Sodium hydride → HCID 21949844, compound

Participants

Reaction Steps

Sodium hydride (60% dispersion in oil, 250 mg, 6.17 mmol) was added to a stirred solution of 4-(3,5-dichlorophenoxy)-3,5-diethyl-1H-pyrazole (800 mg, 2.81 mmol, Example 3) in dry N,N-dimethylformamide (5 ml) at 0° C. under nitrogen. The mixture was stirred for 5 minutes during which time hydrogen was evolved and then ethyl 4-chloroacetoacetate (0.42 ml, 3.09 mmol) was added. After 30 minutes the reaction mixture was quenched by the addition of water (0.5 ml) and concentrated under reduced pressure. A solution of the residue in ethyl acetate (50 ml) was washed with saturated aqueous ammonium chloride solution (20 ml) and water (20 ml), dried over magnesium sulphate and concentrated under reduced pressure. The crude product was purified by flash chromatography on silica gel eluting with ethyl acetate:pentane (30:70, by volume) to provide the title compound (1.1 g) as a white solid, m.p. 82–84° C.

Provenance & Evidence