Synthesis and characterization of a series of 3-methyl-3-{3-[1-methyl-3-aryl-2-triazenyl]propyl}-1-aryl-1-triazenes and related compounds

Abstract

A series of diazonium salts has been coupled to both secondary nitrogen atoms of the bis-secondary amine, N,N′-dimethyl-1,3-propanediamine (MeNHCH2CH2CH2NHMe), to afford the new bistriazene series, the 3-methyl-3-{3-[1-methyl-3-aryl-2-triazenyl]propyl}-1-aryl-1-triazenes (9). These compounds have been fully characterized by IR and NMR spectroscopy, with supporting data from elemental analysis and high-resolution mass spectrometry. A limited number of model compounds in the N,N-dimethyl-N-{3-[1-methyl-3-aryl-2-triazenyl]propyl}amine series (10) have been synthesized to aid in the interpretation of the NMR spectra of the bistriazenes (9). A series of related compounds, the 3-ethyl-3-{(E)-4-[1-ethyl-3-aryl-2-triazenyl]-2-butenyl}-1-aryl-1-triazenes (11), have been synthesized by diazonium coupling with the bis-secondary amine N,N′-diethyl-2-butene-1,4-diamine (15), and the diazonium coupling reaction with trans-N,N′-dimethycyclohexane-1,2-diamine (19) has been used to prepare another related series of bistriazenes, the 3-methyl-3-{2-[1-methyl-3-aryl-2-triazenyl]cyclohexyl}-1-aryl-1-triazenes (12). The 1H NMR spectra of these compounds are complex because of the presence of two chiral centres in the cyclohexanediamine moiety; the diastereotopic protons of the methylene groups in the cyclohexane ring are clearly distinguished in the 500 MHz spectra of these compounds.Key words: triazene, bistriazene, synthesis, nuclear magnetic resonance, propanediamine, 1,4-diamino-2-butene, cyclohexanediamine.