Ethyl bromoacetate → Ethyl 2-(2,6-dimethylphenyl)acetate

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Reaction Conditions

Reaction Steps

A 25 ml three-neck flask with magnetic stirrer, reflux condenser and dropping funnel is initially charged with 20 ml of tetrahydrofuran (THF) which has been dried over molecular sieve. The THF is heated to 50° C. while passing argon through for a few minutes, and then cooled again to room temperature. Still under argon, the following are now added: 17.2 mg [0.03 mmol=0.3 mol %] of bis(dibenzylideneacetone)palladium, 27.4 mg of P(o-tolyl)3 (tri-o-tolylphosphine) [0.09 mmol], 2.91 g of potassium fluoride (dried over P2O5 at 140° C.), 272 mg [1 mmol=10 mol %] of benzyltriethylammonium bromide, 1.5 g [10 mmol] of 2,6-dimethylphenylboronic acid and 2.56 g [15 mmol] of ethyl bromoacetate. This mixture is stirred under reflux in a gentle argon stream for 24 hours. Then it is filtered through a little Celite, and the filtercake is washed three times with 20 ml each time of ethyl acetate. The combined filtrates are extracted by shaking with 20 ml of 1 N hydrochloric acid. The aqueous phase is re-extracted twice with 20 ml of ethyl acetate each time. The combined organic phases are then washed with 20 ml of saturated aqueous NaCl solution, dried and concentrated. This gives 2.16 g of an oil which, according to GC-MS, as well as 8.9 area % of m-xylene, contains 72.9 area % of ethyl 2,6-dimethylphenylacetate. This corresponds to a yield of 81.9% of theory.

Provenance & Evidence