(2S)-5-amino-2-[(2-methylpropan-2-yl)oxycarbonylamino]pentanoic acid

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

Procedure: A solution containing Boc-L-ornithine (2.3 g, 6.3 mmol) in NMP (5 mL) was treated with HATU (2.4 g, 6.3 mmol) followed by NMM (1.5 mL, 13.7 mmol) at ambient temperature. After 10 min, amine 48 (1.6 g, 5.3 mmol) in NMP (10 mL) was added in a dropwise fashion. After 16 h, the reaction mixture was diluted with diethyl ether and washed successively with NaHCO3, 1 M HCl, water, and brine. The organic extract was dried over anhydrous Na2SO4, filtered and concentrated to afford 3.0 g (87%) of 53 as an orange-colored oil which was used without further purification. 1H NMR (CDCl3, 300 MHz) δ7.78-7.75 (m, 1H), 7.40-7.20 (m, 8H), 5.48 (d, J=8.4 Hz, 1H), 5.10 (s, 2H), 4.48-4.42 (m, 1H), 4.17-4.09 (m, 2H), 3.64-3.56 (m, 1H), 3.27-3.19 (m, 1H), 3.12 (app t, J=7.8 Hz, 1H), 2.81-2.74 (m, 2H), 2.52-2.35 (m, 1H), 2.09-1.95 (m, 2H), 1.83-1.63 (m, 4H), 1.45 (s, 9H), 1.29-1.19 (m, 6H) ppm. After 16 h washed successively with NaHCO3, 1 M HCl, water, and brine The organic extract was dried over anhydrous Na2SO4 filtered concentrated

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

Procedure: A solution containing Boc-L-ornithine (2.3 g, 6.3 mmol) in NMP (5 mL) was treated with HATU (2.4 g, 6.3 mmol) followed by NMM (1.5 mL, 13.7 mmol) at ambient temperature. After 10 min, amine 48 (1.6 g, 5.3 mmol) in NMP (10 mL) was added in a dropwise fashion. After 16 h, the reaction mixture was diluted with diethyl ether and washed successively with NaHCO3, 1 M HCl, water, and brine. The organic extract was dried over anhydrous Na2SO4, filtered and concentrated to afford 3.0 g (87%) of 53 as an orange-colored oil which was used without further purification. 1H NMR (CDCl3, 300 MHz) δ7.78-7.75 (m, 1H), 7.40-7.20 (m, 8H), 5.48 (d, J=8.4 Hz, 1H), 5.10 (s, 2H), 4.48-4.42 (m, 1H), 4.17-4.09 (m, 2H), 3.64-3.56 (m, 1H), 3.27-3.19 (m, 1H), 3.12 (app t, J=7.8 Hz, 1H), 2.81-2.74 (m, 2H), 2.52-2.35 (m, 1H), 2.09-1.95 (m, 2H), 1.83-1.63 (m, 4H), 1.45 (s, 9H), 1.29-1.19 (m, 6H) ppm. After 16 h washed successively with NaHCO3, 1 M HCl, water, and brine The organic extract was dried over anhydrous Na2SO4 filtered concentrated

Conditions: temp:75.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 6.00 g (12.33 mmol) of the compound from example 1A was dissolved in 120 ml dichloromethane. 2.57 g (12.33 mmol) N2-(tert-Butoxycarbonyl)-L-ornithine was added. The reaction mixture was split into 6 portions. The portions were heated for 90 min in a sealed tube at 75° C. in a microwave synthesizer. The combined reaction mixture was extracted with approx. 100 ml saturated ammonium chloride solution. The aqueous phase was twice back extracted with approx. 30 ml dichloromethane each. The combined organic phases were extracted with approx. 50 ml brine and dried over sodium sulfate. The solvent was removed under reduced pressure. The raw product was dissolved in dichloromethane and chromatographed over approx. 600 ml silica gel. Solvents used were dichloromethane, dichloromethane/methanol 40/1 to dichloromethane/methanol 1/1. The product-containing fractions were combined and concentrated to dryness under reduced pressure. This gave 2.63 g (4.06 mmol, 33% of theory, 89% purity) of the desired product. The reaction mixture was split into 6 portions The combined reaction mixture was extracted with approx. 100 ml saturated ammonium chloride solution The aqueous phase was twice back extracted with approx. 30 ml dichloromethane each The combined organic phases were extracted with approx. 50 ml brine dried over sodium sulfate The solvent was removed under reduced pressure The raw product was dissolved in dichloromethane chromatographed over approx. 600 ml silica gel concentrated to dryness under reduced pressure

