Ethanol → HCID 178469268, compound

Temperature

100 °C

A 100 mL Schlenk tube was dried under vacuum, filled with nitrogen and charged with 0.5 g (4.461 mmol, 1.0 eq) 1H-pyrazol-3-carboxylic acid which was dissolved in 20 mL EtOH. After adding 1.31 g (0.72 mL, 13.382 mmol, 3.0 eq) conc. H2SO4 the colorless reaction mixture was heated to reflux (100° C.) and stirred at this temperature for 4 h. TLC analysis (DCM/MeOH 95:5) indicated full conversion of the starting material. After cooling to rt the mixture was transferred to a flask to remove the solvent at a rotary evaporator. The colorless residue was diluted in 20 mL water and neutralized with 17 mL saturated aqueous NaHCO3 solution. Thereby a white solid precipitated. The aqueous layer was extracted with EtOAc (4×50 mL), dried over MgSO4 and the solvent was evaporated under reduced pressure to yield the pure title compound.

1. customA 100 mL Schlenk tube was dried under vacuum
2. additionfilled with nitrogen
3. temperaturewas heated
4. temperatureAfter cooling to rt the mixture
5. customwas transferred to a flask
6. customto remove the solvent
7. customat a rotary evaporator
8. additionThe colorless residue was diluted in 20 mL water and neutralized with 17 mL saturated aqueous NaHCO3 solution
9. customThereby a white solid precipitated
10. extractionThe aqueous layer was extracted with EtOAc (4×50 mL)
11. dry with materialdried over MgSO4
12. customthe solvent was evaporated under reduced pressure

ORD record

ord-fff8d665f0c44e9cb412c6a8c2dcd30c

Source dataset

uspto-grants-2015_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09206115B2