Preparation of phthalamic acid derivatives and ring closure to phthalimidobarbituric acids
作者:Agnieszka Ambrożk、Michael Gütschow
DOI:10.1002/jhet.5570440606
日期:2007.11
Phthalamic acid derivatives with a barbiturate moiety were prepared from 5-amino-5-ethylbarbituric acids. To circumvent an undesired acetylation in glacial acetic acid during the preparation of phthalimidobarbituric acids, two routes were proven exemplarily. On the one hand, a phthalamic acid (6a) was isolated and subsequently cyclized with acetic anhydride to the corresponding phthalimide 2a. On the
由5-氨基-5-乙基巴比妥酸制备具有巴比妥酸酯部分的邻氨基苯甲酸衍生物。为了避免在邻苯二甲酰亚胺巴比妥酸的制备过程中在冰醋酸中发生不希望的乙酰化,示例性地证明了两种途径。一方面,分离邻苯二甲酸(6a),随后用乙酸酐环化成相应的邻苯二甲酰亚胺2a。另一方面,依次用三氟乙酸和三氟乙酸酐处理邻苯二甲酸叔丁酯(5b),以实现与邻苯二甲酰亚胺2b的杂环化。这些路线可能对制备衍生自空间受阻伯胺的其他邻苯二甲酰亚胺有用。