Tetramethyltin → HCID 178498939, compound

Participants

Reaction Conditions

Reaction Steps

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).

Provenance & Evidence