Pyridyl azides

Reisinger, A., Koch, R. and Wentrup, C. (1998) Dihydro-1,3-diazepinones and diazabicyclo[3,2.0]heptenones from pyridyl azides. Journal of the Chemical Society, Perkin Transactions 1, (15), 2247-2249. 

Sawanishi, H., Tajima, K. and Tsuchiya, T. (1987) Studies on diazepines. XXVI. Syntheses of 6H-l,4-diazepines and l-acyl-lH-l,4-diazepines from 4-pyridyl azides. Chemical e[ Pharmaceutical Bulletin, 35 (8), 3171-3181. 

Heteroaryl Azides - 2-Pyridyl azides exist in equilibrium with bicyclic tetrazoles, with the latter predominating under normal conditions. A number of trifluoromethyl-substituted derivatives of tetrazoles, e.g. (53), have been synthe-... 

Pyridyl azide (193) can be prepared by mild pyrolysis2228 or photolysis233 of tetrazolo[ 1,5-a]pyridine. Pyrolysis at 480°C222a or photolysis in argon... 

Chemical activation in azide and nitrene chemistry Methyl azide, phenyl azide, naphthyl azides, pyridyl azides, benzotriazoles, and triazo-lopyridines 137yC825. 

A number of pyridyl azides have been prepared by conventional methods. The reaction of 4-hydrazino-2-picoline with nitrous add, for example, gives 4-azido-2-picoline. 4-Azidopyridine-l-oxide is obtained in a similar manner. The reaction of 4-chloropyridine with sodium azide is less satisfactory, and gives the product in low yield. ... 

Photolysis of Ar matrix isolated trifluoromethyl-substituted 2-pyridyl azides/tetrazolo[l,5-a]pyridines at 12-18 K caused rapid and mostly clean... 

Diazacyclohepta-l,2,4,6-tetraene Rearrangements in the Trifluoromethyl-2-pyridyl Azide Series, 7. Amer. Chem. Soc., 1996,118,4009-4017. 

A. Reisinger, R. Koeh, C. Wentrup, Dihydro-l,3-diazepinones and diazabieyelo[3.2.0]heptenones from pyridyl azides, J. Chem. Soc. Perkin Trans. 1, 1998, 2247-2250. 

H. Sawanishi, K. Tajima, M. Osada, T. Tsuchiya, Photolysis of pyridyl azides in the presence of methoxide ions formation of fiiUy unsaturated 1,3- and 1,4-diazepines, Chem. Pharm. Bull., 1984,32,4694-4697. 

A number of trifluoromethyl-substituted 2-pyridyl azides, e.g., 97, have been matrix-isolated and photolyzed in Ar at 12-18 Like other 2-pyridyl azides, 97 exists in equilibrium with the tetrazole valence tautomer 98, but sublimation for the purpose of matrix isolation usually causes significant ring opening to the azido forms. In any case, the tetrazole forms as weU as the azides eliminate Nj when photolyzed. All the 2-pyridyl azides or tetrazoles investigated underwent conversion into the corresponding l,3-diazacyclohepta-l,2,4,6-tetraenes, e.g., 99 from 97, and these ring expanded products, which are cycHc carbodiimides, had v(N=C=N)35 bands at about 2000 cm" in their IR spectra. In the case of 97, the triplet nitrene was also observed by both IR and EPR spectroscopy, and it was seen to give 99 on further photolysis. 

Wentrup, C., Reisinger, A., Qiao, G.G., and Visser, R, Photochemistry of pyridyl azides and diazoketones in matrix and solution. Pure Appl. Chem., 69, 847,1997. 

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