Syntheses of medium-sized heterocycles using an intramolecular Michael reaction.
作者:YUTAKA MASUOKA、TSUNEHIKO(deceased) ASAKO、GIICHI GOTO、SHUNSAKU NOGUCHI
DOI:10.1248/cpb.34.140
日期:——
1, 2, 3, 5-Tetrahydro-2-oxo-4, 1-benzoxazepine-3-acetates (5, 13, 16), 2, 3, 5, 6-tetrahydro-2-oxo-1H-4, 1-benzoazocine-3-acetates (21), and 1, 2, 3, 5, 6, 7-hexahydro-2-oxo-4, 1-benzoxazonine-3-acetate (25) were obtained from 3-[[2-(ω-hydroxyalkyl)phenyl]carbamoyl]acrylates (4, 12, 15, 20, 24) by the intramolecular Michael addition previously developed for the synthesis of 3, 4-dihydro-2H-1, 4-benzoxazine-2-acetates. In the case of 5-phenyl-3-oxo-4, 1-benzoxazepine-3-acetates (13), the 3, 5-cis and 3, 5-trans isomers were obtained in a ratio of 1 : 1. Under basic conditions, each isomer was equilibrated to a mixture of cis- and trans-13 in a ratio of 1 : 3. A deuterium exchange experiment revealed that the isomerization proceeded through the retro-Michael reaction. The stereochemistry of trans-13e was confirmed by X-ray analysis.Among the compounds (13) synthesized, N-isopropyl (cis-13c), N-benzyl (cis- and trans-13e) and N-phenethyl (cis-13f) derivatives showed considerable anxiolytic activity in the conflict test in rats.
3-[[2-(ω-羟基烷基)苯基]氨基甲酰基]丙烯酸酯(4、12、15、20、24),通过之前合成 3,4-二氢-2H-1,4-苯并恶嗪-2-乙酸酯时开发的分子内迈克尔加成法,得到了 1,2,3,5,6,7-六氢-2-氧代-4,1-苯并恶嗪-3-乙酸酯(25)。在 5-苯基-3-氧代-4, 1-苯并氧氮杂卓-3-乙酸酯(13)中,3, 5-顺式和 3, 5-反式异构体的比例为 1:1。在碱性条件下,每种异构体按 1 : 3 的比例平衡成顺式和反式-13 的混合物。氘交换实验表明,异构化是通过逆迈克尔反应进行的。在合成的化合物(13)中,N-异丙基(顺式-13c)、N-苄基(顺式和反式-13e)和 N-苯乙基(顺式-13f)衍生物在大鼠冲突试验中表现出相当强的抗焦虑活性。