Ethyl Acetate → 3-(3-chloro-1H-pyrazol-1-yl)pyridine

Temperature

120 °C

3-Chloro-1-(pyridin-3-yl)-1H-pyrazole-5-carboxylic acid hydrochloride (1.00 g, 3.65 mmol) was stirred in N,N-dimethylformamide (10 mL). Copper(II) oxide (58.0 mg, 0.730 mmol) was added and the reaction was heated at 120° C. for 16 hours, at which point the reaction was ˜20% complete. Additional copper(II) oxide (112 mg, 1.46 mmol) was added and the reaction was stirred for 5 hours, at which point the reaction was complete by thin layer chromatography (TLC) [Eluent: ethyl acetate]. The mixture was diluted with ammonium hydroxide (NH4OH) and water and extracted with ethyl acetate. The organic layer was washed with 15% lithium chloride and concentrated to provide an orange solid. The residue was purified by flash column chromatography using ethyl acetate as eluent and the pure fractions were concentrated to afford the desired product as a white solid (481 mg, 69.7%). The spectral characterization was in agreement with the product prepared previously.

1. extractionextracted with ethyl acetate
2. washThe organic layer was washed with 15% lithium chloride
3. concentrationconcentrated
4. customto provide an orange solid
5. customThe residue was purified by flash column chromatography
6. concentrationthe pure fractions were concentrated

ORD record

ord-e057a9d09fff4e41a0af34e569f9968e

Source dataset

uspto-grants-2016_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09434712B2