Synthèse de N‐Alkyl‐arylamines par Thermolyse ou Photolyse d'Alkyl‐3‐diaryl‐1,3‐triazènes

Abstract

Synthesis of N‐Alkyl‐arylamines by Thermolysis or Photolysis of 3‐Alkyl‐1,3‐bis(p‐chlorophenyl)triazenesThe thermolysis of 3‐alkyl‐1,3‐bis(p‐chlorophenyl)triazenes in benzene or methanol leads to the formation of N‐alkyl‐p‐chloroanilines (2) in 19–50% yield, N‐alkyl‐bis(p‐chlorophenyl)amines (3) in 7.5–15.5% yield and 4,4′‐dichlorobiphenyle (4) in 1–7% yield; besides with benzene as the substrate, 4‐chlorobiphenyle (5) (12–20% yield) was also formed. The photolysis in methanol gives only the N‐alkyl‐p‐chloroanilines (2) in 32–40% yield. In these two cases the results are consistent with a radical pair formation in a solvent cage, recombination (thermolysis) and/or diffusion (thermolysis and photolysis) with intermolecular abstraction of hydrogen. A free radical chain mechanism is involved in the photolytic process and the quantum yield is high.