Ammonia → 2-Nitro-4,5,6,7-tetrahydropyrazolo[1,5-a]pyrazine

A 250-mL single-neck round-bottomed flask equipped with a magnetic stirrer was charged with 1-(2-bromoethyl)-5-(bromomethyl)-3-nitro-1H-pyrazole 125c (3.0 g, 9.64 mmol) in THF (35 mL) and aqueous ammonia (135 mL, 25-28%). The mixture was stirred at room temperature for 72 h under nitrogen. The reaction mixture was then concentrated under reduced pressure and the resulting residue was partitioned between ethyl acetate (100 mL) and water (100 mL). The aqueous layer was extracted with ethyl acetate (2×50 mL). The combined organic layer was washed with 10% potassium carbonate (2×100 mL), brine (200 mL), and dried over sodium sulfate. The drying agent was removed by filtration, and the filtrate was concentrated under reduced pressure to afford 205a as a yellow solid (1.23 g, 76%). MS: [M+H]+ 169

1. customA 250-mL single-neck round-bottomed flask equipped with a magnetic stirrer
2. concentrationThe reaction mixture was then concentrated under reduced pressure
3. customthe resulting residue was partitioned between ethyl acetate (100 mL) and water (100 mL)
4. extractionThe aqueous layer was extracted with ethyl acetate (2×50 mL)
5. washThe combined organic layer was washed with 10% potassium carbonate (2×100 mL), brine (200 mL)
6. dry with materialdried over sodium sulfate
7. customThe drying agent was removed by filtration
8. concentrationthe filtrate was concentrated under reduced pressure

ORD record

ord-c7e89dc1d97141ee84d5174c27a65d42

Source dataset

uspto-grants-2014_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08716274B2