Br[CH2:2][CH2:3][CH2:4][O:5][C:6]1[CH:11]=[CH:10][C:9]([B:12]2[O:16][C:15]([CH3:18])([CH3:17])[C:14]([CH3:20])([CH3:19])[O:13]2)=[CH:8][CH:7]=1.Cl.[CH3:22][C@@H:23]1[CH2:27][CH2:26][CH2:25][NH:24]1.C([O-])([O-])=O.[K+].[K+]>CC#N>[CH3:22][C@@H:23]1[CH2:27][CH2:26][CH2:25][N:24]1[CH2:2][CH2:3][CH2:4][O:5][C:6]1[CH:11]=[CH:10][C:9]([B:12]2[O:16][C:15]([CH3:18])([CH3:17])[C:14]([CH3:20])([CH3:19])[O:13]2)=[CH:8][CH:7]=12-[4-(3-Bromopropoxy)phenyl]-4,4,5,5-tetramethyl-[1,3,2]-dioxaborolane (20.47 g, 60 mmol), (R)-2-methylpyrrolidine hydrochloride (7.663 g, 63 mmol) and dry, pulverized K2CO3 (24.96 g, 180 mmol) were mixed in dry CH3CN (650 mL). After stirring for 12 h at 78° C. under a nitrogen atmosphere, the reaction mixture was cooled and further (R)-2-methylpyrrolidine hydrochloride (10.0 g, 82 m mol) was introduced and heating at 78° C. was continued for 24 h. The reaction mixture was cooled, filtered and the filtrate was evaporated. Chromatography on silica gel, eluting initially with CH2Cl2, then with a mixture of CH2Cl2/EtOH/aq. NH3 (290:10:1) and later with a (90:10:1) and (40:10:1) mixture of these solvents provided the title compound (17.44 g, 84%). The material crystallized on seeding. A sample was converted into a hydrochloride salt, m.p. 212-214° C.
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