Synthesis of 2‐Oxopyridine‐Fused 1,3‐Diazaheterocyclic Compounds via a Three‐Component Reaction

Abstract

An efficient and simple route for the preparation of 2-oxopyridine-fused 1,3-diazaheterocyclic compounds via a three component reaction is described. It involves the reaction between alkylenediamines 1, 1,1-bis(methylsulfanyl)-2-nitroethene, and alkyl prop-2-ynoates 2 in refluxing THF (Table). The structures were corroborated by spectroscopic (IR, 1 H-and 13 C-NMR, and EI-MS) and elemental analyses. A plausible mechanism for this type of cyclization is proposed (Scheme).Introduction. -The development of new and simple methods for the efficient preparation of compounds containing 2-oxopyridine-fused 1,3-diazaheterocycle moieties is a beneficial and interesting challenge [1 -6]. As a part of our research program, which is aimed at developing libraries of bioactive compounds, and in continuation of our interest in one-pot and multicomponent reactions (MCRs), a three-component reaction toward fused heterocycles is described herein.

Uncatalyzed One-Pot Synthesis of Highly Substituted Pyridazines and Pyrazoline-Spirooxindoles via Domino SN/Condensation/Aza-ene Addition Cyclization Reaction Sequence

“…Recently, we have become interested in the application of ketene aminal intermediates resulting from the reaction of 1,1-bis­(methylthio)-2-nitroethylene (BMTNE) and nitrogen nucleophiles such as diamines or ammonia for the synthesis of interesting heterocycles in one-pot processes. − Following this lead and to achieve a diaza-intermediate to employ in one-pot synthesis of diaza heterocycles, we first evaluated the reaction of hydrazine and BMTNE under different conditions. The maximum yield of 1,1-dihydrazino-2-nitroethylene (DHNE) 3 was obtained when the reaction was performed in EtOH at room temperature for 7 h with 2.6:1 ratio of hydrazine:BMTNE (Table ).…”

Synthesis of 2‐Oxopyrrole‐fused 1,n‐Diazaheterocyclic Compounds and Substituted 2‐Oxopyrroles via a Three‐Component Reaction

“…Accordingly, and because of their scarce occurrence in exotic organisms, novel strategies for the synthesis of these N ‐heterocycles have received considerable attention in the past decades . In the course of our research program on the design of new routes for the synthesis of a variety of biologically active N ‐heterocycles in our laboratory via one‐pot synthesis and reactions of enamines , we become interested in the application of nitroketene dithioacetal (1,1‐di(methylthio)‐2‐nitroethene) for preparation of β ‐nitroenamines and their behavior in one‐pot multicomponent reaction. Our strategy to reach this goal is displayed in Table .…”