Ortho-functionalized arene-ethanals

Cyclodehydration of 2-hydroxy- or 2-aminobenzene-ethanal derivatives is known as a general procedure for the synthesis of benzo-fused heteroaromatic compounds [95]. Although numerous modifications of this general method have been explored, the major difficulty seems to be the lack of a general method for the synthesis of the required ortho-functionalized arene-ethanals. 

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