Facile synthesis of 6-cyano-9-substituted-9H-purines and their ring expansion to 8-(arylamino)-4-imino-3-methylpyrimidino[5,4-d]pyrimidines
作者:Amal Al-Azmi、Brian L. Booth、Robert A. Carpenter、Alice Carvalho、Elodie Marrelec、Robin G. Pritchard、M. Fernanda J. R. P. Proença
DOI:10.1039/b106539b
日期:2001.10.11
6-Cyano-9-substituted-9H-purines were prepared in a high yielding, one-step process by refluxing triethyl orthoformate or triethyl orthopropionate with the corresponding (Z)-N1-(aryl- or benzyl)-N2-(2-amino-1,2-dicyanovinyl)formamidines. Attempted reaction of these cyanopurines with aqueous methylamine furnished 8-(arylamino)-4-imino-3-methylpyrimidino[5,4-d]pyrimidines, by attack at the imidazole ring rather than addition to the 6-cyano group. All compounds have been fully characterised by spectroscopic data and an X-ray crystal structure determination has been carried out on the 8-(4-methoxyanilino)-4-imino-3-methylpyrimidino[5,4-d]pyrimidine.
(Z)-N<sup>3</sup>-(2-amino-1,2-dicyanovinyl)formamidrazone: a precursor in the synthesis of 1,5-diaminoimidazoles and 6-carbamoyl-1,2-dihydropurines
作者:M. José Alves、Brian L. Booth、A. Paula Freitas、M. Fernanda J. R. P. Proença
DOI:10.1039/p19920000913
日期:——
The reaction of ethyl (Z)-N-(2-amino-1,2-dicyanovinyl)formimidate with hydrazine monohydrate leads to (Z)-N3-(2-amino-1,2-dicyanovinyl)formamidrazone in almost quantitative yield. This compound proved to be an important starting material for the synthesis of the corresponding N1-isopropylidene-and N1-acetyl-formamidrazones.