Methyl iodide → {2-[6-Chloro-3-(2,2,2-trifluoro-acetyl)-indol-1-yl]-ethyl}-methyl-carbamic acid tert-butyl ester

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Reaction Steps

To a solution of 14.1 g (36.1 mmol) {2-[6-chloro-3-(2,2,2-trifluoro-acetyl)-indol-1-yl]-ethyl}-carbamic acid tert-butyl ester in 360 ml dry tetrahydrofuran were slowly added 44 ml (40 mmol) of a 0.91 M solution of potassium hexamethyldisilazide in tetrahydrofuran at −78° C. After stirring for 20 min. were added 2.5 ml (40 mmol) iodomethane at −78° C. Stirring was continued for 15 min. at −78° C. The cooling bath was removed and the mixture was stirred for another 3 h at room temperature. Quenching with water was followed by evaporation of the solvent in a rotary evaporator. The residue was diluted with a mixture of 200 ml water and 100 ml of a saturated aqueous solution of ammonium chloride. After extraction with three 250-ml portions of tert-butyl methyl ether the combined organic extracts were washed with 200 ml of an ice-cold 0.2 M aqueous solution of hydrochloric acid and 100 ml brine, dried over sodium sulfate and concentrated in vacuo to give 14.9 g of the crude product as a brown oil.

Provenance & Evidence