra and by X-ray crystallographicanalysis of one member among the interrelated compounds in the series. © 1979, American Chemical Society. All rights reserved.