Benzo[f]isoindole analogs II. Thieno[3,4‐b]quinoxaline

Abstract

The transient existence of thieno[3,4‐b]quinoxaline (2d) as a product of dehydration of 1,3‐dihydrothieno[3,4‐b]quinoxaline 2‐oxide (5) was demonstrated by trapping experiments with N‐phenylmaleimide and dimethyl acetylenedicarboxylate. Attempts to isolate 2d from reaction mixtures arising from dehydration of 5 and from dehydrogenation of 1,3‐dihydro‐thieno[3,4‐b]quinoxaline (8) were unsuccessful.

Synthesis of Amino‐ and Bis(bromomethyl)‐Substitued Bi‐ and TetradentateN‐Heteroaromatic Ligands: Building Blocks for Pyrazino‐Functionalized Fullerene Dyads

“…The synthesis of bis(bromomethyl)-substituted quinoxaline derivatives by the condensation of 1,4-dibromo-2,3-butanedione 33, that can be easily prepared according to a literature procedure, [25] with appropriate diamines in ethanol at 0°C was reported by Roland et al [26] By analogy, the diketone 33 was reacted with an excess of phendiamine 13 affording the bis(bromomethyl)-substituted pphen derivative 29a in 83 % yield. In contrast to the published procedure refluxing of the reaction mixture was required.…”

Synthesis of Stable Seleno[3,4-b]quinoxaline Derivatives

“…Theoretical analysis indicates that polymers derived from the parent 1 should exhibit an exceptionally small band gap, making this heterocycle attractive in the field of conducting π-conjugated polymers. In earlier studies, the transient formation of 1 was shown by trapping experiments with N -phenylmaleimide . Recently, we reported the synthesis of 1 by a base-catalyzed Pummerer reaction .…”

Novel dicyanomethylene compounds from the reaction of 2-aryl-2,3-dihydro-1H-pyrrolo[3,4-b]quinoxalines with ethenetetracarbonitrile

“…[1][2][3][4][5][6] A π-deficient anellation should make the pyrrole ring more stable towards electrophilic attack. 5 On the other hand, the successful [4+2]-cycloaddition of electron deficient dienophiles, namely dimethyl ethynedicarboxylate and N-methylmaleimide, to 2-tertbutylpyrrolo [3,4-b]quinoxaline has been reported.…”