... 31) and recently thoroughly explored by us(32) (and, as chelates for zinc, by Seto and co ... Method B: 12 was prepared from squaric acid monoester monoamide 9 and N-isopropylhydroxylamine (i-PrNHOH ... was prepared by addition of a solution of KOH in dry MeOH (0.6 M, 3.5 mL ...