4-(piperazin-1-ylmethyl)benzonitrile

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

Procedure: A mixture of 13.1 g. of p-cyanobenzaldehyde and 15 ml. of piperazine-1-carboxaldehyde was heated to 100° C. Over 10 minutes, 6 g. of 99% formic acid were added. The mixture was heated for 3 hours, then 200 ml. of 3.6 N hydrochloric acid in ethanol were added and the mixture was refluxed for 4 hours. The solid was collected, washed with ether and suspended in water. 10 N Sodium hydroxide extracted with three 100 ml. portions of chloroform and the combined extracts were evaporated. The residue was suspended in a mixture of 6 N hydrochloric acid and chloroform and filtered. The filtrate was adjusted to pH>7 with 10 N sodium hydroxide, extracted with chloroform, and the extract dried and evaporated to an oil which was distilled, giving α-(1-piperazinyl)-p-tolunitrile as a colorless liquid, b.p. 207°-209° C. (15 mm.). A mixture of 13.1 g The mixture was heated for 3 hours the mixture was refluxed for 4 hours The solid was collected washed with ether 10 N Sodium hydroxide extracted with three 100 ml portions of chloroform and the combined extracts were evaporated The residue was suspended in a mixture of 6 N hydrochloric acid and chloroform filtered extracted with chloroform the extract dried evaporated to an oil which was distilled

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

Procedure: A mixture of 13.1 g. of p-cyanobenzaldehyde and 15 ml. of piperazine-1-carboxaldehyde was heated to 100° C. Over 10 minutes, 6 g. of 99% formic acid were added. The mixture was heated for 3 hours, then 200 ml. of 3.6 N hydrochloric acid in ethanol were added and the mixture was refluxed for 4 hours. The solid was collected, washed with ether and suspended in water. 10 N Sodium hydroxide extracted with three 100 ml. portions of chloroform and the combined extracts were evaporated. The residue was suspended in a mixture of 6 N hydrochloric acid and chloroform and filtered. The filtrate was adjusted to pH>7 with 10 N sodium hydroxide, extracted with chloroform, and the extract dried and evaporated to an oil which was distilled, giving α-(1-piperazinyl)-p-tolunitrile as a colorless liquid, b.p. 207°-209° C. (15 mm.). A mixture of 13.1 g The mixture was heated for 3 hours the mixture was refluxed for 4 hours The solid was collected washed with ether 10 N Sodium hydroxide extracted with three 100 ml portions of chloroform and the combined extracts were evaporated The residue was suspended in a mixture of 6 N hydrochloric acid and chloroform filtered extracted with chloroform the extract dried evaporated to an oil which was distilled

Conditions: temp:80.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of 4-cyanobenzylpiperazine (4.0 g), bis(2-chloroethyl) disulfide (1.9 g), potassium hydroxide (5.0 g), and dimethylsulfoxide (50 ml) is heated at 80° C. until the solution turns pink in color. The heat is then removed and the reaction mixture allowed to stir overnight at room temperature. The solution is diluted with water, and the product extracted with ether, dried, and concentrated to give 4.4 g of an oil, which is purified on a silica gel column (methylene chloride: methanol, 98:2). The resulting light brown oil is dissolved in ether and the salt precipitated with ethereal hydrochloric acid to give, after recrystallization from aqueous ethanol, 1,1'-(dithiodi-2,1-ethanediyl)bis[4-(4-cyanobenzyl)piperazine] tetrahydrochloride as a white crystalline solid, m.p. 272°-275° C. The heat is then removed The solution is diluted with water the product extracted with ether dried concentrated

Conditions: temp:80.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of 4-cyanobenzylpiperazine (4.0 g), bis(2-chloroethyl) disulfide (1.9 g), potassium hydroxide (5.0 g), and dimethylsulfoxide (50 ml) is heated at 80° C. until the solution turns pink in color. The heat is then removed and the reaction mixture allowed to stir overnight at room temperature. The solution is diluted with water, and the product extracted with ether, dried, and concentrated to give 4.4 g of an oil, which is purified on a silica gel column (methylene chloride: methanol, 98:2). The resulting light brown oil is dissolved in ether and the salt precipitated with ethereal hydrochloric acid to give, after recrystallization from aqueous ethanol, 1,1'-(dithiodi-2,1-ethanediyl)bis[4-(4-cyanobenzyl)piperazine] tetrahydrochloride as a white crystalline solid, m.p. 272°-275° C. The heat is then removed The solution is diluted with water the product extracted with ether dried concentrated

