Synthesis and Crystal Structure of 7,8,9,10-Tetrahydro-2-bromo-cyclohepta[b]indol-6(5H)-one

The title compound, C 13 H 12 BrNO, was synthesized and characterised by IR, 1 H and 13 C NMR spectroscopy. The proposed structure was confirmed by single crystal X-ray diffraction. The single crystal data revealed that the compound crystallizes in the triclinic system, sp. gr. P 1, with Z = 2. The sevenmembered ring exhibits a slightly distorted envelope conformation. N–H···O hydrogen bonds form a centrosymmetric dimer, these interactions create a stair-like chain of molecules that interacts only loosely with neighbouring chains via van der Waals interactions, and C–H···π contacts are found in the crystal structure.