Sodium Carbonate → 1,1-Dioxo-3-butyl-3-ethyl-5-phenyl-7-bromo-8-(1-ethoxycarbonylethoxy)-2,3,4,5-tetrahydro-1,5-benzothiazepine

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Reaction Steps

Sodium carbonate (0.30 g, 2.83 mmol), 2-bromopropanoic acid ethyl ester (0.145 g, 0.796 mmol) and tetrabutylammonium bromide (0.022 g, 0.07 mmol) was added to a solution of 1,1-dioxo-3-butyl-3-ethyl-5-phenyl-7-bromo-8-hydroxy-2,3,4,5-tetrahydro-1,5-benzothiazepine (WO 96/16051; 0.300 g, 0.663 mmol) in MeCN (10 ml). The suspension was heated under reflux overnight. The solvent was evaporated and the crude mixture was extracted (DCM/H2O), dried. (MgSO4), evaporated and purified by flash chromatography (Hex:EtOAc-5:1) to give the title compound 0.346 g (95%) as a white solid. NMR 0.70–0.85 (m, 6H), 1.00–1.75 (m, 8H), 1.35 (t, 3H), 1.70 (d, 3H), 3.05–3.25 (m, 2H), 3.55–3.90 (m, 2H), 4.20–4.35 (m, 2H), 4.80 (q, 1H), 7.00–7.10 (m, 3H), 7.15 (s, 1H), 7.25–7.35 (m, 2H), 7.45 (s, 1H).

Provenance & Evidence