反应详情

A solution of methyl 7-methoxy-2′,3′,5′,6′-tetrahydro-spiro[1,3-benzodioxole-2,4′-(4H)-pyran]-4-carboxylate (1.80 g, 6.42 mmol) and 3,5-dichloro-4-picoline (1.46 g, 8.99 mmol) in tetrahydrofuran (33 mL) was cooled to 0° C. A 1.0 M solution of lithium bis(trimethylsilyl)amide in tetrahydrofuran (19.3 mL, 19.3 mmol) was added and the reaction mixture was allowed to reach room temperature overnight. Saturated aqueous NH4Cl (70 mL) was added. The aqueous phase was extracted with dichloromethane (3×100 mL). The combined organic phase was washed with water (50 mL), dried over MgSO4 and evaporated to dryness under reduced pressure. Standard silica gel column chromatography followed by recrystallization from isopropanol afforded 2-(3,5-dichloropyridine-4-yl)-1-(7-methoxy-2′,3′,5′,6′-tetrahydro-spiro[1,3-benzodioxole-2,4′-(4H)-pyran]-4-yl)ethanone (1.90 g, 71%). 13C NMR (DMSO) δ 189.1, 148.2, 147.7, 147.0, 141.2, 134.5, 132.8, 122.0, 118.0, 113.0, 107.8, 64.4, 56.3, 43.5, 35.2.

1. extractionThe aqueous phase was extracted with dichloromethane (3×100 mL)
2. washThe combined organic phase was washed with water (50 mL)
3. dry with materialdried over MgSO4
4. customevaporated to dryness under reduced pressure
5. customStandard silica gel column chromatography followed by recrystallization from isopropanol