2-aminopropanenitrile

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

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

Procedure: To a stirring solution of 23.5 g (0.2 mole) 2,2-dimethylbutanoic acid in 150 ml. acetone, there is added 30 ml. triethylamine. The temperature is lowered to 0°, and 21.1 ml. (0.22 mol) ethyl chloroformate are added over one-half hour, keeping the temperature at 0°. At the end of the addition, the mixture is stirred for 15 minutes, keeping the temperature at 0°. At the end of this period, a solution of 26.0 g. (0.4 mole) sodium azide in 75 ml. of water is added over one-half hour, keeping the temperature at 0°. The resulting mixture is stirred one hour at 0°. At the end of this period, the mixture is poured into 750 ml. of ice water. This mixture is extracted 4 times with 200 ml. toluene. The toluene portions are combined and dried. The toluene solution is added dropwise to 150 ml. of toluene refluxing in a nitrogen atmosphere. After the addition is complete, the solution is heated to reflux until the IR shows the disappearance of the azide peak (about two and one-half hours). The solution is then cooled and 14.0 g. (0.2 mole) 2-aminopropionitrile are added. The resulting mixture is refluxed for 5 hours. At the end of this period, the toluene is removed at reduced pressure. The residue is put through a column of Silica AR CC7 using toluene:ethyl acetate, 80:20 as the liquid phase. The desired portions are combined and the toluene and ethyl acetate are removed under reduced pressure. The residue is recrystallized from ethyl acetate/cyclohexane to give the product, N-(1-cyanoethyl)-N'-(1,1-dimethylpropyl)urea, m.p. 129°-30°. Anal. Calcd. for C8H17N3O: C: 58.99, H: 9.35, N: 22.93; Found: C: 58.82, H: 9.13, N: 22.92. is lowered to 0° at 0° At the end of the addition at 0° at 0° The resulting mixture is stirred one hour at 0° At the end of this period, the mixture is poured into 750 ml This mixture is extracted 4 times with 200 ml dried The toluene solution is added dropwise to 150 ml After the addition the solution is heated to reflux until the IR The solution is then cooled The resulting mixture is refluxed for 5 hours At the end of this period, the toluene is removed at reduced pressure the toluene and ethyl acetate are removed under reduced pressure The residue is recrystallized from ethyl acetate/cyclohexane

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

Procedure: To a stirring solution of 23.5 g (0.2 mole) 2,2-dimethylbutanoic acid in 150 ml. acetone, there is added 30 ml. triethylamine. The temperature is lowered to 0°, and 21.1 ml. (0.22 mol) ethyl chloroformate are added over one-half hour, keeping the temperature at 0°. At the end of the addition, the mixture is stirred for 15 minutes, keeping the temperature at 0°. At the end of this period, a solution of 26.0 g. (0.4 mole) sodium azide in 75 ml. of water is added over one-half hour, keeping the temperature at 0°. The resulting mixture is stirred one hour at 0°. At the end of this period, the mixture is poured into 750 ml. of ice water. This mixture is extracted 4 times with 200 ml. toluene. The toluene portions are combined and dried. The toluene solution is added dropwise to 150 ml. of toluene refluxing in a nitrogen atmosphere. After the addition is complete, the solution is heated to reflux until the IR shows the disappearance of the azide peak (about two and one-half hours). The solution is then cooled and 14.0 g. (0.2 mole) 2-aminopropionitrile are added. The resulting mixture is refluxed for 5 hours. At the end of this period, the toluene is removed at reduced pressure. The residue is put through a column of Silica AR CC7 using toluene:ethyl acetate, 80:20 as the liquid phase. The desired portions are combined and the toluene and ethyl acetate are removed under reduced pressure. The residue is recrystallized from ethyl acetate/cyclohexane to give the product, N-(1-cyanoethyl)-N'-(1,1-dimethylpropyl)urea, m.p. 129°-30°. Anal. Calcd. for C8H17N3O: C: 58.99, H: 9.35, N: 22.93; Found: C: 58.82, H: 9.13, N: 22.92. is lowered to 0° at 0° At the end of the addition at 0° at 0° The resulting mixture is stirred one hour at 0° At the end of this period, the mixture is poured into 750 ml This mixture is extracted 4 times with 200 ml dried The toluene solution is added dropwise to 150 ml After the addition the solution is heated to reflux until the IR The solution is then cooled The resulting mixture is refluxed for 5 hours At the end of this period, the toluene is removed at reduced pressure the toluene and ethyl acetate are removed under reduced pressure The residue is recrystallized from ethyl acetate/cyclohexane

