4-Piperidinone, 3,5-dibromo-2,2,6,6-tetramethyl-, hydrobromide

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

Procedure: Analogously to Example 7, 78.79 g (200 mmol) of 3,5-dibromo-2,2,6,6-tetramethylpiperidin-4-one hydrobromide, 69.34 g of potassium tert-butylate, and 35.47 g (220 mmol) of 6-amino-2,2-dimethyl-1,3-dioxepan-5-ol are reacted in 800 ml of isopropanol and then extracted with dichloromethane. Yield: 37.66 g (60.3% of theory) of 2,2,5,5-tetramethyl-3-pyrroline-3-carboxylic acid (5-hydroxy-2,2-dimethyl-1,3-dioxepan-6-yl)amide which, crystallized from diethyl ether/hexane, shows a melting point of 125°-127° C. extracted with dichloromethane Yield: 37.66 g (60.3% of theory) of 2,2,5,5-tetramethyl-3-pyrroline-3-carboxylic acid (5-hydroxy-2,2-dimethyl-1,3-dioxepan-6-yl)amide which, crystallized from diethyl ether/hexane

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

Procedure: Under agitation, cooling between -5° and 0° C., and covering with argon, 68.94 g (175 mmol) of 3,5-dibromo-2,2,6,6-tetramethylpiperidin-4-one hydrobromide is added in portions to a solution of 22.93 g (175 mmol) of (2,2-dimethyl-1,3-dioxolan-4-yl)methylamine and 58.9 g (525 mmol) of potassium tert-butylate in 700 ml of isopropanol. A white paste is thus obtained which is stirred for one hour without cooling, suctioned off from the solid matter, and concentrated to dryness under vacuum. The residue is distributed between dichloromethane and water. The organic phase is dried over sodium sulfate and concentrated to dryness under vacuum. The residue is crystallized. After recrystallization from pentane, 30.1 g (60.9% of theory) of 2,2,5,5-tetramethyl-3-pyrroline-3-carboxylic acid (2,2-dimethyl-1,3-dioxolan-4-ylmethyl)amine is obtained, mp 55°-57° C. Under agitation, cooling between -5° and 0° C. A white paste is thus obtained which without cooling concentrated to dryness under vacuum The organic phase is dried over sodium sulfate concentrated to dryness under vacuum The residue is crystallized After recrystallization from pentane

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

Procedure: Analogously to Example 7, 78.79 g (200 mmol) of 3,5-dibromo-2,2,6,6-tetramethylpiperidin-4-one hydrobromide, 69.34 g of potassium tert-butylate, and 35.47 g (220 mmol) of 6-amino-2,2-dimethyl-1,3-dioxepan-5-ol are reacted in 800 ml of isopropanol and then extracted with dichloromethane. Yield: 37.66 g (60.3% of theory) of 2,2,5,5-tetramethyl-3-pyrroline-3-carboxylic acid (5-hydroxy-2,2-dimethyl-1,3-dioxepan-6-yl)amide which, crystallized from diethyl ether/hexane, shows a melting point of 125°-127° C. extracted with dichloromethane Yield: 37.66 g (60.3% of theory) of 2,2,5,5-tetramethyl-3-pyrroline-3-carboxylic acid (5-hydroxy-2,2-dimethyl-1,3-dioxepan-6-yl)amide which, crystallized from diethyl ether/hexane

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

Procedure: Under agitation, cooling between -5° and 0° C., and covering with argon, 68.94 g (175 mmol) of 3,5-dibromo-2,2,6,6-tetramethylpiperidin-4-one hydrobromide is added in portions to a solution of 22.93 g (175 mmol) of (2,2-dimethyl-1,3-dioxolan-4-yl)methylamine and 58.9 g (525 mmol) of potassium tert-butylate in 700 ml of isopropanol. A white paste is thus obtained which is stirred for one hour without cooling, suctioned off from the solid matter, and concentrated to dryness under vacuum. The residue is distributed between dichloromethane and water. The organic phase is dried over sodium sulfate and concentrated to dryness under vacuum. The residue is crystallized. After recrystallization from pentane, 30.1 g (60.9% of theory) of 2,2,5,5-tetramethyl-3-pyrroline-3-carboxylic acid (2,2-dimethyl-1,3-dioxolan-4-ylmethyl)amine is obtained, mp 55°-57° C. Under agitation, cooling between -5° and 0° C. A white paste is thus obtained which without cooling concentrated to dryness under vacuum The organic phase is dried over sodium sulfate concentrated to dryness under vacuum The residue is crystallized After recrystallization from pentane

