A new procedure for regioselective synthesis of 8,9-dichloro-2,3,4,5-tetrahydro-1<i>H</i>-2-benzazepine (LY134046) and its 3-methyl analogue as inhibitors of phenylethanolamine<i>N</i>-methyltransferase (PNMT)
作者:Gary L. Grunewald、Vidyadhar M. Paradkar、Duane M. Stillions、Feei Ching
DOI:10.1002/jhet.5570280622
日期:1991.10
4-hydride addition to the α,β-unsaturated nitrile 17 to give the saturated nitrile 18 using sodium borohydride in 2-propanol. In the preparation of LY134046 10, the COOH group in 18 was first esterified and then the nitrile function was selectively reduced with borane to yield the aminoester 20. The aminoester 20 was then cyclized to the azepinone 21 which on reduction with borane provided LY134046 10 in
的8,9-二氯-2,3,4,5-四氢-1H-1的区域选择性合成ħ -2-苯并吖庚因(LY134046,10)和它的3甲基类似物26从6,7-二氯-3- hydroxyphthalide(16)进行了说明。关键步骤涉及在2-丙醇中使用硼氢化钠将α,β-不饱和腈17中的1,4-氢化物加成,得到饱和腈18。在LY134046 10的制备中,首先将18中的COOH基酯化,然后用硼烷选择性地还原腈官能团,得到氨基酯20。然后将氨基酯20环化成氮杂one酮用硼烷还原的21得到的LY134046 10的总产率为22%。该路线适用于迄今未知的3-取代-2-苯并ze庚因的制备,如3-甲基类似物26的制备所示。在这种情况下,使腈18与过量的甲基碘化镁反应以得到酮酸22。酯化22,然后用氰基硼氢化钠和乙酸铵还原胺化,得到氨基酯24,然后将其转化为目标苯并enza庚因26如前面对标题化合物所述。在整个序列中使用的