Hydrochloric Acid → (1-Benzylpiperidin-4-yl)-[2-(5-methoxy-2-nitrophenyl)-ethyl]-amine

Participants

Reaction Steps

34.0 ml (268.2 mmol) of trimethylsilyl chloride were slowly added dropwise to a solution of 27.0 g (70.4 mmol) of 5-methoxy-2-nitro-N-[1-(phenylmethyl)-4-piperidinyl]-benzeneacetamide in 400 ml of anhydrous tetrahydrofuran and then stirred for another 1 hour at ambient temperature. 4.9 g (213.7 mmol) of lithium borohydride were added batchwise, stirring was continued for another 30 minutes at ambient temperature and then for 4 hours at reflux temperature. After cooling, 25 ml of water and 25 ml of semiconcentrated hydrochloric acid were added dropwise one after the other and the mixture was refluxed for 90 minutes. It was left to stand overnight at ambient temperature, then cooled in an ice bath and the precipitate formed was suction filtered. The aqueous phase of the filtrate was made ammoniacal and extracted exhaustively with EE. The combined ethyl acetate extracts were dried with sodium sulphate, then combined with ethereal hydrogen chloride solution until the precipitation ended. The product precipitated was combined with the earlier precipitate, presumed to be the dihydrochloride of the desired compound, suspended in ethanol and suction filtered. The filter cake was dissolved in 100 ml of water, the solution was made ammoniacal and extracted exhaustively with EE. Conventional, working up of the ethyl acetate extracts yielded a pale yellow oil, Rf 0.69 (El D). Yield: 11.3 g (43% of theoretical).

Provenance & Evidence