An Efficient and Green Synthesis of New 6-Iodo- Pyrano[2,3-d] Pyrimidine-4-Ones via a One-Pot Four-Component Reaction Followed by Iodocyclization in Water

Abstract

Eco-friendly one-pot synthesis of new 6-iodo-4H-pyrano[2,3-d]pyrimidin-4-ones via the condensation of pyrimidine-4,6-diol, aldehydes, phenylacetylene, and iodine has been reported in water at 60 °C. To obtain the optimal reaction conditions, the effects of reaction temperature, bases and solvents were investigated. Under the optimal condition, formaldehyde and different aromatic aldehydes bearing both electron-donating and withdrawing groups underwent the reaction to give the corresponding 6-iodo-5,7-disubstituted-3H-pyrano[2,3-d] pyrimidin-4(5H)-one derivatives in high to excellent (90–97%) yields. This transformation generates 6-iodo-4H-pyrano[2,3-d]pyrimidin-4-one derivatives using a domino reaction involving Knoevenagel condensation and iodocyclization in the absence of metal or acidic/basic catalysts. The prepared products were characterized using FT-IR, 1HNMR, 13CNMR, and Mass spectroscopies.