Diisopropylethylamine → tert-Butyl {4-[({4-[4-(3-chlorophenyl)-5-oxo-4,5-dihydro-1,2,4-oxadiazol-3-yl]-1,2,5-oxadiazol-3-yl}amino)carbonyl]benzyl}carbamate

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Reaktionsschritte

A solution of 3-(4-amino-1,2,5-oxadiazol-3-yl)-4-(3-chlorophenyl)-1,2,4-oxadiazol-5(4H)-one (50 mg, 0.18 mmol) and 4-{[(tert-butoxycarbonyl)amino]methyl}benzoic acid (49 mg, 0.2 mmol) in dichloromethane (3.5 mL) was treated with 4-dimethylaminopyridine (13 mg, 0.1 mmol) and N,N-diisopropylethylamine (93 μL, 0.54 mmol). After the reaction mixture turned clear, it was treated with bromotris(pyrrolydino)phosphonium hexafluorophosphate (50 mg, 0.11 mmol) and additional N,N-diisopropylethylamine (93 μL, 0.54 mmol). The reaction mixture was stirred for 16 h, treated with additional bromotris(pyrrolydino)phosphonium hexafluorophosphate (50 mg, 0.11 mmol), and stirred for another 6 h. The reaction mixture was diluted with ethyl acetate (60 mL) and washed with 0.1 M HCl (2×25 mL) and brine (25 mL), dried with sodium sulfate, filtered, and concentrated. Purification of the crude reaction mixture by preparative LCMS gave the desired product (22 mg, 24%).

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