Potassium tert-butoxide → (S)-2-(trimethylsilyl)ethyl 2-(6-(1-tert-butoxy-2-(tert-butyldimethylsilyloxy)ethyl)-5-(4-chlorophenyl)-7-methyl-2-oxoquinolin-1(2H)-yl)ethylcarbamate

Participants

Reaction Steps

To a solution of (S)-6-(1-tert-butoxy-2-(tert-butyldimethylsilyloxy)ethyl)-5-(4-chlorophenyl)-7-methylquinolin-2(1H)-one (0.4061 g, 0.812 mmol) in DMF (8.0 mL) was added potassium tert-butoxide (0.137 g, 1.22 mmol) and the mixture stirred for 30 minutes. A solution of 2-(trimethylsilyl)ethyl 2-bromoethylcarbamate (0.327 g, 1.22 mmol) in DMF (1 mL) was added and the reaction mixture was allowed to slowly warm to room temperature overnight. The reaction mixture was cooled to 0° C., potassium tert-butoxide (0.200 g) was added and the resulting reaction mixture was stirred for 30 minutes. A solution of 2-(trimethylsilyl)ethyl 2-bromoethylcarbamate (0.5 g) in DMF (1 mL) was added and the reaction mixture was warmed to room temperature overnight. Reaction mixture was diluted with ethyl acetate and washed with 5% lithium chloride solution (2×), brine, dried (MgSO4), filtered, concentrated and purified by flash column chromatography (silica gel, 10 to 50% ethyl acetate/hexanes) to give desired product a yellow foam (0.2725 g). Some O-alkylation side-product was also observed.

Provenance & Evidence