ethyl 3-(1,3,5-trimethyl-1H-pyrazol-4-yl)propanoate → 3-(1,3,5-Trimethyl-1H-pyrazol-4-yl)-propionaldehyde

Participants

Reaction Conditions

Reaction Steps

Dissolve 3-(1,3,5-trimethyl-1H-pyrazol-4-yl)-propionic acid ethyl ester (1.94 g, 9.23 mmol) in tetrahydrofuran (78 mL). Cool to −78° C. in a dry ice/acetone bath and treat dropwise with 1 M diisobutylaluminum hydride in toluene (10.15 mL). Stir reaction mixture at −78° C. for one hr. and add 1 M diisobutylaluminum hydride in toluene (10.15 mL). Stir reaction mixture at −78° C. for one hr. and add 1 M diisobutylaluminum hydride in toluene (10.15 mL). Stir reaction mixture at −78° C. for 1 hr. and add 1 M diisobutylaluminum hydride in toluene (10.15 mL). Stir reaction mixture at −78° C. for 1 hr. and quench with aqueous saturated potassium sodium tartrate tetrahydrate solution. Add ethyl acetate (150 mL), and stir for 3 hr. at room temperature. Separate organic layer, extract aqueous layer 3 times with ethyl acetate, dry (magnesium sulfate), filter, concentrate and purify (silica gel chromatography, eluting with 1:1 to 100% ethyl acetate:hexanes), to give the title preparation (760 mg, 51%). GC-MS m/z=166 [M+].

Provenance & Evidence