反应详情

To a solution of 3-amino-5-bromopyridine-2-carboxamide (40.0 g, 185.2 mmol) in CH2Cl2 was added nitrosonium tetrafluoroborate (22.71 g, 191.4 mmol). The reaction was stirred at room temperature for 4.5 hours, then concentrated in vacuo and azeotroped with toluene. The residue was suspended in toluene (1100 mL) and heated to 100° C. for 2 hours. The reaction was concentrated in vacuo, and the residue suspended in CH2Cl2. The solid was collected to provide 5-bromo-3-fluoropyridine-2-carboxamide that gave proton NMR spectra consistent with theory and a mass ion (ES+) of 219.1 for M+H+(79Br).

1. concentrationconcentrated in vacuo
2. customazeotroped with toluene
3. temperatureheated to 100° C. for 2 hours
4. concentrationThe reaction was concentrated in vacuo
5. customThe solid was collected