1-hydroxypiperidine

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:; See reaction.notes.procedure_details.

Procedure: The hydrochloride (18 g) of 2-(p-methoxybenzyl)-1,3,3-trimethyl-4-piperidone is converted to the free base by shaking with ether and aqueous sodium hydroxide, followed by evaporation of the ethereal solution. The oily base is dissolved in 30 ml of absolute ether and subsequently reacted with ethyl lithium (3.6 g in 300 ml of benzene) under conditions as described in example 39. According to gaschromatographic examination, conversion to the piperidinol occurs to the extent of only 25 percent. After the addition of water the reaction mixture is worked up as described in example 39 and the crude mixture of piperidone and piperidonal so obtained is treated again with ethyl lithium (2.7 g in 250 ml of benzene). This procedure is repeated once more whereafter still 20 percent of the piperidone appears to be present. Processing as usually furnishes 19 g of an oily base, which is converted to the hydrochloride with the aid of ethanolic hydrogen chloride. After the addition of acetone and ether, 9 g of the above crystalline product separates. Yield 45%. Melting point 232 -234° C with decomposition. followed by evaporation of the ethereal solution The oily base is dissolved in 30 ml of absolute ether subsequently reacted with ethyl lithium (3.6 g in 300 ml of benzene) under conditions piperidonal so obtained

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

Procedure: The hydrochloride (18 g) of 2-(p-methoxybenzyl)-1,3,3-trimethyl-4-piperidone is converted to the free base by shaking with ether and aqueous sodium hydroxide, followed by evaporation of the ethereal solution. The oily base is dissolved in 30 ml of absolute ether and subsequently reacted with ethyl lithium (3.6 g in 300 ml of benzene) under conditions as described in example 39. According to gaschromatographic examination, conversion to the piperidinol occurs to the extent of only 25 percent. After the addition of water the reaction mixture is worked up as described in example 39 and the crude mixture of piperidone and piperidonal so obtained is treated again with ethyl lithium (2.7 g in 250 ml of benzene). This procedure is repeated once more whereafter still 20 percent of the piperidone appears to be present. Processing as usually furnishes 19 g of an oily base, which is converted to the hydrochloride with the aid of ethanolic hydrogen chloride. After the addition of acetone and ether, 9 g of the above crystalline product separates. Yield 45%. Melting point 232 -234° C with decomposition. followed by evaporation of the ethereal solution The oily base is dissolved in 30 ml of absolute ether subsequently reacted with ethyl lithium (3.6 g in 300 ml of benzene) under conditions piperidonal so obtained

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

Procedure: Activated MnO2 (1.29 g, 14.8 mmol) was added to a solution of N-hydroxypiperidine (0.50 g, 4.95 mmol) in dichloromethane (25 mL) at 0° C. and the mixture was stirred for 1 h. The reaction mixture was filtered through a pad of Celite™ and Na2SO4. The filtrate was added dropwise to a solution of cyclohexylmagnesium chloride (2.0 M in diethyl ether, 4.95 mL, 9.90 mmol) at −10° C. The reaction mixture was stirred at 0° C. for 0.5 h and then saturated aqueous ammonium chloride solution (25 mL) and dichloromethane (25 mL) were added. The aqueous phase was separated and extracted with dichloromethane (2×30 mL). The combined organic layers were dried (Na2SO4) and concentrated under reduced pressure. The crude product was subjected to flash chromatography on SiO2 eluting with 40% diethyl ether in hexanes to give the title compound (0.241 g, 27%) as a white crystalline solid. The reaction mixture was filtered through a pad of Celite™ and Na2SO4 The reaction mixture was stirred at 0° C. for 0.5 h The aqueous phase was separated extracted with dichloromethane (2×30 mL) The combined organic layers were dried (Na2SO4) concentrated under reduced pressure

