反应详情

4-Amino-2-bromothiazole hydrobromide (6.5g) was suspended in propionic anhydride (25 ml.) with stirring; then treated with pyridine (12.5 ml.) over 15 minutes, maintaining reaction temperature at 0° C. with an ice bath. After the addition was complete, the reaction mixture was stirred for 2 hours at room temperature, then poured onto 20% aqueous sodium acetate (250 ml.) and stirred for 30 minutes. The precipitate was removed by filtration and washed with water. The solid was air dried and extracted with hexane, in a Soxhlet apparatus. The hexane was cooled and the crystals collected and recrystallised to give the title compound (2.8 g.) m.p. 122°-5° C. (Found: C, 31.1; H, 3.1; N, 11.9. C6H7BrN2OS requires C, 30.7; H, 3.0; N, 11.9%).

1. temperaturemaintaining
2. customreaction temperature at 0° C. with an ice bath
3. additionAfter the addition
4. stirringthe reaction mixture was stirred for 2 hours at room temperature
5. stirringstirred for 30 minutes
6. customThe precipitate was removed by filtration
7. washwashed with water
8. customdried
9. extractionextracted with hexane, in a Soxhlet apparatus
10. temperatureThe hexane was cooled
11. customthe crystals collected
12. customrecrystallised