Reaction of picryl azide with N-methylindoles: the crystal structure of 1-methyl-2-picryliminoindoline

Abstract

Picryl azide reacts with N-methylindoles to form 2-N-picryl derivatives of 2-aminoindole. These compounds exist in the amino-form (I) in solution, but the three-dimensional crystal structure determination for the 1-methyl-2-N-picryl derivative shows it to be in the iminoindoline form (II). The structure was determined from diffractometer data by direct methods and refined by least squares to R 0·053. The carbon–carbon bonds at C(3) are both of length 1·52 Å, and the positions of the two hydrogen atoms were clearly established from difference Fourier syntheses.