反应详情

温度

0 °C

To an ice cold solution of 1-dimethylamino-4-phenyl-2-butyne (0.5 g; prepared by the Mannich reaction of 3-phenyl-1-propyne with formaldehyde and dimethylamine as per Mornet, et.al. Bull.Soc.Chim.Fr. 1974, 206) in dichloromethane (12 ml) was added in small portions 3-chloroperoxybenzoic acid (0.52 g). After the reaction was stirred at 0° C. for 20 minutes, the mixture was passed over twenty weight equivalents of basic alumina (Brockmann Grade I, 150 mesh) and the N-oxide was eluted using a solution of 10% methanol in dichloromethane. All fractions containing the desired amine N-oxide were combined and evaporated to near dryness in vacuo. The residue was treated successively three times with small portions of methanol (ca. 10 ml) followed by evaporation to near dryness, and the volume of the solution was adjusted to 25 mL by addition of methanol. The methanolic solution of the N-oxide was heated to reflux for approximately 4 hours and cooled. The solvent was evaporated to dryness in vacuo and the residue was chromatographed over silica gel (95:5 ethyl acetate-hexanes was used as the eluant) to give upon evaporation of the solvent in vacuo the desired product as an oil. MS(+ES) m/z: 190 (M+H)+.

1. washthe N-oxide was eluted
2. additionAll fractions containing the desired amine N-oxide
3. customevaporated
4. additionThe residue was treated successively three times with small portions of methanol (ca. 10 ml)
5. customfollowed by evaporation
6. additionthe volume of the solution was adjusted to 25 mL by addition of methanol
7. temperatureThe methanolic solution of the N-oxide was heated
8. temperatureto reflux for approximately 4 hours
9. temperaturecooled
10. customThe solvent was evaporated to dryness in vacuo
11. customthe residue was chromatographed over silica gel (95:5 ethyl acetate-hexanes