Synthesis of 1 ,2,3,4-tetrahydro-2,4-dioxo-7-(2,4-dialkoxyphenyl)-5-substitutedPhenyl- 5H-pyrano-[2,3-d]-pyrimidines and 3-(2,4-dialkoxyphenyl)-5-substitutedphenylisoxazoles

Abstract

1,2,3,4-Tetrahydro-2,4-dioxo-7-(2,4-dialkoxyphenyl)-5-substitutedphenyl-5H-pyrano-[2,3-d]-pyrimidines were prepared by condensing chalcones with barbituric acid in glacial acetic acid in presence of P 2 O 5 and 3-(2,4-dialkoxyphenyl)-5-substitutedphenylisoxazoles were prepared by adding Br 2 dissolved in chlorofonn dropwise to cold solutions of 1-(2,4-dialkoxyphenyl)-3-substituted phenylprop-2-en-1-one on stirring to obtain the dibromoderivatives. Ethanolic solution of dibromoderivatives were refluxed with hydroxylamine hydrochloride in presence of aqueous KOH to get the required compounds.