Photoreaktionen von 1‐Alkylbenztriazolen

Abstract

1. Einleitung. -Im Rahmen unserer Untersuchungen uber das photochemische Verhalten von Indazolen [ 11, Anthranilen [2], Benzisoxazolen [3] und 2,l-Benzisothiazolen [4] in saurem Milieu bzw. protischen Losungsmitteln [4] interessierten wir uns auch fur die Photoreaktionen von 1-substituierten Benztriazolen in protischen und aprotischen, aromatischen Losungsmitteln, woruber wir vor langerer Zeit I)

Nickel‐2,2′‐Bipyridyl and Palladium‐Triphenylphosphine Complex Promoted Synthesis of New π‐Conjugated Poly(2‐hexylbenzotriazole)s and Characterization of the Polymers

“…[12] The reaction of 1,2,3-benzotriazole, 1-bromohexane, and potassium tert-butoxide in methanol gave 2-hexylbenzotriazole (1a) and 1-hexylbenzotriazole (1b), and 1a and 1b were easily separated by column chromatography. The positions of the alkyl group in 1a and 1b was confirmed by comparison of 1 H NMR spectra of 1a and 1b with those of the reported 1R-and 2R-BTzs (R ¼ hexyl), although the reported 1 H NMR spectra [13] did not give a higher order of coupling patterns for the aromatic signals which are shown in Figures 1a and 1b.…”

“…The organic solution was condensed by evaporation and purified by column chromatography on SiO 2 (eluent ¼ CHCl 3 ) to afford 2 as a yellow oil; yield: 75%. Elemental analysis: predicted for C 12 s, 2H, aromatic).…”

“…Separation of 1a and 1b was reported to be a difficult procedure, [13] however, use of the column chromatography conditions made the separation easy. Elemental analysis: predicted for C 12 Compound 1a (4.8 g, 22 mmol) and an aqueous HBr (5.8 M) solution (20 mL) were added to a flask and the mixture was stirred for 1 h at 100 8C. Bromine (7.8 g, 48 mmol) was added and the mixture was stirred for 4 h at 135 8C.…”

Synthesis of P,N-2,2′-biphenyl derivatives with central chirality

“…The mixture was heated to 95 °C for 12 h. The crude product was extracted with CH 2 Cl 2 , dried over MgSO 4 and concentrated under reduced pressure. (2'-Bromo-biphenyl-2-yl)-methyl-amine (8) [12] A solution of aniline 7 (8.3 g, 23.7 mmol) in dry THF (100 mL) was added slowly at room temperature to a suspension of LiAlH 4 (2 g, 52.6 mmol) in dry THF (100 mL). The mixture was refluxed for 2 h under N 2 , cooled to room temperature and carefully treated with water (2 mL), aqueous sodium hydroxyde (15%, 2 mL) and water (6 mL).…”

The Graebe–Ullmann Carbazole‐Carboline Synthesis

“…The adaptation of the Graebe-Ullmann carbazole synthesis to indoles was apparently first described by Schmid's group [27,28], but Wender and Cooper parlayed the photochemistry of 1-alkenylbenzotriazoles into a viable indole synthesis (Scheme 6, equations 1, 2) [37]. The yield of cyclopent[b]indole was 44%.…”