Water → (1-(2-bromoethyl)-3-nitro-1H-pyrazol-5-yl)methanol

To a suspension of lithium borohydride (755 mg, 34.7 mmol) in tetrahydrofuran (100 mL) at 0° C. was added a solution of methyl 1-(2-bromoethyl)-3-nitro-1H-pyrazole-5-carboxylate (4.82 g, 17.3 mmol) in tetrahydrofuran (10 mL) drop wise maintain a temperature below 0° C. The resulting solution was allowed to stir at room temperature for 2 h. To the resulting mixture was slowly added ethyl acetate (20 ml) and water (20 ml). The biphasic mixture was separated and aqueous layer extracted with ethyl acetate (3×20 mL). The combined organic layers were dried over magnesium sulfate and the resulting mixture was filtered and concentrated in vacuo to give (1-(2-bromoethyl)-3-nitro-1H-pyrazol-5-yl)methanol (4.24 g, 98%) as a light yellow oil.

1. temperaturedrop wise maintain a temperature below 0° C
2. customThe biphasic mixture was separated
3. extractionaqueous layer extracted with ethyl acetate (3×20 mL)
4. dry with materialThe combined organic layers were dried over magnesium sulfate
5. filtrationthe resulting mixture was filtered
6. concentrationconcentrated in vacuo

ORD record

ord-e89407bc11fc4aa4ad839d45bd35d3ed

Source dataset

uspto-grants-2015_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08940741B2