反应详情

To a mixture of 2-(2,4-dichloro-phenyl)-1H-pyrrole-3-carbonitrile (6.00 g, 25.30 mmol, see EP 0312,723) in 120 mL of dichloromethane was added acetyl chloride (3.18 g; 40.49 mmol) at room temperature, under nitrogen. The resulting mixture was cooled to +2° C. and anhydrous aluminum trichloride (8.10 g, 60.73 mmol) was added in small portions during a period of 20 minutes, keeping the internal temperature below 5° C. Upon complete addition, the mixture was brought to room temperature and allowed to stir for 3 hours. Then, the mixture was slowly poured in a solution of ice-cooled 2M HCl (120 mL) and isopropanol (28 mL). The aqueous layer was separated and extracted twice with a mixture of dichloromethane (120 mL) and isopropanol (28 mL). The combined organic extracts were concentrated under reduced pressure to slurry, which was treated under stirring with isopropanol (30 mL) and diluted with water (60 mL) at room temperature. The solid was collected by suction and dried under vacuum at +50° C. to afford the 6.51 g of product as white, fluffy crystals. Yield=92%.

1. temperatureThe resulting mixture was cooled to +2° C.
2. customthe internal temperature below 5° C
3. additionUpon complete addition
4. customwas brought to room temperature
5. additionThen, the mixture was slowly poured in a solution of ice-
6. customThe aqueous layer was separated
7. extractionextracted twice with a mixture of dichloromethane (120 mL) and isopropanol (28 mL)
8. concentrationThe combined organic extracts were concentrated under reduced pressure
9. additionwhich was treated
10. stirringunder stirring with isopropanol (30 mL)
11. additiondiluted with water (60 mL) at room temperature
12. customThe solid was collected by suction
13. customdried under vacuum at +50° C.