2-piperazin-1-ylethanamine

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

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

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: N-(2-Aminoethyl)piperazine (4.93 g) was dissolved in tetrahydrofuran (40 ml), and the solution was added with triethylamine (10.6 ml). The mixture was added with a solution of benzyl chloroformate (4.9 ml) in tetrahydrofuran (40 ml) under ice cooling, and the mixture was stirred at room temperature for 1 hour. The reaction mixture was added with ethyl acetate and saturated aqueous sodium hydrogencarbonate, the layers were separated, and then the organic layer was dried over anhydrous magnesium sulfate and filtered. The filtrate was concentrated under reduced pressure, and the resulting residue was purified by silica gel column chromatography (chloroform:methanol:28% aqueous ammonia=10:1:0.1) to obtain the title compound (400 mg). the layers were separated the organic layer was dried over anhydrous magnesium sulfate filtered The filtrate was concentrated under reduced pressure the resulting residue was purified by silica gel column chromatography (chloroform:methanol:28% aqueous ammonia=10:1:0.1)

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

Procedure: A solution of 2-imino-3-(3-trifluoromethylphenyl)-5-methylthiazoline (1.29 g, 5.0 mmol) and 1-(2-aminoethyl)piperazine (0.78 g, 6.0 mmol) in N,N-dimethylformamide (10 ml) charged in a reaction flask was reacted with tetrafluoroethylene, which was made to flow into the flask (ca. 0.7 liter/hr), with vigorous stirring at 50° C. for 33 hours. After cooling to an ambient temperature, the reaction mixture was poured into saturated aqueous sodium carbonate solution, and extracted with diethyl ether. The diethyl ether layer was washed with water and then brine, and dried over anhydrous magnesium sulfate. The solvent was distilled off, and the residue was subjected to silica gel column chromatography, which afforded 2-difluoroacetylimino-3-(3-trifluoromethylphenyl)-5-methylthiazoline (1.18 g, 3.5 mmol, yield 70%). Unreacted part of 2-imino-3-(3-trifluoromethylphenyl)-5-methylthiazoline (0.12 g) was recovered. After cooling to an ambient temperature extracted with diethyl ether The diethyl ether layer was washed with water brine, and dried over anhydrous magnesium sulfate The solvent was distilled off

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

Procedure: Starting with 182.7 g of chloropropylmethyldimethoxysilane and 79 g of 2-aminoethylpiperazine, the procedure described in Example 2 was used to prepare 75 g of the title compound, boiling point range 90°-110° C. at 5 mm Hg (34 kPa).

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

Procedure: A one-liter, four-necked flask was equipped with a thermometer, a condensor, an inlet tube for nitrogen gas and an outlet tube for vent gases. Chloropropyltrimethoxysilane (198.72 g) was introduced into the flask, together with 50 g of anhydrrous 1,1,1-trichloroethane and 86.14 g of 1-(2-aminoethyl)- piperazine. The mixture was heated to 80° C. with continuous agitation for four hours and then cooled to room temperature. The reaction mixture was rapidly filtered to collect the 1-(2-aminoethyl)piperazine hydrochloride salt which had formed. The filtrate was distilled to yield 182 g of 1-[2-[3-(trimethoxysilyl)- propyl]aminoethyl]piperazine, bp 120°-143° C. at 10 mm Hg (69 kPa) as a pale yellow oil. The yield corresponded to 64% of theoretical. This material was used as an accelerator and adhesion promoter in the sealant compositions of this invention as detailed below in Example 5. A one-liter, four-necked flask was equipped with a thermometer cooled to room temperature The reaction mixture was rapidly filtered to collect the 1-(2-aminoethyl)piperazine hydrochloride salt which had formed The filtrate was distilled

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

Procedure: Three portions of benzyl chloroformate (260 ml) in dichloromethane (170 ml) were added sequentially over 1 h 40 min to a vigorously stirred mixture of 4-aminobutyraldehyde diethyl acetal (910 ml) in dichloromethane (3 l ) and aqueous sodium carbonate (1M, 3 l). Stirring was continued for 50 min until gas evolution ceased. N-(2-aminoethyl)piperazine (40 ml) was added and stirring was continued for 1 h 15 min. The layers were separated and the organic layer was washed with aqueous citric acid (1M, 3.8 l) and saturated aqueous sodium bicarbonate (2 l), dried (MgSO4), filtered and concentrated in vacuo to give the title compound as a yellow oil (1.6 kg). T.l.c. (Ether) Rf 0.5. stirring was continued for 1 h 15 min The layers were separated the organic layer was washed with aqueous citric acid (1M, 3.8 l) and saturated aqueous sodium bicarbonate (2 l) dried (MgSO4) filtered concentrated in vacuo

