A practical method for N-methylation of NH-containing heterocycles using an environmentally safe and less toxic methylating reagent, dimethyl carbonate, has been developed. N,N,N′,N ′-tetramethylethylenediamine (TMEDA), an extremely active organocatalyst for the methylation of imides, indoles, benzimidazoles, and piperazines in conjunction with dimethyl carbonate, can lead to N-methylation products with high conversion. The reaction sequence consists ...
