1-benzyl-3-methoxypiperidin-4-one

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:-70.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: a') A solution of 3-methoxy-1-(phenylmethyl)-4-piperidinone (4.4 g) in tetrahydrofuran was cooled to -75° C. Lithium tris-sec-butylborohydride was added dropwise and the reaction mixture was stirred for 2 hours at -70° C. Acetic acid 10% (100 ml) was added dropwise at room temperature. The organic solvent was evaporated. The aqueous residue was alkalized with NH4OH, then extracted twice with diisopropylether. The separated organic layer was washed with water, dried over MgSO4, filtered and the solvent was evaporated. The residue was purified by short column chromatography over silica gel (eluent: CH2Cl2 /CH3OH 95/5 upgrading to 98/2), yielding 1.3 g (29.4%) of cis-3-methoxy-1-(phenylmethyl)-4-piperidinol (intermediate 2). The organic solvent was evaporated extracted twice with diisopropylether The separated organic layer was washed with water dried over MgSO4 filtered the solvent was evaporated The residue was purified by short column chromatography over silica gel (eluent: CH2Cl2 /CH3OH 95/5 upgrading to 98/2)

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Sodium borohydride (7.7 g) was added portionwise to a stirred solution of 3-methoxy-1-(phenylmethyl)-4-piperidinone (44.8 g) in ethanol (610 ml). Upon completion, the whole was cooled to room temperature and stirring was continued for 3 hours at room temperature. The reaction mixture was concentrated to a volume of about 150 ml. Water (300 ml) was added to the concentrate and all traces of ethanol were evaporated. After cooling, the mixture was extracted with diethylether. The extract was washed with water, dried, filtered and evaporated. The oily residue was purified by column-chromatography over silica gel (eluent: CHCl3 /CH3OH 96/4). The pure fractions were collected and the eluent was evaporated. The residue was separated by column-chromatography over silica gel (eluent: hexane/CHCl3 /(CH3OH/NH3) 50/50/1). The first fraction was collected and the eluent evaporated, yielding 11.5 g (25.5%) of trans-3-methoxy-1-(phenylmethyl)-4-piperidinol (intermediate 1). The second fraction was collected and the eluent evaporated, yielding 7.7 g (17.1%) of cis-3-methoxy-1-(phenylmethyl)-4-piperidinol (intermediate 2). The reaction mixture was concentrated to a volume of about 150 ml Water (300 ml) was added to the concentrate all traces of ethanol were evaporated After cooling the mixture was extracted with diethylether The extract was washed with water dried filtered evaporated The oily residue was purified by column-chromatography over silica gel (eluent: CHCl3 /CH3OH 96/4) The pure fractions were collected the eluent was evaporated The residue was separated by column-chromatography over silica gel (eluent: hexane/CHCl3 /(CH3OH/NH3) 50/50/1) The first fraction was collected the eluent evaporated

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of 83 parts of 3-methoxy-1-(phenylmethyl)-4-piperidinone, oxime and 400 parts of methanol saturated with ammonia was hydrogenated at normal pressure and at 50° C. with 6 parts of Raney-nickel catalyst. After the calculated amount of hydrogen was taken up, the catalyst was filtered off and the filtrate was evaporated, yielding 78 parts (100%) of (cis+trans)-3-methoxy-1-(phenylmethyl-4-piperidinamine as a residue (intermediate 71). the catalyst was filtered off the filtrate was evaporated

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of 38.1 parts of 3,4,4-trimethoxy-1-(phenylmethyl)piperidine and 1200 parts of sulfuric acid solution 1% was stirred and refluxed for 7 hours. The reaction mixture was allowed to cool overnight to room temperature and treated with sodium carbonate till a turbid solution was obtained. The product was extracted with 1,1'-oxybisethane. The extract was washed with water, dried, filtered and evaporated, yielding 28.8 parts (98.6%) of 3-methoxy-1-(phenylmethyl)-4-piperidinone as an oily residue (intermediate 60). refluxed for 7 hours to cool overnight to room temperature was obtained The product was extracted with 1,1'-oxybisethane The extract was washed with water dried filtered evaporated

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of 38.1 parts of 3,4,4-trimethoxy-1-(phenylmethyl)piperidine and 1200 parts of sulfuric acid solution 1% was stirred and refluxed for 7 hours. The reaction mixture was allowed to cool overnight to room temperature and treated with sodium carbonate till a turbid solution was obtained. The product was extracted with 1,1'-oxybisethane. The extract was washed with water, dried, filtered and evaporated, yielding 28.8 parts (98.6%) of 3-methoxy-1-(phenylmethyl)-4-piperidinone as an oily residue (intermediate 60). refluxed for 7 hours to cool overnight to room temperature was obtained The product was extracted with 1,1'-oxybisethane The extract was washed with water dried filtered evaporated