Abstract The reaction of o-phthaldehyde with potassium cyanide and methylamine hydrochloride afforded 1-cyano-2-methylisoindole (1) in 92% yield. Possible mechanism and supporting nmr, ir, mass spectrum and single X-ray structure analysis for 1 are discussed. The X-ray study revealed that the true structure of 1 can best be represented as a resonance hybrid of the canonical forms a, b, c and d.
