683223-84-9

Upstream product

• 1189055-67-1 (4-tert-butyl-2,6-dimethylphenyl)(1,2-di-tert-butyldiaziridin-3-ylidene)amine 
• 1189055-54-6 N,N'-di(tert-butyl)-N-[4-(tert-butyl)-2-methylphenyl]-N-hydoxyguanidine O-sulfonic acid 

Relevant academic research and scientific papers

Thermal rearrangements of (arylimino)diaziridines by simultaneous cascades of pericyclic reactions

(Arylimino) diaziridines rearrange in several cascade reactions at temperatures 60-100 °C. Those that possess unoccupied ortho positions yield fluorescent: 3-amino-2H-indazoles and 2-amino-1H-benzimidazoles. If both ortho positions are blocked by methyl groups, indazoles are not formed and deeply yellow 2-imino-2,3-dihydro-3aH-benzimidazoles are formed, which partly dimerize through Diels-Alder reaction or regenerate the aromatic system, by formal loss of CH2. In addition, one of the methyl groups of 2,6-dimethylphenyl rings is involved in a [1,7] H shift affording orthoquinonoid intermediates which undergo 1,6-electrocyclization to furnish 2-amino-3,4-dihydroquinazolines. The formation of fivemembered ring heterocycles is interpreted in terms of valence isomerization by [1,3] N shift to yield elusive 1-ary 1-3iminodiaziridines as first step. These immediately experience triaza-Cope rearrangement to benzimidazole derivatives or electrocyclic opening of the N-C bond to generate conjugated azomethine imines (1,5-dipoles), followed by their 1,5electrocyclization to indazoles. First-order rate constants of the decay of (arylimino) diaziridines refer to the [1,3] N shifts as rate-determining steps. They are larger than the corresponding rate constants for alkylsubstituted iminodiaziridines.

Syntheses and15N NMR Spectra of Iminodiaziridines - Ring-Expansions of 1-Aryl-3-iminodiaziridines to 1H- and 3aH-Benzimidazoles, 2H-Indazoles, and 5H-Dibenzo[d,f] [1,3]diazepines

Iminodiaziridines are synthesized, by (i) 1,3-dehydrochlorination with potassium, teri-butoxide of N-chloroguanidines, generated in situ from. N,N′,N″-substituted guanidines with tert-butyl hypochlorite, and (ii) base-mediated 1,3-elimination of sulfuric acid from N,N',N″- substituted hydroxyguanidine O-sulfonic acids. At elevated temperatures, (alkylimino)diaziridines undergo valence isomerization by 1,3shift, [2+1] cycloelimination to afford isocyanides and diazenes, and ring-opening elimination to yield alkylideneguanidines. N′-Aryl-N-hydroxyguanidine O-sulfonic acids furnish (N-arylimino)diaziridines, but no 1-aryl-3- iminodiaziridines, instead giving rearranged isomere. Precursors containing perdeuterated feri-butyl groups give rearranged products that show complete scrambling. This indicates that l-aryl-3iminodiaziridines are intermediates that undergo very rapid I degenerate valence isomerization. Provided that the ortho aryl positions are substituted, high yields of (arylimino)diaziridines are obtained, along with 2-imino-2,3-dihydro-3aHbenzimidazoles, Otherwise, 2-amino-lH-benzimidazoles and strongly fluorescent 3-amino-2H-indazoles, originating from rearrangements of the elusive l-aryl-3-iminodiaziridines, predominate. N',N″-Diaryl-N-hydroxyguanidine O-sulfonic acids give only rearranged products: a 2-amino-1H-benzimidazole and a 6-amino-5H-dibenzo[d,f][1. 3]diazepine if aryl = phenyl, or a 2-imino-2,3-dihydro-3aH-benzimidazole if aryl = mesityl. 3aH-Benzimidazoles slowly dimerize through Diels-Alder reactions. 15N NMR signals were assigned, to the syn and anti ring nitrogen atoms of iminodiaziridines with the help of a combination of homonuclear NOE and HNHMBC or HN-gHMBC experiments.