Triethylamine → (2,4-Bis-benzyloxy-5-isopropenyl-phenyl)-{4-[2-(2-methoxy-ethoxy)-ethoxy]-1,3-dihydro-isoindol-2-yl}-methanone

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Reaction Steps

A solution of 2,4-bis-benzyloxy-5-isopropenyl-benzoic acid (96 mg, 0.26 mmol) and DMF (1 drop, cat.) in DCM (3 mL) was cooled in ice then treated with oxalyl chloride (112 μL, 1.28 mmol). After 2 hours the mixture was concentrated in vacuo then azeotroped with toluene. The resulting acid chloride was dissolved in DCM (4 mL) and added to a solution of 4-[2-(2-methoxy-ethoxy)-ethoxy]-2,3-dihydro-1H-isoindole (0.26 mmol, assuming a quantitative yield from the preceding step (debenzylation procedure C16)) and triethylamine (0.20 mL, 1.4 mmol) in DCM (1 mL). After 2 hours the mixture was diluted with ethyl acetate and washed with 1N hydrochloric acid, brine, sodium bicarbonate solution and brine. The organic phase was dried (MgSO4) and concentrated to give a black residue. This was partially purified by flash chromatography on silica (ethyl acetate/petrol gradient, 20-33%) to afford an impure sample of the intermediate (2,4-bis-benzyloxy-5-isopropenyl-phenyl)-{4-[2-(2-methoxy-ethoxy)-ethoxy]-1,3-dihydro-isoindol-2-yl}-methanone.

Provenance & Evidence