Piperidine-4,4-diol Hydrochloride

Conditions: temp:20.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of O-phenylhydroxylamine hydrochloride (1:1) (0.625 mol) and 4,4-piperidinediol hydrochloride (1:1) (0.682 mol) in 2-propanol (615 ml) was stirred at 20° C. HCl (353 ml) was added dropwise at 20 ° C. The reaction mixture was gently heated to reflux temperature. The reaction mixture was stirred and refluxed for 3 hours, then cooled to room temperature. The precipitate was filtered off, washed with diisopropyl ether, and dried. This fraction was crystallized from water (1600 ml). The desired compound was allowed to crystallize out while stirring. The precipitate was filtered off, washed with 2-propanol and diisopropyl ether, then dried, yielding 84 g (64%) of 1,2,3,4-tetrahydrobenzo-furo[3,2-c]pyridine hydrochloride (1:1) (interm. 1). The reaction mixture was gently heated to reflux temperature The reaction mixture was stirred refluxed for 3 hours cooled to room temperature The precipitate was filtered off washed with diisopropyl ether dried This fraction was crystallized from water (1600 ml) to crystallize out while stirring The precipitate was filtered off washed with 2-propanol and diisopropyl ether dried

Conditions: temp:20.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of O-phenylhydroxylamine hydrochloride (1:1) (0.625 mol) and 4,4-piperidinediol hydrochloride (1:1) (0.682 mol) in 2-propanol (615 ml) was stirred at 20° C. HCl (353 ml) was added dropwise at 20 ° C. The reaction mixture was gently heated to reflux temperature. The reaction mixture was stirred and refluxed for 3 hours, then cooled to room temperature. The precipitate was filtered off, washed with diisopropyl ether, and dried. This fraction was crystallized from water (1600 ml). The desired compound was allowed to crystallize out while stirring. The precipitate was filtered off, washed with 2-propanol and diisopropyl ether, then dried, yielding 84 g (64%) of 1,2,3,4-tetrahydrobenzo-furo[3,2-c]pyridine hydrochloride (1:1) (interm. 1). The reaction mixture was gently heated to reflux temperature The reaction mixture was stirred refluxed for 3 hours cooled to room temperature The precipitate was filtered off washed with diisopropyl ether dried This fraction was crystallized from water (1600 ml) to crystallize out while stirring The precipitate was filtered off washed with 2-propanol and diisopropyl ether dried

Conditions: temp:20.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of O-phenylhydroxylamine hydrochloride (1:1) (0.625 mol) and 4,4-piperidinediol hydrochloride (1:1) (0.682 mol) in 2-propanol (615 ml) was stirred at 20° C. HCl (353 ml) was added dropwise at 20 ° C. The reaction mixture was gently heated to reflux temperature. The reaction mixture was stirred and refluxed for 3 hours, then cooled to room temperature. The precipitate was filtered off, washed with diisopropyl ether, and dried. This fraction was crystallized from water (1600 ml). The desired compound was allowed to crystallize out while stirring. The precipitate was filtered off, washed with 2-propanol and diisopropyl ether, then dried, yielding 84 g (64%) of 1,2,3,4-tetrahydrobenzo-furo[3,2-c]pyridine hydrochloride (1:1) (interm. 1). The reaction mixture was gently heated to reflux temperature The reaction mixture was stirred refluxed for 3 hours cooled to room temperature The precipitate was filtered off washed with diisopropyl ether dried This fraction was crystallized from water (1600 ml) to crystallize out while stirring The precipitate was filtered off washed with 2-propanol and diisopropyl ether dried

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

Procedure: To a solution of 2-methylbenzoyl chloride (800 mg, 5.2 mmol) in 5 mL of DICHLOROMETHANE was added a mixture of piperidine-4,4-diol hydrochloride salt 800 mg, 5.2 mmol) and potassium carbonate (716 mg, 5.2 mmol) in 5 mL H2O and stirred at room temperature for 2 hours. Layers were separated and aqueous layer was extracted with dichloromethane (3×10 mL). Organic layers were combined, dried, filtered and the filtrate was concentrated in vacuo to give the tile compound (1.2 g) as light yellow oil. MS (M+1): 218.0 Layers were separated aqueous layer was extracted with dichloromethane (3×10 mL) dried filtered the filtrate was concentrated in vacuo

