Hydrochloric Acid → 2-Methyl-4-morpholino-5-fluoroindoline

Participants

Reaction Steps

2-Methyl-5-fluoro-4-morpholinoindole (138 g) was dissolved in 1.5 l of acetic acid. To this solution was added 200 g of metal tin and the mixture was under reflux of acetic acid. During reflux 1.5 l of concentrated hydrochloric acid was added dropwise in 1 hour. After completion of addition, the mixture was allowed to react for 2 hours at the same temperature as above. After completion of reaction, the solvent was distilled off under reduced pressure. To the residue was added 1 l of water and the solution was adjusted to pH 13 with a 20% aqueous sodium hydroxide solution followed by adding 1 l of ether. After stirring insoluble substances were removed by filtration. An ether layer was separated from the filtrate and dried over anhydrous potassium carbonate. Removal of ether by distillation gave 75 g of 2-methyl-4-morpholino-5-fluoroindoline.

Provenance & Evidence