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

Procedure: 3,5-Dibromo-4-oxo-2,2,6,6-tetramethylpiperidine (II, 30 gm) was added slowly, with stirring, to ammonium hydroxide (500 mL). When the solid is dissolved, potassium hydroxide is added, which results in the precipitation of (III). After filtering the solid, additional potassium hydroxide is added to the remaining solution until the precipitation of more material no longer is observed. The precipitates are combined, dried and recrystallized from benzene, giving a white solid (III, 10 gm, 68%) mp 176°-178° C. (lit ref. [1, except pg. 204] mp 180°-181° C). Both I.R. and NMR confirm the structure of (III). When the solid is dissolved

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

Procedure: Analogously to Example 7, 78.79 g (200 mmol) of 3,5-dibromo-2,2,6,6-tetramethylpiperidin-4-one hydrobromide, 69.34 g of potassium tert-butylate, and 35.47 g (220 mmol) of 6-amino-2,2-dimethyl-1,3-dioxepan-5-ol are reacted in 800 ml of isopropanol and then extracted with dichloromethane. Yield: 37.66 g (60.3% of theory) of 2,2,5,5-tetramethyl-3-pyrroline-3-carboxylic acid (5-hydroxy-2,2-dimethyl-1,3-dioxepan-6-yl)amide which, crystallized from diethyl ether/hexane, shows a melting point of 125°-127° C. extracted with dichloromethane Yield: 37.66 g (60.3% of theory) of 2,2,5,5-tetramethyl-3-pyrroline-3-carboxylic acid (5-hydroxy-2,2-dimethyl-1,3-dioxepan-6-yl)amide which, crystallized from diethyl ether/hexane

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

Procedure: Under agitation, cooling between -5° and 0° C., and covering with argon, 68.94 g (175 mmol) of 3,5-dibromo-2,2,6,6-tetramethylpiperidin-4-one hydrobromide is added in portions to a solution of 22.93 g (175 mmol) of (2,2-dimethyl-1,3-dioxolan-4-yl)methylamine and 58.9 g (525 mmol) of potassium tert-butylate in 700 ml of isopropanol. A white paste is thus obtained which is stirred for one hour without cooling, suctioned off from the solid matter, and concentrated to dryness under vacuum. The residue is distributed between dichloromethane and water. The organic phase is dried over sodium sulfate and concentrated to dryness under vacuum. The residue is crystallized. After recrystallization from pentane, 30.1 g (60.9% of theory) of 2,2,5,5-tetramethyl-3-pyrroline-3-carboxylic acid (2,2-dimethyl-1,3-dioxolan-4-ylmethyl)amide is obtained, mp 55°-57° C. Under agitation, cooling between -5° and 0° C. A white paste is thus obtained which without cooling concentrated to dryness under vacuum The organic phase is dried over sodium sulfate concentrated to dryness under vacuum The residue is crystallized After recrystallization from pentane

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

Procedure: Analogously to Example 7, 78.79 g (200 mmol) of 3,5-dibromo-2,2,6,6-tetramethylpiperidin-4-one hydrobromide, 69.34 g of potassium tert-butylate, and 35.47 g (220 mmol) of 6-amino-2,2-dimethyl-1,3-dioxepan-5-ol are reacted in 800 ml of isopropanol and then extracted with dichloromethane. Yield: 37.66 g (60.3% of theory) of 2,2,5,5-tetramethyl-3-pyrroline-3-carboxylic acid (5-hydroxy-2,2-dimethyl-1,3-dioxepan-6-yl)amide which, crystallized from diethyl ether/hexane, shows a melting point of 125°-127° C. extracted with dichloromethane Yield: 37.66 g (60.3% of theory) of 2,2,5,5-tetramethyl-3-pyrroline-3-carboxylic acid (5-hydroxy-2,2-dimethyl-1,3-dioxepan-6-yl)amide which, crystallized from diethyl ether/hexane

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

Procedure: Under agitation, cooling between -5° and 0° C., and covering with argon, 68.94 g (175 mmol) of 3,5-dibromo-2,2,6,6-tetramethylpiperidin-4-one hydrobromide is added in portions to a solution of 22.93 g (175 mmol) of (2,2-dimethyl-1,3-dioxolan-4-yl)methylamine and 58.9 g (525 mmol) of potassium tert-butylate in 700 ml of isopropanol. A white paste is thus obtained which is stirred for one hour without cooling, suctioned off from the solid matter, and concentrated to dryness under vacuum. The residue is distributed between dichloromethane and water. The organic phase is dried over sodium sulfate and concentrated to dryness under vacuum. The residue is crystallized. After recrystallization from pentane, 30.1 g (60.9% of theory) of 2,2,5,5-tetramethyl-3-pyrroline-3-carboxylic acid (2,2-dimethyl-1,3-dioxolan-4-ylmethyl)amine is obtained, mp 55°-57° C. Under agitation, cooling between -5° and 0° C. A white paste is thus obtained which without cooling concentrated to dryness under vacuum The organic phase is dried over sodium sulfate concentrated to dryness under vacuum The residue is crystallized After recrystallization from pentane