Pyruvaldehyde 2-phenylhydrazone

The name phenylosazone formazan is suggested for this group of compounds, of which a few simple representatives have been known for some time, such as those where R = CH3 or R = CO2H however, these were not made from osazones, but by treatment of the corresponding a-keto-formazans with phenylhydrazine (as shown in the lower left of the above equation). For example, pyruvaldehyde phenylosazone formazan (C-acetyl-A, A -diphenylformazan phenylhydrazone) was prepared by Bamberger and Lorenzen as early as 1892 by condensation of acetyl-formazan with phenylhydrazine. The violet or brownish-black color characteristic of all known compounds of this group can be attributed to the three chromophoric groups present in the structure. 

T. Umemoto, T. Kawashima, Y. Sakata, and S. Misumi, Tetrahedron Letters, 1005 (1975). Pyruvaldehyde 2-phenylhydrazone (2-Phenylhydrazonopropanal), ct ccHO... 

Thiazolylhydrazone, in P-00405 Pyridoin phenylhydrazone, P-00413 Pyridoxal nicotinoylhydrazone, P-00415 Pyridoxal Salicyloylhydrazone, in P-00414 l)/-Pyrrole-2-carboxaldehyde 8-quinolinylhydrazone, P-00438 Pyruvaldehyde l-(2-... 

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