Trifluoroacetic acid → N-[4-cyano-3-(trifluoromethyl)phenyl]piperidin-4-amine
Reaction equation
[C:1]([C:3]1[CH:8]=[CH:7][C:6]([NH:9][CH:10]2[CH2:15][CH2:14][N:13](C(OC(C)(C)C)=O)[CH2:12][CH2:11]2)=[CH:5][C:4]=1[C:23]([F:26])([F:25])[F:24])#[N:2].FC(F)(F)C(O)=O>ClCCl>[C:1]([C:3]1[CH:8]=[CH:7][C:6]([NH:9][CH:10]2[CH2:11][CH2:12][NH:13][CH2:14][CH2:15]2)=[CH:5][C:4]=1[C:23]([F:26])([F:24])[F:25])#[N:2]Participants
4
Procedure
To a solution of tert-butyl 4-[[4-cyano-3-(trifluoromethyl)phenyl]amino]piperidine-1-carboxylate (150 mg, 0.41 mmol) in dichloromethane (4 mL) was added trifluoroacetic acid (1 ml). The solution was stirred for 2 hours at room temperature and then concentrated under vacuum. The crude material was diluted with 100 ml of EtOAc and washed with sodium bicarbonate (saturated aqueous) and then brine. The organic layer was dried over anhydrous sodium sulfate, filtered, and concentrated under vacuum. The crude solids were recrystallized from EtOAc/PE to afford N-[4-cyano-3-(trifluoromethyl)phenyl]piperidin-4-amine as a yellow powder (93.1 mg, 85% yield); (ES, m/z): [M+H]+ 270.1; 1H NMR (300 MHz, CDCl3): δ 7.69 (d, J=8.7 Hz, 1H), 7.16 (d, J=7.8 Hz, 1H), 7.03 (d, J=1.2 Hz, 1H), 6.85 (dd, J=2.1, 8.7 Hz, 1H), 3.42 (m, 1H), 2.94 (m, 2H), 2.53 (m, 2H), 1.82 (d, J=10.2 Hz, 2H), 1.27 (m, 2H).