对称双吡咯甲烷的合成与分子内氢键的研究

Synthesis and Intramolecular Hydrogen Bonding ofSymmetric Dipyrrylmethanes

５－甲基吡咯－２－羧酸酯在磺酰氯、溴或四乙酸铅的作用下，生成相应的在５－甲基上含取代基的产物，后者不经分离便可自缩合得标题化合物。核磁共振氢谱研究和分子构象模拟计算表明，当３，３＇位的取代基为甲酸（酯）基或乙酸（酯）基时，可形成３，３＇位酯基与另一吡咯环上的氮氢之间的分子内氢键，而３，３＇位是其它取代基，如乙酰基、丙酸（酯）基、丁酸（酯）基时不能形成类似的分子内氢键。

The title compounds were prepared by converting ethyl 5-methylpyrrole-2-car boxylates into corresponding 5-methyl substituted pyrroles oxydized by surfuryl chloride,bromine,or lead tetraacetate, and then self-condensed without separation and purification.The 1H NMR analysis and molecular conformation computation revealed that strong in tramolecular hydrogen bondings exist in dipyrrylmethane 4b and 4c (3 . 3' substituents are for mate and acetate esters),while very weak or no intramolecular hydrogen bonding exists in other dipyrrylmethanes.