Potassium Hydroxide → 3-Bromo-2-(4-nitrophenylazo)-5-hydroxypyridine
Reaction equation
[Br:1][C:2]1[CH:3]=[C:4]([OH:8])[CH:5]=[N:6][CH:7]=1.[OH-].[K+].F[B-](F)(F)F.[N+:16]([C:19]1[CH:24]=[CH:23][C:22]([N+:25]#[N:26])=[CH:21][CH:20]=1)([O-:18])=[O:17]>O.C(O)(=O)C>[OH:8][C:4]1[CH:3]=[C:2]([Br:1])[C:7]([N:26]=[N:25][C:22]2[CH:21]=[CH:20][C:19]([N+:16]([O-:18])=[O:17])=[CH:24][CH:23]=2)=[N:6][CH:5]=1Participants
6
Procedure
5-bromo-3-pyridinol (8.7 g, 0.05 mol) and potassium hydroxide (Fisher Scientific) were dissolved in water (200 ml). A suspension of p-nitrobenzenediazonium tetrafluoroborate (J. Org. Chem., Vol. 44, No 9. 1979 p 1572-1573) (11.845 g, 0.5 mol) was added, and the mixture was stirred for 1 hour, diluted with acetic acid (50 ml) and filtered. The crude product was allowed to dry in air, then was chromatographed (silica gel; CHCl3/MeOH, 95:5 to 90:10) provided 5.45g (33.7 %) of the title compound. MS (CI/NH3) m/e 323/325 (M+H)+. 1H NMR (DMSO-d6, 300 MHz) δ8.48-8.43 (m, 2H), 8.21-8.20 (d, J=2.37 Hz, 1H) 8.09-8.06 (m, 2H), 7.72-7.71 (d, J=2.37 Hz, 1H).
Workup
- addition1979 p 1572-1573) (11.845 g, 0.5 mol) was added
- filtrationfiltered
- customto dry in air
- customwas chromatographed (silica gel; CHCl3/MeOH, 95:5 to 90:10)
Sources & evidence
- ORD record
- ord-170b365ee639478d9fde5020246fa61f
- Source dataset
- uspto-grants-2000_10
- Patent number
- US06127386
Reaction notes
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