1-Ethyl-3-(3'-dimethylaminopropyl)carbodiimide → 3-Phenyl-5-(1-phenylcyclohexyl)-1,2,4-oxadiazole

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A solution of 1-phenylcyclohexanecarboxylic acid (1 g, 4.9 mmol), EDAC (1.032 g, 5.39 mmol), HOBT (825 mg, 5.39 mmol), and N,N-diisopropylethylamine (2.57 mL, 14.69 mmol) in DMF (5 mL) was stirred at room temperature for 30 min under an argon atmosphere. (E)-N′-hydroxybenzimidamide (733 mg, 5.39 mmol) was added and the reaction mixture was heated to 95° C. for 8 h. The reaction mixture was cooled to room temperature and a portion (˜10%) was purified by automated preparative HPLC (PHENOMENEX® Luna Axia 21.2×100 mm 5 μm, Flow rate 20 mL/min, Gradient time 15 min, Mobile Phase: solvent A: 5% aq. MeOH, 0.05% TFA; solvent B: 95% aq. MeOH, 0.05% TFA). HPLC: tR=3.95 min, Waters Sunfire C18 4.6×50 mm, 4 min gradient, Detection Wave length 220 nm, Starting solvent: 10% aq. MeOH-0.1% TFA; Final solvent: 90% aq. MeOH-0.1% TFA to obtain 3-phenyl-5-(1-phenylcyclohexyl)-1,2,4-oxadiazole (60 mg). LC/MS: m/e 305.2 (M+H)+. 1H NMR (400 MHz, DMSO-d6): δ ppm 7.95-8.14 (2 H, m), 7.47-7.66 (3H, m), 7.31-7.44 (4 H, m), 7.17-7.31 (1H, m), 2.57-2.75 (2 H, m), 2.01-2.18 (2 H, m), 1.71 (2H, bs), 1.51-1.65 (1H, m), 1.27-1.51 (3 H, m).

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