S. B. Tsogoeva, S. B. Jagtap, Z. A. Ardemasova, V. N. Kalikhevich
FULL PAPER
[D6]DMSO): δ ϭ 9.03 (s, 1 H), 8.0 (d, 1 H, NH), 7.75Ϫ7.08 (m, Tripeptide
6 was prepared from HϪProϪArgϪOH (2.6 g,
11 H, 4 NH, NH2 and 5 ArϪH), 3.89 (m, 1 H), 3.38 (m, 1 H), 9.6 mmol), by the same procedure as described for 3, to give 6
1
3.09Ϫ2.98 (m, 3 H), 2.62 (m, 1 H), 1.67Ϫ1.38 (m, 4 H) ppm. ESI-
MS (positive ion): m/z ϭ 322.3 [M ϩ H]ϩ. ESI-MS (negative ion): NMR (600 MHz, D2O): δ ϭ 4.52 (m, 2 H), 4.17 (dd, J ϭ 5.2,
m/z ϭ 320.5 [M Ϫ H]Ϫ. HRMS (ESI): calcd. for C15H24N5O3 [M
8.1 Hz, 1 H), 3.75Ϫ3.72 (m, 1 H), 3.67Ϫ3.63 (m, 1 H), 3.23Ϫ3.19
ϩ H]ϩ 322.18737; found 322.18751. The residue (1.85 g, 5.8 mmol) (m, 2 H), 2.86 (dd, J ϭ 3.5, 17.4 Hz, 1 H), 2.61 (dd, J ϭ 10.4,
was taken up in DMF (5 mL) and treated with 17.4 Hz, 1 H), 2.34Ϫ2.29 (m, 1 H), 2.10Ϫ1.97 (m, 3 H), 1.88Ϫ1.83
ZϪAsp(OBzl)ϪOPfp (3.71 g, 7.08 mmol). After 15 h at ambient (m, 1 H), 1.76Ϫ1.70 (m, 1 H), 1.65Ϫ1.60 (m, 2 H) ppm. 13C NMR
(1.72 g) as a white solid. [α]2D0 ϭ Ϫ58.8 (c ϭ 0.165, 1 HCl). H
temperature, the reaction mixture was diluted with Et2O (100 mL).
The solvent was decanted and the residue was purified by silica
gel chromatography (mobile phase: 5Ϫ20% MeOH/CHCl3; TLC:
(75.4 MHz, D2O): δ ϭ 178.2 (CO2H), 175.8 (CO2H), 172.9 (CϭO),
168.1 (CϭO), 156.8 (CϭNH), 60.9 (CH), 54.8 (CH), 50.1 (CH),
47.9 (CH2), 40.7 (CH2), 35.7 (CH2), 29.3 (CH2), 28.9 (CH2), 24.7
nBuOH/AcOH/H2O, 3:1:1) to afford Z؊Asp(OBzl)؊Phe؊ (CH2), 24.5 (CH2) ppm. ESI-MS (positive ion): m/z ϭ 387.2 [M ϩ
Arg؊OH (2.3 g, 61%) as a colourless oil, which was dissolved in
MeOH (45 mL). Palladium on charcoal (10% Pd/C) was added,
and then the mixture was saturated with hydrogen gas. The precipi-
tated product was dissolved by dropwise addition of 25% NH4OH
and water. The charcoal was separated from the reaction product
by filtration. The solvent was co-evaporated with 2-propanol, and
the product was isolated by precipitation from Et2O and HPLC
H]ϩ. ESI-MS (negative ion): m/z ϭ 385.3 [M Ϫ H]Ϫ. HRMS (ESI):
calcd. for C15H27N6O6 [[M ϩ H]ϩ] 387.19866; found 387.19883.
Dipeptide 9: A solution of 7 (1.8 g, 3.9 mmol) in ethyl acetate
(35 mL) was added to a stirred solution of amine 8 (1.19 g,
4.3 mmol) in ethyl acetate (20 mL). The reaction mixture was
stirred at room temperature for 12 h and then washed with H2SO4
(2 , 2 ϫ 30 mL), H2O, NaHCO3 (5%, 2 ϫ 30 mL), H2O and brine
and dried with Na2SO4. The solvent was removed under reduced
pressure to give an oily residue, which was precipitated from diethyl
ether (75 mL); filtration gave 9 as the white precipitate (2.3 g, 94%).