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

Procedure: To a stirring solution of 21.1 g (0.3 mole) 2-aminopropionitrile in 300 ml. dry tetrahydrofuran under a nitrogen atmosphere, there is added 30.7 g (0.3 mole) t-butyl isocyanate (97%). The resulting mixture is heated at reflux for five hours. At the end of this period, the tetrahydrofuran is removed at reduced pressure. The solid is recrystallized from methanol:water, 60:40, to give N-(1-cyanoethyl)-N'-(1,1-dimethylethyl)urea, m.p. 161°-3°. The resulting mixture is heated at reflux for five hours At the end of this period, the tetrahydrofuran is removed at reduced pressure The solid is recrystallized from methanol

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

Procedure: To a stirring solution of 21.1 g (0.3 mole) 2-aminopropionitrile in 300 ml. dry tetrahydrofuran under a nitrogen atmosphere, there is added 30.7 g (0.3 mole) t-butyl isocyanate (97%). The resulting mixture is heated at reflux for five hours. At the end of this period, the tetrahydrofuran is removed at reduced pressure. The solid is recrystallized from methanol:water, 60:40, to give N-(1-cyanoethyl)-N'-(1,1-dimethylethyl)urea, m.p. 161°-3°. The resulting mixture is heated at reflux for five hours At the end of this period, the tetrahydrofuran is removed at reduced pressure The solid is recrystallized from methanol

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

Procedure: To a stirring solution of 23.5 g (0.2 mole) 2,2-dimethylbutanoic acid in 150 ml. acetone, there is added 30 ml. triethylamine. The temperature is lowered to 0°, and 21.1 ml. (0.22 mol) ethyl chloroformate are added over one-half hour, keeping the temperature at 0°. At the end of the addition, the mixture is stirred for 15 minutes, keeping the temperature at 0°. At the end of this period, a solution of 26.0 g. (0.4 mole) sodium azide in 75 ml. of water is added over one-half hour, keeping the temperature at 0°. The resulting mixture is stirred one hour at 0°. At the end of this period, the mixture is poured into 750 ml. of ice water. This mixture is extracted 4 times with 200 ml. toluene. The toluene portions are combined and dried. The toluene solution is added dropwise to 150 ml. of toluene refluxing in a nitrogen atmosphere. After the addition is complete, the solution is heated to reflux until the IR shows the disappearance of the azide peak (about two and one-half hours). The solution is then cooled and 14.0 g. (0.2 mole) 2-aminopropionitrile are added. The resulting mixture is refluxed for 5 hours. At the end of this period, the toluene is removed at reduced pressure. The residue is put through a column of Silica AR CC7 using toluene:ethyl acetate, 80:20 as the liquid phase. The desired portions are combined and the toluene and ethyl acetate are removed under reduced pressure. The residue is recrystallized from ethyl acetate/cyclohexane to give the product, N-(1-cyanoethyl)-N'-(1,1-dimethylpropyl)urea, m.p. 129°-30°. Anal. Calcd. for C8H17N3O: C: 58.99, H: 9.35, N: 22.93; Found: C: 58.82, H: 9.13, N: 22.92. is lowered to 0° at 0° At the end of the addition at 0° at 0° The resulting mixture is stirred one hour at 0° At the end of this period, the mixture is poured into 750 ml This mixture is extracted 4 times with 200 ml dried The toluene solution is added dropwise to 150 ml After the addition the solution is heated to reflux until the IR The solution is then cooled The resulting mixture is refluxed for 5 hours At the end of this period, the toluene is removed at reduced pressure the toluene and ethyl acetate are removed under reduced pressure The residue is recrystallized from ethyl acetate/cyclohexane

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

Procedure: To a stirring solution of 21.1 g (0.3 mole) 2-aminopropionitrile in 300 ml. dry tetrahydrofuran under a nitrogen atmosphere, there is added 30.7 g (0.3 mole) t-butyl isocyanate (97%). The resulting mixture is heated at reflux for five hours. At the end of this period, the tetrahydrofuran is removed at reduced pressure. The solid is recrystallized from methanol:water, 60:40, to give N-(1-cyanoethyl)-N'-(1,1-dimethylethyl)urea, m.p. 161°-3°. The resulting mixture is heated at reflux for five hours At the end of this period, the tetrahydrofuran is removed at reduced pressure The solid is recrystallized from methanol

