Dimethylformamide → 1-(Pyridin-3-yl)-1H-pyrazol-3-amine

Temperature

110 °C

A 4-neck round bottomed flask (500 mL) was charged with copper(I) chloride (2.51 g, 25.3 mmol), 1H-pyrazol-3-amine (15.8 g, 190 mmol), potassium carbonate (35.0 g, 253 mmol), and N,N-dimethylformamide (100 mL). The mixture was stirred under nitrogen for 10 minutes and 3-bromopyridine (12.2 mL, 127 mmol) was added. The mixture was heated at 110° C. for 18 hours, at which point HPLC analysis indicated that ˜15.5% 3-bromopyridine remained. The reaction was allowed to cool to 20° C. and concentrated to give a brown residue. Water (200 mL) was added and the resulting suspension was stirred at 20° C. for 2 hours and filtered. The solid was rinsed with water (2×50 mL) and dried to afford a pale green solid. The solid was suspended in water (200 mL) and the resulting suspension was heated at 90° C. for 2 hours and was filtered hot through a Celite® pad. The pad was rinsed with hot water (50 mL). The combined filtrates were allowed to cool to 20° C. to afford a yellow suspension, which was stirred at 20° C. for 2 hours and filtered. The solid was rinsed with water (2×50 mL) and air dried to afford the desired product as a light yellow crystalline solid (11.6 g, 57%).

1. temperatureto cool to 20° C.
2. concentrationconcentrated
3. customto give a brown residue
4. stirringthe resulting suspension was stirred at 20° C. for 2 hours
5. filtrationfiltered
6. washThe solid was rinsed with water (2×50 mL)
7. customdried
8. customto afford a pale green solid
9. temperaturethe resulting suspension was heated at 90° C. for 2 hours
10. filtrationwas filtered hot through a Celite® pad
11. washThe pad was rinsed with hot water (50 mL)
12. temperatureto cool to 20° C.
13. customto afford a yellow suspension, which
14. stirringwas stirred at 20° C. for 2 hours
15. filtrationfiltered
16. washThe solid was rinsed with water (2×50 mL) and air
17. customdried

ORD record

ord-4fc1c4fd786a408290520406fad5e01a

Source dataset

uspto-grants-2015_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09108946B2