1-(2-Nitrophenyl)spiro[indoline-3,4'-piperidine]hydrochloride → HCID 12801640, compound

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Reaction Steps

3.76 g of iron powder is added portionwise to a rapidly stirred ice cold slurry of 7.66 g of 1-(2-nitrophenyl)spiro[indoline-3,4'-piperidine] hydrochloride of Example 38 in 11.8 ml of concentrated hydrochloric acid and 300 ml of methanol. After heating at reflux for 3 hours, the reaction mixture (at room temperature) is filtered, made basic using 10% aqueous sodium hydroxide and extracted with chloroform. The organic phase is filtered through a pad of celite on a sintered glass funnel and the filtrate is washed with brine, dried over anhydrous sodium sulfate and concentrated to give 4.50 g of the crude free base of the product. Conversion to the hydrochloric acid salt with dichloromethane-ether/ethereal hydrochloric acid and two recrystallizations from hot isopropanol-methanol affords 1-(2-aminophenyl)spiro[indoline-3,4'-piperidine] dihydrochloride, mp 282.5° C., dec.

Provenance & Evidence