Hydrochloric Acid → 5,6-Difluoroindoline

Participants

Reaction Conditions

Reaction Steps

Under an argon atmosphere 0.30 g (1.8 mmol) 5,6-difluoroxindole were dissolved in 10 mL THF and 3.0 mL of a 1 molar borane solution in THF were added dropwise. Then the reaction mixture was heated to 70° C. for 2 h and then cooled. After mixing with 3 mL MeOH another 5 mL of a 4N aqueous hydrochloric acid solution were added and the mixture was refluxed for 1 h. The organic phase was evaporated down, the aqueous phase was washed with DCM and then made alkaline with a 4N aqueous sodium hydroxide solution and extracted several times with EtOAc. The combined organic phases were dried on sodium sulphate, filtered and evaporated down.

Provenance & Evidence