One step cyclocondensation of (thio)barbituric acid with chalcones in glacial acetic acid and phosphorous pentoxide: Part-I

Abstract

Some new 5, 7-diaryl-1,5-dihydro (or 1, 2, 3, 5-tetrahydro)- pyrano[2, 3-d] pyrimidin-2, 4-diones (or 2-thioxo-4-ones) (3a-h) have been synthesized in one-step by cyclocondensation of barbituric acid or thiobarbituric acid (1) with arylideneacetophenones (2a-d), in glacial acetic acid in the presence of phosphorous pentoxide. The structures of the compounds 3a-h have been determined by UV, IR, 1H NMR, 13C NMR, mass spectral data and elemental analyses. The compounds 3a-h do not seem to be available in the literatureBangladesh J. Sci. Ind. Res. 51(2), 129-138, 2016

One step cyclocondensation of (thio) barbituric acid with chalcones in glacial acetic acid and phosphorous pentoxide, Part-II

“…With this background, in continuation to our works (Ahmed et al, 2006;Ahmed et al, 2011;Ullah et al, 2012;Rahman et al, 2013;Akhter et al, 2016) on the synthesis of barbituric acid and thio-barbituric acid derivatives, we report herein syntheses of 5, 7-diaryl-1,5-dihydro -pyrano [2, 3-d] pyrimidin-2, 4-diones (3b, 3d & 3e) and 5, 7-diaryl-2-thioxo -1, 2, 3, 5-tetrahydro-pyrano [2, 3-d] pyrimidin -4-ones) (3a, 3c, 3f & 3g) by selecting a number of arylideneacetophenones (2a-d) as the a , ß-unsaturated carbonyl system having different substituents on the aromatic *Corresponding author e-mail: kawsariakhter@yahoo.com rings for reaction with barbituric acid or thiobarbituric acid (1) as the active methylene component in presence of glacial acetic acid and phosphorus pentoxide (Scheme 1). The compounds 3a-g do not seem to be available in the literature.…”