Hydrochloric Acid → 1-(2-Nitrophenyl)spiro[indoline-3,4'-piperidine]hydrochloride

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Reaction Steps

A slurry of 14.62 g of 1'-cyano-1-(2-nitrophenyl)spiro[indoline-3,4'-piperidine] of Example 37 in 100 ml of glacial acetic acid and 190 ml. of 3 N aqueous hydrochloric acid is heated at reflux for 18 hours, the mixture becomes homogeneous at 70°-80° C. The mixture is made basic using aqueous sodium hydroxide and extracted with chloroform. The organic portions are combined, washed with brine, dried over anhydrous magnesium sulfate and concentrated to give a solid comprising the free base of the product. The salt is prepared from the freshly alkali washed and dried free base using chloroform/ethereal hydrochloric acid, to yield the product mp, 222°-224° C. of 1-(2-nitrophenyl)spiro[indoline-3,4'-piperidine]hydrochloride.

Provenance & Evidence