7092-76-4Relevant academic research and scientific papers
DIAZABICYCLOALKANES WITH NITROGEN ATOMS IN THE NODAL POSITIONS. 10. INTRAMOLECULAR CYCLIZATION OF β-BROMOETHYL-AND γ-BROMOPROPYL-N,N'-ALKYLENE-o-PHENYLENEDIAMINES
Gall', A. A.,Shishkin, G. V.
, p. 553 - 558 (1983)
The overall scheme of the intramolecular cyclization of bromoalkyl derivatives of N,N'-alkylene-o-phenylenediamines in HBr was established, and the rates of the individual steps of this complex process were estimated.It is shown that N-(β-bromoethyl)-N,N'-trimethylene-o-phenylenediamine undergoes virtually irreversible cyclization at a high rate to give benzo-1,5-diazabicyclo-nonene in significant yield, while the cyclization of N-(γ-bromopropyl)-1,2,3,4-tetrahydroquinoxaline proceeds at commensurable rates via two pathways, viz., C- and N-alkylation.This makes it impossible to use the latter reaction to obtain benzo-1,5-diazabicyclononene in high yield.
DIAZABICYCLOALKANES WITH NITROGEN ATOMS IN THE NODAL POSITIONS. 9. INTRAMOLECULAR CYCLIZATION OF N-(γ-BROMOPROPYL)-TETRAHYDROQUINOXALINES AND BEHAVIOR OF BENZO-1,5-DIAZABICYCLONONENE IN HYDROBROMIC ACID
Gall', A. A.,Shishkin, G. V.
, p. 549 - 553 (2007/10/02)
The introduction of an N,N'-trimethylene bridge in the tetrahydroquinoxaline molecule is complicated by cyclization of γ-bromopropyl derivatives of tetrahydroquinoxaline at the carbon atom of the aromatic ring.The reaction of N-R-tetrahydroquinoxalines (R = H, COCH3) which 1,3-dibromopropane leads to products of cyclization at the aromatic ring (1,2,3,5,6,8,9,10-octahydropyrazinophenanthroline and N-acetyl-1,2,6,7-tetrahydro-3H,5H-pyridoquinoxaline) and to an N-alkylation product .Benzo-1,5-diazabicyclononene is formed in only trace amounts in the cyclization of N-(γ-bromopropyl) tetrahydroquinoxaline and upon heating in HBr can be isomerized with migration of the trimethylene bridge to the aromatic ring.
