1.6 g of a 55% w/w suspension of sodium hydride in mineral oil was added to a mixture of 11 g of 6-hydroxy-2,5,7,8-tetramethyl-2-(4-nitrophenoxymethyl)chroman and 100 ml of dimethylformamide, and the reaction mixture was stirred for 1 hour at room temperature. Then a mixture of 5.7 g of ethyl iodide and 5 ml of benzene was added dropwise, whilst ice-cooling, and the reaction mixture was stirred for 2 hours at room temperature. The reaction mixture was then poured into water and extracted with benzene. This extract was washed with water and dried over anhydrous sodium sulfate. The solvent was distilled from the extract under reduced pressure, and the residue was purified by silica gel column chromatography eluted with a 3:7 by volume mixture of cyclohexane and benzene, to give the title compound.
