1.2.3- Triazole 5- nitro-2-phenyl

Unter zusatzlicher Gerustumlagerung reagieren l-(2-Nitro-phenyl)-4,5-dihydro-l,2,3-triazole... 

SO3H H0-ttn=nh n02 H03S> s NH2 Cu2B/H202 Cu /02/Pyridin so3h ho XYn n TVno2 5, S-Disulfo-6-kydroxy-2- (4-nitro-phenyl)-2H-(napktho 1,2-d triazol E8 ... 

S -Nilxo-2- [4-nitro- enyl]-[naphtiio-l. 2 4.S-triazol] 86 U 45. 8 -Nitro-2-[4-nitro-phenyl]-[naphtho-l. 2 4.5-tria >l] 86 II 45. duB,Ns0 4.6-l>iiiitro.2.a-naphthy l.benz. triazol-l-oxyd 86, S3. 

Attempted dehydrocyclization of the 6-acylhydrazinopyrimidine 65 by heating with polyphosphoric acid led, instead, to pyrimidine ring rupture, yielding the l,l-diamino-2-nitro-2-(3-phenyl-l,2,4-triazol-5-yl)ethene 66. Cyclocondensation of the latter with triethyl orthoformate gave the fully aromatic triazolopyrimidine 67 (94JHC1171) (Scheme 23). 

A nitro group in the 4-position markedly increases the instability of the isoxazole ring in alkaline medium. This effect is clearly demonstrated by 3,5-dime thy 1-4-nitroisoxazole. Whereas 3,5-dimethyl-isoxazole is not affected by alkali, its 4-nitro-derivative (134) is cleaved by 2% sodium hydroxide. The structure of the product was proved by its conversion into a triazole (135) with phenyl diazonium chloride, according to the original authors. ... 

Three methods for making 4,5,6,7-tetrahydrotriazoIopyridines use two fragments to form the triazole ring. The lithium derivative of A/-nitro-sopiperidine reacts with benzonitrile to give the 3-phenyl derivative 19.28 Diazonium salts react with a-amino acids to give mesoionic triazole oxides if pipecolic acid is used, the product is a tetrahydrotriazolopyridine 3-oxide... 

Reaction of 1-azidoadamantane with nitro and sulfoxy olefins (Scheme 77, R = H or Ph and X = N02 R = Ph and X = SOPh) leads directly to the triazoles two isomers are obtained from the /i-nitrostyrene reaction with the 5-phenyl-1-adamantyltriazole as the major product.155 Likewise, triazoles are the only products formed in the reaction of aryl azides with /J-nitrostyrene (Scheme 77)294,295 however, unlike the azidoadamantane reaction, a... 

The first study of the nitration of 2-phenyl-1,2,3[2//]-triazole suggested that the products, using mixed acid at 20°C, were the ortho and para isomers (48JOC815). However, later work showed the two products to be the para isomer and the 4-nitro-2-(4-nitrophenyl) dinitrated product. Further nitration gives the 4-nitro-2-(2,4-dinitrophenyl) trinitrated product. Exclusive mononitration to produce the 4-nitrophenyl product can be effected using nitric acid in acetic anhydride (63CJC274). 

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