反应详情

温度

90 °C

A 3-L reaction flask equipped with a cooling bath, air stirrer, and thermometer probe is charged with 4-chloro-N-dimethylaminomethylene-2-thiophene carboxamide. (155 g, 0.715 moles) and HOAc (1500 mL) to form a solution. Using an ice-water cooling bath to maintain the temperature at ≦30° C., methylhydrazine (33.2 g, 0.721 moles) is added dropwise via an addition funnel over 15-20 minutes to form a light yellow slurry. Gradually, the reaction is heated to 90° C. and held at 90° C. for 30 minutes. After analysis of the mixture by GC, the reaction is cooled to ˜70° C.; then, concentrated to a thick oil/slurry. De-ionized H2O (1.67 L) is slowly added to precipitate solids; then, the mixture is cooled to <30° C., filtered and washed with de-ionized H2O (1.67 L). The wet solids (125.8 g) are re-dissolved in warm MTBE (1.64 L), dried over Na2SO4, filtered and concentrated to dryness giving the title compound as a pale yellow solid (85.8 g, 60.1% 91.9% area % by GC).

1. customequipped with a cooling bath, air stirrer
2. temperatureto maintain the temperature at ≦30° C.
3. customto form a light yellow slurry
4. temperatureAfter analysis of the mixture by GC, the reaction is cooled to ˜70° C.
5. concentrationthen, concentrated to a thick oil/slurry
6. additionDe-ionized H2O (1.67 L) is slowly added
7. customto precipitate solids
8. temperaturethen, the mixture is cooled to <30° C.
9. filtrationfiltered
10. washwashed with de-ionized H2O (1.67 L)
11. dissolutionThe wet solids (125.8 g) are re-dissolved in warm MTBE (1.64 L)
12. dry with materialdried over Na2SO4
13. filtrationfiltered
14. concentrationconcentrated to dryness