Synthesis of Amino-N-heteroaromatic via SNAr
2,3-dichloro-6,7-dinitroquinoxaline. Piridine. SNAr. Anilines
N-heteroaromatic derivatives containing amine groups in their structures are of great interest in the development of new drugs, due to the reported biological activities that these compounds present. The development of novel protocols for obtaining amino-N-heteroaromatic compounds in a mild manner and without the use of metal catalysts is much desired in synthetic organic chemistry. In this work a method was developed to obtain quinoxalinic derivatives through a SNAr reaction using 2,3-dichloro-6,7-dinitroquinoxaline (DCDNQX) and substituted anilines. After optimization, 14 examples of unpublished products were obtained under mild conditions and without the use of metallic catalysts, with yields varying from low to excellent (trace-98%). In addition to the use of the quinoxaline derivative DCDNQX, the C-H functionalization reaction with pyridine and t-butylamine was studied. The use of molecular iodine (I2) as an additive in this transformation allowed the formation of a dissubstituted product. A preliminary analysis of the results indicates that this dissubstitution occurs at the C3 and C5 positions of the pyridine ring, a reactivity rarely seen in reports in the literature, which may lead to the formation of novel compounds with potential biological activity.