Tetramethyltin → 5-Methyl-6-(trifluoromethyl)indoline

Participants

Reaction Conditions

Reaction Steps

To a mixture of the trifluoromethylsulphonyloxyindoline (D6, 1.77 g, 4.69 mmol), lithium chloride (0.60 g, 14.1 mmol) and bis(triphenylphosphine) palladium (II) chloride (0.10 g, 0.14 mmol) in dry dimethylformamide (15 ml) was added tetramethyltin (0.72 ml, 5.2 mmol). The mixture was heated at 110° C. for 3.5 h, then cooled and evaporated. The residue was partitioned between dichloromethane and water, and the organic phase was washed with brine, dried and evaporated. The crude product was dissolved in ethanol (30 ml), 10% aqueous sodium hydroxide solution (7.5 ml) and solid sodium hydroxide (1 g) were added and the mixture was heated under reflux overnight. Ethanol was removed in vacuo, and the residue was diluted with water and extracted with dichloromethane. The organic extract was washed with brine, dried and evaporated. The residue was chromatographed on silica gel (50 g), eluted under suction with 2:1 ether/petroleum ether to give the title compound (0.70 g, 74%), m.p. 43-4° C.

Provenance & Evidence