Rearrangements in heterocyclic synthesis: a novel translocation of an (N-amino-N-methylamino)methylene group from a heterocyclic N-amino-N-methylformamidine side chain to the vinylogous nitrile function
Rearrangements in heterocyclic synthesis: a novel translocation of an (N-amino-N-methylamino)methylene group from a heterocyclic N-amino-N-methylformamidine side chain to the vinylogous nitrile function
A Novel Method for the Synthesis of 9-Benzyl-6-(2-methylhydrazino)purine and 1-Methyl-4-(2-methylhydrazino)-1<i>H</i>-pyrazolo[3,4-<i>d</i>]pyrimidine
作者:Ramachandra S. Hosmane、Benjamin B. Lim
DOI:10.1055/s-1988-27530
日期:——
A novel method for the synthesis of 9-benzyl-6-(2-methylhydrazino) purine (8a) and 1-methyl-4-(2-methylhydrazino)-1H-pyrazole [3,4-d]pyrimidine (8b) is reported. The method consists of reacting the formimidates of the corresponding 5-amino-4-cyanoimidazole and -pyrazole (i.e. 6a and 6b, respectively) with excess methylhydrazine catalyzed by trifluoroacetic acid. A tentative mechanism for the reaction is proposed.
AN IMPROVED SYNTHESIS OF 9-BENZYLADENINE: A MODEL FOR ADENOSINE AND ITS ANALOGUES
作者:Zhiyuan Sun、Ramachandra S. Hosmane
DOI:10.1081/scc-100000581
日期:2001.1
significant adenine nucleosides, has been reported. The target compound was synthesized by condensation of 1-benzyl-4-cyano-5-methoxymethyleneimino-imidazole (14) with guanidine. Compound 14 was prepared from 5-amino-1-benzyl-4-cyanoimidazole (5), which in turn was prepared by reaction of benzylamine with ethyl (Z)-N-(2-amino-1,2-dicyanovinyl) formimidate (13). The latter was synthesized by reaction of diaminomaleonitrile