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

Procedure: A solution of 1-[5-acetyl-3-(4-trifluoromethyl-phenyl)-4,5,6,7-tetrahydro-pyrazolo[4,3-c]pyridin-1-yl]-3-(4-o-tolyl-piperazin-1-yl)-propan-2-one (54 mg, 0.1 mmol) in 1,2-dichloroethane (0.5 mL) was treated with 1-(2-aminoethyl)piperazine (26 μL, 0.2 mmol) and glacial acetic acid (34 μL, 0.6 mmol) at 25° C. and stirred for 30 min. Sodium triacetoxyborohydride (63.6 mg, 0.3 mmol) was added and the reaction mixture was stirred for an additional 4 h before it was quenched with CH2Cl2 (5 mL) and sat. NaHCO3 (5 mL). The organic layer was separated, washed with H2O (2×5 mL), dried over Na2SO4, and concentrated. Preparative TLC (silica, 10% MeOH/CH2Cl2) afforded 22 mg (35%) of a light yellow film. TLC (10% MeOH/CH2Cl2): Rf=0.2. MS (electrospray): m/z 653.3 ([M+H]+, C35H47F3N8O requires 652.4). 1H NMR (CDCl3, 400 MHz, a mixture of two rotamers): 7.78-7.60 (m, 4H), 7.18-6.82 (m, 4H), 4.88-4.30 (m, 2H), 4.23-3.90 (m, 2H), 3.85-3.70 (m, 2H), 3.22-2.85 (m, 10H), 2.85-2.30 (m, 15H), 2.30 (s, 3H), 2.21 (s, 1.5H), 2.17 (s, 1.5H). the reaction mixture was stirred for an additional 4 h before it was quenched with CH2Cl2 (5 mL) and sat. NaHCO3 (5 mL) The organic layer was separated washed with H2O (2×5 mL) dried over Na2SO4 concentrated Preparative TLC (silica, 10% MeOH/CH2Cl2) afforded 22 mg (35%) of a light yellow film

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

Procedure: A solution of 1-[5-acetyl-3-(4-trifluoromethyl-phenyl)-4,5,6,7-tetrahydro-pyrazolo[4,3-c]pyridin-1-yl]-3-(4-o-tolyl-piperazin-1-yl)-propan-2-one (54 mg, 0.1 mmol) in 1,2-dichloroethane (0.5 mL) was treated with 1-(2-aminoethyl)piperazine (26 μL, 0.2 mmol) and glacial acetic acid (34 μL, 0.6 mmol) at 25° C. and stirred for 30 min. Sodium triacetoxyborohydride (63.6 mg, 0.3 mmol) was added and the reaction mixture was stirred for an additional 4 h before it was quenched with CH2Cl2 (5 mL) and sat. NaHCO3 (5 mL). The organic layer was separated, washed with H2O (2×5 mL), dried over Na2SO4, and concentrated. Preparative TLC (silica, 10% MeOH/CH2Cl2) afforded 22 mg (35%) of a light yellow film. TLC (10% MeOH/CH2Cl2): Rf=0.2. MS (electrospray): m/z 653.3 ([M+H]+, C35H47F3N8O requires 652.4). 1H NMR (CDCl3, 400 MHz, a mixture of two rotamers): 7.78-7.60 (m, 4H), 7.18-6.82 (m, 4H), 4.88-4.30 (m, 2H), 4.23-3.90 (m, 2H), 3.85-3.70 (m, 2H), 3.22-2.85 (m, 10H), 2.85-2.30 (m, 15H), 2.30 (s, 3H), 2.21 (s, 1.5H), 2.17 (s, 1.5H). the reaction mixture was stirred for an additional 4 h before it was quenched with CH2Cl2 (5 mL) and sat. NaHCO3 (5 mL) The organic layer was separated washed with H2O (2×5 mL) dried over Na2SO4 concentrated Preparative TLC (silica, 10% MeOH/CH2Cl2) afforded 22 mg (35%) of a light yellow film

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

Procedure: 1-(2-aminoethyl)piperazine (1.29 g, 10 mmol) is dissolved in 20 mL of dioxane:water (1:1) mixture and 2-(tert-butoxycarbonyloxyimino)-2-phenylacetonitrile (2.46 g, 10 mmol) is added. The mixture is then stirred until no starting material is detected on thin layer chromatography. The obtained mixture is fractionally separated by silica gel chromatography, followed by RP-HPLC to obtain 1-[2-tert-butoxycarbonylaminoethyl]piperazine. Following the procedure of Example 6, but replacing 1-benzylpiperazine with 1-[2-tert-butoxycarbonylaminoethyl]piperazine, provides the desired compound. The product of Example 3 (2.1 g, 2.03 mmol), 1-[2-tert-butoxycarbonylaminoethyl]piperazine (1.396 g, 6.09 mmol), and triethylamine (0.85 mL, 6.09 mmol) in 10 mL of methylene chloride are used. The obtained product (1.0 g) is treated with 48%-HF (4 mL) in 35 mL of acetonitrile in the procedure described in Example 5, followed by a carefully deprotection of N-tert-butoxycarbonyl group with 10% trifluoroacetic acid to obtain the pure title compound. is added The obtained mixture is fractionally separated by silica gel chromatography