18-Crown-6 → HCID 23573456, compound

Participants

Reaction Steps

Under argon, 328 mg (1.24 mmol) of 1,4,7,10,13,16-hexaoxacyclooctadecane (18-crown-6) are initially charged in 61 ml of dichloromethane, and 15 ml (14.93 mmol) of a 1-molar potassium tert-butoxide solution in THF and 3.50 g (12.44 mmol) of 5-nitro-N-phenyl-1H-indole-2-carboxamide from Example XLVIII are added. The mixture is stirred at RT for 15 minutes and then cooled to. 0° C. A solution of 3.64 g (18.67 mmol) of tert-butyl bromoacetate in 100 ml of THF is slowly added dropwise. The ice-bath is removed and the mixture is stirred at RT overnight. For work-up, the mixture is diluted with water and the THF is removed under reduced pressure using a rotary evaporator. The aqueous residue is extracted with ethyl acetate and the organic phase is washed with sat. sodium chloride solution, dried with sodium sulphate, filtered and dried under reduced pressure.

Provenance & Evidence