Hydrochloric Acid → 3-Vinyl-phthalide

反応式

COC1C=C(OC)N=C(O[C:12]2[CH:13]=[CH:14][CH:15]=[C:16]3[C:21]=2[C:19](=O)[O:18][CH:17]3[OH:22])N=1.[CH:23]([Mg]Cl)=[CH2:24].Cl>O1CCCC1>[CH:23]([CH:19]1[C:21]2[C:16](=[CH:15][CH:14]=[CH:13][CH:12]=2)[C:17](=[O:22])[O:18]1)=[CH2:24]

参加物

実験手順

3.6 g of 7-[(4,6-dimethoxy-pyrimidin-2-yl)oxy]-3-hydroxyphthalide (see Example 84) are placed in 60 ml of absolute tetrahydrofuran at -45° C., and the solution is treated within 10 minutes with 18 ml of a 2M solution of vinylmagnesium chloride solution in tetrahydrofuran. The reaction solution is then stirred for approximately 16 hours at room temperature, a further 6 ml of vinylmagnesium chloride solution are added and the reaction solution is heated at reflux temperature for a further hour. When it has cooled, the reaction solution is acidified with 1N hydrochloric acid and freed of tetrahydrofuran in a rotary evaporator. The aqueous phase is then extracted with tert-butyl methyl ether, and the organic phase in washed and concentrated by evaporation under reduced pressure. Silica gel chromatography using ethyl acetate/n-hexane (2:3) as eluant yields pure 7-[4,6-dimethoxy-pyrimidin-2-yl)oxy]-3-vinyl-phthalide, m.p. 94°-97° C.