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

Temperature

60 °C

Crude 3-(3-chloro-4,5-dihydro-1H-pyrazol-1-yl)pyridine (54.1 g, 232 mmol, 77.8% purity) was introduced into a 3 L three-neck round bottom flask. Water (530 mL) was then added. The mixture was heated to 60° C. and a potassium hydroxide solution (165 g, 2940 mmol) in water (500 mL) was added. The dark brown mixture was heated to 90° C. A potassium ferricyanide solution (253 g, 768 mmol) in water (700 mL) was added slowly over 30 minutes leading to brown-red mixture. The mixture was stirred at 90° C. for another 1.5 hours. The reaction mixture was cooled to below 45° C. and filtered. The filter cake was washed with water (300 mL) affording crude product as a brown solid. The crude product was then dissolved in acetonitrile (400 mL) and filtered. The organic filtrate was dried and concentrated to afford the title product as a brown solid (28.8 g, 69%, 94% purity).

1. temperatureThe dark brown mixture was heated to 90° C
2. temperatureThe reaction mixture was cooled to below 45° C.
3. filtrationfiltered
4. washThe filter cake was washed with water (300 mL)
5. customaffording crude product as a brown solid
6. filtrationfiltered
7. customThe organic filtrate was dried
8. concentrationconcentrated

ORD record

ord-0b39f45b79e14dbea0b4ef356a9ff862

Source dataset

uspto-grants-2016_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09414594B2