Sodium Hydroxide → HCID 18962967, compound

Participants

Reaction Steps

1.2 g (1.9 mmol) 5-acetyl-1,4-dihydro-2,6-dimethyl-3-[5-(4,4-diphenyl-1-piperidinyl)pentanoyl)-4-(3-nitrophenyl)-pyridine hydrochloride are converted into the free base by shaking with excess 1N NaOH, and the base is extracted with ethyl acetate. The organic phase is dried over magnesium sulphate, filtered and concentrated. The residue is dried in vacuo and is then taken up in 30 ml anhydrous methylene chloride. 2.5 g(29 mmol) manganese dioxide are added. The mixture is stirred vigorously at room temperature for 12 h. Another 2 g (23 mmol) manganese dioxide are added in portions of 0.5 g each in the course of a further 8 h. The mixture is then centrifuged and the sediment is decanted off. The supernatant is concentrated and the residue is chromatographed over silica gel with toluene/acetone=8/2. The product thus obtained is taken up in 30 ml isopropanol, and 0.22 g (1.9 mmol) fumaric acid in 20 ml isopropanol is added. The title compound crystallized overnight. Yield: 0.7 g (52%). M.p.: 181°-190° C. decomp. (acetonitrile).

Provenance & Evidence