An improved microwave-assisted facile one-pot synthesis of novel pyrazolylphosphonates via Knoevenagel-phospha-Michael protocol

In this study, a highly effective microwave-assisted method employing a multicomponent domino Knoevenagel/phospha-Michael reaction has been established. This approach facilitates the synthesis of a novel set of pyrazolylphosphonate derivatives in good yields by combining aryl aldehydes with pyrazolones and trialkylphosphites, utilizing piperidine as a Bronsted base catalyst. All pyrazolylphosphonates have been characterized by means of IR, 1H-NMR, 13C-NMR, and HRMS analyses and physical methods. This protocol can be characterized by its eco-friendly nature, exceptional efficiency in terms of product yields, and short reaction times. This study describes a microwave-assisted method employing a domino Knoevenagel/phospha-Michael reaction, enabling the synthesis of pyrazolylphosphonate derivatives from aryl aldehydes, pyrazolones, and trialkylphosphites with piperidine as a catalyst. image