Synthesis of novel 7-substituted pyrido[3,2-b]pyrazin-3(4H)-one derivatives via Suzuki-Miyaura cross-coupling reaction

Abstract

In this work, 7-substituted Pyrido[3,2-b]pyrazin-3(4H)-one derivatives are reported starting from 4-methyl-3-nitropyridin-2-amine [1], which underwent further transformations followed by Suzuki–Miyaura coupling reaction under microwave conditions. Primarily, 5-bromo-4-methyl-3-nitropyridin-2-amine (Conejo-Garcia et al., 2010) [2] was prepared according to literature, was converted into many other derivative forms that involve different types of reactions like, reduction, cyclization, chlorination, N-alkylation and yielded as 7-bromo-2,8-dimethyl-4-(2-oxo-2-(pyrrolidin-1-yl)ethyl)pyrido[2,3-b]pyrazin-3(4H)-one (Kamble et al., 2016) [6] which was further subjecting with versatile boronic acids via Suzuki–Miyaura coupling to make comparable novel 7-substituted Pyrido[3,2-b]pyrazin-3(4H)-one derivatives (8a-p). The chemical constructions of all yielded compounds were well elucidated by analytical and spectral analyses (TLC, 1H NMR, 13C NMR, and HRMS).