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

Procedure: To a solution of (2R,4S)-5-biphenyl-4-yl-4-(3-carboxy-propionylamino)-2-methyl-pentanoic acid ethyl ester (prepared by using the procedure described in US005217996) (200 mg, 0.486 mmol) in DMF (3 mL) are added EDC-HCl (112 mg, 0.583 mmol) and HOAt (79 mg, 0.583 mmol) at room temperature. After stirring for 10 minutes, 3-aminopropionitrile (41 mg, 0.583 mmol) and triethylamine (0.081 mL, 0.583 mmol) is added and stirred overnight. Additional EDC-HCl (66 mg, 0.292 mmol), HOAt (40 mg, 0.292 mmol), aminopropionitrile (21 mg, 0.292 mmol), and triethylamine (0.081 mL, 0.583 mmol) are added. After stirring for 1 hour, the reaction mixture is heated to 50° C. and stirred for 5 hours. The reaction mixture is diluted with ethyl acetate and washed with H2O and brine. The organic layer is dried over Na2SO4 and concentrated. The residue is purified by silica gel column chromatography to give (2R,4S)-5-biphenyl-4-yl-4-[3-(2-cyano-ethylcarbamoyl)-propionylamino]-2-methyl pentanoic acid ethyl ester. HPLC Retention time 1.37 minutes (condition B); MS 464 (M+1); 1H NMR (400 MHz, CDCl3) δ ppm 1.17 (d, J=7.33 Hz, 3H), 1.25 (t, J=7.07 Hz, 3H), 1.51 (ddd, J=4.29, 0.85, 14.14 Hz, 1H), 1.95 (ddd, J=4.29, 9.60, 13.89 Hz, 1H), 2.41-2.59 (m, 5H), 2.58 (t, J=6.57 Hz, 2H), 2.83 (d, J=6.57 Hz, 2H), 3.45 (ddd, J=2.53, 8.00, 12.0 Hz, 2H), 4.14 (ddd, J=2.53, 8.00, 14.01 Hz, 2H), 4.21-4.31 (m, 1H), 5.64 (d, J=9.09 Hz, 1H), 6.60-6.67 (m, 1H), 7.24 (d, J=8.34 Hz, 2H), 7.34 (t, J=7.33 Hz, 1H), 7.43 (t, J=7.83 Hz, 2H), 7.53 (d, J=8.34 Hz, 2H), 7.58 (d, J=7.07 Hz, 2H). stirred overnight After stirring for 1 hour stirred for 5 hours washed with H2O and brine The organic layer is dried over Na2SO4 concentrated The residue is purified by silica gel column chromatography

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

Procedure: To a solution of (2R,4S)-5-biphenyl-4-yl-4-(3-carboxy-propionylamino)-2-methyl-pentanoic acid ethyl ester (prepared by using the procedure described in US005217996) (200 mg, 0.486 mmol) in DMF (3 mL) are added EDC-HCl (112 mg, 0.583 mmol) and HOAt (79 mg, 0.583 mmol) at room temperature. After stirring for 10 minutes, 3-aminopropionitrile (41 mg, 0.583 mmol) and triethylamine (0.081 mL, 0.583 mmol) is added and stirred overnight. Additional EDC-HCl (66 mg, 0.292 mmol), HOAt (40 mg, 0.292 mmol), aminopropionitrile (21 mg, 0.292 mmol), and triethylamine (0.081 mL, 0.583 mmol) are added. After stirring for 1 hour, the reaction mixture is heated to 50° C. and stirred for 5 hours. The reaction mixture is diluted with ethyl acetate and washed with H2O and brine. The organic layer is dried over Na2SO4 and concentrated. The residue is purified by silica gel column chromatography to give (2R,4S)-5-biphenyl-4-yl-4-[3-(2-cyano-ethylcarbamoyl)-propionylamino]-2-methyl pentanoic acid ethyl ester. HPLC Retention time 1.37 minutes (condition B); MS 464 (M+1); 1H NMR (400 MHz, CDCl3) δ ppm 1.17 (d, J=7.33 Hz, 3H), 1.25 (t, J=7.07 Hz, 3H), 1.51 (ddd, J=4.29, 0.85, 14.14 Hz, 1H), 1.95 (ddd, J=4.29, 9.60, 13.89 Hz, 1H), 2.41-2.59 (m, 5H), 2.58 (t, J=6.57 Hz, 2H), 2.83 (d, J=6.57 Hz, 2H), 3.45 (ddd, J=2.53, 8.00, 12.0 Hz, 2H), 4.14 (ddd, J=2.53, 8.00, 14.01 Hz, 2H), 4.21-4.31 (m, 1H), 5.64 (d, J=9.09 Hz, 1H), 6.60-6.67 (m, 1H), 7.24 (d, J=8.34 Hz, 2H), 7.34 (t, J=7.33 Hz, 1H), 7.43 (t, J=7.83 Hz, 2H), 7.53 (d, J=8.34 Hz, 2H), 7.58 (d, J=7.07 Hz, 2H). stirred overnight After stirring for 1 hour stirred for 5 hours washed with H2O and brine The organic layer is dried over Na2SO4 concentrated The residue is purified by silica gel column chromatography

