Differentiation of Cinchonine and Cinchonidine Derivatives Through 13C NMR Analysis of the Quinuclidine Ring

Artículo

With a view to developing a procedure for the diferentiation of cinchonine derivatives from cinchonidine derivatives by NMR analysis, experimental data on cinchonine and cinchonidine, after their dissolution in diferent solvents (CDCl3, CD3OD and DMSO-d6), were compared with theoretical data, originating from diferent methodologies: DP4, DP4+, J-DP4 and ANN. Taking into account the lower computational consumption, as well as the greater efciency in diferentiation, the method selected was the trained artifcial neural networks (ANN), which considered only the 13C data from the quinuclidine ring. The method successfully diferentiated derivatives originating from OH group protection in ester and ether forms; replacement of the OH group by F and NH2; insertions of N3, 1H-1,2,3-triazol-1-yl and CH3O groups, linked to the quinoline ring; conversion of the vinyl group to the 1-benzyl-1H-1,2,3-triazol-4-yl; and of hydrogenation, dehydrogenation, and bromination of the vinyl group. In all cases the application of the ANN method succeeded in diferentiation of cinchonine from cinchonidine derivatives.