Microwave-assisted multicomponent reaction: An efficient synthesis of indolyl substituted and spiroxindole pyrido[2,3-d]pyrimidine derivatives

An efficient and catalyst-free protocol for the synthesis of a series of indole substituted or spiroxindole-consisted dihydropyrido[2,3-d]pyrimidine derivatives by one-pot three-component reaction of 2,6-diaminopyrimidin-4-one, various aryl aldehydes or isatins, and 3-cyanoacetyl indoles under microwave irradiation was investigated. The advantages of this methodology include high yields of products, short reaction time, easy work-up procedure...