Dimethyl Sulfoxide → 6-Chloro-4-methoxy-pyrazolo[1,5-a]pyrazine

Temperature

110 °C

Crude 6-chloro-4-methoxypyrazolo[1,5-a]pyrazine-3-carboxylic acid from above (611 mg, 2.68 mmol) was dissolved along with palladium(II) trifluoroacetate (401 mg, 1.2 mmol) in DMF (24 mL). DMSO (1.6 mL) and TFA (2 mL, 26 mmol) were added and the resulting mixture was heated to 110° C. After stirring 2.5 h, the reaction mixture was cooled and filtered. The filtrate was concentrated in vacuo and was partitioned between EtOAc, saturated aqueous NaHCO3 and water. The phases were separated, and the aqueous phase was extracted with EtOAc. The combined organic phase was washed with water and was dried over Na2SO4, filtered, and concentrated. The concentrate was purified by silica gel (5-30% EtOAc in hexanes) to provide 6-chloro-4-methoxypyrazolo[1,5-a]pyrazine 5.36. LCMS-ESI+ (m/z): [M+H]+ calcd for C7H7ClN3O: 184.0; found: 184.2.

1. temperaturethe reaction mixture was cooled
2. filtrationfiltered
3. concentrationThe filtrate was concentrated in vacuo
4. customwas partitioned between EtOAc, saturated aqueous NaHCO3 and water
5. customThe phases were separated
6. extractionthe aqueous phase was extracted with EtOAc
7. washThe combined organic phase was washed with water
8. dry with materialwas dried over Na2SO4
9. filtrationfiltered
10. concentrationconcentrated
11. customThe concentrate was purified by silica gel (5-30% EtOAc in hexanes)

ORD record

ord-32180541b22843c1a2e236066ff4398d

Source dataset

uspto-grants-2016_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09376441B2