Facile synthesis of 6-cyano-9-substituted-9H-purines and their ring expansion to 8-(arylamino)-4-imino-3-methylpyrimidino[5,4-d]pyrimidines

Al‐Azmi, Amal; Booth, Brian L.; Carpenter, R; Carvalho, M. Alice; Marrelec, Elodie; Pritchard, Robin G.; Proença, M. Fernanda

doi:10.1039/b106539b

Cited by 38 publications

(28 citation statements)

References 20 publications

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“…The regioselective synthesis of purine derivatives 6 has been reported and allowed the preparation of 6-cyano, 11 6-carbamoyl, 6 6-amidino, 12 6-amino 13 and 6-enamino purines. 14 Functionalized imidazo [4,5-b] pyridines 7 were also produced 15 upon reaction with various carbon acids.…”

Section: Methodsmentioning

confidence: 99%

Guanidine: studies on the reaction with ethyl N-(2-amino-1,2-dicyanovinyl)formimidate

Assunção¹,

Marinho²,

Proença³

2009

Arkivoc

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Section: Methodsmentioning

confidence: 99%

Guanidine: studies on the reaction with ethyl N-(2-amino-1,2-dicyanovinyl)formimidate

Assunção¹,

Marinho²,

Proença³

2009

Arkivoc

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“…[3,4,6,[18][19][20] In our research group we have developed a simple and efficient method by which to prepare 9-substituted 6-cyanopurines 1 by treatment of 5-amino-4-(cyanoformimidoyl)-imidazole with dimethylformamide diethyl acetal or triethyl orthoformate in the presence of acid catalysis. [21,22] When these compounds were treated with methylamine, 7,8-dihydropyrimido [5,4-d]pyrimidine structures 4 were formed exclusively. [22] These products were considered to arise from nucleophilic attack of the amine on C8 of the purine ring, by an ANRORC-type mechanism.…”

Section: Introductionmentioning

confidence: 99%

“…[21,22] When these compounds were treated with methylamine, 7,8-dihydropyrimido [5,4-d]pyrimidine structures 4 were formed exclusively. [22] These products were considered to arise from nucleophilic attack of the amine on C8 of the purine ring, by an ANRORC-type mechanism. However, the results reported in the literature concerning reactions between 6-cya-…”

Section: Introductionmentioning

confidence: 99%

An Efficient Synthesis of 7,8‐Dihydropyrimido[5,4‐d]pyrimidines

et al. 2007

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Keywords: Cyanopurines / Amines / Rearrangement / Pyrimido [5,4-d]pyrimidines 7,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

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“…As a consequence, the development of highly efficient methods for these synthetic transformations is potentially very useful. Recent work on the synthesis of 6-cyanopurines 2 1 has shown that these compounds can be prepared in a simple and efficient way from 5-amino-4-(cyanoformimidoyl)imidazoles 1 and triethyl orthoformate under reflux conditions or at room temperature, in the presence of sulfuric acid (Scheme 1). Only a few reactions are described in the literature for these compounds, 2,3,4 and to our knowledge, the nucleophilic substitution of a cyano group in the 6-position of the purine ring by an alkoxy group has never been reported.…”

Section: Introductionmentioning

confidence: 99%

Efficient conversion of 6-cyanopurines into 6-alkoxyformimidoylpurines

et al. 2004

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An extremely simple method for the selective synthesis of 9-aryl and 9-alkyl 6-alkoxy or 6-alkoxyformimidoylpurines from the corresponding 6-cyanopurines is described. The reaction is carried out with methanol or ethanol in the presence of DBU. At room temperature, nucleophilic attack by the primary alcohol occurs selectively on the cyano carbon atom, leading to 6-alkoxyformimidoylpurines in good yields. Heating the reaction mixture at a temperature greater than or equal to 78 ЊC leads to nucleophilic substitution of the substituent in the 6-position by the alkoxy group, generating the corresponding 6-alkoxypurines, also in excellent yields. The 6-alkoxyformimidoylpurines were used as intermediates in the synthesis of 6-carboxamidinopurines by reaction with methylamine (for 9-methylpurine 5a) or methyl ammonium chloride (for 9-arylpurines 5b and 5c).

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Facile synthesis of 6-cyano-9-substituted-9H-purines and their ring expansion to 8-(arylamino)-4-imino-3-methylpyrimidino[5,4-d]pyrimidines

Cited by 38 publications

References 20 publications

Guanidine: studies on the reaction with ethyl N-(2-amino-1,2-dicyanovinyl)formimidate

Guanidine: studies on the reaction with ethyl N-(2-amino-1,2-dicyanovinyl)formimidate

An Efficient Synthesis of 7,8‐Dihydropyrimido[5,4‐d]pyrimidines

Efficient conversion of 6-cyanopurines into 6-alkoxyformimidoylpurines

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