反应详情

To a stirred solution of methyl 3-amino-5-(pyridin-4-yl)thiophene-2-carboxylate (1.21 g, 5.00 mmol) in DMF (25 mL) was added sodium hydride (60%, 0.220 g, 5.50 mmol). After 10 min, 1-iodobutane (0.626 mL, 5.50 mmol) was added and stirring was continued for 5 h. The mixture was poured into water (60 mL) and sat. aqueous sodium hydrogen carbonate (60 mL). Ethyl acetate (100 mL) and THF (33 mL) were added to the mixture for extraction, and the insoluble precipitate was filtered off. The organic layer was washed with brine, dried over magnesium sulfate, filtrated and concentrated at reduced pressure. The obtained residue was purified by column chromatography (Combiflash, 40 g silica gel, hexanes to 30:70 hexanes/ethyl acetate) to afford the title compound (0.460 g, 32%) as a yellow oil:

1. waitwas continued for 5 h
2. filtrationthe insoluble precipitate was filtered off
3. washThe organic layer was washed with brine
4. dry with materialdried over magnesium sulfate
5. filtrationfiltrated
6. concentrationconcentrated at reduced pressure
7. customThe obtained residue was purified by column chromatography (Combiflash, 40 g silica gel, hexanes to 30:70 hexanes/ethyl acetate)