Imidazole aus Aldehyden, 1,2‐Diketonen und flüssigem Ammoniak. 3. Mitt. über Imidazolsynthesen mit flüssigem Ammoniak

Abstract

Bei der Darstellung von Imidazolen (3) aus aliphatischen oder aromatischen Aldehyden (1) und 1,2-Diketonen (2) in fliissigem Ammoniak unter Druck konnen die verschiedenen Moglichkeiten der C-Substitution des Imidazolkerns realisiert werden Imidazoles from Aldehydes, 1,2-Diketones and Liquid Ammonia If imidazoles (3) are prepared from aliphatic or aromatic aldehydes(1) and 1,Zdiketones (2) in liquid ammonia under pressure, all possibilities of C-substitution of the imidazole nucleus can be realized. * Teilergebnisse der Dissertation K. Wegner.1

A Practical Synthesis of 2,4(5)-Diarylimidazoles from Simple Building Blocks

“…2,4(5)-Diphenylimidazole (3a). 83% yield, mp 274−275 °C. 1 H NMR (300 MHz, DMSO- d 6 ): δ 7.46 (t, J = 7.23, 1H), 7.55 (t, J = 7.68, 2H), 7.66 (t, J = 3.24, 3H), 8.05 (d, J = 7.35, 2H), 8.30−8.33 (m, 3H).…”

.beta.1-Selective adrenoceptor antagonists: examples of the 2-[4-[3-(substituted amino)-2-hydroxypropoxy]phenyl]imidazole class. II

“…A third approach involved efforts to eliminate a direct ISA component by reducing the postulated interaction of the acidic imidazole proton with the receptor site by preparing 4-methyl-5-substituted-imidazoles as demonstrated by examples [24][25][26][27][28] In these examples, the tautomeric N-H group of the imidazole ring is always flanked by two substituents. This modification resulted in a decrease in selectivity and ISA (Table VI) on the basis of a comparison with 2…”

“…A mixture of 4-(benzyloxy)benzaldehyde (21.2 g, 0.1 mol) and diacetyl (8.6 g, 0.1 mol) in liquid NH3 (200 mL) was heated at 30-60 °C in a glass-lined bomb for 5 h at 370 psi. 28 The contents were then removed by rinsing with CH3OH, the mixture was filtered, and the fíltrate was concentrated to dryness. The residue was chromatographed on silica gel by eluting with 10% CH3OH-CHCI3 to yield 4.…”

“…Compound S-27 was prepared as described in method I for 5-21. (S )-5-Acetyl-2- [4-[3-[[2-(3,4-dimethoxyphenyl)ethyl]amino]-2-hydroxypropoxy]phenyl]-4-methylimidazole Dihydrochloride (28). Method F. To a solution of 3-(hydroxyimino)pentane-2,4-dione (23 g, 0.18 mol) in EtOAc (300 mL) was added p-methoxybenzylamine (24.4 g, 0.18 mol).…”