1H NMR (300 MHz, CD3OD): δ ϭ 7.35Ϫ7.23 (m, 10 H),
5.19Ϫ5.03 (m, 4 H, 2 ϫ PhCH2), 4.48Ϫ4.14 (m, 4 H), 3.83 and
3.64 (m, 2 H), 3.72 and 3.58 (s, 3 H, CH3O), 3.49Ϫ3.01 (m, 2 H),
2.28Ϫ2.09 (m, 4 H), 1.42 [s, 9 H, C(CH3)3] ppm. ESI-MS (positive
ion): m/z ϭ 647.3 [M ϩ Na]ϩ. C32H40N4O9 (624.68): calcd. C
61.53, H 6.45; found C 61.35, H 6.52.
chromatography to give 3 (1.5 g, 98%) as a white solid. [α]2D0
ϭ
ϩ12.5 (c ϭ 0.24, 1 HCl). 1H NMR (600 MHz, [D6]DMSO): δ ϭ
9.32 (br. s, 1 H), 8.68 (br. s, 1 H), 7.59 (d, 1 H), 7.22Ϫ7.15 (m, 5
H, Ar-H), 4.42 (br. s, 1 H), 3.89 (dd, J ϭ 7.0, 11.7 Hz, 1 H), 3.58
(t, J ϭ 6.4 Hz, 1 H), 3.12Ϫ3.00 (m, 4 H), 2.83 (dd, J ϭ 9.8, 13.9 Hz,
1 H), 2.34 (dd, J ϭ 6.7, 16.3 Hz, 1 H), 1.71Ϫ1.60 (m, 2 H),
1.46Ϫ1.44 (m, 2 H) ppm. 13C NMR (75.4 MHz, [D6]DMSO): δ ϭ
174.3 (CO2H), 173.9 (CO2H), 170.9 (CϭO), 169.6 (CϭO), 157.5
(CϭNH), 138.1 (Cquat.,arom), 129.1 (CH), 129.0 (CH), 128.1 (CH),
128.0 (CH), 126.1 (CH), 54.4 (CH), 53.3 (CH), 50.9 (CH), 40.4
(CH2), 36.5 (CH2), 29.1 (CH2), 26.1 (CH2), 24.5 (CH2) ppm. ESI-
MS (positive ion): m/z ϭ 437.4 [M ϩ H]ϩ, 459.4 [M ϩ Na]ϩ. ESI-
MS (negative ion): m/z ϭ 435.5 [M Ϫ H]Ϫ. HRMS (ESI): calcd.
for C19H29N6O6 [M ϩ H]ϩ 437.21431; found 437.21454.
Tripeptide 10: Trifluoroacetic acid (10 mL) was added at 0 °C to a
stirred solution of 9 (1 g, 1.6 mmol) in CH2Cl2 (20 mL). The stir-
ring was continued at room temperature for 2 h, followed by con-
centration in vacuo. The oily residue was precipitated with dry di-
ethyl ether (50 mL), filtered off and dried in vacuo. The crude prod-
uct (843 mg, 1.32 mmol) was dissolved in CH2Cl2 (20 mL). TEA
N-Benzyloxycarbonyl-L-prolyl-L-arginine (Z؊Pro؊Arg؊OH, 5):
This dipeptide was prepared from ZϪProϪOPfp (4, 8.93 g,
21.5 mmol) and HϪArgϪOH (3.15 g, 18.1 mmol) by the same pro- (0.187 mL, 1.32 mmol) and 7 (670 mg, 1.45 mmol) were then ad-
cedure as described above for 2, to give 5 (6.35 g, 87%) as a white ded, and the resultant mixture was stirred at room temperature
solid. 1H NMR (600 MHz, D2O): δ ϭ 7.44Ϫ7.31 (m, 5 H, ArϪH), overnight. The reaction mixture was then washed with H2SO4 (2
5.14Ϫ5.08 (m, 2 H), 4.38Ϫ4.29 (m, 1 H), 4.08Ϫ4.06 (m, 1 H), , 2 ϫ 30 mL), H2O, NaHCO3 (5%, 2 ϫ 30 mL), H2O and brine
3.56Ϫ3.49 (m, 2 H), 3.18Ϫ2.93 (m, 2 H), 2.33Ϫ2.28 (m, 1 H), and dried with Na2SO4. The solvent was removed under reduced
2.00Ϫ1.88 (m, 3 H), 1.70Ϫ1.32 (m, 4 H). 13C NMR (150.8 MHz, pressure to give 10 (1.084 g, 96%) as a white solid. 1H NMR
D2O): δ ϭ 177.9 (CO2H), 174.2 (CϭO), 156.4 (CϭO), 156.1 (Cϭ (600 MHz, CD3OD): δ ϭ 7.36Ϫ7.24 (m, 15 H), 5.15Ϫ4.89 (m, 6
NH), 136.14 (Cquat.,arom), 128.8 (CH), 128.7 (CH), 128.2 (CH), H, 3 ϫ PhCH2), 4.42Ϫ4.16 (m, 6 H), 3.83 and 3.64 (m, 3 H), 3.78
127.6 (CH), 127.2 (CH), 67.4 (CH2, OCH2Ph), 60.4 (CH), 54.6
and 3.58 (s, 3 H, CH3O), 3.48Ϫ3.05 (m, 3 H), 2.24Ϫ2.02 (m, 6 H),
(CH), 47.5 (CH2), 40.6 (CH2), 31.1 (CH2), 29.1 (CH2), 24.4 (CH2), 1.41 [s, 9 H, C(CH3)3] ppm. ESI-MS (positive ion): m/z ϭ 893.5
23.53 (CH2) ppm. ESI-MS (positive ion): m/z ϭ 406.4 [M ϩ H]ϩ, [M ϩ Na]ϩ, 1763.1 [2M ϩ Na]ϩ. HRMS (ESI): calcd. for
428.3 [M ϩ Na]ϩ. ESI-MS (negative ion): m/z ϭ 404.3 [M Ϫ H]Ϫ.