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

Procedure: Boc-Orn-OH (0.51 g) [obtained by catalytically reducing Boc-Orn(Z)-OH in methanol in a stream of hydrogen using 10% Pd-carbon as a catalyst] was dissolved in DMF, and the solution was cooled with ice. TEA (0.61 ml) and PhCOONB [prepared from PhCOOH (0.30 g), HONB (0.47 g) and DCC (0.54 g)] were added thereto, followed by stirring overnight. The reaction solution was concentrated, and the residue was dissolved in AcOEt. The resulting solution was washed with 10% aqueous citric acid. After washing with water, the solution was dried with Na2SO4 and concentrated. Then, ether and dicyclohexylamine (438 μl) were added to the residue to separate out a precipitate, which was collected by filtration.

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

Procedure: Boc-Orn-OH (0.51 g) [obtained by catalytically reducing Boc-Orn(Z)-OH in methanol in a stream of hydrogen using 10% Pd-carbon as a catalyst] was dissolved in DMF, and the solution was cooled with ice. TEA (0.61 ml) and PhCOONB [prepared from PhCOOH (0.30 g), HONB (0.47 g) and DCC (0.54 g)] were added thereto, followed by stirring overnight. The reaction solution was concentrated, and the residue was dissolved in AcOEt. The resulting solution was washed with 10% aqueous citric acid. After washing with water, the solution was dried with Na2SO4 and concentrated. Then, ether and dicyclohexylamine (438 μl) were added to the residue to separate out a precipitate, which was collected by filtration.

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

Procedure: A solution of 928 mg (4 mmoles) of Nα -Boc-L-ornithine and 968 mg (8 mmoles) of 2-fluorobenzonitrile in 4 mL of ethanol and 4 mL of 1N NaOH were heated at reflux for 24 hours. Another 8 mmoles each of 1N NaOH and 2-fluorobenzonitrile were then added and reflux was continued for another 24 hours. The clear solution was cooled to room temperature, and the white paste dumped into 125 mL of CH2Cl2 and extracted with 100 mL of water made basic (pH 12) with NaOH. The aqueous extract was acidified with 5N HCl, and extracted with 125 mL of CH2Cl2. The organic phase was washed with 1M HCl, dried (Na2SO4) and concentrated in vacuo to give an oil. The oil was purified by flash chromatography on silica gel, eluting with 2:1 ethyl acetate:ethanol containing 1% triethylamine. The sole fluorescent product was an oil, 132 mg (10%), with rf of 0.49 in the elution solvent. 125 mg of the oil was dissolved in 22 mL of 5:1:1 acetic acid/water/12M HCl, and stirred for 3 hours at room temperature. The sample was concentrated in vacuo, then ethanol was added and the sample again concentrated in vacuo to give a waxy solid. This was recrystallized from water to give 22.5 mg of white needles. The mother liquor yielded 67 mg of white foam on concentration. Yield (100%).: mp >265°; MS (FAB) m/e calc'd for C12H10N3O2 : 234.1243, found 234.1231; M/Z 223 (M+), 224 (M+H)+. 1H NMR (300 MHz, D2O) δ: 1.74 (m, 2H), 1.96 (m, 2H), 3.33 (t, J=6.0 Hz, 2H), 3.79 (t, J=5.8 Hz, 1H), 6.71 (t, J=7 Hz, 1H), 6.92 (d, J=9 Hz, 1H), 7.55 (m, 1H). at reflux for 24 hours reflux extracted with 100 mL of water The aqueous extract extracted with 125 mL of CH2Cl2 The organic phase was washed with 1M HCl dried (Na2SO4) concentrated in vacuo to give an oil The oil was purified by flash chromatography on silica gel eluting with 2:1 ethyl acetate 125 mg of the oil was dissolved in 22 mL of 5:1:1 acetic acid/water/12M HCl The sample was concentrated in vacuo ethanol was added the sample again concentrated in vacuo to give a waxy solid This was recrystallized from water

