Enaminouraciles as Precursors for Synthesis of Pyrimido[4,5-a]pyrimidine- 2,4-diones

Hamama, Wafaa S.

doi:10.1515/znb-2000-0515

Cited by 9 publications

(3 citation statements)

References 10 publications

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“…Recently, we noted that the reactions of 6-amino-1,3dimethyluracil with primary amines and formaldehyde have been used for preparations of pyrimido [4,5-d]pyrimidine-2,4diones. 30 It was found that stirring a mixture of 6-amino-1-(2chlorobenzyl)uracil 8 with an equimolar amount of a primary aromatic or aliphatic amine and excess of formalin in the presence of acetic acid at room temperature affords 5,6,7, 8-tetrahydropyrimido [4,5-d] pyrimidine-2,4(1H,3H)-dione (11) in good yield (Scheme 3) but 8-hydroxymethyl derivative of 11 was not obtained as reported earlier. 29 This conclusion was supported by the following evidence, in the 1 H NMR spectra of compounds 11a-d no signals for an 8-CH2OH group were found.…”

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6-Aminouracils as precursors for the syntheses of fused di- and tricyclic pyrimidines

Youssif

2004

Journal of Chemical Research

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Bicyclic and tricyclic fused pyrimidine derivatives have received much attention in connection with biologically significant systems such as purines, 1-7 pteridines 8-14 and alloxazines. The synthesis of the above categories has been accomplished by the cyclisation of 6-aminouracil derivatives and ring transformation of other fused pyrimidine-2,4diones. 15,16 In extending our recent work on simple bicyclic xanthines, 6,7 tricyclic alloxazines 17,18 and pyridodi pyrimidines 19 this paper reports a novel synthesis of 3-benzyl-9-methylxanthine (5), 3,9-dimethyl-8-phenylxanthine (7), 7 dipyrimidopyridines 10a-f and pyrimido [4,5-d]pyrimidines 11a-d via Mannich reactions.The synthesis of 3,9-disubstituted xanthines 5,7 has been performed by various approaches [20][21][22] and we report a more favoured sequence from the 1-substituted-6-chlorouracils 1a, b 23,24 (Scheme 1) by reaction with methylamine and N-methyl benzylamine respectively where the 6-amino compounds 2 and 6 were obtained in a good yield. Nitrosation of 2 afforded the 5-nitroso compound 3, which underwent reductive formylation to 4 which readily undergoes intramolecular cyclization with formamide to furnish the xanthine 5 or refluxing the tertiary amine 6 with sodium nitrite in the presence of acetic acid resulted in ring closure in one step giving the 3,9-dimethyl-8-phenylxanthine (7), probably via a 5-nitroso compound 6a and its tautomer 6b. All the products were assigned by 1 H NMR, UV spectra and microanalysis.It was found that the intramolecular cyclisation of 6-(Nalkylanilino)uracils with dimethylformamide (DMF)-POCl 3 25

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6-Aminouracils as precursors for the syntheses of fused di- and tricyclic pyrimidines

Youssif

2004

Journal of Chemical Research

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“…Furthermore, the interesting Psychopharmacological activity of benzodiazepine [26,27] enthused us to synthesize the 5,10 (20). Compound 20 has been obtained through cyclocondensation of 5 with 1,2-bis(chloromethyl)benzene [28].…”

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confidence: 99%

Behavior of 2‐iminothiazolidin‐4‐one with different reagents

Hamama¹,

Ismail²,

Soliman³

et al. 2011

Journal of Heterocyclic Chem

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Annulations of 2‐imino‐4‐thiazolidinone (5) via cycloaddition followed by cyclocondensation reaction with 1,3‐diphenylpropenone (6), benzylidenemalonate, and 1,2‐bis(chloromethyl)benzene gave 7, 19 and 20, respectively. Reaction of 5 with suitable electrophiles (Mannich bases of arylalkanone), 1,4‐dichlorobenzene (diarylmethylation), and formylation afforded 8/9, 21/22, and 23, respectively. J. Heterocyclic Chem., (2011).

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“…A number of biological significant compounds were used to regulate the growth of plants in their protection area [20]. These studies revealed the introduction of expedient methods to synthesize pyrimido [4,5-d]pyrimidine-2,4-dione [21]. Now a days, pyrimido-pyrimidines (annulated uracil) is a very interesting class of compounds as they display a large number of pharmacological activities with their effective inhibitory characteristics about tyrosine kinase area for the receptors of epidermal growth [22], dihydrofolate-reductase [23] and 5-phosphoribosyl-1pyrophosphate synthetase [24].…”

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confidence: 99%

Facile Synthesis of 5,6,7,8-tetrahydropyrimido[4,5-d] pyrimidine-2,4 (1H,3H) -dione Analogs via One Pot Multicomponent Reaction

Shafi¹,

Chand²,

Nawaz³

et al. 2020

FCS

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Indeed, MCR technology is widely acknowledged now for its impact on drug discovery projects and is strongly supported by industry as well as academia. Uracil is an important one of the five nucleobases and significantly important because of their biological properties; of which 6-amino uracil is most important and can act as nucleophile and electrophile. 6-Aminouracils being rich are used as starting materials for the synthesis of heterocyclic compounds of biological significance such as pyrido-, pyrazolo, pyrimido and pyrimidines derivatives. 5,6,7,8-tetrahydropyrimido[4,5-d]pyrimidine-2,4(1H,3H)-dione have been synthesized by various conventional methods. However, these methods have drawbacks such as unsatisfactory yields and tedious work-up etc. In the present work, we would like to report a new route for the synthesis of 5,6,7,8-tetrahydropyrimido[4,5-d]pyrimidine-2,4 (1H,3H)-dione in MCRs.

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Enaminouraciles as Precursors for Synthesis of Pyrimido[4,5-a]pyrimidine- 2,4-diones

Cited by 9 publications

References 10 publications

6-Aminouracils as precursors for the syntheses of fused di- and tricyclic pyrimidines

6-Aminouracils as precursors for the syntheses of fused di- and tricyclic pyrimidines

Behavior of 2‐iminothiazolidin‐4‐one with different reagents

Facile Synthesis of 5,6,7,8-tetrahydropyrimido[4,5-d] pyrimidine-2,4 (1H,3H) -dione Analogs via One Pot Multicomponent Reaction

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