Diisopropylethylamine → 4-[(4-Fluorophenyl)sulfanyl]aniline

Beteiligte Stoffe

Reaktionsschritte

To a suspension of 2-methylisonicotinic acid (596 mg, 4.35 mmol) in dichloromethane (100 mL) are added N,N-diisopropylethylamine (1.15 mL, 6.72 mmol) and 2-(1H-7-azabenzotriazol-1-yl)-1,1,3,3-tetramethyl uronium hexafluorophosphate methanaminium (1.91 g, 5.02 mmol). The mixture was stirred at room temperature for 1 h, after which benzyl 5-(4-fluorophenylthio)spiro[indoline-3,4′-piperidine]-1′-carboxylate (1.51 g, 3.37 mmol) is added. The reaction mixture is stirred at room temperature. After 18 h, additional 2-(1H-7-azabenzotriazol-1-yl)-1,1,3,3-tetramethyl uronium hexafluorophosphate methanaminium (0.75 equiv) is added. After 2 days reaction time, the mixture is diluted with dichloromethane (300 mL), washed with saturated aqueous sodium hydrogen carbonate (100 mL) and brine (100 mL). The organic layer is dried over sodium sulphate, filtered and is concentrated under reduced pressure to give a brown oil. Purification of the crude by column chromatography on silica gel (heptane/ethyl acetate 40 to 100% as eluent) affords the desired product (1.09 g, 1.92 mmol, 57% yield) (HPLC-MS Method 2: retention time: 2.284 min, m/z 568.1).

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