Triphenylphosphine → N,N-dimethyl-3-[(benzo[1,3]dioxolan-4-yl)-oxy]-3-(thiophen-2-yl)-propylamine

関与物質

反応手順

3-Dimethylamino-1-(thiophen-2-yl)-1-propanol (1.85 g, 0.01 mol), 4-hydroxyl-benzo[1,3]dioxolane (1.38 g, 0.01 mol) and triphenylphosphine (3.93 g, 0.015 mol) were dissolved in 80 ml of anhydrous tetrahydrofuran. The mixture was slowly added dropwise with the solution of diethyl azodicarboxylate (2.61 g, 0.015 mol) in 20 ml anhydrous tetrahydrofuran, the reaction temperature was controlled to be lower than −5° C. in an ice-salt bath. After completion of the addition, the ice-salt bath was removed, and the reaction was performed at room temperature for 24 h. After the end of reaction, tetrahydrofuran was distilled out under a reduced pressure, the resultant oily liquid was dissolved in 100 ml of ethyl acetate, washed with diluted sodium hydroxide aqueous solution and saturated sodium chloride aqueous solution separately once, dried over anhydrous sodium sulfate, and separated by silica gel column chromatography to obtain 1.07 g of N,N-dimethyl-3-[(benzo[1,3]dioxolan-4-yl)-oxy]-3-(thiophen-2-yl)-propylamine as a pale yellow oily liquid, which was dissolved in 30 ml of ethyl acetate, added with oxalic acid (0.32 g, 0.035 mol) to generate a pale yellow solid. The mixture was heated to reflux, cooled to room temperature, frozen for 2 h and filtrated. The filter cake was washed with cold ethyl acetate to obtain 1.31 g of the target compound as a pale yellow powdery solid in a yield of 33.2% and a melting point of 85-88° C. MS (m/e): 306.5 (M+1+); 1H-NMR δ (ppm, DMSO-d6): 7.46-7.48 (d, 1H, 5′-H); 7.11-7.12 (d, 1H, 3′-H); 6.95-6.97 (dd, 1H, 4′-H); 6.66-6.70 (t, 1H, 6-H); 6.53-6.59 (dd, 2H, 5,7-H); 5.97-5.98 (d, 2H, 2-H); 5.71-5.75 (t, 1H, CHO); 2.27-2.30 (t, 2H, CH2N); 2.19-2.21 (m, 1H, CH2CH2N); 2.11 (s, 6H, N(CH3)2); 2.06-2.08 (m, 1H, CH2CH2N).

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