Relative Reactivity and Structures of Benzoyltrimethylhydrazine and 1-Benzoyl-2-methylpyrazolidine

Article abstract of DOI:10.1021/jo00325a012

Benzoyltrimethylhydrazine (1a) exhibits a less nucleophilic and less basic N(2) compared with N(2) of 1-benzoyl-2-methylpyrazolidine (2a).The X-ray crystallographic analyses of 1a and 2a suggest that the reactivity differences are a consequence of the larger N(1)-N(2) lone pair-lone pair torsional angle and the greater distortion from planarity at N(1) in 2a, as compared with those in 1a.The configuration of 1a, 2a and related 1,2,2-trisubstituted hydrazines about the amide bond is E, as evidenced by X-ray and 1H NMR studies.In support of the configurational results, ab initio molecular orbital calculations show that N-unsubstituted hydrazides should preferentially adopt the Z configuration, while fully N-substituted hydrazides should adopt the E form.Compound 1a readily forms a one-to-one complex with copper(II) chloride (7), whose X-ray structure shows a chelating hydrazide in the Z configuration.