(2,3-Dihydro-1-benzofuran-2-yl)methyl 4-methylbenzene-1-sulfonate → ethyl-dihydrobenzofuran

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Reaction Conditions

Reaction Steps

Methyl lithium (1.6M in diethyl ether, 313 mL, 500 mmol) was added to a solution of copper (I) iodide (47.6 g, 250 mmol) in diethyl ether (750 mL) at −70° C. The solution was then allowed to warm to −10° C. and was stirred for 30 minutes. The mixture was then added to a solution of 2,3-dihydro-1-benzofuran-2-ylmethyl4-methylbenzenesulfonate (preparation 97) (15.2 g, 50 mmol) in diethyl ether (500 mL) and the reaction mixture was stirred at −40° C. for 1 hour and at room temperature for 2 hours. The mixture was then cooled to −70° C. and quenched with 10% ammonium chloride solution (750 mL) and 2M hydrochloric acid (50 mL), diluted with 0.88 ammonia (100 mL) and then stirred for 18 hours. The reaction mixture was extracted with diethyl ether (3×500 mL) and the organic solution was dried over magnesium sulfate and concentrated in vacuo to afford the title compound as a brown oil in 98% yield, 7.25 g.

Provenance & Evidence