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

Procedure: To a solution of piperazine (5.17 g, 60 mmol, 2 equiv) in EtOH (40 mL) was added 1 M HCl-EtOH (60 mL) dropwise over 1 h and the suspension was heated to 70° C. for 1 h. α-Bromo-p-tolunitrile (5.88 g, 30 mmol, 1 equiv) was added and the reaction was heated to reflux for 16 h. After cooling the solvent was removed by rotary evaporation and the residue was partitioned between CH2Cl2 (70 mL) and 2N aqueous KOH (70 mL) and the combined organic phase was washed with saturated aqueous NaCl (100 mL) and dried (MgSO4). Chromatography (SiO2, 20% CH3OH-5% Et3N-CH2Cl2) afforded the monoalkylated material (2.6 g, 6.0 g theoretical, 43%) as an amber oil. was added the reaction was heated to reflux for 16 h After cooling the solvent was removed by rotary evaporation the residue was partitioned between CH2Cl2 (70 mL) and 2N aqueous KOH (70 mL) the combined organic phase was washed with saturated aqueous NaCl (100 mL) dried (MgSO4) Chromatography (SiO2, 20% CH3OH-5% Et3N-CH2Cl2) afforded the monoalkylated material (2.6 g, 6.0 g theoretical, 43%) as an amber oil

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

Procedure: The method of Example 12 was repeated using a mixture of 6-chloro-7-methyl-3-(trifluoromethyl)-[1,2,4]triazolo[4,3-b]pyridazine (0.078 g, 0.33 mmol) and 1-(4-cyanobenzyl)-piperazine (0.199 g, 0.99 mmol) to give 4-((4-(7-methyl-3-(trifluoromethyl)-[1,2,4]triazolo[4,3-b]pyridazin-6-yl)piperazin-1-yl)methyl)benzonitrile (0.099 g, 75%).

Conditions: temp:70.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of 1-(4-cyanobenzyl)-piperazine (0.158 g, 0.79 mmol) and 6-chloro-8-methyl-3-(trifluoromethyl)-[1,2,4]triazolo[4,3-b]pyridazine 0.062 g, 0.26 mmol) in ethanol (5 mL) was heated to 70° C. for 20 hours. The reaction mixture was allowed to cool and then concentrated to give an involatile residue that was purified by flash chromatography on silica-gel using an increasing gradient of ethyl acetate in dichloromethane to give 4-((4-(8-methyl-3-(trifluoromethyl)-[1,2,4]triazolo[4,3-b]pyridazin-6-yl)piperazin-1-yl)methyl)benzonitrile (0.0676 g, 64.3%) as a white solid; 1H NMR spectrum (CDCl3) δ 2.47-2.55 (4H, m), 2.61 (3H, d), 3.50-3.60 (6H, m), 6.72-6.76 (1H, m), 7.42 (2H, d), 7.57 (2H, d); m/z 402.69 (M+1)+. to cool concentrated to give an involatile residue that was purified by flash chromatography on silica-gel

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

Procedure: A mixture of 13.1 g. of p-cyanobenzaldehyde and 15 ml. of piperazine-1-carboxaldehyde was heated to 100° C. Over 10 minutes, 6 g. of 99% formic acid were added. The mixture was heated for 3 hours, then 200 ml. of 3.6 N hydrochloric acid in ethanol were added and the mixture was refluxed for 4 hours. The solid was collected, washed with ether and suspended in water. 10 N Sodium hydroxide extracted with three 100 ml. portions of chloroform and the combined extracts were evaporated. The residue was suspended in a mixture of 6 N hydrochloric acid and chloroform and filtered. The filtrate was adjusted to pH>7 with 10 N sodium hydroxide, extracted with chloroform, and the extract dried and evaporated to an oil which was distilled, giving α-(1-piperazinyl)-p-tolunitrile as a colorless liquid, b.p. 207°-209° C. (15 mm.). A mixture of 13.1 g The mixture was heated for 3 hours the mixture was refluxed for 4 hours The solid was collected washed with ether 10 N Sodium hydroxide extracted with three 100 ml portions of chloroform and the combined extracts were evaporated The residue was suspended in a mixture of 6 N hydrochloric acid and chloroform filtered extracted with chloroform the extract dried evaporated to an oil which was distilled