Ethyl 1-indole-2-carboxyl-ate.

Our work in the area of synthesis of tris indole compounds as a potential chelator led to the synthesis and crystallization of ethyl 1-indole-2-carboxyl-ate, CHNO, an indole that was synthesized by the thionyl chloride reaction of 1-indole-2-carb-oxy-lic acid, followed by dissolution in ethanol. The mol-ecular packing exhibits a herringbone pattern with the zigzag running along the -axis direction; the compound crystallizes as a hydrogen-bonded dimer resulting from O⋯H-N hydrogen bonds, between the indole N-H group and the keto oxygen atom, which build centrosymmetric (10) ring motifs in the crystal.