反应详情

温度

120 °C

A mixture of 5-bromo-6-(cyclopropylmethoxy)-pyridine-2-carboxylic acid methyl ester (0.5 g, 1.7 mmol), 2,5-dihydrofuran (CAN 1708-29-8, 1.2 g, 17 mmol), palladium(II) acetate (CAN 3375-31-3, 0.02 g, 0.09 mmol), sodium acetate (0.17 g, 2 mmol) and tri-tert-butylphosphine (CAN 13716-12-6, 0.037 g, 0.2 mmol) in DMF (10 mL) was stirred at 120° C. for 2.5 h under a nitrogen atmosphere. Water was poured into the reaction mixture and the resulting mixture was extracted with ethyl acetate (3×30 mL). The combined organic extracts were washed with water and brine, dried over anhydrous sodium sulfate and evaporated. The residue was purified by column chromatography (silica gel, 10 g, eluting with 5% ethyl acetate in petroleum ether) to yield 6-(cyclopropylmethoxy)-5-(2,5-dihydrofuran-3-yl)-pyridine-2-carboxylic acid methyl ester (b1) and 6-(cyclopropylmethoxy)-5-(4,5-dihydrofuran-2-yl)-pyridine-2-carboxylic acid methyl ester (b2) (mixture b1:b2=3:2, 0.38 g, 1.4 mmol, 79%) as yellow oil; MS (EI): m/e=376.1 [M+H]+.

1. extractionthe resulting mixture was extracted with ethyl acetate (3×30 mL)
2. washThe combined organic extracts were washed with water and brine
3. dry with materialdried over anhydrous sodium sulfate
4. customevaporated
5. customThe residue was purified by column chromatography (silica gel, 10 g, eluting with 5% ethyl acetate in petroleum ether)