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

Procedure: A solution of 928 mg (4 mmoles) of Nα -Boc-L-ornithine and 968 mg (8 mmoles) of 2-fluorobenzonitrile in 4 mL of ethanol and 4 mL of 1N NaOH were heated at reflux for 24 hours. Another 8 mmoles each of 1N NaOH and 2-fluorobenzonitrile were then added and reflux was continued for another 24 hours. The clear solution was cooled to room temperature, and the white paste dumped into 125 mL of CH2Cl2 and extracted with 100 mL of water made basic (pH 12) with NaOH. The aqueous extract was acidified with 5N HCl, and extracted with 125 mL of CH2Cl2. The organic phase was washed with 1M HCl, dried (Na2SO4) and concentrated in vacuo to give an oil. The oil was purified by flash chromatography on silica gel, eluting with 2:1 ethyl acetate:ethanol containing 1% triethylamine. The sole fluorescent product was an oil, 132 mg (10%), with rf of 0.49 in the elution solvent. 125 mg of the oil was dissolved in 22 mL of 5:1:1 acetic acid/water/12M HCl, and stirred for 3 hours at room temperature. The sample was concentrated in vacuo, then ethanol was added and the sample again concentrated in vacuo to give a waxy solid. This was recrystallized from water to give 22.5 mg of white needles. The mother liquor yielded 67 mg of white foam on concentration. Yield (100%).: mp >265°; MS (FAB) m/e calc'd for C12H10N3O2 : 234.1243, found 234.1231; M/Z 223 (M+), 224 (M+H)+. 1H NMR (300 MHz, D2O) δ: 1.74 (m, 2H), 1.96 (m, 2H), 3.33 (t, J=6.0 Hz, 2H), 3.79 (t, J=5.8 Hz, 1H), 6.71 (t, J=7 Hz, 1H), 6.92 (d, J=9 Hz, 1H), 7.55 (m, 1H). at reflux for 24 hours reflux extracted with 100 mL of water The aqueous extract extracted with 125 mL of CH2Cl2 The organic phase was washed with 1M HCl dried (Na2SO4) concentrated in vacuo to give an oil The oil was purified by flash chromatography on silica gel eluting with 2:1 ethyl acetate 125 mg of the oil was dissolved in 22 mL of 5:1:1 acetic acid/water/12M HCl The sample was concentrated in vacuo ethanol was added the sample again concentrated in vacuo to give a waxy solid This was recrystallized from water

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

Procedure: A solution of 928 mg (4 mmoles) of Nα -Boc-L-ornithine and 968 mg (8 mmoles) of 2-fluorobenzonitrile in 4 mL of ethanol and 4 mL of 1N NaOH were heated at reflux for 24 hours. Another 8 mmoles each of 1N NaOH and 2-fluorobenzonitrile were then added and reflux was continued for another 24 hours. The clear solution was cooled to room temperature, and the white paste dumped into 125 mL of CH2Cl2 and extracted with 100 mL of water made basic (pH 12) with NaOH. The aqueous extract was acidified with 5N HCl, and extracted with 125 mL of CH2Cl2. The organic phase was washed with 1M HCl, dried (Na2SO4) and concentrated in vacuo to give an oil. The oil was purified by flash chromatography on silica gel, eluting with 2:1 ethyl acetate:ethanol containing 1% triethylamine. The sole fluorescent product was an oil, 132 mg (10%), with rf of 0.49 in the elution solvent. 125 mg of the oil was dissolved in 22 mL of 5:1:1 acetic acid/water/12M HCl, and stirred for 3 hours at room temperature. The sample was concentrated in vacuo, then ethanol was added and the sample again concentrated in vacuo to give a waxy solid. This was recrystallized from water to give 22.5 mg of white needles. The mother liquor yielded 67 mg of white foam on concentration. Yield (100%).: mp >265°; MS (FAB) m/e calc'd for C12H10N3O2 : 234.1243, found 234.1231; M/Z 223 (M+), 224 (M+H)+. 1H NMR (300 MHz, D2O) δ: 1.74 (m, 2H), 1.96 (m, 2H), 3.33 (t, J=6.0 Hz, 2H), 3.79 (t, J=5.8 Hz, 1H), 6.71 (t, J=7 Hz, 1H), 6.92 (d, J=9 Hz, 1H), 7.55 (m, 1H). at reflux for 24 hours reflux extracted with 100 mL of water The aqueous extract extracted with 125 mL of CH2Cl2 The organic phase was washed with 1M HCl dried (Na2SO4) concentrated in vacuo to give an oil The oil was purified by flash chromatography on silica gel eluting with 2:1 ethyl acetate 125 mg of the oil was dissolved in 22 mL of 5:1:1 acetic acid/water/12M HCl The sample was concentrated in vacuo ethanol was added the sample again concentrated in vacuo to give a waxy solid This was recrystallized from water

