A Clean and Highly Efficient Synthesis of Oxindole Substituted Pyrrolo[2,3-d]Pyrimidines under Ultrasound Irradiation

A practical and new method for the synthesis oxindole substituted pyrrolo[2,3-d]pyrimidines by the condensation of isatin, acetophenone and 6-amino-uracil under ultrasound irradiation conditions at 60 °C was described. The reaction was developed via a sequential tandem process to afford the oxindole substituted pyrrolo[2,3-d]pyrimidines in good to excellent yields. All reactions performed efficiently under ultrasound irradiation and results were compared with conventional heating method. In this field, several types of acetophenones, amino-uracils, and isatins were rapidly changed to the corresponding derivatives. The remarkable features of the new procedure are shorter reaction time, excellent yields, cleaner reaction profile, and simple experimental and workup procedure.