Studies On Michael Additions And Ullmann Reactions Assisted By Microwave

Michael Reaction and Ullmann Reaction are two types of important reactions which are always the focus in organic chemistry. In order to study the influence of microwave radiation on Michael reaction, single module focusing microwave reactor was employed for five Michael addition reactions, including: DL-aspartic acid formed by treating the maleic acid or fumaric acid with ammonia; 3-methyl maleic acid formed by treating the 3-methyl maleic acid with ammonia; beta-alanin formed by treating methyl acrylate with ammonia; beta-aminopropionitrile formed by treating acrylonitrile with ammonia in this paper. The better technology parameters of synthesis of DL-aspartic acid, beta-alanin and beta-aminopropionitrile were obtained through the orthogonal test. Effects of microwave power, reaction time, reaction temperature, solvent etc. on reaction were studied by a single factor tests. The results show that maleic acid is more active than fumaric acid; the introduction of methyl group on the double bond can weak the reactivity of the Michael addition reaction; the ester base is more propitious to complete the Michael addition reaction than the nitrile base.Triphenylamine and its derivatives are important raw materials which can be produced charge transport material and electro-luminescent materials. They are also used as organic dyestuffs and the pharmaceutical intermediate materials. The influence of microwave radiation on Ullmann reaction has been investigated by three Ullmann reactions, including triphenylamine formed by treating the diphenylamine with bromobenzene or Chlorobenzene which substitutes Iodobenzene; 4,4'-dimethyltriphenylamine formed by treating 4,4'-dimethyldiphenylamine with bromobenzene which substitutes Iodobenzene; 4,4',4"-trinitrotriphenylamine formed by treating 4-chloronitrobenzene with p-nitroaniline in this paper. The better technology parameters of synthesis of triphenylamine, 4,4'-dimethyltriphenylamine and 4,4',4"-trinitrotriphenylamine were obtained through the orthogonal test. Effects of microwave power, reaction time, reaction temperature, solvent, etc. on reaction were studied by a single factor test. The results showed that the derivatives of triphenylamine which their phenyl were connected the donor substituent were harder to be synthesized than the triphenylamine; the derivatives of triphenylamine which their phenyl were connected the acceptor substituents were easier to be synthesized than the triphenylamine; the Ullmann reaction was easy to process when the halogenated benzene which their halogen'radius was bigger under microwave irradiation.In a word, law of Michael reaction and Ullmann Reactions under microwave radiation is the same as that on conventional heating conditions. Microwave heating is much faster, energy-saving and environmental, simpler operation, more economical and safer than conventional heating for Ullmann Reactions and Ullmann Reactions.