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

Procedure: A solution of 696 mg (3.0 mmol) of Nα -BOC-L-ornithine and 513 mg (3 mmol) of 5-methoxy-2-nitrofluorobenzene in 3 mL of 1N NaOH and 3 mL of ethanol were heated at reflux for 20 hours, then concentrated in vacuo to a yellow oil. The oil was dissolved in 21 mL of 4N HCl in 33% acetic acid and stirred for 12 hours, then suspended in 50 mL of water and washed with 30 mL of dichloromethane and concentrated in vacuo to give a yellow powder. This was recrystallized twice from acetic acid/water to afford the title product as yellow crystals. mp 245°-246°; MS M/Z (DCl/NH3) 284 [M+H]; 1H NMR (300 MHz, D2O/NaOD) δ: 8:1.45 (m, 4H), 2.81 (m, 2H), 3.10 (d, J=1 Hz, 4.2H), 3.52 (d, J=3 Hz, 5.7H), 5.52 (d, J=1 Hz, 3.0H), 5.69 (m, 1H), 7.33 (dd, J=1, 8.4 Hz, 5.7H); 13C NMR (75.5 MHz, D2O/NaOD) δ: 185.47, 168.65, 150.74, 131.00, 127.20, 108.64, 96.78, 58.48, 45.27, 35.37, 27.37; Analysis calc'd for C12H17N3O5.0.2 H2O: C, 50.24; H, 6.11; N, 14.65; found: C, 50.09; H, 6.03; N, 14.60. at reflux for 20 hours concentrated in vacuo to a yellow oil The oil was dissolved in 21 mL of 4N HCl in 33% acetic acid washed with 30 mL of dichloromethane concentrated in vacuo to give a yellow powder This was recrystallized twice from acetic acid/water

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

Procedure: A solution of 696 mg (3.0 mmol) of Nα -BOC-L-ornithine and 513 mg (3 mmol) of 5-methoxy-2-nitrofluorobenzene in 3 mL of 1N NaOH and 3 mL of ethanol were heated at reflux for 20 hours, then concentrated in vacuo to a yellow oil. The oil was dissolved in 21 mL of 4N HCl in 33% acetic acid and stirred for 12 hours, then suspended in 50 mL of water and washed with 30 mL of dichloromethane and concentrated in vacuo to give a yellow powder. This was recrystallized twice from acetic acid/water to afford the title product as yellow crystals. mp 245°-246°; MS M/Z (DCl/NH3) 284 [M+H]; 1H NMR (300 MHz, D2O/NaOD) δ: 8:1.45 (m, 4H), 2.81 (m, 2H), 3.10 (d, J=1 Hz, 4.2H), 3.52 (d, J=3 Hz, 5.7H), 5.52 (d, J=1 Hz, 3.0H), 5.69 (m, 1H), 7.33 (dd, J=1, 8.4 Hz, 5.7H); 13C NMR (75.5 MHz, D2O/NaOD) δ: 185.47, 168.65, 150.74, 131.00, 127.20, 108.64, 96.78, 58.48, 45.27, 35.37, 27.37; Analysis calc'd for C12H17N3O5.0.2 H2O: C, 50.24; H, 6.11; N, 14.65; found: C, 50.09; H, 6.03; N, 14.60. at reflux for 20 hours concentrated in vacuo to a yellow oil The oil was dissolved in 21 mL of 4N HCl in 33% acetic acid washed with 30 mL of dichloromethane concentrated in vacuo to give a yellow powder This was recrystallized twice from acetic acid/water

