“…Formation of the di‐esters 6 and 7 is confirmed by NMR, IR, elemental analysis and by a crystal structure of 6 . Formation of di‐esters rather than the free acid has been previously observed for several amino acids (30,31). Addition of the primary amine to the p ‐chloranil produced intensely coloured solutions that were filtered after 4 h. In the case of amines I, II, IV, V and IX, highly coloured powders of products 1 , 2 , 4 , 5 and 9 precipitated immediately and were collected by suction filtration and recrystallized from acetone or hot acetonitrile yielding X‐ray quality crystals of 1 , 2 , 6 and 9 (Table 1).…”