5-Amino imidazole 4-substituted carboxamidines and 4-substituted imidoyl cyanides were selectively obtained under mild experimental conditions from reaction of the easily accessible 5-amino-4-cyanoformimidoyl imidazoles with primary aliphatic and aromatic amines, ammonia, and amino acids in a one-pot reaction. When alcohols were used, the corresponding 5-aminoimidazole 4-carboximidates were isolated. An equally simple reaction occurred when the starting imidazoles were combined with water to give 5-aminoimidazole 4-acyl cyanides.
5-(5-Aminoimidazol-4-yl)-1,2,4-triazol-3-ones were obtained under mild experimental conditions from 5-amino-4-(N-ethoxycarbonyl) cyanoformimidoyl imidazoles and hydrazine in a rapid one-pot reaction. When hydroxylamine hydrochloride was used, in the presence of base, the corresponding 1,2,4-oxadiazol-5-ones were isolated. An equally fast reaction occurred when 5-amino-4-(N-acetyl/benzoyl) cyanoformimidoyl imidazoles were combined with hydrazine to give 5-(5-aminoimidazol-4-yl)-1,2,4-triazoles.
N1- and C6-substituted adenines: a regioselective and efficient synthesis
作者:Nádia Senhorães、A. Luísa Costa、Deolinda I. Silva、M. Fernanda Proença、Alice M. Dias
DOI:10.1016/j.tet.2013.09.063
日期:2013.11
New and efficient methods for the synthesis of N1-substituted and C6-substitued adenines were developed from the easily accessible 5-aminoimidazole-4-carboxamidines. Condensation of these compounds with triethyl orthoformate led to the selective synthesis of the N1-substituted adenines. Regioselective preparation of C6-substituted adenines could be accomplished when the same precursors were combined