Hydrogen sulfide hydrazo compounds

The most widely used method for forming the benzo[c]cinnoline nucleus has been the reduction of 2,2 -dinitrobiphenyl (3) and its derivatives under alkaline conditions, analogous to the bimolecular reduction of nitroarenes. As in the latter reaction, the end product is a hydrazo compound (Scheme 1), in this case the cyclic 5,6-dihydrobenzo[c]cinnoline (6), but this is so easily oxidized back to the fully aromatic 1 that it is not isolated unless special precautions are taken (Section IV,D). Tauber originally employed 3% sodium amalgam in methanol or zinc and alkali to reduce 2,2 -dinitro-biphenyl, and these reagents have been used subsequently by other work-ers. ° Reductions using sodium sulfide or hydrosulfide and catalyst/hydrogen or catalyst/hydrazine systems have been used... 

Mild reduction to sensitive hydrazo compounds s. 1,18 Hydrogen sulfide Selective reduction of nitrazo compounds s. 1,19 HjS... 

HYDRAZOIC ACID, SODIUM SALT (26628-22-8) Reacts with hot water. Explosive decomposition in elevated temperatures above 525°F/274°C. Forms ultra-sensitive explosive compounds with heavy metals copper, copper alloys, lead, silver, mercury, carbon disulfide, trifluoroacryloyl fluoride. Violent reaction with acids, forming explosive hydrogen azide. Violent reaction with bromine, barium carbonate, chromyl chloride, dimethyl sulfate, dibromomalononitrile. Incompatible with caustics, cyanuric chloride, metal oxides, metal sulfides, methyl azide, phosgene. 

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