Triphenylphosphine → 3-(3-Piperidin-1-yl-propoxy)-isoxazole-5-carboxylic acid methyl ester

Beteiligte Stoffe

Reaktionsschritte

3-Hydroxy-isoxazole-5-carboxylic acid methyl ester (0.859 g., 6.00 mmol) and 3-piperidin-1-yl-propan-1-ol (0.860 g., 6.00 mmol) were dissolved in DCM (30 mL), and polymer-supported Ph3P resin (3 mmol/g, 3.1 g, 9.30 mmol) was added. The mixture was stirred for 10 min and di-tert-butyl azodicarboxylate (2.14 g, 9.30 mmol) was then added. The reaction mixture was stirred under nitrogen for 18 h. The reaction was quenched with 1 N NaOH (20 mL) and was stirred for 30 min. The resulting mixture was extracted with DCM (3×30 mL). The combined organic extracts were dried over Na2SO4, filtered, and concentrated to yield a crude oily product (3.1 g), which was purified (SiO2: 5% 2 M NH3 in MeOH/DCM) to yield the title compound (0.88 g, 58%). MS (ESI): exact mass calcd. for C13H20N2O4, 268.14; m/z found, 269.4 [M+H]+. 1H NMR (500 MHz, CDCl3): 6.53 (s, 1H), 4.34-4.30 (m, 2H), 3.94 (s, 3H), 2.47-2.34 ( 6H), 2.02-1.94 (m, 2H), 1.61-1.54 (m, 4H), 1.47-1.39 (m, 2H).

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