tert-Butyl piperazine-1-carboxylate → HCID 130471524, Verbindung

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To methyl 3-bromo-5-fluorobenzoate (1.5 g, 6.44 mmol) dissolved in dry THF (20 mL) was added tert-butyl piperazine-1-carboxylate (1.199 g, 6.44 mmol), Sodium-t-butoxide (1.856 g, 19.31 mmol) and purged with N2 gas for 10 min followed by the addition of2-(Dicyclohexylphosphino)-2',4',6'-tri-i- propyl-1,1'-biphenyl (0.307 g, 0.64 mmol), Palladium II acetate (0.145 g, 0.64 mmol) . The contents were further purged with N2 gas for further 10 min and heated at 85 °C for overnight. The reaction mass was concentrated and the reside diluted with water and extracted with ethyl acetate . The combined organic extracts were washed with brine solution and dried over anhydrous sodium sulphate. The organic layer was evaporated under reduced pressure to obtain the crude product which was purified by 60-120 mesh silica gel column chromatography using 25% Ethyl acetate ; hexanes mixture to obtain 3-(4-(tert- butoxycarbonyl)piperazin-1-yl)-5-fluorobenzoic acid (1.500 g, 71.8 %) an oil. m/z (ES-), M- = 323

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