Various novel pyrano [2,3-d]pyrimidines 5 and furopyrano [2,3-d]pyrimidines 7 were synthesized in 80-99% yields via a multicomponent domino Knoevenagel/hetero-Diels-Alder reaction of 1,3-dimethyl barbituric acid with an aromatic aldehyde and ethyl vinyl ether/2,3-dihydrofuran in presence of 1 mol% of indium(III) chloride. The reaction also proceeds in aqueous media without using any catalyst, b...

The three possible structural isomers of 4-(pyridyl)pyrimidine were employed for the synthesis of new pyrrolo[1,2-c]pyrimidines and new indolizines, by 1,3-dipolar cycloaddition reaction of their corresponding N-ylides generated in situ from their corresponding cycloimmonium bromides. In the case of 4-(3-pyridyl)pyrimidine and 4-(4-pyridyl)pyrimidine the quaternization reactions occur as expect...

Pyrazolo[3,4-d]pyrimidines are a class of compounds with a good activity against several cancer cell lines. Despite the promising anticancer activity, these molecules showed a poor aqueous solubility. This issue could threat the future development of pyrazolo[3,4-d]pyrimidines as clinical drug candidates. With the aim of improving their solubility profile and consequently their pharmacokinetic ...

Silica-bonded N-propyldiethylenetriamine sulfamic acid (SPDTSA) is employed as a recyclable heterogeneous solid acid catalyst for the synthesis of benzopyrano[2,3-d]pyrimidines  through one-pot condensation reaction of salicylaldehydes, malononitrile and secondary amines  at room temperature under solvent-free conditions. SPDTSA showed much the same efficiency when used in con...

BACKGROUND Pyrazolo[1,5-a]pyrimidines are purine analogues. They have beneficial properties as antimetabolites in purine biochemical reactions. This division compounds have attracted wide pharmaceutical interest because of their antitrypanosomal activity. RESULTS The present work depicts an effective synthesis convention of pyrazolo[1,5-a]pyrimidines, pyrazolo[5,1-c]triazines, thieno[2,3-b]py...

* Present address: Department of Chemistry, College of Science, Sulaimaniya, Iraq. Dimers/Radiolysis/Pyrimidines/N2O Aqueous solutions of pyrimidines (such as uracil and thymine) containing N2O (125 mM) were irradiated with Co-60 gamma rays source and analysed with paper chromatography technique using suitable solvent developing systems. Among the various radiation-induced products, the three d...

5-Aryl-7-hydrazino-2-phenylpyrazolo[1,5-c]pyrimidines 1 were used as precursors for the preparation of a new series of 5-aryl-8-phenylpyrazolo[1,5-c]-1,2,4- triazolo[4,3-a]pyrimidines 2. The reactions of 2 with certain electrophilic reagents gave the respective 6-substituted derivatives 3-5 rather than the 7-isomeric products. Formylation of the key compounds 1 with ethyl formate yielded the fo...

Enzyme induction in Escherichia coli is stimulated by certain 5-amino-2,4-bis(substitutedamino)pyrimidines (Kunkee, 1960a). Other 2,4diaminopyrimidines have been reported to be antagonists of folic acid (Hitchings et al., 1952; Doctor, 1956). Since there are indications that the stimulation of enzyme induction involves nucleic acid metabolism (Kunkee, 1960b) and since folic acid is involved in ...

Thiophene substituted chalcones (1a-e) were cyclised with thiourea in presence of potassium hydroxide to get 4-substituted-6-(thiophen-2-yl)pyrimidine-2-thiols (2a-e) which were then stirred with methyl iodide to obtain 4-substituted-2-(methylsulfanyl)-6-(thiophen-2-yl)pyrimidines (3a-e). Compounds (3a-e) were refluxed with different N-methylpiperazine and N-phenylpiperazine to afford 4-substit...