Methanol → 3-Amino-5-methyl-4-(4-phenylthiophenyl)pyrazole

Temperature

0 °C

A mixture of 520 mg of α-acetyl-4-phenylthiophenylacetonitrile, 217 mg of semicarbazide hydrochloride, 15 ml of methanol and 3 ml of water was stirred at 0° C. for 10 minutes. Removing the ice bath, 40 hours later, the mixture was stirred at room temperature for 1 hour while keeping the pH at 9 to 10 by using aqueous solution of 2N sodium hydroxide. Adding 50 ml of water, the mixture was stirred for 30 minutes in ice-cooling, and the precipitate was filtered. It was directly added to the mixed solution of 5 ml of aqueous solution of 2N sodium hydroxide and 50 ml of methanol, and the mixture was stirred for 4 hours at room temperature, and then 80 ml of water was added, and the mixture was stirred for 30 minutes in ice-cooling, then the precipitate was filtered, Washed in water and dried, thereby obtaining 500 mg of the title compound.

1. customRemoving the ice bath, 40 hours later
2. stirringthe mixture was stirred at room temperature for 1 hour
3. additionAdding 50 ml of water
4. stirringthe mixture was stirred for 30 minutes in ice-
5. temperaturecooling
6. filtrationthe precipitate was filtered
7. additionIt was directly added to the mixed solution of 5 ml of aqueous solution of 2N sodium hydroxide and 50 ml of methanol
8. stirringthe mixture was stirred for 4 hours at room temperature
9. addition80 ml of water was added
10. stirringthe mixture was stirred for 30 minutes in ice-
11. temperaturecooling
12. filtrationthe precipitate was filtered
13. washWashed in water
14. customdried

ORD record

ord-0e139b0d9c6a49fbb305c957012777d5

Source dataset

uspto-grants-1995_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05420128