反应详情

To a solution of acid 327 (2.10 g, 11.8 mmol) in dry dichloromethane (50 mL) was added oxalyl chloride (2.0 mL, 2.9 g, 23 mmol) and dry DMF (0.1 mL). The mixture was stirred for 1 h, then concentrated under reduced pressure. The residue was re-dissolved in toluene (75 mL) and lead thiocyanate (4.0 g, 12 mmol) was added. The resulting suspension was heated to reflux with vigorous stirring for 3 h, then cooled, filtered through celite, and concentrated to afford crude 321 which was used without further purification.

1. concentrationconcentrated under reduced pressure
2. dissolutionThe residue was re-dissolved in toluene (75 mL)
3. temperatureThe resulting suspension was heated
4. temperatureto reflux
5. stirringwith vigorous stirring for 3 h
6. temperaturecooled
7. filtrationfiltered through celite
8. concentrationconcentrated
9. customto afford crude 321 which
10. customwas used without further purification