Synthesis of pyridine N-imine complexes of methylcobaloxime and reactions of bis(dimethylglyoximato)methyl(Pyridine N-imine)cobalt with acid anyhydrides and acetylenedicarboxylic acid dimethyl ester

Abstract

Pyridine N-imine complexes of methylcobaloxime, CH 3Co(Hdmg) 2(R 1— C 5H n N +N −H) ( n = 4; R 1 = H, 2-CH 3, 3-CH 3, 4-CH 3: n = 3; R 1 = 2,6-CH 3), have been synthesized by the reaction of CH 3Co(Hdmg) 2S(CH 3) 2 with a pyridine N-imine which is generated from a pyridine, hydroxylamine- O-sulfonic acid and K 2CO 3. The reactions of CH 3Co(Hdmg) 2(C 5H 5N +N −H) with acid anhydrides form new methylcobaloxime complexes with N-substituted pyridine N-imines, CH 3Co(Hdmg) 2(C 5H 5N +N −R 2) R 2 = COPh, COMe, COEt). With maleic anhydride, (pyridine N-acryloylimine)carboxylic acid is formed. With acetylenedicarboxylic acid dimethyl ester, 1,3-dipolar cycloaddition of the ligand gives pyrazolo[1,5-a]pyridine-2,3-dicarboxylic acid dimethyl ester.