Inhibitors of Tripeptidyl Peptidase II
J ournal of Medicinal Chemistry, 2000, Vol. 43, No. 4 673
ether/petroleum: yield 0.19 g, 28.8%; mp 201-202 °C; 1H NMR
(DMSO-d6) δ 9.00 (1H, d, NH), 8.18 (2H, bs, NH2), 7.28 (5H,
bs, Ar CH), 4.53 (1H, d, NCHCO), 3.65 (1H, d, NCHCO), 3.52
(3H, s, OCH3), 3.04 (2H, d, CH2), 2.13 (1H, m, (CH3)2CH), 0.93
(6H, d, (CH3)2CH); MS m/z 278 [M]+; HPLC purity (Lichrosorb
rp select B; water + 0.1% TFA/acetonitrile + 0.1% TFA
80:20) 97.7%. Anal. (C15H22N2O3‚HCl‚0.25H2O) C, H, N.
N-Ben zyloxyca r bon yl-L-va lyl-L-p h en yla la n in e n -Bu tyl
Ester . N-Benzyloxycarbonyl-L-valyl-L-phenylalanine (0.5 g,
1.25 mmol) was suspended in n-butanol (8 mL, dried, distilled)
and cooled in ice. Thionyl chloride (2.03 g, 17 mmol) was added
and the mixture allowed to warm to room temperature. It was
then heated to 40 °C with stirring. The solvent was removed
and the residue twice dissolved in ethanol which was removed
in vacuum. The residue was then triturated with hexane and
a solid isolated: yield 79.4%. It was purified by preparative
HPLC (Lichrosorb rp select B; methanol + 0.1% TFA/water +
0.1% TFA 80:20): 1H NMR (200 MHz CDCl3) δ 7.30-7.44 (1H,
d, NH), 7.36 (5H, s, Ar CH), 7.16 (5H, s, Ar CH), 5.00 (2H, s,
PhCH2O), 4.50-4.58 (1H, m, NCHCO), 3.82-3.98 (2H, m,
COOCH2), 2.90-3.00 (2H, m, PhCH2CH), 1.82-1.92 (1H, m,
(CH3)2CH ), 1.36-1.48 (2H, m, COOCH2CH 2), 1.08-1.27
(2H, m, CH3CH2), 0.74-0.88 (9H, m, 3 × CH3); MS m/z 455
[M + H]+. Anal. (C26H34N2O5‚0.05CF3COOH) C, H, N.
L-Valyl-L-ph en ylalan in e n -Bu tyl Ester Tr iflu or oacetate
(49). Prepared by method E from N-benzyloxycarbonyl-L-valyl-
L-phenylalanine n-butyl ester. Crystallized from ether/hexane
and purified by preparative HPLC (Lichrosorb rp select B;
methanol + 0.1% TFA/water + 0.1% TFA 50:50): yield 77%;
mp 150.5-151.5 °C; 1H NMR (400 MHz DMSO-d6) δ 8.81-
8.83 (1H, d, NH), 7.21-7.31 (5H, m, Ph CH), 4.53-4.55 (1H,
m, NCHCO) 3.97-4.0 (2H, m, COOCH2), 3.56-3.58 (1H, m,
NCHCO), 2.94-3.06 (2H, m, PhCH2), 2.08-2.10 (1H, m,
(CH3)2CH ), 1.41-1.46 (2H, m, COOCH2CH 2), 1.18-1.26
(2H, m, CH3CH2), 0.8-0.94 (9H, m, 3 × CH3); MS m/z 321
[M + H]+; HPLC purity (Lichrosorb rp select B; methanol +
0.1% TFA/water + 0.1% TFA 50:50) 97.3%. Anal. (C18H28N2O4‚
1.25CF3COOH‚0.5H2O) C, H, N.
ester and L-proline. Purified by crystallization from ethyl
acetate/petrol 1:4: yield 45%; 1H NMR (200 MHz CDCl3) δ 5.30
(1H, d, NH), 4.57 (1H, dd, NCHCO of val), 4.26 (1H, t, NCHCO
of pro), 2.19 (1H, q, (CH3)2CH), 2.03 (4H, m, NCH2CH2CH2),
1.39 (9H, s, t-butyl), 0.97 (3H, d, CH3), 0.92 (3H, d, CH3); MS
m/z 314 [M]+.
N-ter t-Bu toxyca r bon yl-L-va lyl-L-p r olin e n -Bu tyla m id e.