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

Procedure: A solution of 4-methoxy-3-(trifluoromethyl)benzoyl chloride (4.00 g, 16.8 mmol) in toluene (16 mL) and a solution of NaOH (3.8 mL of 4.0 M, 15 mmol) were contemporaneously added drop-wise to a solution of piperidine-4,4-diol hydrochloride (2.30 g, 15.2 mmol) in NaOH (7.6 mL of 2.0 M, 15 mmol) at 25° C. The mixture was stirred for 90 min before the toluene was removed in vacuo. The alkaline phase was extracted with dichloromethane (3 times). The organics were combined, washed with brine, dried over Na2SO4, and concentrated in vacuo to provide 1-(4-methoxy-3-(trifluoromethyl)benzoyl)piperidin-4-one (4.2 g, 91%). ESI-MS m/z calc. 301.3, found 302.2 (M+1)+. Retention time: 0.95 minutes (3 min run). 1H NMR (400 MHz, CDCl3) δ 7.77 (d, J=1.9 Hz, 1H), 7.70 (dd, J=8.6, 2.1 Hz, 1H), 7.09 (d, J=8.6 Hz, 1H), 3.98 (s, 3H), 3.94 (s, 4H), 2.55 (s, 4H). at 25° C was removed in vacuo The alkaline phase was extracted with dichloromethane (3 times) washed with brine dried over Na2SO4 concentrated in vacuo

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

Procedure: A solution of 4-methoxy-3-(trifluoromethyl)benzoyl chloride (4.00 g, 16.8 mmol) in toluene (16 mL) and a solution of NaOH (3.8 mL of 4.0 M, 15 mmol) were contemporaneously added drop-wise to a solution of piperidine-4,4-diol hydrochloride (2.30 g, 15.2 mmol) in NaOH (7.6 mL of 2.0 M, 15 mmol) at 25° C. The mixture was stirred for 90 min before the toluene was removed in vacuo. The alkaline phase was extracted with dichloromethane (3 times). The organics were combined, washed with brine, dried over Na2SO4, and concentrated in vacuo to provide 1-(4-methoxy-3-(trifluoromethyl)benzoyl)piperidin-4-one (4.2 g, 91%). ESI-MS m/z calc. 301.3, found 302.2 (M+1)+. Retention time: 0.95 minutes (3 min run). 1H NMR (400 MHz, CDCl3) δ 7.77 (d, J=1.9 Hz, 1H), 7.70 (dd, J=8.6, 2.1 Hz, 1H), 7.09 (d, J=8.6 Hz, 1H), 3.98 (s, 3H), 3.94 (s, 4H), 2.55 (s, 4H). at 25° C was removed in vacuo The alkaline phase was extracted with dichloromethane (3 times) washed with brine dried over Na2SO4 concentrated in vacuo

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

Procedure: A solution of 4-methoxy-3-(trifluoromethyl)benzoyl chloride (4.00 g, 16.8 mmol) in toluene (16 mL) and a solution of NaOH (3.8 mL of 4.0 M, 15 mmol) were contemporaneously added drop-wise to a solution of piperidine-4,4-diol hydrochloride (2.30 g, 15.2 mmol) in NaOH (7.6 mL of 2.0 M, 15 mmol) at 25° C. The mixture was stirred for 90 min before the toluene was removed in vacuo. The alkaline phase was extracted with dichloromethane (3 times). The organics were combined, washed with brine, dried over Na2SO4, and concentrated in vacuo to provide 1-(4-methoxy-3-(trifluoromethyl)benzoyl)piperidin-4-one (4.2 g, 91%). ESI-MS m/z calc. 301.3, found 302.2 (M+1)+. Retention time: 0.95 minutes (3 min run). 1H NMR (400 MHz, CDCl3) δ 7.77 (d, J=1.9 Hz, 1H), 7.70 (dd, J=8.6, 2.1 Hz, 1H), 7.09 (d, J=8.6 Hz, 1H), 3.98 (s, 3H), 3.94 (s, 4H), 2.55 (s, 4H). at 25° C was removed in vacuo The alkaline phase was extracted with dichloromethane (3 times) washed with brine dried over Na2SO4 concentrated in vacuo

