Quantum Chemical Studies on Conformations of Indoles

All the possible tautomeric equilibria and conformers of 1-, 2- 1, 2- substituted indoles inaqueous solution were studied by semi-empirical methods. All possible tautomeric equilibriaand conformers of the indoles were considered to determine the most stable forms. TheAMI PM3 calculations indicate that the compound 2-hydroxymethylindole prefers antianti anti-anti forms, 2-formylindole anti-, ethyl indole-2-carboxylate syn-syn, indole2-carboxylic acid syn-syn, indole-2-carbohydrazide syn-syn, 2-formyl-I-methylindole synforms respectively over other tautomeric forms by different percentages