Ethanol → 3-chloro-1-(pyridin-3-yl)-1H-pyrazol-4-amine

Temperature

80 °C

In a 250 mL 3-neck round bottom flask was added 3-(3-chloro-4-nitro-1H-pyrazol-1-yl)pyridine (5.00 g, 21.8 mmol), ethanol (80 mL), water (40 mL), and ammonium chloride (5.84 g, 109 mmol). The suspension was stirred under nitrogen stream for 5 minutes then iron powder (4.87 g, 87.2 mmol) added. The reaction mixture was heated to reflux (˜80° C.) and held there for 4 hours. After 4 hours a reaction aliquot taken showed by HPLC analysis the reaction had gone to full conversion. Ethyl acetate (120 mL) and Celite® (10 g) were added to the reaction mixture and let stir for 10 minutes. The black colored suspension was then filtered via a Celite® pad and the pad rinsed with ethyl acetate (80 mL). The reaction mixture was washed with saturated sodium bicarbonate (30 mL) and the organic layer was assayed. The assay gave (4.19 g, 99%) of product. The organic solvent was removed in vacuo to give a brown colored crude solid that was used without further purification.

1. temperatureThe reaction mixture was heated
2. waitheld there for 4 hours
3. customAfter 4 hours a reaction
4. stirringlet stir for 10 minutes
5. filtrationThe black colored suspension was then filtered via a Celite® pad
6. washthe pad rinsed with ethyl acetate (80 mL)
7. washThe reaction mixture was washed with saturated sodium bicarbonate (30 mL)

ORD record

ord-7fc5455619084a47b7d7e7b24335c457

Source dataset

uspto-grants-2016_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09255083B2