Methanol → 3-bromo-1-(3,5-dichloropyridin-2-yl)-1H-pyrazole-5-carboxylic acid

To a 100 mL flask, ethyl 3-bromo-1-(3,5-dichloropyridin-2-yl)-1H-pyrazole-5-carboxylate (2.0 g, 5.5 mmol), methanol (10 mL), water (10 mL) and sodium hydroxide (0.3 g, 5.5 mmol) were added. After being stirred at room temperature for 1 hour, the mixture reacted completely. The reaction mixture was concentrated by rotary evaporator to about 10 mL as a dark brown solution. Then water (40 mL) was added into the dark brown solution. The aqueous solution was extracted with ethyl ether (50 mL) and acidified with concentrated hydrochloric acid to pH of 4. The precipitate was isolated by filtration, washed with water (2×50 mL) and dried to give the product (0.97 g) as white solid in 48% yield.

1. customthe mixture reacted completely
2. concentrationThe reaction mixture was concentrated by rotary evaporator to about 10 mL as a dark brown solution
3. additionThen water (40 mL) was added into the dark brown solution
4. extractionThe aqueous solution was extracted with ethyl ether (50 mL)
5. customThe precipitate was isolated by filtration
6. washwashed with water (2×50 mL)
7. customdried

ORD record

ord-0b484d9ea1354459b503e7336870e640

Source dataset

uspto-grants-2013_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08492409B2