[Br:1][C:2]1[CH:3]=[N:4][CH:5]=[C:6]([CH:9]=1)[CH:7]=[O:8].C([O-])([O-])=O.[K+].[K+].CC1C=CC(S([CH2:26][N+:27]#[C-:28])(=O)=O)=CC=1>CO>[Br:1][C:2]1[CH:9]=[C:6]([C:7]2[O:8][CH:28]=[N:27][CH:26]=2)[CH:5]=[N:4][CH:3]=1To a solution of 5-bromonicotinaldehyde (0.2 g, 1 mmol) in MeOH (5 mL) was added K2CO3 (0.3 g, 2 mmol) followed by TOSMIC (0.27 g, 1.39 mmol). The mixture was heated to 85° C. for 2 h. Methanol was evaporated under reduced pressure and the residue was dissolved in DCM then washed with water. The organic extracts were dried over sodium sulfate, filtered and concentrated. The residue was purified by silica gel column chromatography using 2.1% MeOH in DCM as the eluent to provide 5-(5-bromopyridin-3-yl)oxazole (0.12 g. 50%). LCMS Method Y: retention time 1.39 min; [M+1]=225.0.
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