Phenylboronic Acid → 3-Chloro-4-phenyl-1,2,5-thiadiazole

Beteiligte Stoffe

Reaktionsschritte

To a mixture of 3-bromo-4-chloro-1,2,5-thiadiazole (0.2 g, 1 mmol), phenylboronic acid (0.135 g, 1.1 mol) in toluene (5 ml) is added a 1M aqueous solution of KF (3 cc, 3 mmol) and tetrakis(triphenylphosphine)palladium(0) (0.055 g, 0.05 mmol, 5%mol) and the biphasic mixture is refluxed with vigorous stirring for 26 hours. The organic layer is decanted off and the aqueous layer is extracted with toluene (2×10 ml). After drying over magnesium sulfate and concentration under vacuum, the oily material is purified by flash chromatography on silica gel eluting with hexane/ethyl acetate (99/1) to afford 0.18 g (95%) of 3-chloro-4-phenyl-1,2,5-thiadiazole as a colorless oil, which crystallizes on standing (melting point 33° C.).

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