Pyridine 2-cyano-3-hydroxypyridine

Bifunctional catalysis. Some time ago Swain and Brown1 observed that 2-hydroxypyridine catalyzed the mutarotation of tetramethylglucose by a concerted base-acid catalysis and that it is more effective than pyridine plus phenol. A few years later Beyerman and van den Brink2 showed that 2-hydroxypyridine and other bifunctional compounds catalyze the reaction of amines with cyano-methyl esters (reactive esters) as well as low-energy esters in peptide synthesis. Pyrazole and 1,2,4-triazole (1,1188), were equally effective. 

Comments on the diazotization of aminopyridines and their 1-oxides have been made in connection with nucleophilic substitutions leading to cyano-(p. 226), halogeno- (p. 229) and hydroxy-pyridines (p. 239). The formation of a diazotate from 2-aminopyridine (p. 229), and of diazo oxides from 3-amino-2- and -4-hydroxypyridine (p. 270) has also been noted. 

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