С,С-Coupling of indole-3-carbaldehyde arylhydrazones with quinazoline in trifluoroacetic acid proceeds at position 5 or 7′ of the hydrazone molecule with the formation of σ-adducts. C,C-Coupling is accompanied by a change in the E -configuration of the C=N bond of the starting hydrazones to the Z -configuration in the quinazoline trifluoroacetylhydrazides formed.