反应详情

温度

30 °C

Dimethyl-[1,3]dioxane-4,6-dione (5.0 g, 34.6 mmol) was combined with triethyl orthoformate (205 mL, 138 mmol) and stirred at 30° C. for 1 hour. Thiophen-3-ylamine (2.81 g, 28.3 mmol) was added in small portions at room temperature, at which time a white percipitate. The mixture was heated at 85° C. overnight. The reaction mixture was cooled to room temperature and isopropyl ether was added and the suspension was stirred for one hour. The precipitate was filtered off and washed with isopropyl ether and dried in vacuo. The intermediate was dissolved in methylene chloride and potassium carbonate was added and the suspension was stirred for 30 minutes. The solid was filtered off and the solution was concentrated to give 2,2-dimethyl-5-(thiophen-3-ylaminomethylene)-[1,3]dioxane-4,6-dione as the free base. In a single neck round bottom flask, dowtherm A (15 mL) was heated to 260° C. and 2,2-dimethyl-5-(thiophen-3-ylaminomethylene)-11,3]dioxane-4,6-dione was added in small portions. The mixture heated for 30 minutes and then was cooled to room temperature and isopropyl ether was added and the suspension was stirred for one hour. The precipitate was filtered off and washed with isopropyl ether and dried in vacuo to provide 3.43g (79%) of 4H-thieno[3,2-b]pyridin-7-one. 1H NMR (400 MHz, DMSO) d 7.93 (d, 1H), 7.79 (d, 1H), 7.21 (d, 1H), 5.99 (d, 1H); LC-MS: 152 (MH+); HPLC RT: 1.21.

1. temperatureThe mixture was heated at 85° C. overnight
2. temperatureThe reaction mixture was cooled to room temperature
3. stirringthe suspension was stirred for one hour
4. filtrationThe precipitate was filtered off
5. washwashed with isopropyl ether
6. customdried in vacuo
7. dissolutionThe intermediate was dissolved in methylene chloride
8. additionpotassium carbonate was added
9. stirringthe suspension was stirred for 30 minutes
10. filtrationThe solid was filtered off
11. concentrationthe solution was concentrated