6-amino-2,2-dimethyl-1,3-dioxepan-5-ol

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

Conditions: temp:65.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 5-Amino-3-acetoxymethyl-2,4,6-triiodobenzoyl chloride (12.0 g, 19.8 mmol) was dissolved in dioxane (40 ml). 6-Amino-2,2-dimethyl-1,3-dioxepane-5-ol (3.20 g, 19.8 mmol) and sodium carbonate (2.10 g, 19.8 mmol) were added and the mixture heated to reflux for 10 h. The reaction mixture was cooled, methanol (100 ml) and water (50 ml) were added and the solution was neutralized with a strongly acidic ion exchange resin. The resin was filtered off and a aqueous solution of hydrochloric acid (2M, 20 ml) was added. The mixture was stirred at 60-70° C. for 30 min, and then evaporated to dryness, which gave a semisolid residue (13.6 g) which was used without further purification in the next steps. the mixture heated to reflux for 10 h The reaction mixture was cooled The resin was filtered off a aqueous solution of hydrochloric acid (2M, 20 ml) was added evaporated to dryness, which

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:65.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 5-Amino-3-acetoxymethyl-2,4,6-triiodobenzoyl chloride (12.0 g, 19.8 mmol) was dissolved in dioxane (40 ml). 6-Amino-2,2-dimethyl-1,3-dioxepane-5-ol (3.20 g, 19.8 mmol) and sodium carbonate (2.10 g, 19.8 mmol) were added and the mixture heated to reflux for 10 h. The reaction mixture was cooled, methanol (100 ml) and water (50 ml) were added and the solution was neutralized with a strongly acidic ion exchange resin. The resin was filtered off and a aqueous solution of hydrochloric acid (2M, 20 ml) was added. The mixture was stirred at 60-70° C. for 30 min, and then evaporated to dryness, which gave a semisolid residue (13.6 g) which was used without further purification in the next steps. the mixture heated to reflux for 10 h The reaction mixture was cooled The resin was filtered off a aqueous solution of hydrochloric acid (2M, 20 ml) was added evaporated to dryness, which

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:

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:65.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 5-Amino-3-acetoxymethyl-2,4,6-triiodobenzoyl chloride (12.0 g, 19.8 mmol) was dissolved in dioxane (40 ml). 6-Amino-2,2-dimethyl-1,3-dioxepane-5-ol (3.20 g, 19.8 mmol) and sodium carbonate (2.10 g, 19.8 mmol) were added and the mixture heated to reflux for 10 h. The reaction mixture was cooled, methanol (100 ml) and water (50 ml) were added and the solution was neutralized with a strongly acidic ion exchange resin. The resin was filtered off and a aqueous solution of hydrochloric acid (2M, 20 ml) was added. The mixture was stirred at 60-70° C. for 30 min, and then evaporated to dryness, which gave a semisolid residue (13.6 g) which was used without further purification in the next steps. the mixture heated to reflux for 10 h The reaction mixture was cooled The resin was filtered off a aqueous solution of hydrochloric acid (2M, 20 ml) was added evaporated to dryness, which

Conditions: temp:65.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 5-Amino-3-acetoxymethyl-2,4,6-triiodobenzoyl chloride (12.0 g, 19.8 mmol) was dissolved in dioxane (40 ml). 6-Amino-2,2-dimethyl-1,3-dioxepane-5-ol (3.20 g, 19.8 mmol) and sodium carbonate (2.10 g, 19.8 mmol) were added and the mixture heated to reflux for 10 h. The reaction mixture was cooled, methanol (100 ml) and water (50 ml) were added and the solution was neutralized with a strongly acidic ion exchange resin. The resin was filtered off and a aqueous solution of hydrochloric acid (2M, 20 ml) was added. The mixture was stirred at 60-70° C. for 30 min, and then evaporated to dryness, which gave a semisolid residue (13.6 g) which was used without further purification in the next steps. the mixture heated to reflux for 10 h The reaction mixture was cooled The resin was filtered off a aqueous solution of hydrochloric acid (2M, 20 ml) was added evaporated to dryness, which

Conditions: temp:65.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 5-Amino-3-acetoxymethyl-2,4,6-triiodobenzoyl chloride (12.0 g, 19.8 mmol) was dissolved in dioxane (40 ml). 6-Amino-2,2-dimethyl-1,3-dioxepane-5-ol (3.20 g, 19.8 mmol) and sodium carbonate (2.10 g, 19.8 mmol) were added and the mixture heated to reflux for 10 h. The reaction mixture was cooled, methanol (100 ml) and water (50 ml) were added and the solution was neutralized with a strongly acidic ion exchange resin. The resin was filtered off and a aqueous solution of hydrochloric acid (2M, 20 ml) was added. The mixture was stirred at 60-70° C. for 30 min, and then evaporated to dryness, which gave a semisolid residue (13.6 g) which was used without further purification in the next steps. the mixture heated to reflux for 10 h The reaction mixture was cooled The resin was filtered off a aqueous solution of hydrochloric acid (2M, 20 ml) was added evaporated to dryness, which

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