Trifluoroacetic acid → 5,6-Dichloro-2-(2-(R)-pyrrolidinyl)furo[3,2-b]pyridine
Reaction equation
[Cl:1][C:2]1[N:7]=[C:6]2[CH:8]=[C:9]([C@H:11]3[CH2:15][CH2:14][CH2:13][N:12]3C(OC(C)(C)C)=O)[O:10][C:5]2=[CH:4][C:3]=1[Cl:23].C(O)(C(F)(F)F)=O>C(Cl)Cl>[Cl:1][C:2]1[N:7]=[C:6]2[CH:8]=[C:9]([C@H:11]3[CH2:15][CH2:14][CH2:13][NH:12]3)[O:10][C:5]2=[CH:4][C:3]=1[Cl:23]Participants
4
Procedure
5,6-Dichloro-2-(1-t-butyloxycarbonyl-2-(R)-pyrrolidinyl)furo[3,2-b]pyridine (355 mg, 1.0 mmol) was dissolved in CH2Cl2 (3 mL) and TFA (3 mL) was added at ambient temperature. After stirring for 1 hour, the solvent was removed and the residue was redissolved in CH2Cl2 and washed with saturated K2CO3 solution, dried (MgSO4) and concentrated. The crude product was chromatographed (silica gel; CHCl3 /MeOH, 98:2) to afford a solid (220 mg, 87%): 1H NMR (CDCl3, 300 MHz) δ 1.81-2.05 (m, 3H), 2.15-2.29 (m, 1H), 3.04-3.20 (m, 2H), 4.39-4.42 (m, 1H), 6.70 (s, 1H), 7.80 (s, 1H); MS (CI/NH3) m/z: 257 (M+H)+.