N-Nitro Groups

N-Amino and N-nitro groups N-Hydroxy groups and N-oxides N-Hatogeno groups... 

The last step (V) to (1) is reversible if tetryl is dissolved in concentrated sulphuric acid and allowed to stand the N-nitro group is expelled and trinitromethylaniline (V) is formed (cf. p. 5). 

T. Urbanski and Semenczuk found that tetryl prepared with nitric acid alone is of high purity, possibly because it is not contaminated with 2,4,6-f.initro-N-methyl-aniline formed from tetryl as a result of the loss of the N-nitro group on heating with sulphuric acid, present in an ordinary nitrating mixture. 

The conditions of nitration of dinitromethyJaniline with nitric acid were recently studied by Lang [12]. He explained that in order to introduce the N-nitro group it is necessary to use nitric acid with a concentration of more than 70 %. The nitration then proceeds as follows ... 

The A-nitroimidazolcs are stable for a time even in the presence of water, but treatment with concentrated sulfuric acid cleaves the N-nitro group, and strong base opens the ring. Much of the interest in such compounds is related to their multistep complex substitution reactions in which sequential nucleophilic addition of arylamines, ring opening, ring closure, nitroamide elimination, and rearomatization gives l-aryl-4-nitroimidazoles, e.g., 840 839. This method can also be used to prepare isotopically labeled imidazoles when labeled amino acids are used as the amine. 

Polyurethanes with aliphatic C -and N-nitro groups Preparation... 

The addition of a nitro group as one of the groups bonded to an amine nitrogen atom increases the deshielding effect of the amine group. The presence of the N-Nitro group also decreases the relative solubility of these compounds in comparison to the corresponding amines. 

Polyurethanes containing nitro groups, nitration of 409-411 Polyurethanes with aliphatic C- and N nitro groups 405-411 Polyvinylalcohol. nitration of 415-418 (11/173)... 

The third and most recent model III (Fig. 29.1.2b) involves a crucial role for the N-nitro group within the [=X-N02]-pharmacophore, an important contribution from the 6-chloro-pyrid-3-yl ring nitrogen, and a supplemental role for the nitrogen in 1-position. A first confirmation of this model III is exemplified by interaction of 7 with the a7 nAChR, based on the AChBP [109]. 

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