反应详情

Barium oxide (950 mg, 90%, 5.56 mmol) were carefully added into 6 ml water in small portions followed by addition of barium nitrate (983 g, 3.76 mmol) and 3-bromo4-methylpyridine (1.72 g, 10 mmol). The resulting suspension was stirred at r.t. and a solution of hydroxylamine O-sulfonic acid (995 mg, 8.36 mmol) in 2 ml water was added drop-wise. The white suspension was stirred at 90° C. for 15 h before cooling down to r.t. The white precipitate was filtered off and washed with water. The aqueous phase was evaporated to dryness to give 1.065 g of 205 as off-white solid (yield: 45.7%) which were directly used for next step without further purification.

1. stirringThe white suspension was stirred at 90° C. for 15 h
2. temperaturebefore cooling down to r.t
3. filtrationThe white precipitate was filtered off
4. washwashed with water
5. customThe aqueous phase was evaporated to dryness