Boron trifluoride → 3-(3,4-Dichlorophenyl)-1-[(3,5-dimethylphenyl)methoxy]-5-(4-hydroxy-4-phenyl-1-piperidinyl)-2-pentanone

Participants

Reaction Steps

Dissolve 3,5-dimethyl benzyl alcohol (1.32 g, 9.71 mmoles) in 4.0 ml of dry CH2Cl2 and add BF3 etherate (0.44 ml, 3.56 mmoles). Add a dry CH2Cl2 solution (2.0 ml.) of the product of Step 5 (0.7 g, 1.62 mmoles) dropwise at room temperature, under N2, over a period of 4.5 h. Stir the mixture at room temperature for another 30 min, then quench the reaction with water (6.0 ml) followed, after 10 min of stirring, by Et3N (2.0 ml). Stir for 15 min, then dilute with 90 ml of CH2Cl2. Wash the organic layer with water and dry it over anhydrous Na2SO4. Purify the reaction mixture by flash chromatography (SiO2), eluting the column first with 30% EtOAc/hexanes, then, after elution of the excess of 3,5-dimethyl benzyl alcohol, change the eluent to 40% EtOAc/Hexanes. Yield: 0.435 g. HRMS (FAB, M+H+): m/e calc'd for [C31H36NO3Cl2 ]+ : 540.2072; found 540.2075.

Provenance & Evidence