Ethyl Bromide → N-(3-chloro-1-(pyridin-3-yl)-1H-pyrazol-4-yl)-N-ethylacetamide

Temperature

58 °C

To a 3-neck, 100-mL round bottom flask was charged N-(3-chloro-1-(pyridin-3-yl)-1H-pyrazol-4-yl)acetamide (1.66 g, 7.0 mmol) and tetrahydrofuran (16 mL). Sodium tert-butoxide (0.843 g, 8.77 mmol, 1.25 eq) and ethyl bromide (0.78 mL, 10.52 mmol, 1.5 eq) were added and the reactor was capped with a septa. The reaction was stirred at 58° C. for 24 hours, at which point HPLC analysis indicated that only 1.97% starting material remained. The mixture was concentrated to give a brown residue, which was dissolved in water (20 mL) and ethyl acetate (20 mL). The aqueous layer was extracted with ethyl acetate (2×20 mL) and the combined organics were concentrated to dryness. The residue was passed through a silica gel plug (40 g silica) and eluted with ethyl acetate (200 mL). The filtrates were concentrated to dryness and further dried under vacuum at 20° C. to afford a yellow solid (1.68 g, 89%). Characterization matched sample prepared by previous method.

1. customthe reactor was capped with a septa
2. concentrationThe mixture was concentrated
3. customto give a brown residue, which
4. extractionThe aqueous layer was extracted with ethyl acetate (2×20 mL)
5. concentrationthe combined organics were concentrated to dryness
6. washeluted with ethyl acetate (200 mL)
7. concentrationThe filtrates were concentrated to dryness
8. customfurther dried under vacuum at 20° C.

ORD record

ord-ef083e6f33fc4279955262d2e3c20a11

Source dataset

uspto-grants-2016_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09434712B2