[CH3:1][C:2]1[CH:19]=[C:18]([CH2:20][N:21]2[CH2:26][CH2:25][O:24][CH2:23][CH2:22]2)[CH:17]=[CH:16][C:3]=1[O:4][CH:5]1[CH2:8][N:7](C(OC(C)(C)C)=O)[CH2:6]1.Cl>CO>[NH:7]1[CH2:8][CH:5]([O:4][C:3]2[CH:16]=[CH:17][C:18]([CH2:20][N:21]3[CH2:22][CH2:23][O:24][CH2:25][CH2:26]3)=[CH:19][C:2]=2[CH3:1])[CH2:6]1A solution of 12A (2.6 g, 7.17 mmol) in MeOH (10 mL) was treated with HCl in MeOH (40 ml, 50 mmol) and stirred at RT over night. The reaction mixture was concentrated and the residue was dissolved in water (15 mL). The solution was washed with EtOAc. DCM (100 mL) was added to the aqueous phase and then aqueous K2CO3 (sat., 20 mL) was added. The two phases were separated and organic solution was filtered through a phase separator. The solvent was removed by evaporation. There was obtained 1.8 g (96%) of 12B as a colorless oil. 1H NMR (600 MHz, CDCl3): δ 2.21 (s, 3H), 2.33-2.48 (m, 4H), 3.38 (s, 2H), 3.63-3.73 (m, 4H), 3.74-3.84 (m, 2H), 3.87-3.96 (m, 2H), 4.91-5.02 (m, 1H), 6.43 (d, 1H), 7.01 (d, 1H), 7.09 (s, 1H).
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