6-Hydrazino-l,3-dimethyl-5-nitrosouracil

Heteroannelated 1,2,4-triazine 4-oxides—fervenulin 4-oxides 12—were obtained starting from 6-hydrazino-l,3-dimethyl-5-nitrosouracil. Orthocarboxylates, formic acid, dimethyl sulfate, or DMF in the presence of POCI3 were used as cyclization agents (77H273, 78JOC175, 78JOC469). 

A full account of the methods of direct synthesis of the previously inaccessible fervenulin 4-oxides, reported last year, " has appeared. Also noted last year was the value of 6-hydrazino-l,3-dimethyl-5-nitrosouracil (356) as a precursor in purine and pteridine syntheses. Extension of this work has now provided access to 3-aryl-fervenulins (357) and pyrimido[5,4-e]-as-triazines (358), as... 

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