Trifluoroacetic acid → 6-Butyl-8-(4-piperidinyloxy)quinoline
Reaction equation
[CH2:1]([C:5]1[CH:6]=[C:7]2[C:12](=[C:13]([O:15][CH:16]3[CH2:21][CH2:20][N:19](C(OC(C)(C)C)=O)[CH2:18][CH2:17]3)[CH:14]=1)[N:11]=[CH:10][CH:9]=[CH:8]2)[CH2:2][CH2:3][CH3:4].FC(F)(F)C(O)=O>C(Cl)Cl>[CH2:1]([C:5]1[CH:6]=[C:7]2[C:12](=[C:13]([O:15][CH:16]3[CH2:17][CH2:18][NH:19][CH2:20][CH2:21]3)[CH:14]=1)[N:11]=[CH:10][CH:9]=[CH:8]2)[CH2:2][CH2:3][CH3:4]Participants
4
Procedure
1,1-Dimethylethyl 4-[(6-butyl-8-quinolinyl)oxy]-1-piperidinecarboxylate (for example, as prepared for Intermediate 3) (21.5 g, 56 mmol) was dissolved in DCM (50 ml) and trifluoroacetic acid (50 ml) was added very slowly. The mixture was stirred at room temperature for 1 h. The solvent was evaporated to dryness and the residue treated with saturated aqueous sodium carbonate solution. The mixture was extracted with EtOAc (×2), washed with water, and dried (MgSO4). The drying agent was removed by filtration and the filtrate was evaporated to dryness (22 g). This was still a trifluoracetic acid salt and was re-dissolved in EtOAc, washed with aqueous sodium carbonate, water, and dried (MgSO4). The drying agent was removed by filtration and the filtrate was evaporated to dryness to afford the title compound (15.9 g). LCMS RT=2.45 min, ES+ve m/z 285 [M+H]+.