Regiospecific substitution of the 4-nitro group in 3-amino-4,6-dinitrobenzo[b]thiophene-2-carboxylates: unexpected activating effect of the amino group
作者:Svyatoslav A Shevelev、Igor L Dalinger、Tatyana I Cherkasova
DOI:10.1016/s0040-4039(01)01833-0
日期:2001.11
6-trinitrobenzonitrile with the esters of thioglycolic acid results in the formation of 3-amino-4,6-dinitrobenzo[b]thiophene-2-carboxylates 3. The interaction of 3 with anionic nucleophiles RO− (R=CF3CH2, CHCCH2), RS− (R=Ph, PhCH2, (CH3)2CHCH2), N3− in NMP or DMF leads to the substitution of only the 4-NO2 group. The replacement of the electron-donating NH2 group in 3 with hydrogen unexpectedly and significantly
2,4,6-三硝基苯甲腈与巯基乙酸的酯的环缩合导致形成3-氨基-4,6-二硝基苯并[ b ]噻吩-2-羧酸酯3。的相互作用3与阴离子亲核试剂RO -(R = CF 3 CH 2,CHCCH 2),RS -(R = PH,物理信道2,(CH 3)2 CHCH 2),N 3 -在NMP或DMF引线仅取代4-NO 2基团。3中给电子NH 2基团的取代氢意外地并显着阻碍了硝基的亲核取代。如半经验量子化学计算所示,假设在NH 2基团的影响下,4-NO 2 in 3的增加的反应性与该基团相对于芳环平面的扭曲有关。