3,5-二氧哌啶-1-甲酸叔丁酯

反应条件: temp:80.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: To a solution of 122 (12.39 g, 58.11 mmol) in toluene (120 mL) was added 1,1-dimethoxy-N,N-dimethylmethanamine (11.62 mL, 87.16 mmol) and the reaction was heated to 80° C. for 30 min then at 50° C. for 1 h. The reaction was concentrated to afford 16.5 g (105%) of crude tert-butyl 4-((dimethylamino)methylene)-3,5-dioxopiperidine-1-carboxylate (124) which was used without additional purification. The reaction was concentrated

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

实验步骤: To a cooled solution (0° C.) of potassium tert-butoxide (112.0 mL, 112.0 mmol) was added via addition funnel over 1.5 h, a solution 120 (26.41 g, 101.9 mmol) in ether (200 mL). The mixture was stirred for an additional 3 h. The precipitate was filtered off and washed with ether. The solid was dissolved in water and the pH was adjusted to ca. 4 with HOAc. The solids were filtered, washed with water, and dried to afford 13.16 g (60.6%) of tert-butyl 3,5-dioxopiperidine-1-carboxylate (122). The precipitate was filtered off washed with ether The solid was dissolved in water The solids were filtered washed with water dried

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

实验步骤: To a cooled solution (0° C.) of potassium tert-butoxide (112.0 mL, 112.0 mmol) was added via addition funnel over 1.5 h, a solution 120 (26.41 g, 101.9 mmol) in ether (200 mL). The mixture was stirred for an additional 3 h. The precipitate was filtered off and washed with ether. The solid was dissolved in water and the pH was adjusted to ca. 4 with HOAc. The solids were filtered, washed with water, and dried to afford 13.16 g (60.6%) of tert-butyl 3,5-dioxopiperidine-1-carboxylate (122). The precipitate was filtered off washed with ether The solid was dissolved in water The solids were filtered washed with water dried

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

实验步骤: To a cooled solution (0° C.) of potassium tert-butoxide (112.0 mL, 112.0 mmol) was added via addition funnel over 1.5 h, a solution 120 (26.41 g, 101.9 mmol) in ether (200 mL). The mixture was stirred for an additional 3 h. The precipitate was filtered off and washed with ether. The solid was dissolved in water and the pH was adjusted to ca. 4 with HOAc. The solids were filtered, washed with water, and dried to afford 13.16 g (60.6%) of tert-butyl 3,5-dioxopiperidine-1-carboxylate (122). The precipitate was filtered off washed with ether The solid was dissolved in water The solids were filtered washed with water dried

反应条件: temp:80.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: 56.0 g (of 1,1-dimethylethyl 3,5-dioxo-1-piperidinecarboxylate having the empirical formula C10H15NO4 (prepared by a method similar to that described in Heterocycles, 22, 2769-2773, (1984), replacing methyl chloroformate with (BOC)2O, are prepared as a suspension. 55.5 ml of N,N-dimethylformamide dimethyl acetal at 95% are added at room temperature. The medium is stirred for half an hour at 80° C. and then for 3 hours at 50° C. The solvent is evaporated off under reduced pressure. 79 g of 1,1-dimethylethyl 4-[(dimethylamino)methylene]-3,5-dioxo-1-piperidinecarboxylate having the empirical formula C13H20N2O4 are thus obtained. The corresponding yield is 99%. are prepared as a suspension The solvent is evaporated off under reduced pressure