Acid-catalysed rearrangements in the aryliminoindoline series. Part II. Crystal and molecular structure of 2-anilino-3-(1-methyl-2-phenylindol-3-yl)-3-phenyl-3H-indole monohydrate

Abstract

Acid treatment of (N-alkylindolyl)indolinimines and indolylindolinimines gives retrogression, hydrolysis, and phenyl or indolyl transposition (in position 2) reactions: products obtained by phenyl transposition further give rise to a double transposition with formation of 2-arylimino-3-(1-alkyl-2-phenylindol-3-yl)-3-phenyl-3H-indole. The structure of 2-anilino-3-(1-methyl -2-phenylindol-3-yl)-3-phenyl -3H-indole mono hydrate (XIa) has been determined by X-ray analysis by use of 4 972 independent reflections measured by diffractometer and refined by least-squares to R 0.074. A mechanism for the rearrangements is suggested. The structure was solved by direct methods. Crystals are monoclinic, space group P2₁/c. with Z= 4 in a unit cell of dimensions a= 12.60(1), b= 15.74(1), c= 16.45(1)Å, and β= 124.9(2).