N-2-Hydroxybenzaldehyde acylhydrazone-Fe(III) complex: synthesis, crystal structure and its efficient and selective N-methylation.
N-Methyl-N'-2-hydroxybenzaldehyde acylhydrazones have been chemospecifically synthesized in good yield by N-methylation of the Fe(iii) complexes of N-2-hydroxybenzaldehyde acylhydrazones with methyl iodide in tetrahydrofuran. The reaction proceeds with the exclusive formation of the N-methyl derivative without any concurrent O-methylation side reactions. In addition, the N-methylation reaction occurred simultaneously with a complete deprotection step (elimination of the metal ion). As a result, the N-methyl product was obtained in excellent purity without time-consuming chromatographic workup. A free N-2-hydroxybenzaldehyde acylhydrazone ligand could not be methylated under the same conditions.
Key Laboratory of Catalysis and Materials Science of the State Ethnic Affairs Commission & Ministry of Education, South-Central University for Nationalities, Wuhan, 430074, P. R. China. wlm52875@163.com.
Zhiyou
Z
Li
Lamei
L
Wu
Tao
T
Zhang
Zhengxi
Z
Huang
Guofu
G
Qiu
Zhongqiang
Z
Zhou
Longfei
L
Jin
D060326:Chemistry Techniques, Synthetic; D018360:Crystallography, X-Ray; D005290:Ferric Compounds / Q000138:chemical synthesis* / Q000737:chemistry*; D006835:Hydrazones / Q000737:chemistry*; D006878:Hydroxides / Q000737:chemistry; D008745:Methylation; D008958:Models, Molecular; D008968:Molecular Conformation; D019800:Phenol / Q000737:chemistry; D013379:Substrate Specificity
D005290:Ferric Compounds; D006835:Hydrazones; D006878:Hydroxides; D019800:Phenol; C031356:hydroxide ion