ABSTRACT An improved preparative four-step synthesis to isoquinuclidine tosylate salt 4 has been demonstrated in 70% overall yield from p-aminobenzoic acid (PABA) 1. Hydrogenation of PABA 1 affords 4-aminocyclohexane carboxylic acid 2 as an 80 : 20 mixture of cis- and trans-isomers. Heating the mixture at 250°C effected epimerization and cyclization to provide the bicyclic lactam 3. Subsequent Red-Al reduction and treatment with tosic acid furnished the desired bicyclic amine, tosylate salt 4.

中文翻译：

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2-氮杂环[2.2.2]辛烷的改进制备

摘要 改进的制备四步合成异奎宁环甲苯磺酸盐 4 已证明从对氨基苯甲酸 (PABA) 1 的总产率为 70%。PABA 1 的氢化得到 4-氨基环己烷羧酸 2，为 80:20 的顺式混合物- 和反式异构体。将混合物在 250°C 加热，进行差向异构化和环化，得到双环内酰胺 3。随后的 Red-Al 还原和甲苯磺酸处理得到所需的双环胺，甲苯磺酸盐 4。