HRMS (ESI): calcd. for C19H28N5O5 [M ϩ H]ϩ 406.20850;
found 406.20819.
C45H54N6O12 [M ϩ H]ϩ 871.38725; found 871.38735.
Tripeptide 11: The above methyl ester 10 (2.12 g, 2.43 mmol) was
saponified by stirring at room temperature with aqueous methanol
(50%, 20 mL) containing lithium hydroxide monohydrate (112.2 g,
2.67 mmol). The product was isolated in the usual manner to give
L-Aspartyl-L-prolyl-L-arginine (H؊Asp؊Pro؊Arg؊OH, 6): The
same procedure as described for the preparation of 3 was applied,
with substitution of ZϪPheϪArgϪOH for ZϪProϪArgϪOH
(4.05 g, 10 mmol), to afford H؊Pro؊Arg؊OH (2.6 g, 96%) as a
white solid. 1H NMR (600 MHz, D2O): δ ϭ 4.18 (dd, J ϭ 7.9,
5.0 Hz, 1 H), 3.74 (dd, J ϭ 8.4, 5.7 Hz, 1 H), 3.19 (t, 2 H), 2.93 (t,
2 H), 2.17Ϫ2.12 (m, 1 H), 1.89Ϫ1.82 (m, 1 H), 1.78Ϫ1.72 (m, 4
H), 1.60Ϫ1.55 (m, 2 H) ppm. 13C NMR (150.8 MHz, D2O): δ ϭ
178.4 (CO2H), 176.2 (CϭO), 156.8 (CϭNH), 60.3 (CH), 54.4 (CH),
46.5 (CH2), 40.7 (CH2), 30.4 (CH2), 29.1 (CH2), 25.3 (CH2), 24.46
(CH2) ppm. ESI-MS (positive ion): m/z ϭ 272.3 [M ϩ H]ϩ, 294.3
1
11 (1.916 g, 92%) as a white solid. H NMR (600 MHz, CD3OD):
δ ϭ 7.36Ϫ7.24 (m, 15 H), 5.13Ϫ5.05 (m, 6 H, 3 ϫ PhCH2),
4.43Ϫ4.17 (m, 6 H), 3.83Ϫ3.75 (m, 3 H), 3.48Ϫ3.03 (m, 3 H),
2.30Ϫ2.09 (m, 6 H), 1.41 [s, 9 H, C(CH3)3] ppm. ESI-MS (positive
ion): m/z ϭ 879.6 [M ϩ Na]ϩ, 1735.3 [2M ϩ Na]ϩ. ESI-MS
(negative ion): m/z ϭ 855.5 [M Ϫ H]Ϫ, 1711.5 [2 M Ϫ H]Ϫ. HRMS
(ESI): calcd. for C44H52N6O12 [M ϩ H]ϩ 857.37160; found
857.37180.
[M ϩ Na]ϩ. ESI-MS (negative ion): m/z ϭ 270.4 [M Ϫ H]Ϫ. HRMS Tripeptide 12: Compound 11 (200 mg, 0.23 mmol) was hydrogen-
(ESI): calcd. for C11H22N5O3 [M
272.17171.
ϩ
H]ϩ 272.17172; found ated in the presence of 10% Pd/C in methanol (5 mL). The product
was isolated in the usual manner to give 12 (99.5 mg, 94%) as a
4018
2004 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Org. Chem. 2004, 4014Ϫ4019