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Upstream product

• 75511-45-4 4-methyl-5-p-tolyl-2,5-diaza-1-oxapentadiene 
• 75511-46-5 1,4-dimethyl-5-p-tolyl-2,5-diaza-1-oxapentadiene 
• 75511-44-3 5-p-tolyl-1,1,4-trimethyl-1,2,5-triazapentadiene 
• 75511-42-1 3-methyl-1-phenyl-5-p-tolyl-1,2,5-triazapentadiene 
• 75511-43-2 4-methyl-1-phenyl-5-p-tolyl-1,2,5-triazapentadiene 
• 71467-88-4 N-acetonyl-4-methyl-2-nitro-N-p-tolylsulphonylaniline 

Relevant academic research and scientific papers

o-Nitroaniline Derivatives. Part 8. Synthesis of Some Unsymmetrical Dimethylquinoxalines: A Long-Standing Problem Resolved

Reduction of N-acetonyl-4-methyl-2-nitro-N-p-tolylsulphonylaniline, using tin(II) chloride in hydrochloric acid, gives 2,7-dimethylquinoxaline (42percent) together with di-p-tolyl disulphide and toluene-p-thiol. 2,6- and 2,5-Dimethylquinoxalines are similarly obtained from the appropriately substituted nitroanilines; the 2,8-dimethyl isomer, however, is obtained impure and in very low yield.

The Thermolysis of Polyazapentadienes. Part 3. Cyclisation of C-Methyl-1,2,5-triazapentadienes and Related Compounds: The Role of an Intermediate Spirodienyl Radical

A series of C-methyl-1,2,5-triazapentadienes and 2,5-diaza-1-oxapentadienes are prepared from pyruvaldehyde phenylhydrazones and oxime anils respectively.The 4-methyl derivatives show E/Z isomerism about the 4,5-double bond.Pyrolysis of the 5-phenyl derivatives (1), (3), (5), (7), and (10) causes cyclisation to 2-methylquinoxaline, though 2-phenyliminopropanonitrile is obtained from the oxime ester (9).Pyrolysis of the 5-p-tolyl derivatives (2), (4), (6), (8), and (11) qives mixtures of 2,6- and 2,7-dimethylquinoxaline.There are formed predominantly by the rearrangement reaction which involves the spirodienyl radical (19), but also by direct cyclisation of the iminyl radicals (17) and (18).