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

Procedure: Activated MnO2 (1.29 g, 14.8 mmol) was added to a solution of N-hydroxypiperidine (0.50 g, 4.95 mmol) in dichloromethane (25 mL) at 0° C. and the mixture was stirred for 1 h. The reaction mixture was filtered through a pad of Celite™ and Na2SO4. The filtrate was added dropwise to a solution of benzylmagnesium chloride (2.0 M in tetrahydrofuran, 4.95 mL, 9.90 mmol) at −10° C. The reaction mixture was stirred at 0° C. for 0.5 h and then saturated aqueous ammonium chloride solution (25 mL) and dichloromethane (25 mL) were added. The aqueous phase was separated and extracted with dichloromethane (2×30 mL). The combined organic layers were dried (Na2SO4) and concentrated under reduced pressure. The crude product was subjected to flash chromatography on SiO2 eluting with 60% diethyl ether in hexanes to give the title compound (0.309 g, 33%) as a white crystalline solid. The reaction mixture was filtered through a pad of Celite™ and Na2SO4 The reaction mixture was stirred at 0° C. for 0.5 h The aqueous phase was separated extracted with dichloromethane (2×30 mL) The combined organic layers were dried (Na2SO4) concentrated under reduced pressure

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

Procedure: Activated MnO2 (1.29 g, 14.8 mmol) was added to a solution of N-hydroxypiperidine (0.50 g, 4.95 mmol) in dichloromethane (25 mL) at 0° C. and the mixture was stirred for 1 h. The reaction mixture was filtered through a pad of Celite™ and Na2SO4. The filtrate was added dropwise to a solution of benzylmagnesium chloride (2.0 M in tetrahydrofuran, 4.95 mL, 9.90 mmol) at −10° C. The reaction mixture was stirred at 0° C. for 0.5 h and then saturated aqueous ammonium chloride solution (25 mL) and dichloromethane (25 mL) were added. The aqueous phase was separated and extracted with dichloromethane (2×30 mL). The combined organic layers were dried (Na2SO4) and concentrated under reduced pressure. The crude product was subjected to flash chromatography on SiO2 eluting with 60% diethyl ether in hexanes to give the title compound (0.309 g, 33%) as a white crystalline solid. The reaction mixture was filtered through a pad of Celite™ and Na2SO4 The reaction mixture was stirred at 0° C. for 0.5 h The aqueous phase was separated extracted with dichloromethane (2×30 mL) The combined organic layers were dried (Na2SO4) concentrated under reduced pressure

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

Procedure: Activated MnO2 (1.29 g, 14.8 mmol) was added to a solution of N-hydroxypiperidine (0.50 g, 4.95 mmol) in dichloromethane (25 mL) at 0° C. and the mixture was stirred for 1 h. The reaction mixture was filtered through a pad of Celite™ and Na2SO4. The filtrate was added dropwise to a solution of phenylmagnesium chloride (2.0 M in tetrahydrofuran, 4.95 mL, 9.90 mmol) at −10° C. The reaction mixture was stirred at 0° C. for 0.5 h and then saturated aqueous ammonium chloride solution (25 mL) and dichloromethane (25 mL) were added. The aqueous phase was separated and extracted with dichloromethane (2×30 mL). The combined organic layers were dried (Na2SO4) and concentrated under reduced pressure. The crude product was subjected to flash chromatography on SiO2 eluting with 30% diethyl ether in hexanes to give the title compound (0.330 g, 38%) as a white crystalline solid. The reaction mixture was filtered through a pad of Celite™ and Na2SO4 The reaction mixture was stirred at 0° C. for 0.5 h The aqueous phase was separated extracted with dichloromethane (2×30 mL) The combined organic layers were dried (Na2SO4) concentrated under reduced pressure

Conditions: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 4 hydroxypiperidine (Aldrich Chemical Co., Inc., supra) (5q) was dissolved in distilled water (14 mL), cooled to 0° C. and the pH was adjusted to between 4 and 5 by addition of concentrated hydrochloric acid and 4 hydroxypiperidine. After warming to room temperature, 5.2 mL cyclohexanone and 3.3 g potassium cyanide in water (9 mL) were added sequentially. After 18 hours of stirring at room temperature, the solid was filtered. The solid was dissolved in 100 mL methylene chloride, dried over Na2SO4, filtered and the solvent was removed in vacuo to yield pure 1 (1 cyanocyclohexyl) 4 hydroxypiperidine. After warming to room temperature the solid was filtered The solid was dissolved in 100 mL methylene chloride dried over Na2SO4 filtered the solvent was removed in vacuo

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