„Dimere des 1.2‐Dimethyl‐cyclobutadiens”︁

Abstract

Dimethylen-cyclobuten (1) addiert Chlorwasserstoff zu drei isomeren Dichlor-diniethyl-cyclobutenen (3a-c).

Sulfur dioxide extrusion from substituted 1,3-dihydro-1,3-diphenylthieno[3,4-b]quinoxaline 2,2-dioxides. Substituted 6-phenylbenzo[b]phenazines

“…In this paper we conclude our study of this sulfone system with a report on the preparation of cis-trans mixtures of two (4,9) symmetrically and five (5)(6)(7)(8)10) unsymmetrically substituted l,3-diphenyl-l,3-dihydrothieno [3,[4][5] [quinoxaline 2,2-dioxides and their response to similar oxidative and reductive methods of S02 extrusion.…”

“…The extrusion of S02 from cis-trans mixtures of 5,8-dimethyl- (4), 5-methyl-(5), 5-methoxy-(6), 5-nitro- (7), 5-amino-(8), 1,3,5,8-tetramethyl-(9), and 1,5-(10a) and l,8-dimethyl-l,3-diphenyl-l,3-dihydrothieno [3,[4][5][6]quinoxaline 2,2-dioxide (10b) by oxidative (alkaline hydrogen peroxide, oxygen, and peracetic acid) and reductive methods (Raney nickel and sodium borohydride) is reported. Thus, alkaline hydrogen peroxide oxidation of 4, 5, and 6 afforded, respectively, 2-benzoyI-3-benzyl-5,8-dimethylquinoxaIme ( 13) and separable mixtures of 2-benzoyl-3-benzyl-( 14) and 3-benzoyl-2-benzyl-5-methylquinoxaline (15) and 2-benzoyl-3-benzyl-( 16) and 3-benzoyl-2-benzyl-5-methoxyquinoxaline (17).…”

“…Caled for C24H20N2O2S: C, 71.97; , 5.03; N, 6.99. Found: C, 72.01; , 5.20; N, 7.00. cis-and irans-5-Methyl-1,3-diphenyl-1,3-dihydrothieno [3,[4][5]quinoxaline 2,2-Dioxide (5).-A solution of 12.5 g (0.042 mol) of A6 in 70 ml of absolute ethanol and 5.0 g (0.042 mol) of 2,3diaminotoluene in 30 ml of the same solvent was refluxed for 2 hr, cooled to room temperature, and filtered. The residue (14.0 g, 87%) was washed with ethyl ether and recrystallized (Darco) once from nitromethane to give 5 as a hard yellow powder: mp 230-230.5°dec; ir 7.54, 8.60, 8.78, and 8.86 µ (S02); uv max 220 µ (e 27,500), 244 (31,200), 304 (5800), and 320 (6900); nmr (CDC13) 8.0-7.2 (m, 14, aromatic), 5.83 (s, 4, CH), 2.71 (s, 3, CHS), and 2.66 (s, 3, CH3).…”

“…Caled for C23H18N202S: C, 71.48; H, 4.69; N, 7.25. Found: C, 71.34; H, 4.88; N, 7.45. cis-and írans-5-Methoxy-1,3-diphenyl-1,3-dihydrothieno [3,[4][5][6] quinoxaline 2,2-Dioxide (6).•-2,3-Dinitroanisole22 (3.0 g, 0.015 mol) in ethyl acetate was hydrogenated over 10% Pd/C in a Paar apparatus. The mixture was filtered and the solvent was removed in vacuo; the residual oil was dissolved in 60 ml of absolute ethanol; and, after addition of 3.3 g (0.011 mol) of A,6a the solution was refluxed for 2 hr.…”

Ein Beitrag zum Mechanismus der Entstehung von Cyclobutadien-Metall-Komplexen aus 3.4-Dihalogencyclobutenen

“…Äther gewonnen 11 . Neuere Untersuchungen zeigten, daß die Isomerenverteilung durch die Einleitungsgeschwindigkeit des Chlorwasserstoffs beeinflußt werden kann: schnelles Einleiten läßt bevorzugt das Isomere 1 a entstehen, während bei sehr langsamem Einleiten vergleichbare Mengen der Isomeren erhalten werden.…”