Prepared by method B from N-tert-butoxycarbonyl-L-valine
succinimide and L-proline butylamide. Purified by chromatog-
raphy over silica gel using ethyl acetate/petrol 1:1 as eluant:
yield 41%; 1H NMR (200 MHz, CDCl3) δ 6.9 (1H, bs, NH), 5.2
(1H, d, NH), 4.5 (1H, dd, NCHCO), 4.25 (1H, dd, NCHCO),
3.6 (2H, m, NCH2), 3.2 (2H, q, NCH2), 1.1 (5H, (CH3)2CH, 2 ×
CH2), 1.4 (9H, 2, t-Bu), 1.3 (4H, m, 2 × CH2), 0.9 (6H, dd,
(CH3)2CH), 0.8 (3H, t, CH3).
L-Va lyl-L-p r olin e n -Bu tyla m id e Oxa la te (64). Prepared
by method G from N-tert-butoxycarbonyl-L-valyl-L-proline n-
butylamide. Purified by preparative HPLC and converted to
its oxalate salt. Purified again by crystallization from methanol/
ethyl acetate/ether 1:1:3: yield 42%; mp 165-166 °C; 1H NMR
(200 MHz DMSO-d6) δ 7.9 (t, 1H, NH), 7.3 (2H, bs, NH2), 4.25
(1H, t, NCHCO), 3.95 (1H, d, NCHCO), 3.45-3.65 (2H, m,
NCH2 of pro), 3.0 (2H, m, NCH2 of butyl), 1.5-2.2 (5H,
(CH3)2CH, 2 × CH2), 1.3 (4H, m, 2 × CH2), 0.9 (6H, dd, (CH3)2-
CH), 0.8 (t, 3H, CH3); MS m/z 269 [M]+; HPLC purity
(Lichrosorb rp select B; methanol/water/trifluoroacetic acid 30:
70:0.1) 100%; (Kromasil C18; water + 0.1% TFA/methanol +
0.1% TFA 60:40) 95.9%. Anal. (C14H27N3O2‚1.25(COOH)2) C,
H, N.
L-Va lyl-D-p r olin e Bu tyla m id e Oxa la te (65). Prepared
from N-tert-butoxycarbonyl-L-valine succinimide ester and
D-proline by method B then method J then method G. The
product was isolated as the oxalate salt and crystallized from
ethanol/diethyl ether: mp 104 °C; 1H NMR (200 MHz DMSO-
d6) δ 8.0 (1H, t, NH), 4.3 (1H, d, CH), 3.9 (1H, d, CH), 3.75
(1H, m, CH(H)), 3.5 (1H, m, C(H)H), 3.0 (2H, m, CH2), 2.0 (5H,
m, 2 × CH2, CH), 1.3 (4H, m, 2 × CH2), 0.9 (6H, dd, 2 × CH3),
0.85 (3H, t, CH3); MS m/z 269 [M]+; HPLC purity (Kromasil
C18; water + 0.1% TFA/methanol + 0.1% TFA 60:40) 96%.
Anal. (C14H27N3O2‚1.25(COOH)2) C, H, N.
N-Ben zyloxyca r bon yl-L-glycyl-L-glycin e. Prepared by
method B from N-benzyloxycarbonyl-L-glycine succinimide
ester and glycine: yield 50%.
N-Ben zyloxyca r bon yl-L-glycyl-L-glycin e Su ccin im id e
Ester . Prepared by the method of Anderson.37 Crystallized
from ethanol: yield 100%; 1H NMR (200 MHz CDCl3) δ 8.5
(1H, bs, NH), 7.5 (1H, bs, NH), 7.3 (5H, m, Ar CH), 5.5 (1H, d,
NH), 5.0 (2H, s, PhCH2), 4.2 (2H, d, CH2), 3.6 (2H, d, CH2),
2.8 (4H, s, 2 × CH2).
Ack n ow led gm en t. We thank Upjohn Pharmacia,
Kalamazoo, MI, for financial support.
