2- Aryl-l-nitro

Wird mit dcr doppelten Menge an 2-Aryl-l-nitro-cthen umgcsetzt, so lassen sich deutiicn bessere Ausbeuten erzielen (s.o. in Klammern). Gleichzeitig fallen 2-Aryl-l-nitro-ethane (64-81%) an155. Zu einem weiteren Beispiel s. Lit.281. 

Die Michael-Addition von a- bzw. / -Lithium-carbonsaure-amiden an 2-Aryl-l-nitro-ethe-ne fuhrt zu 4- bzw. 5-Nitro-carbonsaure-amiden (71-99%). So erhalt man z.B. aus... 

Tertiare Nitro-aliphaten, mit einer desaktivierten Aryl-Gruppe in a-Stellung lassen sich mit 2-Lithio-2-nitro-propan bzw. -butan in Phosphorsaure-tris-[dimethylamid], DMF oder DMSO durch nukleophile Substitution unter C—C-Knupfung zu 2-Aryl-l -nitro-... 

In a related study, the reaction of the enamine, l,2-dihydro-3-(2-methoxymethyl-l-pyrrolidin-yl)naphthalene [from 3,4-dihydro-2(l//)-naphthalenonc and (S)-2-(methoxymethyl)pyrrolidine] with 2-aryl-l-nitroethenes gave, after hydrolysis, an 83 17 to 95 5 mixture of the (3S,YR)- and (1/ ,1 T )-nitro ketones31. 

Chinon-acylhydrazone lassen sich in milder Reduktion durch Erwarmen mit Ascorbinsaure in waBriger Losung zu Aryl-hydrazinen reduzieren (s.ds. Handb. Bd. X/2, S. 233). Die Herstellung des sehr empfindlichen 2-Hydroxylamino-l-nitro-benzols ist aus 1,2-Dinitro-benzol mit Ascorbinsaure moglich (s. Bd. X/l, S. 1149). Aryl-diazoniumsalze werden liber Oxalsaure-monoarylhydrazide zu Aryl-hydrazinen reduziert (s.Bd. X/2, S. 219). 

Hydroxy-butyl)-l-( -hydroxy-benzyl)- 296 Hydroxylamino- 474, 682 4-Hydroxylamino-l-athylthio- 684 Hydroxylamino-alk(aryl)oxy- 684 2-Hydroxylamino-1 -isopropenyl- 698 4-Hydroxyl amino-1 -methyl- 683 4-Hydroxylamino-1 -methylthio- 684 2-Hydroxylamino-l-nitro- 562 2-Hydroxylamino-l-[penten-(l)-yl-(2)J- 698 4-Hydroxylamino-l-phenylthio- 684 4-Hydroxylamino-1 -sulfonyl- 683 Hydroxymethyl- 499... 

It was shown that furoxans can be transformed to 1,2,3-triazoles. Thus, 4-acetylamino-3-arylazo-l,2,5-oxadiazole 2-oxides undergo two successive (cascade) mononuclear heterocyclic rearrangements in an aqueous basic medium with the formation of 4-acetylamino-2-aryl-5-nitro-2/7-l,2,3-triazoles (Equation 12) <2001MC230>, or 3,3 -disubsti-tuted 4,4 -azo-l,2,5-oxadiazole 2-oxides were found to undergo a rearrangement into 2-(furoxan-4-yl)-4-nitro-2//-1,2,3-triazole 1-oxides on heating in pertrifluoroacetic or peracetic acids (Equation 13) <2003MC272>. 

Arylazo-4-(3-ethoxycarbonylureido)furoxans 62, which were synthesized by the reactions of 4-amino-3-arylazo-furoxans with ethoxycarbonyl isocyanate, were subjected to cascade rearrangements under the action of potassium r/-butoxidc in dimethylformamide or by heating in dimethyl sulfoxide to form 4-amino-2-aryl-5-nitro-2//-l,2,3-triazoles 63 (Scheme 13) <2001MC230, 2003RCB1829>. 

Aryl-l,2-dihydro-3-nitro[l,8]naphthyridines have been obtained by the 6jt-thermal electrocyclization of l-(2-arylide-neamino-3-pyridyl)-2-nitroethylenes, obtained in situ from aromatic aldehydes and l-(2-amino-3-pyridyl)-2-nitroethylene in xylene <2002SC747>. 2-Chlorotetrahydro[l,8]naphthyridines have also been obtained from 2,6-dichloropyridines using a free radical xanthate-mediated cyclization <20040L3671>. 

So erhalt man aus 4-Formyl-benzofurazan-l-oxid mit primaren Aminen die entsprechenden 2-Alkyl-7-nitro- und 2-Aryl-7-nitro-2H-indazole (s.Bd.E8b)270 ... 

