Synthesis of 1-(<i>o</i>-substituted-phenyl)-3,4-dimethylenepyrrolidines by the thermal elimination of sulfur dioxide
作者:Raphael M. Ottenbrite、Henry Chin、Peter V. Alston
DOI:10.1002/jhet.5570230625
日期:1986.11
3,4,6-tetra-hydrothieno[3,4-c]pyrrole 2,2- dioxides 2, were synthesized by reacting o-substituted anilines with 3,4-bis(bromomethyl)-2,5-dihydrothiophene 1,1-dioxide. A disubstitution product along with the desired 2 was obtained when excess amine was used to neutralize the amine salts that were formed from nucleophilic substitution. A 1,4-HBr elimination product was obtained in three out of four cases
1-(邻取代苯基)-3,4-二亚甲基吡咯烷,5-(邻取代苯基)-1,3,4,6-四氢噻吩并[3,4- c ]吡咯2,2的前体-氧化钛2中,通过反应而合成ö与3,4-双(溴甲基)-2,5-二氢噻吩-1,1-二氧化物取代的苯胺。与所需2一起发行的糊状产品当使用过量的胺来中和由亲核取代形成的胺盐时,得到的α-氨基磺酸盐。当使用碳酸钠中和胺盐时,在四分之三的情况下,获得了1,4-HBr消除产物。1,4-HBr消除产物是由于对酸性环丁砜质子的竞争性碱攻击而产生的。通过从2中热消除二氧化硫获得3,4-二亚甲基吡咯烷。