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

Procedure: To a solution of (2R,4S)-5-biphenyl-4-yl-4-(3-carboxy-propionylamino)-2-methyl-pentanoic acid ethyl ester (prepared by using the procedure described in US005217996) (200 mg, 0.486 mmol) in DMF (3 mL) are added EDC-HCl (112 mg, 0.583 mmol) and HOAt (79 mg, 0.583 mmol) at room temperature. After stirring for 10 minutes, 3-aminopropionitrile (41 mg, 0.583 mmol) and triethylamine (0.081 mL, 0.583 mmol) is added and stirred overnight. Additional EDC-HCl (66 mg, 0.292 mmol), HOAt (40 mg, 0.292 mmol), aminopropionitrile (21 mg, 0.292 mmol), and triethylamine (0.081 mL, 0.583 mmol) are added. After stirring for 1 hour, the reaction mixture is heated to 50° C. and stirred for 5 hours. The reaction mixture is diluted with ethyl acetate and washed with H2O and brine. The organic layer is dried over Na2SO4 and concentrated. The residue is purified by silica gel column chromatography to give (2R,4S)-5-biphenyl-4-yl-4-[3-(2-cyano-ethylcarbamoyl)-propionylamino]-2-methyl pentanoic acid ethyl ester. HPLC Retention time 1.37 minutes (condition B); MS 464 (M+1); 1H NMR (400 MHz, CDCl3) δ ppm 1.17 (d, J=7.33 Hz, 3H), 1.25 (t, J=7.07 Hz, 3H), 1.51 (ddd, J=4.29, 0.85, 14.14 Hz, 1H), 1.95 (ddd, J=4.29, 9.60, 13.89 Hz, 1H), 2.41-2.59 (m, 5H), 2.58 (t, J=6.57 Hz, 2H), 2.83 (d, J=6.57 Hz, 2H), 3.45 (ddd, J=2.53, 8.00, 12.0 Hz, 2H), 4.14 (ddd, J=2.53, 8.00, 14.01 Hz, 2H), 4.21-4.31 (m, 1H), 5.64 (d, J=9.09 Hz, 1H), 6.60-6.67 (m, 1H), 7.24 (d, J=8.34 Hz, 2H), 7.34 (t, J=7.33 Hz, 1H), 7.43 (t, J=7.83 Hz, 2H), 7.53 (d, J=8.34 Hz, 2H), 7.58 (d, J=7.07 Hz, 2H). stirred overnight After stirring for 1 hour stirred for 5 hours washed with H2O and brine The organic layer is dried over Na2SO4 concentrated The residue is purified by silica gel column chromatography

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

Procedure: 4-Amino-3-nitropyridine was synthesized by a literature reference [Harris M. G. and Stewart R. Can. J. Chem. 55, 3800 (1977)]; by nitration of 4-aminopyridine with conc. sulfuric acid and fuming nitric acid. This aminonitropyridine was then converted to the aminopropionitrile derivative IV by the method described in Example 1.

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

Procedure: To a solution of (2R,4S)-5-biphenyl-4-yl-4-(3-carboxy-propionylamino)-2-methyl-pentanoic acid ethyl ester (prepared by using the procedure described in US005217996) (200 mg, 0.486 mmol) in DMF (3 mL) are added EDC-HCl (112 mg, 0.583 mmol) and HOAt (79 mg, 0.583 mmol) at room temperature. After stirring for 10 minutes, 3-aminopropionitrile (41 mg, 0.583 mmol) and triethylamine (0.081 mL, 0.583 mmol) is added and stirred overnight. Additional EDC-HCl (66 mg, 0.292 mmol), HOAt (40 mg, 0.292 mmol), aminopropionitrile (21 mg, 0.292 mmol), and triethylamine (0.081 mL, 0.583 mmol) are added. After stirring for 1 hour, the reaction mixture is heated to 50° C. and stirred for 5 hours. The reaction mixture is diluted with ethyl acetate and washed with H2O and brine. The organic layer is dried over Na2SO4 and concentrated. The residue is purified by silica gel column chromatography to give (2R,4S)-5-biphenyl-4-yl-4-[3-(2-cyano-ethylcarbamoyl)-propionylamino]-2-methyl pentanoic acid ethyl ester. HPLC Retention time 1.37 minutes (condition B); MS 464 (M+1); stirred overnight After stirring for 1 hour stirred for 5 hours washed with H2O and brine The organic layer is dried over Na2SO4 concentrated The residue is purified by silica gel column chromatography