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

Abstract

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.