反应详情

Ethyl 6-aminonicotinate (2.5 g., 0.015 mol), methyl 4-oxotetrahydrothiophene-3-carboxylate (6.2 g., 0.039 mol) and p-toluenesulfonic acid monohydrate (0.25 g) are thoroughly mixed and heated at 155°-160° C. under nitrogen for 90 minutes. The distillate is collected in a Dean-Stark trap. The residue is cooled, triturated with boiling ethanol and filtered. Recrystallization from methanol gives yellow crystals (1.2 g.), mp 183°-185° C.

1. temperatureheated at 155°-160° C. under nitrogen for 90 minutes
2. distillationThe distillate is collected in a Dean-Stark trap
3. temperatureThe residue is cooled
4. customtriturated with boiling ethanol
5. filtrationfiltered
6. customRecrystallization from methanol
7. customgives yellow crystals (1.2 g.), mp 183°-185° C.