Phase Transfer Catalysis for Tandem Alkylation of Azo Dyes for the Synthesis of Novel Multifunctional Molecules

Potentially photorefractive molecules, which possess both a charge transfer component and a nonlinear optical chromophore, were prepared by the direct N-monoalkylation of Disperse Orange 3 (1) with a carbazole alkyl bromide (2) utilizing phase transfer catalysis. Further N-alkylation of the remaining active N–H with alkyl halides with various chain lengths allowed the thermal properties of the Disperse Orange 3 derivatives to be fine-tuned.