2,2,5,5-四甲基-1,3-二恶烷-4,6-二酮

反应条件: temp:75.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: A mixture of Meldrum's acid (5.52 g, 38.3 mmol), potassium carbonate (26.5 g, 191 mmol) and methyl iodide (7.15 mL, 115 mmol) in acetonitrile (75 mL) was heated at 75° C. in a sealed tube for 7 hrs. The mixture was cooled to room temperature, diluted with dichloromethane (300 mL), filtered and the filtrate evaporated to dryness in vacuo. Ethyl acetate (75 mL), hexanes (75 mL) and water (50 mL) were added and phases were separated. The organic layer was washed with 10% aqueous solution of sodium thiosulfate (50 mL) and water (50 mL); dried over anhydrous magnesium sulfate and solvent removed in vacuo to give 2,2,5,5-tetramethyl-[1,3]dioxane-4,6-dione as white solid. The mixture was cooled to room temperature filtered the filtrate evaporated to dryness in vacuo Ethyl acetate (75 mL), hexanes (75 mL) and water (50 mL) were added phases were separated The organic layer was washed with 10% aqueous solution of sodium thiosulfate (50 mL) and water (50 mL) dried over anhydrous magnesium sulfate and solvent removed in vacuo

反应条件: temp:75.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: A mixture of Meldrum's acid (5.52 g, 38.3 mmol), potassium carbonate (26.5 g, 191 mmol) and methyl iodide (7.15 mL, 115 mmol) in acetonitrile (75 mL) was heated at 75° C. in a sealed tube for 7 hrs. The mixture was cooled to room temperature, diluted with dichloromethane (300 mL), filtered and the filtrate evaporated to dryness in vacuo. Ethyl acetate (75 mL), hexanes (75 mL) and water (50 mL) were added and phases were separated. The organic layer was washed with 10% aqueous solution of sodium thiosulfate (50 mL) and water (50 mL); dried over anhydrous magnesium sulfate and solvent removed in vacuo to give 2,2,5,5-tetramethyl-[1,3]dioxane-4,6-dione as white solid. The mixture was cooled to room temperature filtered the filtrate evaporated to dryness in vacuo Ethyl acetate (75 mL), hexanes (75 mL) and water (50 mL) were added phases were separated The organic layer was washed with 10% aqueous solution of sodium thiosulfate (50 mL) and water (50 mL) dried over anhydrous magnesium sulfate and solvent removed in vacuo

反应条件: temp:75.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: A mixture of Meldrum's acid (5.52 g, 38.3 mmol), potassium carbonate (26.5 g, 191 mmol) and methyl iodide (7.15 mL, 115 mmol) in acetonitrile (75 mL) was heated at 75° C. in a sealed tube for 7 hrs. The mixture was cooled to room temperature, diluted with dichloromethane (300 mL), filtered and the filtrate evaporated to dryness in vacuo. Ethyl acetate (75 mL), hexanes (75 mL) and water (50 mL) were added and phases were separated. The organic layer was washed with 10% aqueous solution of sodium thiosulfate (50 mL) and water (50 mL); dried over anhydrous magnesium sulfate and solvent removed in vacuo to give 2,2,5,5-tetramethyl-[1,3]dioxane-4,6-dione as white solid. The mixture was cooled to room temperature filtered the filtrate evaporated to dryness in vacuo Ethyl acetate (75 mL), hexanes (75 mL) and water (50 mL) were added phases were separated The organic layer was washed with 10% aqueous solution of sodium thiosulfate (50 mL) and water (50 mL) dried over anhydrous magnesium sulfate and solvent removed in vacuo

反应条件: temp:75.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: A mixture of Meldrum's acid (5.52 g, 38.3 mmol), potassium carbonate (26.5 g, 191 mmol) and methyl iodide (7.15 mL, 115 mmol) in acetonitrile (75 mL) was heated at 75° C. in a sealed tube for 7 hrs. The mixture was cooled to room temperature, diluted with dichloromethane (300 mL), filtered and the filtrate evaporated to dryness in vacuo. Ethyl acetate (75 mL), hexanes (75 mL) and water (50 mL) were added and phases were separated. The organic layer was washed with 10% aqueous solution of sodium thiosulfate (50 mL) and water (50 mL); dried over anhydrous magnesium sulfate and solvent removed in vacuo to give 2,2,5,5-tetramethyl-[1,3]dioxane-4,6-dione as white solid. The mixture was cooled to room temperature filtered the filtrate evaporated to dryness in vacuo Ethyl acetate (75 mL), hexanes (75 mL) and water (50 mL) were added phases were separated The organic layer was washed with 10% aqueous solution of sodium thiosulfate (50 mL) and water (50 mL) dried over anhydrous magnesium sulfate and solvent removed in vacuo

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: 1.72 g (10 mmol) —2,2,5,5-Tetramethyl-[1,3]dioxane-4,6-dione and 1.02 ml butylamine were stirred in 7 ml N,N-diisopropyl-ethylamine for 18 hours at room temperature. The excess N,N-diisopropyl-ethylamine was decanted and the residue was extracted with 1N aqueous hydrochloric acid/ethylacetate. The ethylacetate phase was washed with 1N aqueous hydrochloric acid, brine and was dried over sodiumsulfate. Evaporation of the solvent and recrystallisation from dichloromethane/heptane yielded 60% N-butyl-2,2-dimethyl-malonamic acid as white solid, MS m/e (%): 188.4 (M+H+, 100). The excess N,N-diisopropyl-ethylamine was decanted the residue was extracted with 1N aqueous hydrochloric acid/ethylacetate The ethylacetate phase was washed with 1N aqueous hydrochloric acid, brine was dried over sodiumsulfate Evaporation of the solvent and recrystallisation from dichloromethane/heptane

反应条件: temp:75.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: A mixture of Meldrum's acid (5.52 g, 38.3 mmol), potassium carbonate (26.5 g, 191 mmol) and methyl iodide (7.15 mL, 115 mmol) in acetonitrile (75 mL) was heated at 75° C. in a sealed tube for 7 hrs. The mixture was cooled to room temperature, diluted with dichloromethane (300 mL), filtered and the filtrate evaporated to dryness in vacuo. Ethyl acetate (75 mL), hexanes (75 mL) and water (50 mL) were added and phases were separated. The organic layer was washed with 10% aqueous solution of sodium thiosulfate (50 mL) and water (50 mL); dried over anhydrous magnesium sulfate and solvent removed in vacuo to give 2,2,5,5-tetramethyl-[1,3]dioxane-4,6-dione as white solid. The mixture was cooled to room temperature filtered the filtrate evaporated to dryness in vacuo Ethyl acetate (75 mL), hexanes (75 mL) and water (50 mL) were added phases were separated The organic layer was washed with 10% aqueous solution of sodium thiosulfate (50 mL) and water (50 mL) dried over anhydrous magnesium sulfate and solvent removed in vacuo