反应详情

1,1'-Carbonyldiimidazole (4.1 g, 25 mmoles) is added to a solution of 3-methoxy-4,5-dimethyl-2-thiophenecarboxylic acid (4.5 g, 24 mmoles) in tetrahydrofuran (80 mL) under argon. The mixture is stirred and heated under reflux for 1.5 hours. 5-Aminotetrazole (2.0 g, 24 mmoles) is added and heating under reflux is continued for an additional 2.5 hours. The mixture is cooled, and the precipitate is filtered off, rinsed with tetrahydrofuran, dried, and stirred in 2N HCl. After 10 minutes the suspended solid is collected by filtration, rinsed with water and dried to afford the product (4.4 g); mp 229° C. (dec).

1. temperatureheated
2. temperatureunder reflux for 1.5 hours
3. temperatureheating
4. temperatureunder reflux
5. temperatureThe mixture is cooled
6. filtrationthe precipitate is filtered off
7. washrinsed with tetrahydrofuran
8. customdried
9. stirringstirred in 2N HCl
10. filtrationAfter 10 minutes the suspended solid is collected by filtration
11. washrinsed with water
12. customdried