C([O:3][C:4]([C:6]1[N:7]([C:15]2[CH:20]=[CH:19][C:18]([CH3:21])=[CH:17][CH:16]=2)[N:8]=[C:9]([C:11]([CH3:14])([CH3:13])[CH3:12])[CH:10]=1)=O)C.C1COCC1.CC(C[AlH]CC(C)C)C>C(OCC)C>[C:11]([C:9]1[CH:10]=[C:6]([CH2:4][OH:3])[N:7]([C:15]2[CH:16]=[CH:17][C:18]([CH3:21])=[CH:19][CH:20]=2)[N:8]=1)([CH3:14])([CH3:12])[CH3:13]To an oven dried round bottom flask containing 5-tert-Butyl-2-p-tolyl-2H-pyrazole-3-carboxylic acid ethyl ester (0.64 g, 2.2 mmol) was added anhydrous THF (20 mL) followed by the drop wise addition of DIBAL-H (0.96 mL, 4.9 mmol) under nitrogen. After stirring at room temperature for 30 minutes the reaction was diluted with 100 mL diethyl ether and quenched with 5 mL Methanol stirring for an additional 30 minutes at room temperature. The resulting slurry was treated with 5 g MgSO4 and filtered through a pad of diatomaceous earth. The filter cake was washed with 3×75 mL portions of ether and the combined filtrates concentrated under vacuo to afford the desired alcohol as a clear oil (0.515 g, 96%). No further purification was necessary. Expected mass=244. Observed mass=245.
Wird geladen…
