Novel heterocyclic dihydropyrimidine chromenopyrimidine-2,5-diones and thioxochromenopyrimidin-5-ones were synthesised by a three-component reaction between 4-hydroxycoumarin, urea or thiourea, and aromatic aldehydes in H2O under reflux in the presence of sodium dodecyl sulfate (20 mol%) and two drops of acetic acid. The products were obtained in good yields and their structures of all the synthesised compounds were established by spectroscopic methods..