Cesium carbonate → Ethyl 4-bromo-5-(3-cyano-5-fluorophenyl)thiophene-2-carboxylate

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Reaction Conditions

Reaction Steps

Under argon, 1.50 g (4.78 mmol) of the compound from Example 8A are provided in 75 ml of 1,2-dimethoxyethane, and 1.30 g (5.26 mmol) of the compound from Example 5A, 4.67 g (14.3 mmol) of cesium carbonate, 159 mg (0.33 mmol) of dicyclohexyl[2′,4′,6′-tri(propan-2-yl)biphenyl-2-yl]phosphane and 32.0 mg (0.14 mmol) of palladium(II) acetate are added. The mixture is stirred at 50° C. overnight. Water is subsequently added, the mixture is extracted with ethyl acetate and the extract is dried over sodium sulfate, filtered and concentrated. The crude product is purified by preparative HPLC (RP18 column; eluent: acetonitrile/water gradient with addition of 0.1% formic acid). 1.05 g of ethyl 4-bromo-5-(3-cyano-5-fluorophenyl)thiophene-2-carboxylate are obtained.

Provenance & Evidence