Improved Synthesis of Thromboxane A2 Receptor Antagonists with a Dibenzoxepin Ring System
作者:Toru Sugaya、Nobuyuki Kato、Akihiko Sakaguchi、Shinji Tomioka
DOI:10.1055/s-1995-4088
日期:1995.10
Two derivatives of sodium (E)-11-[2-(1-benzimidazolyl)ethylidene]-11-oxo-6,11-dihydrodibenz[b,e]oxepin-2-carboxylate, novel non-prostanoid thromboxane A2 (TXA2) receptor antagonists, were synthesized from methyl 11-oxo-6,11-dihydrodibenz[b,e]oxepin-2-carboxylate. The carbonyl group at C11 was converted into a formylmethylene, then into a 1-azadiene moiety by reaction with a 2-aminoformanilide derivative. Stereo- and regioselective elaboration of the unsymmetrical imidazoles was achieved through a sequence of the transformation of E,Z-1-azadiene intermediates to E isomers under acidic conditions followed by cyclization to imidazoles.
两种钠盐衍生物(E)-11-[2-(1-苯并咪唑基)乙烯基]-11-氧代-6,11-二氢二苯并[b,e]苯并噁嗪-2-羧酸酯,是新型非前列腺素的血栓素A2(TXA2)受体拮抗剂,由甲基11-氧代-6,11-二氢二苯并[b,e]苯并噁嗪-2-羧酸酯合成。C11的羰基被转化为甲酰亚甲基,然后通过与一个2-氨基芳基甲酰胺衍生物反应转化为1-氮杂烯烃基团。通过将E,Z-1-氮杂烯中间体在酸性条件下转化为E异构体,然后环化为咪唑的序列,实现了不对称咪唑的立体选择性和区域选择性扩展。