反应详情

Procedure analogous to WO 2007/073303: 12.4 g (73 mmol) of silver nitrate are added to a mixture of 128.8 g (560 mmol) of 3-bromo-6-trimethylsilylpyridine [291312-74-8], 286.0 g (2.8 mol) of pivalic acid [75-98-9] and 400 ml of water, and the mixture is stirred at room temperature for min. 1000 ml of 10% by weight sulfuric acid are added dropwise to the reaction mixture over the course of 15 min., the mixture is warmed to 70° C., and a solution of 168.5 g (730 mmol) of ammonium peroxodisulfate in 300 ml of water is added dropwise over the course of 30 min. When the evolution of carbon dioxide is complete, the mixture is stirred at 70° C. for a further 3 h, the reaction mixture is allowed to cool, 500 ml of ethyl acetate are added, the aqueous phase is separated off, extracted again with 500 ml of ethyl acetate, the organic phases are combined, washed ten times with 300 ml of sat. sodium hydrogencarbonate solution each time, finally washed once with 500 ml of sat. sodium chloride solution, dried over magnesium sulfate, the solvent is removed in vacuo, and the oil obtained in this way is dried at 60° C. in an oil-pump vacuum. Yield: 59.4 g (207 mmol), 37%. Purity: >95% according to 1H-NMR.

1. temperaturethe mixture is warmed to 70° C.
2. stirringthe mixture is stirred at 70° C. for a further 3 h
3. temperatureto cool
4. customthe aqueous phase is separated off
5. extractionextracted again with 500 ml of ethyl acetate
6. washwashed ten times with 300 ml of sat. sodium hydrogencarbonate solution each time
7. washfinally washed once with 500 ml of sat. sodium chloride solution
8. dry with materialdried over magnesium sulfate
9. customthe solvent is removed in vacuo
10. customthe oil obtained in this way
11. customis dried at 60° C. in an oil-pump vacuum