反应详情

To a solution of 2-(5-amino-pyridin-3-yl)-1-methyl-1H-indole (Example 100, 0.400 g, 1.756 mmol) and 1-formyl-cyclobutanecarboxylic acid ethyl ester (0.457 g, 2.633 mmol) in dichloromethane (13 mL) is added acetic acid (0.102 g, 1.756 mmol) and the mixture is refluxed. After 2 h, the mixture is cooled with an ice-water bath and sodium triacetoxyborohydride (1.175 g, 5.267 mmol) is added. After 13 h, the mixture is heated to reflux for 1.5 h, cooled to room temperature, diluted with dichloromethane, washed with 1M aqueous NaOH, water and brine. The combined aqueous phase is extracted once with dichloromethane and the combined organic phase is dried over MgSO4, filtered and concentrated in vacuo. The residue is purified by silica gel flash chromatography (heptane-ethyl acetate, 1:1) to give 1-{[5-(1-methyl-1H-indol-2-yl)-pyridin-3-ylamino]-methyl}-cyclobutanecarboxylic acid ethyl ester as an oil. 1H NMR (400 MHz, CDCl3) δ ppm 1.28 (t, J=7.1 Hz, 3H), 1.99-2.12 (m, 4H), 2.49-2.59 (m, 2H), 3.53 (d, J=5.8 Hz, 2H), 3.78 (s, 3H), 4.12-4.18 (m, 1H), 4.20 (q, J=7.1 Hz, 2H), 6.61 (d, J=0.8 Hz, 1H), 7.04 (dd, J=2.8, 1.9 Hz, 1H), 7.15-7.19 (m, 1H), 7.26-7.30 (m, 1H), 7.39 (dd, J=8.2, 0.8 Hz, 1H), 7.65 (d, J=7.7 Hz, 1H), 8.09 (d, J=2.8 Hz, 1H), 8.12 (d, J=1.9 Hz, 1H).

1. temperaturethe mixture is refluxed
2. temperaturethe mixture is cooled with an ice-water bath
3. waitAfter 13 h
4. temperaturethe mixture is heated
5. temperatureto reflux for 1.5 h
6. washwashed with 1M aqueous NaOH, water and brine
7. extractionThe combined aqueous phase is extracted once with dichloromethane
8. dry with materialthe combined organic phase is dried over MgSO4
9. filtrationfiltered
10. concentrationconcentrated in vacuo
11. customThe residue is purified by silica gel flash chromatography (heptane-ethyl acetate, 1:1)