347s NOTES VOl. 73 to be able to determine the presence of unreacted positions ortho or para to the phenolic hydroxyl group. Thus, Niederl and McCoy'used the coupling reaction with a diazonium salt as a qualitative test for open end positions in a phenolic polymer. The general applicability of the coupling reaction to phenol-formaldehyde intermediates is, however, open to question because of the possible (or, indeed, probable) presence of ...
