反应详情

温度

180 °C

A solution of dimethyl 4,7-dimethylpyrazolo[1,5-a]pyrazine-2,3-dicarboxylate (900 mg, 3.42 mmol) in sulfuric acid (4 mL) and water (1 mL) was stirred and heated to 180° C. After stirring for 2 h at that temperature, the reaction mixture was cooled, and 40 mL of methanol (MeOH) was added. The mixture was refluxed at 70° C. for 2 h. Then the mixture was concentrated to dryness. The residue was treated with water and adjusted with saturated sodium bicarbonate solution to pH 8, then extracted with EtOAc (3×100 mL). The combined organic layer was washed with brine, dried over sodium sulfate, filtered, and evaporated to give 560 mg (80% yield) of the title compound as a yellow solid. ESI MS: m/z 206.1 [M+H]+. 1H NMR (400 MHz, CDCl3) δ 7.73 (d, J=0.8 Hz, 1H), 7.36 (s, 1H), 4.03 (s, 3H), 2.77 (s, 3H), 2.75 (s, 3H).

1. temperaturethe reaction mixture was cooled
2. temperatureThe mixture was refluxed at 70° C. for 2 h
3. concentrationThen the mixture was concentrated to dryness
4. additionThe residue was treated with water
5. extractionextracted with EtOAc (3×100 mL)
6. washThe combined organic layer was washed with brine
7. dry with materialdried over sodium sulfate
8. filtrationfiltered
9. customevaporated