Reductive N-Methylation Of Amines Using Formic Acid Via Simple Inorganic Base Catalysis

The synthesis of amines containing N-methyl structure is a very important reaction in organic reactions,which is widely used in agriculture,dyes and drug intermediates.Therefore,N-methyl amines have broad application prospects.The development of a new methylation reagent is more environmentally friendly to the environment than methyl iodide and methyl sulfate and other traditional methylation reagents.It is also a very desirable method.In this paper,a simple method of N-methylation of amino group catalyzed by a simple inorganic base is reported.In this paper,the catalytic system works without transition metal and air resistance.Catalyst dipotassium phosphate and reductant polymethylhydrosiloxane(PMHS)are both relatively cheap compared to transition metals,and the reaction products are easily separated from the mixture of crude reaction products.In the first chapter,the optimum conditions of the reaction were determined by screening the catalyst,reducing agent,catalytic dose,reaction time,reaction temperature and solvent.At the same time,14 n-methylation products were obtained by substrates of various secondary amines.The yield of the reaction was higher,and the highest yield was 88%.In chapter 2,indirect methylation products of primary amine were obtained by ternary reaction of aldehyde,primary amine and formic acid.And 10 indirect nmethylation products were finally obtained.In chapter 3,through the study of the reaction mechanism,it was shown that the N-methylation reaction of the catalytic system was realized after the formation of acetal intermediates,which were reduced again and the C-N bond was formed.In this paper,formic acid is used as a carbon source to realize n-methylation of amine compounds.The conditions are mild and the cost is low.Transition metals are not required as catalysts,nor are phosphine ligands added.It is a very useful method in the industrial reaction of n-methylation of amines.