Ammonium Chloride → 2-[5-Formyl-1-(2-trimethylsilanyl-ethoxymethyl)-1H-imidazol-2-yl]-pyrrolidine-1-carboxylic acid tert-butyl ester

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Reaction Steps

2-[5-Bromo-1-(2-trimethylsilanyl-ethoxymethyl)-1H-imidazol-2-yl]-pyrrolidine-1-carboxylic acid tert-butyl ester (3.804 g, 8.52 mmol) was dissolved in THF (42 mL) and cooled to −78° C. n-BuLi (3.4 mL of a 2.5 M hexane solution, 8.52 mmol) was added dropwise over 3 min. After 65 min, DMF (4 mL) was added and the reaction mixture was warmed to RT. After stirring at RT for 75 min, a saturated aqueous solution of ammonium chloride (50 mL) was added and the entire content of the flask was poured into saturated aqueous sodium bicarbonate. The aqueous phase was extracted 3 times with diethyl ether. The combined organic layers were dried over magnesium sulfate, concentrated and purified by silica column chromatography (30% to 70% EtOAc/hexanes) to provide 2-[5-Formyl-1-(2-trimethylsilanyl-ethoxymethyl)-1H-imidazol-2-yl]-pyrrolidine-1-carboxylic acid tert-butyl ester (1.50 g, 45%).

Provenance & Evidence