Solid base catalyzed highly efficient N-alkylation of amines with alcohols in a solvent-free system

•Reactions were run in a solvent-free system without transition metal or additive.•Solid NaOH catalyzed N-alkylations of amines with alcohols to the secondary amines.•The reaction between aniline and benzyl alcohol yielded 99.1 mol% of the product.•This novel reaction most likely proceeds with a base-catalyzed mechanism.

Different from any other catalytic systems containing transition metals and additives, sodium hydroxide itself was found to be a unique and effective catalyst for the solvent-free synthesis of the secondary amines via the N-alkylation of amines with alcohols. For the reaction of aniline with benzyl alcohol, 99.6 mol% conversion of aniline and 99.5% selectivity of the product were achieved under optimal conditions. Also, high conversion and selectivity could be acquired for the N-alkylations of various amines with alcohols, implying the universality of this methodology. Mechanistic studies revealed that this novel reaction most possibly proceeds with a base-catalyzed mechanism.

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