Acetic Anhydride → 2-[2-(Acetyloxy)phenyl][1,2]oxazolo[2,3-a]pyridin-8-ium bromide
Reaction equation
[Br-:1].[OH:2][C:3]1[CH:8]=[CH:7][CH:6]=[CH:5][C:4]=1[C:9]1[O:17][N+:12]2=[CH:13][CH:14]=[CH:15][CH:16]=[C:11]2[CH:10]=1.[C:18](OC(=O)C)(=[O:20])[CH3:19]>>[Br-:1].[C:18]([O:2][C:3]1[CH:8]=[CH:7][CH:6]=[CH:5][C:4]=1[C:9]1[O:17][N+:12]2=[CH:13][CH:14]=[CH:15][CH:16]=[C:11]2[CH:10]=1)(=[O:20])[CH3:19]Participants
3
Procedure
2-(2-Hydroxyphenyl)isoxazolo[ 2,3-a]pyridinium bromide from Example 1 (5.0 g) is refluxed in acetic anhydride (40 ml) under nitrogen for 60-90 minutes. The solution is cooled, and the solvent is evaporated. The oily residue is diluted with ethyl acetate to crystallize the product. Recrystallization from isopropanol gives gray-white crystals (4.16 g, 73%) m.p. 198°-201°C.
Workup
- temperatureThe solution is cooled
- customthe solvent is evaporated