Eco‐Efficient Synthesis of New Pyrido [2, 3‐c] Coumarin Scaffolds Under Sonochemical Method

We have explored a green and simple approach to assembling of pyrido[2,3‐c]coumarin derivatives via one‐pot multi‐component condensation of 4‐hydroxy‐2H‐chromen‐2‐one, benzaldehyde, acetoacetanilide, and ammonium acetate in the absence of catalyst in ethanol under ultrasound irradiation. Compared with thermal method, this methodology has significant advantages, for example, it can be easily operated, it has an easy work‐up and short reaction times, and it produces satisfactory yields.