85107-04-6Relevant academic research and scientific papers
An efficient synthesis of 7,8-dihydropyrimido[5,4-d]pyrimidines
Carvalho, M. Alice,Esperanca, Sandra,Esteves, Teresa,Proenca, M. Fernanda
, p. 1324 - 1331 (2008/09/18)
7,8-Dihydropyrimido[5,4-d]pyrimidines 4 were isolated in very good yields by treatment of 9-aryl-6-cyanopurines 1 with primary amines. Nucleophilic attack of the amine on C8 of the purine ring was followed by ring-opening of the imidazole unit, and subsequent intramolecular cyclization involving the newly formed amidine group and the cyano substituent in the pyrimidine ring produced the 7,8-dihydropyrimido[5,4-d]pyrimidine structure 4. When ammonia was used instead of primary amines, compound 4 rapidly reacted further to afford the more stable pyrimido[5,4-d]pyrimidine 6 as a result of tautomeric equilibration. The aromatic structure 6 was also isolated when purine 1a and an excess of ethanolamine were heated at reflux in methanol, and also when purine 1c was combined with an excess of (4-methoxyphenyl)-hydrazine in THF at room temperature in the presence of a catalytic amount of DBU. In both cases the product is formed by a Dimroth rearrangement of the precursor 7,8-dihydropyrimido[5,4-d]pyrimidine 4. Wiley-VCH Verlag GmbH & Co. KGaA, 2007.
Purines. V. Reaction of 9-Phenyl-9H-purine-6-carbonitrile with Nucleophilic Reagents
Higashino, Takeo,Yoshida, Shizuo,Hayashi, Eisaku
, p. 4521 - 4525 (2007/10/02)
The reaction of phenyl-9H-purine-6-carbonitrile (1) with nucleophilic reagents occurred by addition of the reagent across the C-N triple bond of the cyano group, and substitution of the cyano group was not observed.Thus the reaction with hydroxylamine, hy
