Synthetic Studies on Indoles and Related Compounds. XXXVIII. .BETA.-Acylation of Ethyl Pyrrole-2-carboxylate by Friedel-Crafts Acylation: Scope and Limitations.
作者:Masanobu TANI、Takahiro ARIYASU、Chika NISHIYAMA、Hiroko HAGIWARA、Toshiko WATANABE、Yuusaku YOKOYAMA、Yasuoki MURAKAMI
DOI:10.1248/cpb.44.48
日期:——
The Friedel-Crafts acylation of ethyl pyrrole-2-carboxylate (3) was studied under several conditions using various Lewis acids and acyl chlorides. The acylation with various acyl chlorides in the presence of aluminum chloride gave exclusively ethyl 4-acylpyrrole-2-carboxylate (5), whereas weaker Lewis acids such as zinc chloride and boron trifluoride etherate gave a mixture of ethyl 4- and 5-acylpyrrole-2-carboxylates.
在多种条件下,使用各种路易斯酸和酰基氯对吡咯-2-羧酸乙酯(3)的弗里德尔-卡夫酰化进行了研究。在有氯化铝存在的情况下,用各种酰基氯进行酰化反应,只得到 4-酰基吡咯-2-羧酸乙酯(5),而用氯化锌和三氟化硼醚酸等较弱的路易斯酸进行酰化反应,则得到 4-酰基吡咯-2-羧酸乙酯和 5-酰基吡咯-2-羧酸乙酯的混合物。