Potassium Carbonate → 1-(propan-2-yl)-1H-pyrazol-3-amine

Temperature

45 °C

2-Chloroacrylonitrile (3.41 mL, 42.59 mmol) was added at RT to a stirring solution of N-isopropylhydrazine hydrochloride (4.71 g, 42.6 mmol), potassium carbonate (11.8 g, 85.2 mmol) in water (50 mL). The reaction was warmed to 45° C. for 4 hours before cooling back to RT. The aqueous layer was then extracted with ethyl acetate (5×30 mL) and the combined organic layers were dried (MgSO4), treated with activated charcoal, filtered and evaporated. The residue was purified by chromatography, eluting with 67%-100% ethyl acetate in hexanes, to afford the title compound (3.08 g, 58%) as a 6:1 mixture of authentic product to regioisomeric product as an oil. The material was used without further purification. 1H NMR δ (CDCl3): 1.42 (m, 6H), 3.58 (br. s, 2H), 4.25 (sept, 1H), 5.58 (d, 1H), 7.15 (d, 1H).

1. temperaturebefore cooling back to RT
2. extractionThe aqueous layer was then extracted with ethyl acetate (5×30 mL)
3. dry with materialthe combined organic layers were dried (MgSO4)
4. additiontreated with activated charcoal
5. filtrationfiltered
6. customevaporated
7. customThe residue was purified by chromatography
8. washeluting with 67%-100% ethyl acetate in hexanes

ORD record

ord-34fd04a03c0045169e87d2772a3a7e66

Source dataset

uspto-grants-2011_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07977328B2