反应详情

温度

62.5 °C

301.7 ml of a 33% solution of hydrobromic acid in acetic acid are added to a suspension of 100 g of N-((S)-2,3-dihydroxypropyl)-5-chlorothiophene-2-carboxamide (VIII) in 250 ml of glacial acetic acid at from 21 to 26° C. over a period of 30 minutes. Subsequently, 40 ml of acetic anhydride are added and the reaction mixture is stirred at from 60 to 65° C. for three hours. At 20 to 25° C., 960 ml of methanol are then added over a period of 30 minutes. The reaction mixture is stirred under reflux for 2.5 hours and then overnight at from 20 to 25° C. For workup, the solvents are distilled off under reduced pressure at approx. 95 mbar. The remaining suspension is admixed with 50 ml of 1-butanol and 350 ml of water. The precipitated product is filtered off with suction, washed with water and dried.

1. stirringThe reaction mixture is stirred
2. temperatureunder reflux for 2.5 hours
3. customovernight
4. customat from 20 to 25° C
5. distillationFor workup, the solvents are distilled off under reduced pressure at approx. 95 mbar
6. filtrationThe precipitated product is filtered off with suction
7. washwashed with water
8. customdried