反应详情

A solution of methyl 5-bromofuranoate (0.75 g, 3.66 mmol), hexamethylditin (1.0 g, 3.05 mmol) and Pd(PPh3)4 (90 mg, 0.078 mmol) in DME (50 mL) was heated to reflux overnight. The initial amber coloured solution became black The solution was allowed to cool and then filtered and concentrated under reduced pressure. The crude stannane was purified by passage through a plug of silica (1:9 EtOAc:cyclohexane) to give methyl 2-trimethylstannyl-5-furanoate (0.17 g, 19%): 1H-NMR (CDCl3); The low yield of the product may be due to its suspected volatility. Pd(PPh3), (9 mg, 0.008 mmol) was added to a solution of 1-benzyl-3-iodo-1H-indazole (0.13 g, 0.39 mmol) and methyl 2-trimethylstannyl-5-furanoate (0.17 g, 0.588 mmol) in DME (20 mL) and the mixture was heated to reflux overnight. The reaction mixture was allowed to cool to rt, filtered and concentrated under reduced pressure. Purification of the residue by chromatography on silica (3:7 EtOAc:cyclohexane) gave the product as a slightly contaminated yellow solid (88.6 mg, 69%).

1. temperaturethe mixture was heated
2. temperatureto reflux overnight
3. filtrationfiltered
4. concentrationconcentrated under reduced pressure
5. customPurification of the residue by chromatography on silica (3:7 EtOAc:cyclohexane)