Cesium carbonate → (S)-4-((3-Bromopyridin-4-yl)methyl)-7-cyano-1,2,3,4-tetrahydrocyclopenta[b]indol-2-ylcarbamic acid isopropyl ester

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Reaction Steps

A mixture of 3-bromo-4-(chloromethyl)pyridine (3.16 g, 11.5 mmol), ((S)-7-cyano-1,2,3,4-tetrahydro-cyclopenta[b]indol-2-yl)-carbamic acid isopropyl ester (2.50 g, 8.82 mmol) and cesium carbonate (4.31 g, 13.2 mmol) in dimethylformamide (20 mL) is stirred at room temperature under nitrogen overnight. The reaction mixture is then diluted with ethyl acetate, dichloromethane, and water. The organic phase is separated, washed with water twice, dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo to obtain a brown oil (˜4.75 g). The oil is triturated with hexanes twice, then with ether twice. It is then purified by flash chromatography eluting with 30 to 60% ethyl acetate/hexanes to obtain an off-white solid (3.23 g, 81%). LC-ES/MS m/z (79Br/81Br) 453.0/455.0 [M+H]+.

Provenance & Evidence