86663-66-3Relevant academic research and scientific papers
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 (1983)
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.
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 (2007/10/02)
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.
