Methyl iodide → 5-Methyl-2,3-dihydrobenzo[B][1,4]dioxine-6-carbaldehyde

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Reaction Conditions

Reaction Steps

To a solution of N,N,N′-trimethylethylenediamine (3.3 g, 32.3 mmol) in THF (100 mL) at −15° C. was dropwise added n-BuLi (19.2 mL, 30.5 mmol, 1.6 M in THF). After stirring at −15° C. for 15 minutes, a solution of solution of 1,4-benzodioxane-6-aldehyde (5.0 g, 30.5 mmol) in THF (10 mL). After 20 minutes, another batch of n-BuLi (5 mL, 3.1 mmol, 1.6 M in THF) was added and stirred for 3 h. The resulting solution was cooled down to −72° C. and the mixture was treated with MeI (25.9 g, 182.5 mmol) slowly. After stirring at −72° C. for 3 h, the mixture was diluted with HCl solution (1M in water). The aqueous layer was extracted several times with diethyl ether. The organic fractions were combined, concentrated and purified with column chromatography (silica, 5-40% ethyl acetate in hexane) to provide the title compound as an off-white compound (1.0 g, 18%): %): MS (ES) m/z 179 (M+H)+.

Provenance & Evidence