反应详情

To a solution of 318 mg (0.951 mmol) of 3-(5-chloro-1,3-dimethyl-pyrazole-4-sulfonyloxy)-5-methylphenol, as prepared in the preceding step, in 5 mL of anhydrous tetrahydrofuran containing 360 mg (1.42 mmol) of 1,1'-(azodicarbonyl)dipiperidine and 150 μL (2.07 mmol) of 1,3-propanediol was added slowly 350 μL (1.41 mmol) of tri-n-butylphosphine. The reaction mixture was stirred for 1 h at ambient temperature, diluted with diethyl ether, and filtered. The filtrate was concentrated and purified by flash chromatography (ethyl acetate/dichloromethane (2:1)) to give 227 mg (64% yield) of the title compound as an oil. 1H-NMR (300 MHz, CDCl3) δ 6.64-6.65 (m, 1H), 6.52-6.54 (m, 1H), 6.46-6.47 (t, 1H), 4.06 (t, 2H, J=6 Hz), 3.83 (t, 2H, J=6 Hz), 3.82 (s, 3H), 2.29 (s, 3H), 2.28 (s, 3H), 2.00 (pentet, 2H, J=6 Hz). Mass spectrum (MALDI-TOF, α-cyano-4-hydroxycinnamic acid matrix) calcd. for C15H19ClN2O5S: 375.1 (M+H), 397.1 (M+Na). Found: 374.9, 397.1.

1. filtrationfiltered
2. concentrationThe filtrate was concentrated
3. custompurified by flash chromatography (ethyl acetate/dichloromethane (2:1))