a practical and new method for the synthesis oxindole substituted pyrrolo[2,3-d]pyrimidines by the condensation of isatin, acetophenone and 6-amino-uracil under ultrasound irradiation conditions at 60 °c was described. the reaction was developed via a sequential tandem process to afford the oxindole substituted pyrrolo[2,3-d]pyrimidines in good to excellent yields. all reactions performed effic...

Oxazolo[5,4-d]pyrimidines can be considered as 9-oxa-purine analogs of naturally occurring nucleic acid bases. Interest in this ring system has increased due to recent reports of biologically active derivatives. In particular, 5-aminooxazolo[5,4-d]pyrimidine-7(6H)-ones (9-oxa-guanines) have been shown to inhibit ricin. The preparation of a series of 2-substituted 5-aminooxazolo[5,4-d]pyrimidin-...

Five series of tetrahydrobenzothieno[2,3-d]pyrimidine and tetrahydrobenzothienotriazolopyrimidine derivatives have been synthesized namely: 4-(substituted amino)-5,6,7,8-tetrahydro[1]benzothieno[2,3-d]pyrimidines 4a–d, 4-substituted (methylidenehydrazino)-5,6,7,8-tetrahydro[1]benzothieno[2,3-d]pyrimidines 6a–c, 4-(3,5-disubstituted pyrazol-1-yl)-5,6,7,8-tetrahydro[1]benzothieno[2,3-d]pyrimidine...

This paper describes the photophysical properties of a series seven selected examples 5-(alkyl/aryl/heteroaryl)-2-methyl-7-(trifluoromethyl)pyrazolo[1,5-a]pyrimidines (3), which contain alkyl, aryl, and heteroaryl substituents attached to scaffolds 3. Given electron-donor groups -withdrawing groups, optical absorption emission in solid state solution showed interesting results. Absorption UV–Vi...

A straightforward and effective strategy for the synthesis of novel 7-cyano-4-imino-3-phenyl-6-(pyrrolidin-1-yl)-2-substituted-3,4-dihydroselenopheno[3,2-d]pyrimidines have been accomplished through a base-promoted cascade addition/cyclization sequence employing phenyl isothiocyanate followed by S-alkylation obtained fused Se-containing heterocyclic framework with various alkyl halides. Free ra...

The Mannich reaction of 7-aryl-5,6-dihydropyrido[2,3-d]pyrimidines 3, easily accessible by condensation of 6-amino-1,3-dimethyluracil (1) with Mannich bases 2a – c, gives rise to a mixture of 7-aryl-6-(N,N-dimethylaminomethyl)pyrido[2,3-d]pyrimidines 6 and 7 as well as 1,2-bis(7-arylpyrido[2,3-d]pyrimidin-6-yl)ethane 13 the ratio of which depends on the reaction conditions and the amine used. 6...