Abstract Reactions of methyl 3-amino-1 H-indole-2-carboxylates with aryl isocyanates, aryl isothiocyanates, and cyanamides led to the formation of 5 H-pyrimido [5, 4-b] indole derivatives. In the reaction with isocyanates formed 3-aryl-1 H-pyrimido [5, 4-b] indole-2, 4 (3 H, 5 H)-diones that were involved into the alkylation at two nitrogen atoms. The reaction with isothiocyanates afforded 3-aryl-2-thioxo-2, 3-dihydro-1 H-pyrimido [5, 4-b] indol-4 (5 H)- ...
