68167-79-3Relevant academic research and scientific papers
Diazepines. Part 25. Preparation and Properties of 6-Aryl-2,3-dihydro-1,4-diazepinium Salts. Electronic Interaction between the Rings and Steric Inhibition thereof
Lloyd, Douglas,Tucker, Kanwaljit S.,Marshall, Donald R.
, p. 726 - 735 (2007/10/02)
A variety of 6-aryldihydrodiazepinium salts (including also 6-biphenyl-4-yl, 6-α-naphthyl, and 6-N-pyridyl) has been prepared, mostly by reactions of 1,2-diamines with 3-aryl-1,5-diazapentadienium salts.The electron-rich dihydrodiazepinium cation activates the 6-aryl substituent towards electrophilic attack, and halogenation and nitration take place at the p-position.Substituents vicinal to the ring junction in either the six- or seven-membered rings inhibit this reactivity, presumably by preventing coplanarity of the two rings; the 13C n.m.r. spectra of these vicinally substituted compounds also show the lowered electronic interactions between the rings.NN'-diphenyl and NN'-dibenzyl substituents also inhibit electrophilic substitution in the 6-phenyl ring.Solution in deuteriosulphuric acid generates a stable radical species.Nucleophiles (monoamines, diamines, sodium hydroxide) attack the 5- and 7-positions of the diazepine ring.The 13C n.m.r. and mass spectra of these compounds are discussed.
