Methyl 4-(3-bromopropyl)benzoate → 4-(3-{2-[4-Biphenyl-3-yl-3-(tert-butyl-dimethyl-silanyloxy)-butyl]-5-oxo-pyrrolidin-1-yl}-propyl)-benzoic acid methyl ester

Participants

Reaction Steps

Analogous to the procedure described for Example 1A, Step D, 5-[4-biphenyl-3-yl-3-(tert-butyl-dimethyl-silanyloxy)-butyl]-pyrrolidin-2-one (5.116 g, 12.08 mmol) was alkylated with 4-(3-bromo-propyl)-benzoic acid methyl ester (3.41 g, 13.3 mmol) over 20 h. Purification by medium pressure chromatography using a solvent gradient (5:1 hexanes:EtOAc to 1:1 hexanes:EtOAc to EtOAc to 1% MeOH in CH2Cl2 to 5% MeOH in CH2Cl2) provided 4-(3-{2-[4-biphenyl-3-yl-3-(tert-butyl-dimethyl-silanyloxy)-butyl]-5-oxo-pyrrolidin-1-yl}-propyl)-benzoic acid methyl ester (5.38 g). 1H NMR (CDCl3) δ7.93 (d, 2H), 7.56 (d, 2H), 7.43 (m, 3H), 7.34 (m, 3H), 7.23 (m, 2H), 7.12 (m, 1H), 3.89 (m, 1H), 3.87 (s, 3H), 3.64 (m, 1H), 3.49 (m, 1H), 2.95–2.61 (m, 5H), 2.30 (m, 2H), 2.01 (m, 1H), 1.89–1.70 (m, 3H), 1.59–1.24 (m, 4H), 0.84 (s, 9H), −0.04 (d, 3H), −0.16 (d, 3H).

Provenance & Evidence