Deep eutectic solvent mediated synthesis of pyrazolo[3,4-b]- and pyrimido[4,5-b]quinolines

Herein, this research explores the versatility and efficiency of choline chloride based deep eutectic solvent (DES) as a catalyst as well as reaction media for the cyclocondensation of pyrazolo[3,4-b]quinolines and pyrimido[4,5-b]quinolines. The eutectic solvent employed for this protocol is recyclable, non-toxic, non-volatile and biodegradable with high chemical and thermal stability, making it ideal for the sustainable synthesis of quinoline derivatives. These protocols are simple, straightforward, highly scalable and aligned with green chemistry principles. Additionally, these methods are eco-friendly, economical and outperform existing methodologies in operational efficiency.