Synthesis of New Imidazo [1,2-a] Pyridine and their NMR Spectral Data

Abstract

This paper describes synthesis of new imidazo[1,2-a] pyridine derivatives. The products structures were confirmed by elemental analysis, 1H-NMR, and 13C-NMR.

A Quick and Advantageous Synthesis of 2H-1-Benzopyran-2-ones Unsubstituted on the Pyranic Nucleus

“…2 Previously, we realized the synthesis of several organic compounds using a chemical paste medium and microwave irradiation. 19,20 In this medium, during microwave irradiation, hot points are created that function like catalytic centers and, hence, chemical reactions take place rapidly. 20 The synthesis of 2H-1-benzopyran-2-ones unsubstituted on the pyranic heterocyclic nucleus constitutes a chemistry challenge because poor yields are frequently obtained.…”

An Excellent Procedure for the Synthesis of Oxazolidin-2-ones

“…This medium resulted from the addition of a small amount of polar solvent, nitromethane, which does not react with the reagents. 22,23 Nitromethane molecules absorb the microwaves and generate hot spots in the reaction medium, the hot spots then act like catalytic centers. 20,21 As a result the oxazolidin-2-ones 3 were easily obtained with short reaction times and high yields.…”

“…19 We have previously utilized microwave-chemical activation for the synthesis of new organic compounds. [20][21][22][23] Therefore, we realized a procedure for the synthesis of oxazolidin-2-ones 3 from the condensation of ethanolamine derivatives 1 and urea (2) (Scheme 1).…”

Synthesis and Chemical Reactivity of Pyrano[3,2‐c]quinolinones

“…Treating 4‐hydroxy‐1‐methylquinolin‐2(1 H )‐one ( 2 ) with trimethylortho‐ formate and urea gave 1‐methyl‐3‐ureidomethylene‐1,2,3,4‐tetrahydroquinoline‐2,4‐dione ( 32 ). Condensation of 32 with acetonitrile derivatives in potassium hydroxide gave 3‐substituted‐6‐methylpyrano[3,2‐ c ]quinoline‐2,5‐(6 H )dione ( 33 ) as published by Bratulescu or its corresponding 2‐imino derivative 34 (Scheme ).…”