- Synthetic Approaches to some Aza-analogues of Benzimidazole N-Oxides. Part 1. The Imidazopyridine Series
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The 3-oxide of 2-p-nitrophenylimidazopyridine (8) may be obtained in good yield by base-induced cyclisation of 2-nitro-3-(p-nitrobenzylamino)pyridine (18).It is also obtained in lower yield, along with p-nitrobenzoic acid and other cleavage products, by the corresponding reactions of bases with the N-ethoxycarbonyl, N-methylsulphonyl, and N-p-tolylsulphonyl derivatives of 2-nitro-3-(p-nitrobenzylamino)pyridine .Cleavage is the main reaction when N-(2-nitro-3-pyridyl)-N-phenacylmethanesulphonamide (17) is treated with bases: phenylglyoxal, or its Schiff base with 3-amino-2-nitropyridine, are possible intermediates in the cleavage process. 3-Nitro-2-(p-nitrobenzylamino)pyridine (31) is similarly cyclised in basic media to give the 1-oxide of 2-p-nitrophenylimidazopyridine (32).
- Andrews, Adrian F.,Smith, David M.,Hodson, Harold F.,Thorogood, Peter B.
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p. 2995 - 3006
(2007/10/02)
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- Chemotherapeutically effective nitro compounds. III. Nitropyridines, nitroimidazopyridines and related compounds
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New 2 nitropyridines and 3 nitropyridines, and 3 nitroimidazo [1,2 a] pyridines and related compounds (together 106) were synthesized and tested for their chemotherapeutic efficacy against trichomonads, amoebas and other organisms, such as Eimeria tenella, bacteria, fungi and helminths. Several 2 nitropyridines revealed a detectable systemic effect against Entamoeba histolytica (extraintestinal amoebiasis of the golden hamster) and also a weak activity against Trichomonas fetus in the NMRI mouse. Only a few 3 nitropyridines showed a marked systemic effect against trichomonads. Of the 3 nitroimidazo [1,2 a] pyridines, only the electroneutral carboxylic acid amide group exhibited a pronounced activity, exclusively against trichomonads; however, the activity was nullified by electronegative, electropositive and other electroneutral substituents. As they were not superior in chemotherapeutic respect compared to the known standard preparations (metronidazole), no further tests were carried out with the most effective compounds.
- Winkelmann,Raether,Hartung,Wagner
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