反应详情

温度

122.5 °C

To a mixture of 7-bromo-4-hydroxy-2-oxo-2H-thiochromene-3-carboxylic acid methyl ester (Example 5 e) (150 mg, 0.48 mmol) in DMF was added tetramethyltin (254 mg, 1.43 mmol) and PdCl2(PPh3)2 (17 mg, 0.024 mmol). The resulting mixture was purged with nitrogen gas for 20 seconds and heated in a 120-125° C. oil bath for 1 h. The reaction mixture was diluted with water (15 mL) and the suspended black solid was filtered off. The clear filtrate was acidified to pH 4 using 1 N HCl and extracted with EtOAc (2×). The combined organic layers were washed with brine, dried over MgSO4, filtered and concentrated. The crude product was triturated with MeOH (1 mL) and the solid collected to provide 4-hydroxy-7-methyl-2-oxo-2H-thiochromene-3-carboxylic acid methyl ester (82 mg). 1H NMR (200 MHz, CDCl3): δ (ppm)=15.20 (s, 1H), 8.23 (d, J=8.5 Hz, 1H), 7.17 (m, 2H), 4.00 (s, 3H), 2.44 (s, 3H).

1. customThe resulting mixture was purged with nitrogen gas for 20 seconds
2. additionThe reaction mixture was diluted with water (15 mL)
3. filtrationthe suspended black solid was filtered off
4. extractionextracted with EtOAc (2×)
5. washThe combined organic layers were washed with brine
6. dry with materialdried over MgSO4
7. filtrationfiltered
8. concentrationconcentrated
9. customThe crude product was triturated with MeOH (1 mL)
10. customthe solid collected