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

To a solution of methyl 1-(2-bromoethyl)-3-nitro-1H-pyrazole-5-carboxylate (500 mg, 1.8 mmol) in tetrahydrofuran (20 mL) was cooled to 0° C. and lithium borohydride (78.3 mg, 3.6 mmol) was added in portions. The resulting mixture was allowed to warm to room temperature overnight. To the resulting mixture was added ethyl acetate (20 ml) and water (50 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. The residue was purified by flash chromatography (silica gel, AnaLogix system SF25-40 g column, 20% to 60% ethyl acetate in hexanes) to give (1-(2-bromoethyl)-3-nitro-1H-pyrazol-5-yl)methanol (158 mg, 35%) as a light yellow oil.

1. customThe biphasic mixture was separated
2. extractionaqueous layer extracted with ethyl acetate (3×20 mL)
3. dry with materialThe combined organic layers were dried over magnesium sulfate
4. filtrationthe resulting mixture was filtered
5. concentrationconcentrated in vacuo
6. customThe residue was purified by flash chromatography (silica gel, AnaLogix system SF25-40 g column, 20% to 60% ethyl acetate in hexanes)

ORD-Eintrag

ord-1246206081984c13ae9314308259a21a

Quelldatensatz

uspto-grants-2013_07

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08481540B2