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

Procedure: A solution of 4-methoxy-3-(trifluoromethyl)benzoyl chloride (4.00 g, 16.8 mmol) in toluene (16 mL) and a solution of NaOH (3.8 mL of 4.0 M, 15 mmol) were contemporaneously added drop-wise to a solution of piperidine-4,4-diol hydrochloride (2.30 g, 15.2 mmol) in NaOH (7.6 mL of 2.0 M, 15 mmol) at 25° C. The mixture was stirred for 90 min before the toluene was removed in vacuo. The alkaline phase was extracted with dichloromethane (3 times). The organics were combined, washed with brine, dried over Na2SO4, and concentrated in vacuo to provide 1-(4-methoxy-3-(trifluoromethyl)benzoyl)piperidin-4-one (4.2 g, 91%). ESI-MS m/z calc. 301.3. found 302.2 (M+1)+. Retention time: 0.95 minutes (3 min run). 1H NMR (400 MHz, CDCl3) δ 7.77 (d, J=1.9 Hz, 1H), 7.70 (dd, J=8.6, 2.1 Hz, 1H), 7.09 (d, J=8.6 Hz, 1H), 3.98 (s, 3H), 3.94 (s, 4H), 2.55 (s, 4H). at 25° C was removed in vacuo The alkaline phase was extracted with dichloromethane (3 times) washed with brine dried over Na2SO4 concentrated in vacuo

Conditions: temp:20.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of O-phenylhydroxylamine hydrochloride (1:1) (0.625 mol) and 4,4-piperidinediol hydrochloride (1:1) (0.682 mol) in 2-propanol (615 ml) was stirred at 20° C. HCl (353 ml) was added dropwise at 20° C. The reaction mixture was gently heated to reflux temperature. The reaction mixture was stirred and refluxed for 3 hours, then cooled to room temperature. The precipitate was filtered off, washed with diisopropyl ether, and dried. This fraction was crystallized from water (1600 ml). The desired compound was allowed to crystallize out while stirring. The precipitate was filtered off, washed with 2-propanol and diisopropyl ether, then dried, yielding 84 g (64%) of 1,2,3,4-tetrahydrobenzo-furo[3,2-c]pyridine hydrochloride (1:1)(interm. 1). The reaction mixture was gently heated to reflux temperature The reaction mixture was stirred refluxed for 3 hours cooled to room temperature The precipitate was filtered off washed with diisopropyl ether dried This fraction was crystallized from water (1600 ml) to crystallize out while stirring The precipitate was filtered off washed with 2-propanol and diisopropyl ether dried

Conditions: temp:20.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of O-phenylhydroxylamine hydrochloride (1:1) (0.625 mol) and 4,4-piperidinediol hydrochloride (1:1) (0.682 mol) in 2-propanol (615 ml) was stirred at 20° C. HCl (353 ml) was added dropwise at 20° C. The reaction mixture was gently heated to reflux temperature. The reaction mixture was stirred and refluxed for 3 hours, then cooled to room temperature. The precipitate was filtered off, washed with DIPE, and dried. This fraction was crystallized from water (1600 ml). The desired compound was allowed to crystallize out while stirring. The precipitate was filtered off, washed with 2-propanol and DIPE, then dried, yielding 84 g (64%) of 1,2,3,4-tetrahydrobenzofuro[3,2-c]pyridine hydrochloride (1:1) (interm. 1). The reaction mixture was gently heated to reflux temperature The reaction mixture was stirred refluxed for 3 hours cooled to room temperature The precipitate was filtered off washed with DIPE dried This fraction was crystallized from water (1600 ml) to crystallize out while stirring The precipitate was filtered off washed with 2-propanol and DIPE dried

Conditions: temp:20.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of O-phenylhydroxylamine hydrochloride (1:1) (0.625 mol) and 4,4-piperidinediol hydrochloride (1:1) (0.682 mol) in 2-propanol (615 ml) was stirred at 20° C. HCl (353 ml) was added dropwise at 20 ° C. The reaction mixture was gently heated to reflux temperature. The reaction mixture was stirred and refluxed for 3 hours, then cooled to room temperature. The precipitate was filtered off, washed with diisopropyl ether, and dried. This fraction was crystallized from water (1600 ml). The desired compound was allowed to crystallize out while stirring. The precipitate was filtered off, washed with 2-propanol and diisopropyl ether, then dried, yielding 84 g (64%) of 1,2,3,4-tetrahydrobenzo-furo[3,2-c]pyridine hydrochloride (1:1) (interm. 1). The reaction mixture was gently heated to reflux temperature The reaction mixture was stirred refluxed for 3 hours cooled to room temperature The precipitate was filtered off washed with diisopropyl ether dried This fraction was crystallized from water (1600 ml) to crystallize out while stirring The precipitate was filtered off washed with 2-propanol and diisopropyl ether dried