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

Procedure: A solution of 696 mg (3.0 mmol) of Nα -BOC-L-ornithine and 513 mg (3 mmol) of 5-methoxy-2-nitrofluorobenzene in 3 mL of 1N NaOH and 3 mL of ethanol were heated at reflux for 20 hours, then concentrated in vacuo to a yellow oil. The oil was dissolved in 21 mL of 4N HCl in 33% acetic acid and stirred for 12 hours, then suspended in 50 mL of water and washed with 30 mL of dichloromethane and concentrated in vacuo to give a yellow powder. This was recrystallized twice from acetic acid/water to afford the title product as yellow crystals. mp 245°-246°; MS M/Z (DCl/NH3) 284 [M+H]; 1H NMR (300 MHz, D2O/NaOD) δ: 8:1.45 (m, 4H), 2.81 (m, 2H), 3.10 (d, J=1 Hz, 4.2H), 3.52 (d, J=3 Hz, 5.7H), 5.52 (d, J=1 Hz, 3.0H), 5.69 (m, 1H), 7.33 (dd, J=1, 8.4 Hz, 5.7H); 13C NMR (75.5 MHz, D2O/NaOD) δ: 185.47, 168.65, 150.74, 131.00, 127.20, 108.64, 96.78, 58.48, 45.27, 35.37, 27.37; Analysis calc'd for C12H17N3O5.0.2 H2O: C, 50.24; H, 6.11; N, 14.65; found: C, 50.09; H, 6.03; N, 14.60. at reflux for 20 hours concentrated in vacuo to a yellow oil The oil was dissolved in 21 mL of 4N HCl in 33% acetic acid washed with 30 mL of dichloromethane concentrated in vacuo to give a yellow powder This was recrystallized twice from acetic acid/water

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

Procedure: A mixture of 474 mg (2 mmol) of Noc-BOC-L-ornithine (supplier BAChem) and 314 mg (2 mmol) of 3-fluoro-4-nitrotoluene (Aldrich Chemical Co.)in 2 mL of ethanol and 2 mL of 1N NaOH was heated at reflux for 12 hours. Another 2 mmol each of NaOH and 3-fluoro-4-nitrotoluene was added and the reaction was continued another two hours. The solution was poured into 50 mL of water and extracted with dichloromethane (2×80 mL). The organic phase was dried and concentrated to give a solid residue, which was stirred in 20 mL of 4N HCl in 33% acetic acid for four hours, filtered and concentrated to leave a yellow solid, which was recrystallized from ethanol/water to afford 296 mg (56% yield) of the title product as an amorphous orange powder. mp 263°-264° (decomp.); MS M/Z 268 [M+H], 285 [M+NH4 ]; 1H NMR (300 MHz, D2O/NaOD) δ: 1.64 (m, 4H)2.18 (s, 3H), 3.12 (m, 2H), 3.30 (t, J=4.5 Hz, 1H), 6.22 (d, J=8.1 Hz, 1H), 6.43 (s, 1H), 7.58 (d, J=8.1 Hz, 1H); 13C NMR (75.5 MHz, D2O/NaOD) δ: 185.88, 158.28, 148.71, 130.81,128.71,120.22, 116.11, 58.73, 45.24, 35.40, 27.73, 24.24; Analysis calc'd for C12H17N3O4.0.4 HCl: C, 50.81; H, 6.25; N, 14.81; found: C, 50.79; H, 6.27; N, 14.73. was heated at reflux for 12 hours extracted with dichloromethane (2×80 mL) The organic phase was dried concentrated to give a solid residue, which filtered concentrated to leave a yellow solid, which was recrystallized from ethanol/water