Sulfuric Acid → 6-(1-tert-Butyl-3-(2,4-difluorophenyl)-1H-pyrazol-4-yl)-3-isopropyl-[1,2,4]triazolo[4,3-b]pyridazine
Reaction equation
[F:1][C:2]1[CH:7]=[C:6]([F:8])[CH:5]=[CH:4][C:3]=1[C:9]1[C:13]([C:14]2[CH:15]=[CH:16][C:17]3[N:18]([C:20]([CH:23]([CH3:25])[CH3:24])=[N:21][N:22]=3)[N:19]=2)=[CH:12][NH:11][N:10]=1.S(=O)(=O)(O)O>CC(O)(C)C>[C:3]([N:11]1[CH:12]=[C:13]([C:14]2[CH:15]=[CH:16][C:17]3[N:18]([C:20]([CH:23]([CH3:25])[CH3:24])=[N:21][N:22]=3)[N:19]=2)[C:9]([C:3]2[CH:4]=[CH:5][C:6]([F:8])=[CH:7][C:2]=2[F:1])=[N:10]1)([CH3:9])([CH3:4])[CH3:2]Participants
4
Procedure
The 6-(3-(2,4-Difluorophenyl)-1H-pyrazol-4-yl)-3-isopropyl-[1,2,4]triazolo[4,3-b]pyridazine (0.300 g, 0.881 mmol, Example #L.1.1) was suspended in t-BuOH (3.0 mL) then sulfuric acid (0.15 g, 1.5 mmol) was added. The mixture was heated using a CEM® microwave at about 130° C. for about 10 min (250 psi maximum pressure, 10 min ramp, 300 max watts). The reaction mixture was concentrated under reduced pressure then purified by flash chromatography on silica gel using 9:1 DCM/MeOH as an eluent to give the title compound (0.083 g, 24%): LC/MS (Table 1, Method a) Rt=2.90 min; MS m/z: 397.3 (M+H)+.