反应详情

To a solution of tert-butyl 4-(thiazol-2-yl)piperidine-1-carboxylate (530 mg, 1.97 mmol) in acetonitrile (10 mL) was added NBS (1.40 g, 7.86 mmol). The mixture was stirred at RT for 14 hours and heated at 50° C. for 4 hours. The reaction mixture with some starting material recovered was poured into a solution of Na2SO3 (30 mL) and 6N NaOH (2 mL). The aqueous layer was extracted with EtOAc, dried over MgSO4, and the combined organics concentrated in vacuo. The residue was purified by silica gel chromatography to provide tert-butyl 4-(5-bromothiazol-2-yl)piperidine-1-carboxylate as a yellow oil [210 mg (0.61 mmol); 1H NMR (300 MHz, CDCl3) 7.59 (s, 1H), 4.20 (brd, J=12.9 Hz, 2H), 3.13 (tt, J=3.8, 11.5 Hz, 1H), 2.89 (t, J=11.6 Hz, 2H), 2.08 (d, J=11.7 Hz, 2H), 1.72 (dq, J=4.3, 11.9 Hz, 2H), 1.49 (s, 9H)].

1. temperatureheated at 50° C. for 4 hours
2. customThe reaction mixture with some starting material recovered
3. additionwas poured into a solution of Na2SO3 (30 mL) and 6N NaOH (2 mL)
4. extractionThe aqueous layer was extracted with EtOAc
5. dry with materialdried over MgSO4
6. concentrationthe combined organics concentrated in vacuo
7. customThe residue was purified by silica gel chromatography