1-ethylpiperazine-2,3-dione

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

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

Procedure: Into a mixture comprising 8 g of a diethyl ester of oxalic acid and 8 ml of ethanol was dropped at room temperature 4.4 g of N-ethyl ethylenediamine. The resulting mixture was allowed to react for 3 hours, and then heated to remove the ethanol. Subsequently, the residue was recrystallized from 10 ml of dioxane to obtain 5.4 g of 1-ethyl-2,3-dioxo-piperazine, m.p. 124° C, yield 76.0%. to react for 3 hours heated to remove the ethanol Subsequently, the residue was recrystallized from 10 ml of dioxane

Conditions: temp:50.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of 1-ethylpiperazine-2,3-dione (2.13 g, 15 mmol) in 30% aqueous (methanol free) formaldehyde (15 mmol) potassium hydroxide (150 mg, 2.7 mmol) was added and the mixture stirred at 50° C. for 7 days. It was neutralized with 5 N aqueous hydrochloric acid (50 μl) to pH=7. The mixture was evaporated at 15 mm and then dried in high vacuo (0.0013 mbar) (0.001 mm) to give 1-ethyl-4- (hydroxymethyl)-piperazine-2,3-dione as a colourless solid (100%). NMR-spectrum in CDCl3: 1.15 (broad signal, 1H), 1.15 (t, 3H, J=7 Hz), 3.47 (q, 2H, J=7 Hz), 3.54 (m, 2H), 3.68 (m, 2H), 4.88 (s, 2H) ppm. The mixture was evaporated at 15 mm dried in high vacuo (0.0013 mbar) (0.001 mm)

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

Procedure: Into a mixture comprising 8 g of a diethyl ester of oxalic acid and 8 ml of ethanol was dropped at room temperature 4.4 g of N-ethyl ethylenediamine. The resulting mixture was allowed to react for 3 hours, and then heated to remove the ethanol. Subsequently, the residue was recrystallized from 10 ml of dioxane to obtain 5.4 g of 1-ethyl-2,3-dioxo-piperazine, m.p. 124° C., yield 76.0%. to react for 3 hours heated to remove the ethanol Subsequently, the residue was recrystallized from 10 ml of dioxane

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

Procedure: Into a mixture comprising 8 g of a diethyl ester of oxalic acid and 8 ml of ethanol was dropped at room temperature 4.4 g of N-ethyl ethylenediamine. The resulting mixture was allowed to react for 3 hours, and then heated to remove the ethanol. Subsequently, the residue was recrystallized from 10 ml of dioxane to obtain 5.4 g of 1-ethyl-2,3-dioxo-piperazine, m.p. 124° C., yield 76.0%. to react for 3 hours heated to remove the ethanol Subsequently, the residue was recrystallized from 10 ml of dioxane

Conditions: temp:110.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of 5-chloro-N-((1-(4-iodophenyl)-1H-imidazol-4-yl)methyl)thiophene-2-carboxamide 1-6 (70 mg, 0.16 mmol), N-ethylpiperazine-2,3-dione (45 mg, 0.32 mmol), N,N′-dimethylethylenediamine (0.020 mL, 0.19 mmol) and K2CO3 (65 mg, 0.47 mmol) in DMSO (1 mL) and dioxane (1 mL) was degassed with Ar before being charged with CuI (20 mg, 0.10 mmol). The mixture in a sealed tube was heated at 110° C. overnight. The mixture was then purified by HPLC to give the titled compound (10 mg). MS 458.1 and 460.1 (M+H, Cl pattern). was degassed with Ar The mixture was then purified by HPLC

Conditions: temp:110.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of 5-chloro-N-((1-(4-iodophenyl)-1H-imidazol-4-yl)methyl)thiophene-2-carboxamide 1-6 (70 mg, 0.16 mmol), N-ethylpiperazine-2,3-dione (45 mg, 0.32 mmol), N,N′-dimethylethylenediamine (0.020 mL, 0.19 mmol) and K2CO3 (65 mg, 0.47 mmol) in DMSO (1 mL) and dioxane (1 mL) was degassed with Ar before being charged with CuI (20 mg, 0.10 mmol). The mixture in a sealed tube was heated at 110° C. overnight. The mixture was then purified by HPLC to give the titled compound (10 mg). MS 458.1 and 460.1 (M+H, Cl pattern). was degassed with Ar The mixture was then purified by HPLC

Conditions: temp:110.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of 5-chloro-N-((1-(4-iodophenyl)-1H-imidazol-4-yl)methyl)thiophene-2-carboxamide 1-6 (70 mg, 0.16 mmol), N-ethylpiperazine-2,3-dione (45 mg, 0.32 mmol), N,N′-dimethylethylenediamine (0.020 mL, 0.19 mmol) and K2CO3 (65 mg, 0.47 mmol) in DMSO (1 mL) and dioxane (1 mL) was degassed with Ar before being charged with CuI (20 mg, 0.10 mmol). The mixture in a sealed tube was heated at 110° C. overnight. The mixture was then purified by HPLC to give the titled compound (10 mg). MS 458.1 and 460.1 (M+H, Cl pattern). was degassed with Ar The mixture was then purified by HPLC

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

Procedure: Into a mixture comprising 8 g of a diethyl ester of oxalic acid and 8 ml of ethanol was dropped at room temperature 4.4 g of N-ethyl ethylenediamine. The resulting mixture was allowed to react for 3 hours, and then heated to remove the ethanol. Subsequently, the residue was recrystallized from 10 ml of dioxane to obtain 5.4 g of 1-ethyl-2,3-dioxo-piperazine, m.p. 124° C, yield 76.0%. to react for 3 hours heated to remove the ethanol Subsequently, the residue was recrystallized from 10 ml of dioxane

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

Procedure: Into a mixture comprising 8 g of a diethyl ester of oxalic acid and 8 ml of ethanol was dropped at room temperature 4.4 g of N-ethyl ethylenediamine. The resulting mixture was allowed to react for 3 hours, and then heated to remove the ethanol. Subsequently, the residue was recrystallized from 10 ml of dioxane to obtain 5.4 g of 1-ethyl-2,3-dioxo-piperazine, m.p. 124° C, yield 76.0%. to react for 3 hours heated to remove the ethanol Subsequently, the residue was recrystallized from 10 ml of dioxane

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

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

Procedure: Into a mixture comprising 8 g of a diethyl ester of oxalic acid and 8 ml of ethanol was dropped at room temperature 4.4 g of N-ethyl ethylenediamine. The resulting mixture was allowed to react for 3 hours, and then heated to remove the ethanol. Subsequently, the residue was recrystallized from 10 ml of dioxane to obtain 5.4 g of 1-ethyl-2,3-dioxopiperazine, m.p. 124° C, yield 76.0%. to react for 3 hours heated to remove the ethanol Subsequently, the residue was recrystallized from 10 ml of dioxane