Potassium Carbonate → tert-Butyl (S)-5-amino-3,4-dihydro-2H-pyrrole-2-carboxylate
Reaction equation
Cl.[NH2:2][C:3]1[CH2:4][CH2:5][C@@H:6]([C:8]([O:10][C:11]([CH3:14])([CH3:13])[CH3:12])=[O:9])[N:7]=1.C([O-])([O-])=O.[K+].[K+]>C(Cl)(Cl)Cl>[NH2:2][C:3]1[CH2:4][CH2:5][C@@H:6]([C:8]([O:10][C:11]([CH3:14])([CH3:13])[CH3:12])=[O:9])[N:7]=1Participants
4
Procedure
Amidine hydrochloride 1d (11.0 g, 49.8 mmol) was partitioned between CHCl3 and sat. K2CO3. The layers were separated and the aqueous layer was extracted with CHCl3 (2×). The combined organic phase was dried (Na2SO4) and concentrated to afford 8.50 g (93%) of free base 1e. 1H NMR (300 MHz, CDCl3) δ4.44 (br s, 2H), 4.38 (dd, J=8.0, 5.5, 1H), 2.65-2.42 (m, 2H), 2.32-2.18 (m, 1H), 2.12-2.00 (m, 1H), 1.47 (s, 9H).