Reaktion #162804

Reaktionsgleichung

Intermediate 34a

Cyclohexanecarboxylic acid N′-(5-fluoro-pyridin-2-yl)-hydrazide

triphenylphosphine

triethylamine

hexachloroethane

→

title compound

Ausbeute 31.2%

3-Cyclohexyl-6-fluoro-[1,2,4]triazolo[4,3-a]pyridine

Ausbeute 31.2%

Lösungsmittel

Water

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.WAITat RT for 6 h
2. 2
   Waschenthe organics washed with brine
3. 3
   Trocknendried (MgSO4)
4. 4
   Einengenconcentrated in vacuo

Vorschrift

To a solution of Intermediate 34a (1.15 g, 4.83 mmol), triphenylphosphine (2.54 g, 9.67 mmol), and triethylamine (2.68 mL, 19.3 mmol) in dry THF (17 mL) at 0° C. under N2 was added hexachloroethane (2.28 g, 9.67 mmol), and the mixture stirred at 0° C. for 15 min, and at RT for 6 h. Water was added, then the organics washed with brine, dried (MgSO4) and concentrated in vacuo. Flash chromatography (silica gel, 0-100% EtOAc in cyclohexane) gave the title compound as an off-white solid (330 mg, 31%). 1H NMR (400 MHz, CDCl3): 1.36-1.55 (3H, m), 1.78-2.00 (5H, m), 2.05-2.14 (2H, m), 2.97 (1H, tt, J=11.5, 3.5 Hz), 7.16 (1H, ddd, J=10.0, 7.5, 2.3 Hz), 7.76 (1H, dd, J=10.0, 4.9, 0.9 Hz), 7.85 (1H, ddd, J=3.5, 2.2, 0.9 Hz).

Quelle