Su p p or tin g In for m a tion Ava ila ble: Three further tables
of biochemical results, one synthetic scheme, and preparative
details of 47 additional compounds. This material is available
N-Ben zyloxyca r b on yl-L-glycyl-L-glycyl-L-p h en yla la -
n in e. N-Benzyloxycarbonyl-L-glycyl-L-glycine succinimide
ester (3.0 g, 8.26 mmol) was dissolved in a mixture of tetra-
hydrofuran (30 mL) and dimethylformamide (20 mL). It was
treated with phenylalanine (1.36 g, 8.2 mmol) in water (20
mL) containing triethylamine (1 mL). The mixture was stirred
at room temperature for 16 h, made acid to pH 1 (concentrated
HCl) and extracted with ethyl acetate (3 × 50 mL). The
combined extracts were dried (Na2SO4) and concentrated to
give an oil which was purified by chromatography over silica
gel using ethyl acetate/methanol/acetic acid 8:2:0.5 as eluant:
Refer en ces
(1) Crawley, J . N.; Corwin, R. L. Biological Actions of Cholecysto-
kinin. Peptides 1994, 4, 731-755.
(2) Dockray, G. J . Immunochemical Evidence of Cholecystokinin-
like Peptides in Brain. Nature 1976, 264, 568-570.
(3) Anagnostides, A. A.; Chadwick, V. S.; Selden, A. C.; Barr, J .;
Maton, P. N. Human Pancreatic and Biliary Responses to
Physiological Concentrations of Cholecystokinin Octapeptide.
Clin. Sci. 1985, 69, 259-263.
(4) (a) Moran, T. H., McHugh, P. R. Cholecystokinin Suppresses
Food Intake by Inhibiting Gastric Emptying. Am. J . Physiol.
1982, 242, R491-R497. (b) Grider, J . Role of Cholecystokinin
in the Regulation of Gastrointestinal Motility. J . Nutr. 1994,
124, 1334S-1339S. (c) Beglinger, C. Effect of Cholecystokinin
on Gastric Motility in Humans. Ann. N. Y. Acad. Sci. 1994, 713,
219-225.
1
yield 2.0 g (58%); H NMR (200 MHz DMSO-d6) δ 8.1 (1H, d,
NH), 8.0 (1H, d, NH), 7.4 (5H, m, Ar CH), 5.0 (2H, s, PhCH2),
4.4 (1H, m, NCHCO), 3.7 (2H, d, CH2), 3.6 (2H, d, CH2), 2.95
(2H, d, CH2).
L-Glycyl-L-glycyl-L-p h en yla la n in e (57). Prepared by
method F from N-benzyloxycarbonyl-L-glycyl-L-glycyl-L-phenyl-
alanine. The residue was washed with hot methanol and then
crystallized from methanol/water: yield 16%; mp 228-229 °C
(lit.42 mp 228-230 °C); 1H NMR (200 MHz DMSO-d6) δ 8.5
(1H, d, NH), 7.9 (1H, d, NH), 7.2 (5H, m, Ar CH), 4.2 (1H, dd,
NCHCO), 3.6 (2H, dd, CH2), 3.25 (2H, s, CH2), 3.0 (1H, dd,
CH(H)), 2.8 (1H, dd, CH(H)); MS m/z 280 [M + H]+; HPLC
purity (Lichrosorb rp select B; methanol + 0.1% TFA/water +
0.1% TFA 20:80) 99.6%. Anal. (C13H17N3O4) C, H, N.
(5) Dourish, C. T.; Ruckert, A. C.; Tattersall, R. D.; Iverson, S. D.
Evidence that Decreased Feeding Induced by Systemic Injection
of Cholecystokinin is Mediated by CCK-A Receptors. Eur. J .
Pharmacol. 1989, 173, 233-234.
(6) (a) Smith, G. P.; J erome, C.; Norgren, R. Afferent Axons in
Abdominal Vagus Mediate Satiety Effect of Cholecystokinin in
Rats. Am. J . Physiol. 1985, 249, R638-R641. (b) South, E. H.;
Ritter, R. C. Capsaicin Application to Central or Peripheral
Vagal Fibers Attenuates CCK Satiety. Peptides 1988, 9, 601-
612. (c) Schwartz, G. J .; McHugh, P. R.; Moran, T. H. Gastric
Loads and Cholecystokinin Synergistically Stimulate Rat Vagal
Afferents. Am. J . Physiol. 1993, 265, R872-R876. (d) Smith, G.
P.; Gibbs, J . Satiating Effect of Cholecystokinin. Ann. N. Y. Acad.
Sci. 1994, 713, 236-241.
N-ter t-Bu toxyca r bon yl-L-va lyl-L-p r olin e. Prepared by
method D from N-tert-butoxycarbonyl-L-valine succinimide