反应详情

To a stirred solution of 2,4-dibromo-5-thiazole carboxylic acid (48, 400 mg, 1 mmol), O-(benzotriazol-1-yl)-N,N,N′,N′-tetramethyluronium hexafluorophosphate (790 mg, 2.1 mmol) and piperidine (180 uL, 1.8 mmol) in methylene chloride (5.0 mL, 78 mmol) was added triethylamine (580 μL, 4.2 mmol) at room temperature. The resulting turbid mixture was allowed to stir at rt overnight and quenched with water. The product was extracted using dichloromethane and washed with water, citric acid solution, water and brine. Removal of solvent gave the intermediate (49) (2,4-Dibromo-thiazol-5-yl)-piperidin-1-yl-methanone (300 mg, 30%) which was used as such for the next step.

1. customquenched with water
2. extractionThe product was extracted
3. washwashed with water, citric acid solution, water and brine
4. customRemoval of solvent