Water → 4-Bromo-1-phenyl-1H-pyrazole

Temperature

100 °C

A solution of bromine (1.1 g, 6.94 mmol) in acetic acid (10 mL) was added to a mixture of 1-phenylpyrazole (Aldrich, 1 g, 6.94 mmol) in acetic acid (10 mL). This mixture was warmed to 100° C. in a pressure tube for 8 h. The material was cooled to ambient temperature, poured into ice and H2O neutralized with excess saturated, aqueous NaHCO3. Ethyl acetate (50 mL) was added and the layers were separated. The aqueous layer was extracted with EtOAc (2×15 mL) and the combined organic extract was dried over Na2SO4 and concentrated under reduced pressure to give a crude solid. Purification by column chromatography (SiO2, 50% hexanes-EtOAc) provided the title compound (1.5 g, 6.72 mmol, 97% yield). MS (DCl/NH3) m/z 223, 225 (M+H)+.

1. temperatureThe material was cooled to ambient temperature
2. customthe layers were separated
3. extractionThe aqueous layer was extracted with EtOAc (2×15 mL)
4. extractionthe combined organic extract
5. dry with materialwas dried over Na2SO4
6. concentrationconcentrated under reduced pressure
7. customto give a crude solid
8. customPurification by column chromatography (SiO2, 50% hexanes-EtOAc)

ORD record

ord-d61ee454aa6348f4b2eac242bece53a8

Source dataset

uspto-grants-2011_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07872010B2