ウラシルの5, 6位でのヘテロ縮合環合成の試み

ヘテロ環芳香族性の研究第XXVIII報

抄録

Upon treatment with hydrazine hydrate in ethanol, ethyl 5-bromorotate and 5 bromuracil-6-acetate were converted into the corresponding 5-hydrazino esters. An attempt to cyclize orotaldehyde hydrazone in acidic media failed to succeed, and its acyl derivatives were obtained as sole products.
Uracil-6 -acetic acid was converted into uracil-6-acetic hydrazide through its esters. The hydrazide was then treated with carbon disulfide in pyridine to obtain 2- (5-uracilmethyl) -1, 3, 4-oxadiazole-5-thion. Uracil-6-acetic hydrazide was also treated with phenyl isothiocyanate in pyridine to form a semicarbazide, which was subsequently converted into 3- (6-uracilmethyl) -4-phenyl-1, 2, 4-triazole-5-thion through alkali treatment. Treatment of the acyl hydrazide with potassium thiocyanate in hydrochloric acid gave a bis- (acyl hydrazide). Similar treatment with potassium cyanate afforded N₁- (6-uracilacety1) -semicarbazide, which was then cyclized, upon alkali treatment, into 1H, 2H-dihydropyridazo-C3, [3, 4-d] pyrimidine.