Assiut university researches
Synthesis and Reactions of Quinoxaline
Derivatives
M.Z.A. Badr, G.M. El-Naggar,H.A.H. El-Sherief and S.A. Mahgoub
Abstract:
Reaction of 3-methyl-2(1H)quinoxalinone (1) with alkyl,
benzyl, and arenesulfonyl halides in the presence of K2CO3
in dry acetone gave 1-substituted 3-methyl-2(1H)quinoxalinones (2a–g). However 1 reacts with benzoyl
chloride under the same conditions to give 3-methyl-2quinoxalinyl benzoate, while it reacts with P2S5 in dry
pyridine to give 3-methyl-2(1H)quinoxalinethione (4).
Treatment of 4 with methy iodide in the presence of K2CO3 in
dry acetone gave 2-methyl-3-(methylthio)quinoxaline but not
1,3-dimethyl-2(1H)-quinoxalinethione which has been
obtained from 2a and P2S5 in dry pyridine. Treatment of 4
with benzyl bromide and/or p-nitrobenzyl bromide in the
presence of K2CO3 in dry acetone gave 2-benzylthio and 2(p-nitrobenzylthio)-3-methylquinoxalines. Syntheses of 1methyl-3-(substituted styryl)-2(1H)-quinoxalinone (8a–m)
were achieved by condensation of 2a with aromatic
aldehydes. Addition of thiophenols and mercaptoacetic acid
to 8 gives 1-methyl-3-[2-(substituted phenylthio)ethyl]-2(1H)quinoxalinones and 1-methyl-3-[2-(substituted phenyl)-2(carboxymethylthio)ethyl]-2(1H)-quinoxalinones respectively.
1,3-Dimethyl-2(1H)-quinoxalinone (2a) condensed with
ketones in the presence of ZnCl2 to give 1-methyl-3-[2(substituted phenyl)-1-alkenyl]-2(1H)-quinoxalinones. 1Methyl-3-(substituted styryl)-2(1H)-quinoxalinethiones were
produced by refluxing a mixture of 8 with P2S5 in dry pyridine
Published in:
Bull. Chem. Soc. Japan,Vol. 57, No. 6,pp.1653-1657