Methyl azelaaldehydate, soy nitriles, and oleonitrile were compared as starting materials for making nylon-9. Less difficulty was encountered in purifying intermediates from oleonitrile than from the other two. All 3 routes involved hydrolysis of methyl 9-aminononanoate to 9-aminononanoic acid. Self catalyzed hydrolysis of the amino ester in water produced low yields of monomer owing to oligome...