Bei Temperaturen zwischen — 70 und — 110° addieren sich hochreaktive Lithiumenolate und Schwefel-substituiertelithiumorganische Verbindungen glatt an 1-Nitro-l-alkene bzw. 2-Aryl-1-nitro-alkene (Michael-Addition)2 ... 

The reaction of sodium azide with l-bromo-l-nitro-2-arylethenes takes place by a formal 1,3-cycloaddition Scheme leading to 4(5)-aryl-5(4)-nitro-l,2,3-triazoles [487-489], During the synthesis of nitrotriazoles the bromonitroarylethenes can be replaced successfully by the more readily obtainable l,2-dibromo-l-nitro-2-arylethanes [489], The intermediate product in the synthesis of 3-nitropyrazoles from 2,2-dinitroethanol and diazo ketones or diazoacetic ester is 1,1-dinitroethene [490,491] (Scheme 68). 

H NMR spectroscopy was used for the investigation of 2-(2,4-dinitrophenyl)-4-nitro-l,2,3-triazole [600], 4-amino-3-(4-nitro-l,2,3-triazol-l-yl)furazan [601], 2-aryl(heteryl)-4-acetylamino-5-nitro-l,2,3-triazoles [141, 177, 602-604], nucleophilic substitution in the series of 4,5-dinitro-2-alkyl-l,2,3-triazoles [605] and 4,5-dinitro-2-aryl-l,2,3-triazole-l-oxides [606],... 

A modified Friedlander synthesis involving a-nitrocarbonyl and 2-aminocarbonyl compounds was reported (50JCS395, 51JCS2992, 53JCS3914,57JA1502). 2-Aryl-3-nitro-l,2-dihydroquinolines 197 was prepared from )S-nitrostyrenes 196 and 2-aminobenzaldehyde 17 using DABCO. Other alkyl nitro olefins were also used. When 2,3-dichloro-5, 6-dicyanoquinone (DDQ) is added to 3-nitro-l,2-dihydroquinolines 197,... 

Imidazolidin-2-one, l-(5-nitro-2-thiazolyl)-pharmacological activity, 6, 328 Imidazolidin-4-one, l-aryl-3-phenyl-2-thioxo- C NM S, 355 Imidazolidinones C NMR, 5, 355 Imidazolidin-2-ones nucleophilic displacement, 5, 428 polymers, 1, 279-280 reactivity, 5, 376 synthesis, 5, 466, 471 Imidazolidin-4-ones synthesis, 5, 468 Imidazoline, 2-alkyl-synthesis, 5, 463 Imidazoline, 2-amino-applications, 5, 498 Imidazoline, 2-aryl-synthesis, 5, 463 Imidazoline, 2-methyl-synthesis, 5, 487 Imidazoline, 2-nitroamino-synthesis, 5, 471 2-Imidazoline, 2-arylamino-tautomerism, 5, 368 2-Imidazoline, 1-benzyl-methylation, 5, 425 2-Imidazoline, 1,2-diaryl-synthesis, 5, 463... 

Arylisoxazol-5(4//)-oncs 21 react with benzene-1,2-diamines to yield 4-aryl-l,5-benzodiaze-pinones 22 by elimination of hydroxylamine from the intermediate oximes. Unsymmetrically substituted benzene-1,2-diamines are attacked at the more nucleophilic amino group. Thus, 4-methylbenzene-1,2-diamine gives 7-methylbenzodiazepinones 22f-h, whereas 4-nitrobenzene-1,2-diamine gives 8-nitro compounds 22k-n. The benzodiazepinones are accompanied by minor amounts of 2-methylbenzimidazoles 23. Selected examples are given.275... 

Azobenzol wird in fast quantitativer Ausbeute zu Hydrazobenzol reduziert (s.Bd. X/2, S. 716). Die Reduktion von l-Aryl-2-(4-nitro-benzoyl)-diazenen fiihrt unter Erhalt der Nitro-Gruppe zu2-Aryl-l-(4-nitro-benzoyl)-hydrazinen (s.Bd. XI/1, S. 453). In 4-Amino-azobenzol dagegen wird die Azo-Gruppe zum Amin reduziert, so daB 1,4-Diamino-benzol isolicrt wird (s.Bd. XI/1, S. 592). 

Nitro-azobenzole werden primar zu den analogen Hydrazobenzolen reduziert. In Ammoniakpuffer-Losung bildet sich an Quecksilber bei —0,5 bis —0,65 V quantitativ das 2-Aryl-2H-benzotriazol-l-oxid. Bei —1,0 bis —1,4 V entsteht ebenfalls quantitativ das... 

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