Potassium Hydroxide → 3-(3-chloro-1H-pyrazol-1-yl)pyridine

Temperature

60 °C

3-(3-Chloro-4,5-dihydro-1H-pyrazol-1-yl)pyridine (362 mg, 2.0 mol) was introduced into a 25 mL vial. Potassium hydroxide solution (658 mg, 85% pure) in water (H2O) (4.0 mL) was added and the mixture was heated to 60° C. Potassium ferricyanide solution (656 mg in 1.0 mL water) was added over 15 minutes leading to brown mixture. The mixture was stirred at 62° C. for another 15 minutes. Potassium persulfate solution (270 mg, 1.0 mmol, 0.5 eq.) in water (1.0 mL) was added in one portion. The mixture was stirred at 60° C. and monitored by LC. Additional two portions of potassium persulfate solution (270 mg, 1.0 mmol, 0.5 eq.) in water (1.0 mL) was added at 1.5 hours and at 2.5 hours. The reaction mixture was stirred for a total 4.5 hours and LC indicated 88.0% conversion. The mixture was then stirred at 75° C. for 1.5 hours and LC indicated >90% conversion. After filtration, the filter cake was washed with water (10 mL) affording crude product as a pale brown solid. The crude product was then washed with acetonitrile (2×15 mL). The organic filtrate was dried and concentrated to afford desired product as light brown solid (328 mg, 91.6%, 94.0% pure by LC).

1. stirringThe mixture was stirred at 60° C.
2. stirringThe reaction mixture was stirred for a total 4.5 hours
3. stirringThe mixture was then stirred at 75° C. for 1.5 hours
4. filtrationAfter filtration
5. washthe filter cake was washed with water (10 mL)
6. customaffording crude product as a pale brown solid
7. washThe crude product was then washed with acetonitrile (2×15 mL)
8. customThe organic filtrate was dried
9. concentrationconcentrated

ORD record

ord-bb47a5551072442d8ea1d64e6d490c95

Source dataset

uspto-grants-2016_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09414594B2