Synthesis and characterization of formyl-thienylpyridazines as versatile precursors for several optical applications

Dipolar chromophores of the type, donor – π-bridge – acceptor, are currently of great interest due to their applicability in optical and photovoltaic devices such as nonlinear optics (NLO) and dye-sensitized solar cells (DSCCs). Recently, there has been a wide range of structural modifications to the donor and acceptor groups as well as in the π-bridge of organic chromophores, in order to improve their NLO properties and DSCCs performance.¹Conjugated (hetero)aryl-pyridazines, functionalized with the formyl-group on the aryl or on the heteroaryl moiety, could be used as versatile precursors in the preparation of functional π-conjugated heterocyclic systems with several optoelectronic applications (e.g., NLO, DSSC).Having in mind these facts and as part of an on-going research to develop efficient donor-acceptor substituted heterocyclic systems for several optical applications² we synthesized thienyl-pyridazines 3-4 through Suzuki coupling of bromo-thienylpyridazine 2 with commercially available (hetero)aryl-boronic acids. On the other hand, precursor 2 was prepared by reaction of thienylpyridazinone 1 with POBr₃.³In this communication we report on the synthesis and characterization of the novel formyl-thienyl-pyridazine derivatives 3-4. In the future, these heterocyclic systems will be further functionalized and characterized in order to evaluate their potential application in NLO or as dyes sensitizers for DSCCs.