反应详情

Dissolve ethyl 4-acetyl-5-oxohexanoate (2.00 g, 9.99 mmol) in acetic acid (21 mL). Add methyl hydrazine (589 μL, 10.99 mmol) and stir at room temperature for 18 hr. Concentrate and dissolve residue in ethyl acetate. Wash ethyl acetate layer with saturated aqueous sodium bicarbonate solution. Extract aqueous layer twice with ethyl acetate, dry (magnesium sulfate), filter, concentrate and purify (silica gel chromatography, eluting with 0:100 to 100% ethyl acetate:hexanes) to give 3-(1,3,5-trimethyl-1H-pyrazol-4-yl)-propionic acid ethyl ester (1.95 g, 93%). MS (ES): m/z=211 [M+H]+.

1. concentrationConcentrate
2. dissolutiondissolve residue in ethyl acetate
3. dry with materialExtract aqueous layer twice with ethyl acetate, dry (magnesium sulfate)
4. filtrationfilter
5. concentrationconcentrate
6. custompurify
7. wash(silica gel chromatography, eluting with 0:100 to 100% ethyl acetate:hexanes)