1-nitrosopiperazine

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

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

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

Procedure: A mixture of 3-methyl-1-bromo-butane (3.94 g.), N-nitroso-piperazine (3 g.), anhydrous potassium carbonate (3.6 g.) and a small crystal of potassium iodide in dimethyl formamide was heated at 100° for 2 hours. Solvent was removed under reduced pressure and the residue dissolved in ether and water. The ether extract was separated, dried and evaporated to give an oil which was adsorbed on silica gel. Elution with ethyl acetate gave N-(3-methylbutyl)-N'-nitroso piperazine, further purified by dissolving in dilute acid, washing the acid extract with ether, basifying the acid extract and re-extracting with ether. The yield of colourless oil was 3 g (62%). Solvent was removed under reduced pressure the residue dissolved in ether The ether extract was separated dried evaporated to give an oil which Elution with ethyl acetate

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

Procedure: A mixture of 3-methyl-1-bromo-butane (3.94 g.), N-nitroso-piperazine (3 g.), anhydrous potassium carbonate (3.6 g.) and a small crystal of potassium iodide in dimethyl formamide was heated at 100° for 2 hours. Solvent was removed under reduced pressure and the residue dissolved in ether and water. The ether extract was separated, dried and evaporated to give an oil which was adsorbed on silica gel. Elution with ethyl acetate gave N-(3-methylbutyl)-N'-nitroso piperazine, further purified by dissolving in dilute acid, washing the acid extract with ether, basifying the acid extract and re-extracting with ether. The yield of colourless oil was 3 g (62%). Solvent was removed under reduced pressure the residue dissolved in ether The ether extract was separated dried evaporated to give an oil which Elution with ethyl acetate

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

Procedure: 2-Chloromethylthiophene (prepared as described by F. F. Blicke and J. H. Burkhatter in J. Amer. Chem. Soc., 64, 477, 1947) (5.0 g, 0.038 mole) was added to acetone (100 ml) containing N-nitrosopiperazine (5.4 g, 0.038 mole) (prepared as described in U.S. Pat. No. 2,907,767), anhydrous potassium carbonate (6.0 g, 0.04 mole) and a catalytic amount of potassium iodide (1 small crystal). The mixture was heated under reflux for 3 hours, cooled, treated with water (50 ml) evaporated to 1/3 volume and extracted with ethylacetate (3×150 ml). The combined extracts were dried (anhydrous K2CO3), filtered and evaporated in vacuo to yield N-nitroso-N'-2-thenylpiperazine (7.35 g, >99%) as a straw coloured oil. prepared The mixture was heated under reflux for 3 hours cooled evaporated to 1/3 volume extracted with ethylacetate (3×150 ml) The combined extracts were dried (anhydrous K2CO3) filtered evaporated in vacuo

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

Procedure: 2-Chloromethylthiophene (prepared as described by F. F. Blicke and J. H. Burkhatter in J. Amer. Chem. Soc., 64, 477, 1947) (5.0 g, 0.038 mole) was added to acetone (100 ml) containing N-nitrosopiperazine (5.4 g, 0.038 mole) (prepared as described in U.S. Pat. No. 2,907,767), anhydrous potassium carbonate (6.0 g, 0.04 mole) and a catalytic amount of potassium iodide (1 small crystal). The mixture was heated under reflux for 3 hours, cooled, treated with water (50 ml) evaporated to 1/3 volume and extracted with ethylacetate (3×150 ml). The combined extracts were dried (anhydrous K2CO3), filtered and evaporated in vacuo to yield N-nitroso-N'-2-thenylpiperazine (7.35 g, >99%) as a straw coloured oil. prepared The mixture was heated under reflux for 3 hours cooled evaporated to 1/3 volume extracted with ethylacetate (3×150 ml) The combined extracts were dried (anhydrous K2CO3) filtered evaporated in vacuo

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

Procedure: Ethyl iodide (8.13 g, 0.052 mole) was added to acetone (80 ml) containing N-nitroso piperazine (6.0 g, 0.052 mole) (prepared as described in U.S. Pat. No. 2,907,767) and anhydrous potassium carbonate (7.3 g, 0.052 mole). The mixture was heated under reflux for 24 hours, cooled, treated with water (50 ml) evaporated to 1/2 volume and extracted with ether (3×150 ml). The combined extracts were dried (K2CO3) filtered and evaporated in vacuo to yield N-ethyl-N'-nitrosopiperazine (7.71 g, 98%), as a straw coloured oil. prepared The mixture was heated under reflux for 24 hours cooled evaporated to 1/2 volume extracted with ether (3×150 ml) The combined extracts were dried (K2CO3) filtered evaporated in vacuo

Conditions: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A stirred mixture of 3.82 g (0.02 mol) of 5,6-dimethoxy-2-methylindole and 5,80 g (0.044 mol) of potassium carbonate in 50 ml. of chloroform and 15 ml. of water is cooled to -5° C. Then 3.2 g (0.024 mol) of oxalyl chloride is added slowly, maintaining the reaction temperature at 0° C. The resulting mixture is stirred at room temperature for 10 minutes. Then 3.5 g (0.03 mol) of nitrosopiperazine is added over a 5 minute span. The reaction mixture turns red-purple and is stirred for an additional hour. To the solution is slowly added in portions 250 ml. of ethyl ether; the solution appears lighter and a tan precipitate forms. After stirring for one hour, the product is filtered, washed well with water and dried. This product is recrystallized from a DMF and water mixture to give flakes of 1-(5,6-dimethoxy-2-methylindol-3-ylglyoxyloyl)-4-nitrosopiperazine, m.p. 233°-225° C. Analysis: Calculated for C17H20N4O5 : 56.66% C; 5.59% H; 15.55% N Found: 56.65% C; 5.61% H; 15.68% N. is stirred for an additional hour To the solution is slowly added in portions 250 ml After stirring for one hour the product is filtered washed well with water dried This product is recrystallized from a DMF and water mixture

Conditions: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of 34.8 g (0.22 mol) of gramine and 23.9 g (0.20 mol) of nitrosopiperazine in 700 ml. of toluene is refluxed while stirring under nitrogen for 48 hours. The reaction solution is then concentrated under reduced pressure until a precipitate appears and then is cooled to 0° C. and is filtered. The product is washed with cold toluene and dried to produce crystals of 3-(4-nitrosopiperazin-1-yl)methylindole. This product is recrystallized from toluene to yield pure plates, m.p. 116°-118° C. Analysis: Calculated for C13H16N4O: 63.92% C; 6.60% H; 22.93% N Found: 63.84% C; 6.64% H; 23.06% N. The reaction solution is then concentrated under reduced pressure until a precipitate is filtered The product is washed with cold toluene dried

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

Procedure: To a mixture of 1-nitrosopiperazine {1.21 g) and pyridine (2.4 ml) in dioxane (18 ml) was added dropwise 2-thenoyl chloride (1.2 ml) in an ice bath. The mixture was stirred for one hour in an ice.bath and then overnight at ambient temperature. The mixture was poured into a mixture of ethyl acetate (100 ml) and water (100 ml). The separated aqueous layer was extracted twice with ethyl acetate. The combined organic layers were dried and concentrated in vacuo. The residue was pulverized with diisopropyl ether to yield 1-nitroso-4-(2-thenoyl)-piperazine (1.78 g). overnight at ambient temperature The separated aqueous layer was extracted twice with ethyl acetate The combined organic layers were dried concentrated in vacuo