“…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.…”