含对硝基苯磺酰基的α,β-不饱和砜的合成

Synthesis of α,β-Unsaturated Sulfones Containing 4-Nitrophenylsulfonyl Group

α,β-不饱和砜是以对硝基苯磺酰基乙酸酯为原料与芳香醛在六氢吡啶醋酸盐催化下发生缩合反应制得的。研究了催化剂对反应的影响,发现3-二甲氨基苯丙胺(DPA)是最有效催化剂之一。在NaC l/DMSO/H2O体系中,缩合产物(E)-2-(对硝基苯磺酰基)-3-苯丙烯酸乙酯(Ⅲb)在185℃反应,得到脱羧物〔E-1-苯基-2-(4-硝基苯磺酰基)乙烯(Ⅳb)〕。用1HNMR确证了缩合产物构型为E型。

Some new α,β-unsaturated sulfones were prepared by condensation of 4- nitrophenylsulfonylacetates with aromatic aldehydes in cyclohexane/CH3CH2OH in the presence of catalytic amounts of pipefidine. The effects of catalysts on the condensation reactions were examined. （3-Dimethylaminophenyl） propropanamine was found to be one of the most effective catalysts. Dealkoxycarbonylation of the condensation products give the corresponding sulfones. ^1HNMR spectroscopy revealed that only the trans-isomer was found.