反应详情

1,2-Diamino-4-bromopyridinium 2,4,6-trimethylbenzenesulfonate (15.6 g, 40.2 mmole) in pyridine (106 ml) is heated overnight at 100° C. with benzoyl chloride (9.4 ml, 80 mmole) giving a redbrown solution and after 2 hrs a brown suspension. The reaction mixture is concentrated in vacuo and the residue is triturated for 2.5 hr in sat. aqueous ammonium chloride solution (300 ml), while neutralizing to pH 6-7 with sat. aqueous sodium bicarbonate solution. The solid is collected by filtration, washed with water (40 ml) and dried affording 7-bromo-2-phenyl-[1,2,4]triazolo[1,5-a]pyridine (6.78 g, 61.6%) as an off-white solid. mp.: 189-191° C. MS: m/z=276.1, 274.2 (M+H+).

1. customgiving a redbrown solution
2. concentrationThe reaction mixture is concentrated in vacuo
3. customthe residue is triturated for 2.5 hr in sat. aqueous ammonium chloride solution (300 ml)
4. filtrationThe solid is collected by filtration
5. washwashed with water (40 ml)
6. customdried