反应详情

To an ice-cooled white suspension of O-(mesitylsulfonyl)hydroxylamine (1.18 g, 5.48 mmol) in dichloromethane (8.44 ml) is added dropwise a solution of methyl 2-amino-5-fluoroisonicotinate (932 mg, 5.48 mmol) in dichloromethane (2.53 ml). The resulting light brown suspension is stirred for 2 hours at room temperature. The suspension is cooled to −5-0° C., diluted with diethylether (15 ml) and stirred for 30 minutes. The solid is collected by filtration, washed with diethyl ether and dried affording 1,2-diamino-5-fluoro-4-(methoxycarbonyl)pyridinium 2,4,6-trimethylbenzenesulfonate (1.72 g, 81.4%) as a light brown solid. MS: m/z=186.0 (M+).

1. temperatureThe suspension is cooled to −5-0° C.
2. stirringstirred for 30 minutes
3. filtrationThe solid is collected by filtration
4. washwashed with diethyl ether
5. customdried