反应详情

温度

150 °C

A mixture of 2,4-diamino-pyridine (1.26 g, 11.5 mmol), copper (I) bromide (82.8 mg, 0.57 mmol), 1,10-phenanthroline monohydrate (114.0 mg, 0.57 mmol) and benzonitrile (13 mL) was heated in a 50 mL 3-necked flask to 150° C. During 41 h a gentle flow of O2/N2 (5:95) was bubbled through the reaction mixture (conversion 42%, HPLC method see below). The reaction mixture was then filtered. The resulting clear brown solution was evaporated to dryness and the crude was product purified by silica gel chromatography (hexane/EtOAc 2:8) to yield 7-amino-2-phenyl-[1,2,4]triazolo[1,5-a]pyridine (0.72 g, 29%) as a light yellow solid with 99.0% purity (HPLC area-%, HPLC method: X-Bridge C18 column, 150×4.6 mm; mobile phase, A: water/NCMe (95:5), B: NCMe, C: NBu4HSO4 buffer pH 3-4; flow: 1.5 ml/min; gradient from 90/0/10 (A/B/C) to 5/85/10 (A/B/C) within 6 min, isocratic 5/85/10 (A/B/C) for 4 min. Retention time: 0.95 min (2,4-diamino-pyridine), 4.08 min (7-amino-2-phenyl-[1,2,4]triazolo[1,5-a]pyridine)).

1. customDuring 41 h a gentle flow of O2/N2 (5:95) was bubbled through the reaction mixture (conversion 42%, HPLC method see below)
2. filtrationThe reaction mixture was then filtered
3. customThe resulting clear brown solution was evaporated to dryness
4. custompurified by silica gel chromatography (hexane/EtOAc 2:8)