Abstract The isomeric 4, 6-diamino-2-alkoxy-(3), and 2, 4-diamino-6-alkoxy-3-pyridine- carbonitriles (4) are obtained by treatment of 2-amino-1, 1, 3-tricyanopropene (1) with sodium alkoxides. Separation is based on their different pK a-values (3 a= 2.01, 4 a= 4.17). Coupling reaction of 3 ac with benzenediazonium chloride in strong acidic medium leads to the yellow azo dyes 5 ac, whereas coupling of 4 a requires a buffered solution (pH 4–6) to ...
