Lemon juice mediated environmentally benign synthesis of functionalized chromeno[4,3-b]chromene/chromeno[2,3‐d]pyrimidine derivatives via one-pot three component reaction

In this study, an efficient and convenient three component cyclization protocol is presented for the development of synthetically important chromeno[4,3-b]chromene/chromeno[2,3‐d]pyrimidine derivatives via lemon juice mediated reaction of substituted salicylaldehyde, 4-hydroxycoumarin/1,3-dimethylbarbituric acid and electron rich arenes. As lemon juice is cheap, readily accessible, biodegradable, and nontoxic, the present method is environmentally benign and economical. Moreover, our development is simple to handle, produces high yields, tolerates many functional groups, provides easy isolation, and allows for scalable synthesis—all of which align with the basic principles of green chemistry.