Carbon tetrabromide → HCID 19360610, compound

Participants

Reaction Steps

10.2 g (0.33 mol) of 2-(3-hydroxymethyl-piperidin-1-yl)-2-methyl-1-[4-(methylthio)-phenyl]-propan-1-one and 10.5 g of triphenylphosphine are dissolved in 60 ml of methylene chloride. 13.3 g of carbon tetrabromide is dissolved in 15 ml of methylene chloride and is added dropwise to the above solution at 5 ° C. After stirring for 2 h, the resulting solution is concentrated to give a slurry. This material is purified by column chromatography on silica gel with ethyl acetate-hexane (50-50) as an eluent, and an oily product is obtained. The resulting material is used for the next reaction. 13.0 g of the above oily product is dissolved in 80 ml of dried dimethylacetamide and 4.95 g of potassium thioacetate is added. After stirring for 2.5 h at 50 ° C., the reaction mixture is poured into ice-water and extracted with ethyl acetate. The combined organic layer is washed with saturated sodium chloride solution and died over MgSO4. The solvent is removed by evaporator and the crude oil is further purified by column chromatography on silica gel with ethyl acetate-hexane (10:90) as an eluent, and an oily product is obtained. The product is dissolved in 40 ml of ethanol and the solution is bubbled by nitrogen for 10 min. to remove oxygen. To the solution are added 10 ml of 2N sodium hydroxide solution and stirred at 0° C. for 1 h. After the reaction mixture is neutralized by adding 2N hydrochloric acid solution, the resulting solution is poured into 10 ml of water and extracted with ethyl acetate. The organic layer is washed with water and saturated sodium chloride solution, and dried over MgSO4. After ethyl acetate is distilled off, the residue is purified by means of column chromatography on silica gel with ethyl acetate-hexane (5-95) as an eluent, and an oily product is obtained. The structure is confirmed by the 1H-NMR spectrum (CDCl3): δ [ppm] 1.02 (m, 1H), 1.26 (t, 1H), 1.29 (s, 3H), 1.30 (s, 3H), 1.43-1.55 (m, 1H), 1.61-1.66 (m, 2H), 1.87 (m, 1H), 2.06 (m, 1H), 2.23 (m, 1H), 2.40 (t, 2H), 2.52 (s, 3H), 2.69 (m, 1H), 2.88 (d, 1H), 7.22 (d, 2H), 8.49 (d, 2H).

Provenance & Evidence