Acetaldehyde, 2,2-dimethoxy- → N-methyl-N-(4-nitrophenylmethyl)-2,2-dimethoxy-ethylamine

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Reaction Steps

A mixture of 1.56 g N-methyl-N-(4-nitrobenzyl)amine in 40 ml THF is combined with 2.85 ml of a 45% solution of 2,2-dimethoxyacetaldehyde in tert.-butylmethylether. Then 24 mg of p-TsOHx H2O and 1.12 ml glacial acetic acid are added and the mixture is stirred for 2 h. Then 1.81 g of sodium cyanoborohydride are added batchwise and the mixture is stirred for another 2 h. 5 ml of water are added to the mixture, then it is evaporated down to approx. 30% of the volume, the residue is combined with water and extracted 3× with EtOAc. The combined organic phases are dried with Na2SO4, concentrated and the crude product is purified by chromatography (Alox; petroleum ether/EtOAc 8/2->7/3).

Provenance & Evidence