反应详情

温度

45 °C

To a stirred solution of 2-chloro-5 (ethoxy carbonyl)-1,3-thiazole-4-carboxylic acid (Intermediate 7, 2 g, 8.01 mmol) in dry dichloromethane (20 mL) was added oxalyl chloride (1.37 mL, 16.02 mmol) and 2 drops of dry dimethylformamide. The reaction mixture was heated to 45° C. for 90 minutes. After the completion of the reaction, the reaction mixture was evaporated to dryness under reduced pressure. The residue was dissolved in dry dichloromethane (20 mL) and was cooled to 0° C., then 2,6-lutidine (0.97 mL, 8.4 mmol) was added followed by addition of N,N-dimethylamine (2 M solution in tetra hydro furan, 4.19 mL, 8.4 mmol). After completion of the reaction, the reaction mixture was concentrated to dryness and the residue was extracted with ethyl acetate (2×50 mL). The organic layer was washed with 1 N hydrochloric acid, water and brine (1×50 mL), and concentrated after drying over anhydrous sodium sulfate to afford 1.6 g (72.7%) of the title compound as a thick syrup.

1. customAfter the completion of the reaction
2. customthe reaction mixture was evaporated to dryness under reduced pressure
3. dissolutionThe residue was dissolved in dry dichloromethane (20 mL)
4. temperaturewas cooled to 0° C.
5. customAfter completion of the reaction
6. concentrationthe reaction mixture was concentrated to dryness
7. extractionthe residue was extracted with ethyl acetate (2×50 mL)
8. washThe organic layer was washed with 1 N hydrochloric acid, water and brine (1×50 mL)
9. concentrationconcentrated
10. dry with materialafter drying over anhydrous sodium sulfate