Synthesis of New Resorcinarenes Under Alkaline Conditions

The preparation of functionalized resorcinarenes is described. Thus, 2‐nitroresorcinol (= 2‐nitrobenzene‐1,2‐diol), 2‐acetylresorcinol (= 1‐(2,6‐dihydroxyphenyl)ethanone), and 2,6‐dihydroxybenzoic acid were treated with formaldehyde in alkaline medium to give the corresponding resorcinarenes 1 – 3 ( Scheme 1 ). This method is also applicable for resorcinol (= benzene‐1,3‐diol) itself, but the yields are poorer. In this case, the molecule formed is the simplest resorcinarene 4 on which a number of substituents can be inserted between the two OH groups. Thus, bromation of 4 yields 5 ( Scheme 2 ). Some properties and conformations of these new products are discussed, and the X‐ray crystal structures of the nitro and bromo compounds 1 and 5 , respectively, are presented.