反应详情

温度

-78 °C

To a suspension of 1-benzenesulfonyl-1H-pyrrolo[2,3-b]pyridin-5-carboxylic acid methyl ester (prepared as in Example 1, 2.6 g, 8.3 mmol) in dry tetrahydrofuran (60 mL) at −78° C. was added freshly prepared lithium diisopropylamide [prepared by adding 1.6 M n-butyllithium in n-hexane (6.7 mL, 10.7 mmol) to a solution of diisopropylamine (1.6 mL, 11.3 mmol) in dry tetrahydrofuran (15 mL) at 0° C.] dropwise. The mixture was stirred at −78° C. for 5 min and then treated with cyclopentyl acetaldehyde (1.2 g, 10.7 mmol) dropwise. The resulting mixture was stirred at −78° C. for 1 h and then quenched with brine. The mixture was extracted with ethyl acetate (2×150 mL), washed with brine, dried over anhydrous sodium sulfate and concentrated in vacuo. Purification by flash column chromatography (QingDao silica gel, 200-300 mesh, 15% ethyl acetate/hexanes) afforded 1-benzenesulfonyl-2-(2-cyclopentyl-1-hydroxy-ethyl)-1H-pyrrolo[2,3-b]pyridin-5-carboxylic acid methyl ester as a colorless oil (730 mg, 21%): 1H NMR (400 MHz, CDCl3) δ ppm 1.26 (m, 2H), 1.53-1.68 (m, 4H), 1.73-2.16 (m, 5H, H), 3.50 (br, 1 H), 3.89 (s, 3H), 5.41 (dd, J=5.0 Hz, 8.1 Hz, 1H), 6.67 (s, 1H), 7.42 (brt, 2H), 7.53 (brt, 1H), 8.14 (br. d., 2H), 8.33 (m, 1H), 8.96 (m, 1H).

1. customprepared
2. stirringThe resulting mixture was stirred at −78° C. for 1 h
3. customquenched with brine
4. extractionThe mixture was extracted with ethyl acetate (2×150 mL)
5. washwashed with brine
6. dry with materialdried over anhydrous sodium sulfate
7. concentrationconcentrated in vacuo
8. customPurification by flash column chromatography (QingDao silica gel, 200-300 mesh, 15% ethyl acetate/hexanes)