反应详情

Phosphorous oxychloride (500 μL, 5.39 mmol) is added slowly to a stirred solution of dimethylformamide (516 μL) in dichloromethane (516 μL) at 0-5° C. After 15 min, a solution of 1-(pyridin-3-yl)-1,3-dihydroindol-2-one (250 mg, 1.2 mmol) and pyridine (258 μL) in dichloromethane (2 mL) is added. The reaction mixture is warmed to room temperature and stirred for 24 hr. The reaction is diluted with water, made basic with ammonium hydroxide, extracted with dichloromethane and the extract is concentrated. The residue is treated with phosphorous oxychloride (5 mL) and heated at reflux for 2 hr. After cooling to room temperature, the excess phosphorous oxychloride is removed and the residue is treated with ice/water, made basic with ammonium hydroxide and extracted with dichloromethane. The combined extract is washed with brine, dried, filtered and concentrated. The residue is purified by chromatography eluting with pentane-30% ethyl acetate. Product containing fractions are combined and concentrated to afford 2-chloro-1-(pyridin-3-yl)-1,3-dihydroindole-3-carboxaldehyde (42 mg, 14% yield) as a yellow solid.

1. extractionextracted with dichloromethane
2. concentrationthe extract is concentrated
3. additionThe residue is treated with phosphorous oxychloride (5 mL)
4. temperatureheated
5. temperatureat reflux for 2 hr
6. temperatureAfter cooling to room temperature
7. customthe excess phosphorous oxychloride is removed
8. additionthe residue is treated with ice/water
9. extractionextracted with dichloromethane
10. extractionThe combined extract
11. washis washed with brine
12. customdried
13. filtrationfiltered
14. concentrationconcentrated
15. customThe residue is purified by chromatography
16. washeluting with pentane-30% ethyl acetate
17. additionProduct containing fractions
18. concentrationconcentrated