L-Alkyl-4-nitro

This can be of help in structural assignments in the chemistry of heterocycles. The electron spectra of 1- and 2-alkylderivatives of 4-nitro-l,2,3-triazole, which show an identical band /w 257 nm also independent on the medium (pH 1 or 11 or ethanol), are described [634], However for l-alkyl-4-nitro-5-amino-l,2,3-triazoles the absorption maximum is shifted to the long-wave region (332-356 nm). 

When heated with potassium iodide in dimethylformamide, l-alkyl-4-chloro- (or bromo)-5-nitroimidazoles were converted into the 4-iodo analogues (79JGU1251). One would expect the 5-chloro-4-nitro isomers to be even more susceptible to this replacement (87AJC1399). 

Very few synthetic compounds other than the sulfa drugs have shown useful activity against systemic bacterial infections, particularly those due to Gram-negative bacteria. Activity of this kind was discovered in a series of l-alkyl-4-quinolones (60BRP830832), but the most active of these, l,2-dimethyl-6-nitro-4-quinolone and l-methyl-6-nitro-4-quin-olone-3-carboxylic acid, produced eye damage (opacity of the lens) that precluded clinical trial. A closely related 1,8-naphthyridine derivative, nalidixic acid (255), was later found to be effective, and it is largely used for urinary tract infections. The quinolone oxolinic acid (256) is also used for this purpose. These compounds inhibit enzymes concerned in DNA synthesis. 

A rearrangement intermediate, protonated 4-hydroxy-3-(2-imino-propyl)benzonitrile (163) proved to be isolable (67TL2867). Analogously, from l-alkyl-4-nitrophenyloximinopiperidine (165) in ethanolic HC1, 2-methyl-6-nitro-l,2,3,4-tetrahydrobenzofuro[3,2-c]pyridine (167) was ob-... 

The nitration of 1-alkyl- and l,2-dialkyl-5-halogenoimidazoles [151, 155, 158], which are used as intermediates in the pharmaceutical chemistry industry, has been investigated in greatest detail. For instance, the immunodepressant azathioprine ( imuran ) was obtained from l-methyl-4-nitro-5-chloroimidazole [158],... 

Aryl l-methyl-4-nitro-5-imidazolyl sulfones, a new class of radiosensitizing pharmaceuticals [356-359], an extensive series of nitro derivatives of methylthio-[109] and ethylsulfonylimidazoles [360, 361], 1-alkyl [362]-, 1-trialkylsilylalkyl)-2-methyl-4-nitroimidazoles [363], allylated 4-nitroimidazoles [364], 5-amino derivatives of 4-nitroimidazoles [365], 5-azido-4-nitroimidazole [366], 15N-labeled... 

C NMR spectra of 3-nitro-l,2,4-triazol-5-one and seven of its salts with different amines have been studied. The chemical shifts of C-3 and C-5 are independent of the nature of the cation (Table 3.21) [560], NMR spectra of 1-nitro-1,4-dihydro-1-7/-l,2,4-triazol-5-one, 5-(3-azido-l,2,4-triazol-3-yl)-3-nitro-l,2,4-triazoles [611], l-alkyl-3-nitro-l,2,4-triazol-5-one [612], some 3-nitro-2-methyl-l,2,4-triazolone derivatives [613-615], and their mono- and dinitro energetic salts [616] have been discussed. 

Natrium-l-alkyl-4-hydroxy-3-nitro-alkan- E14b, 820 (En-N02 + Nitronat)... 

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