Polyethylene glycol-bonded 1,8-diazabicyclo[5.4.0]undec-7-ene (PEG–DBU) as a surfactant-combined base catalyst for the application of nucleosides as reagents in multi-component syntheses of 8-substituted pyrido[2,3-d]pyrimidine-6-carbonitriles in water

Abstract

Polyethylene glycol-bonded 1,8-diazabicyclo[5.4.0]undec-7-ene (PEG–DBU) was prepared as a new surfactant-combined base catalyst and successfully applied in the syntheses of some novel 8-substituted pyrido[2,3-d]pyrimidine-6-carbonitriles via one-pot multi-component reactions in water using nucleosides (adenosine, guanosine and cytidine) as starting materials. The application of PEG–DBU used water as an available, green, and benign reaction medium instead of commonly used hazardous solvents (DMF, DMSO etc.) for the manipulation of nucleosides.