O2-functionalized methylamine diazeniumdiolates: evidence for E ? Z equilibration in an acyclic system.

ABSTRACT: Diazeniumdiolates that have the structure RHN-N(O)?NOR' are of interest as prodrug (caged) forms of the bioeffectors nitric oxide (NO) and nitroxyl (HNO). Previous work has focused on examples possessing ?-branched R groups, with isopropylamine (IPA)/NO (R = isopropyl) being the smallest examined to date. To probe the effect of minimizing the alkyl-group size on the chemistry of IPA/NO, we prepared the corresponding methylamine derivative as a sodium salt that was highly unstable but could be trapped in very low overall yield as the stable O(2)-benzyl derivative. To prepare enough for efficient characterization, we devised an alternate synthesis involving a novel N-dealkylation route. CH(3)HN-N(O)?NOBn, synthesized in high yield and crystallized as the Z isomer as determined by X-ray crystallography, was observed to exist as a 11:1 mixture of two isomeric forms in dynamic equilibrium in solution. Similar results were seen for the O(2)-ethyl derivative, whose two equilibrium constituents were partially separated by HPLC to reveal essentially identical UV and mass spectra, indicating them to be Z and E isomers of CH(3)HN-N(O)?NOEt. The results could lead the way to a fuller understanding of the chemistry of the acyclic (E)-diazeniumdiolates.

SUBMITTER: Biswas D 

PROVIDER: S-EPMC7243909 | biostudies-literature | 2012 Dec

REPOSITORIES: biostudies-literature