[CH3:1][C:2]1[N:7]=[C:6]([C:8]2[C:16](C(O)=O)=[C:11]3[CH:12]=[CH:13][CH:14]=[CH:15][N:10]3[N:9]=2)[CH:5]=[CH:4][CH:3]=1.C(=O)(O)[O-].[Na+].[Br:25]N1C(=O)CCC1=O>CN(C=O)C.O>[Br:25][C:16]1[C:8]([C:6]2[CH:5]=[CH:4][CH:3]=[C:2]([CH3:1])[N:7]=2)=[N:9][N:10]2[CH:15]=[CH:14][CH:13]=[CH:12][C:11]=12A solution of 2-(6-methyl-pyridin-2-yl)-pyrazolo[1,5-a]pyridine-3-carboxylic acid (0.92 g, 3.6 mmol), sodium bicarbonate (1.04 g, 12.4 mmol), and N-bromosuccinimide (0.71 g, 4.0 mmol) in DMF (25 mL) is stirred for 2 hours at room temperature. The reaction is then diluted with water (50 mL) and extracted with EtOAc (3×15 mL). The organic layer is washed with brine and dried over sodium sulfate. The solvent is removed in vacuo to afford 0.91 g (87%) of desired product as a dark green solid. UV (95% EtOH) λmax 282 nm (ε 12089), 233 nm (ε 21813). TOF MS ES+ exact mass calculated for C13H10BrN3 (p+1): m/z=288.0136. Found: 287.0058. Anal. Calcd for C13H10BrN3: C, 54.19; H, 3.50; N, 14.58. Found: C, 54.10; H, 3.60; N, 14.48.
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