[N+:1]([O-:4])(O)=[O:2].[Br:5][C:6]1[CH:11]=[CH:10][CH:9]=[C:8]([CH2:12][CH3:13])[N+:7]=1[O-:14].OS(O)(=O)=O.[OH-].[Na+]>>[Br:5][C:6]1[CH:11]=[C:10]([N+:1]([O-:4])=[O:2])[CH:9]=[C:8]([CH2:12][CH3:13])[N+:7]=1[O-:14]With ice bath cooling HNO3 (100%, 25 ml) was added dropwise to 2-bromo-6-ethyl-pyridine 1-oxide (20.0 g, 99 mmol), followed by H2SO4 (98%, 17 ml). The mixture was stirred at 90° C. for 90 min and then cooled to rt. Crushed ice (500 g) was added and the mixture was made basic (pH 12) using 28% NaOH solution. After extraction with AcOEt (4×250 ml) the combined organic phases were dried (Na2CO3) and evaporated to give 15.9 g (65%) of a yellow Solid mass which was directly used in the next step
Wird geladen…
