5-Fluoro-2-methyl-N-[4-(5H-pyrrolo[2,1-c]-[1,4]benzodiazepin-10(11H)- ylcarbonyl)-3-chlorophenyl]benzamide (VPA-985): An orally active arginine vasopressin antagonist with selectivity for V2 receptors [2]

Full text of DOI:10.1021/jm980179c

2442
J . Med. Chem. 1998, 41, 2442-2444
5-F lu or o-2-m eth yl-N-[4-(5H-p yr r olo[2,1-c]-
[1,4]ben zod ia zep in -10(11H)-ylca r bon yl)-3-
ch lor op h en yl]ben za m id e (VP A-985): An
Or a lly Active Ar gin in e Va sop r essin
An ta gon ist w ith Selectivity for V2
Recep tor s
J . Donald Albright,*,† Marvin F. Reich,†
Efren G. Delos Santos,† J ohn P. Dusza,†
Fuk-Wah Sum,† Aranapakam M.Venkatesan,†
J oseph Coupet,‡ Peter S. Chan,‡ Xun Ru,‡
Hossein Mazandarani,‡ and Trina Bailey†
Wyeth-Ayerst Research, Pearl River, New York 10965, and
Wyeth-Ayerst Research, Princeton, New J ersey 08543-8000
Received March 23, 1998
Arginine vasopressin (AVP) is released from the
posterior pituitary, in response to either increased
plasma osmolality detected by brain osmoreceptors or
decreased blood volume and blood pressure sensed by
low-pressure volume receptors and arterial barorecep-
tors. The hormone exerts its actions through three well-
defined receptor subtypes: vascular V1a, hormone-
releasing V1b (V3), and renal V2 receptors.1-3
Both V1a and V2 receptors are found in the kidney.
The physiological effects of AVP on different collecting
ducts in the kidney as well as the physiology of fluid
transport in the kidney are under active investigation.4-7
The mechanism for the regulation of water and urea
transport in the renal collecting duct and the mecha-
nism for AVP regulation of water channels and urea
carriers has been reviewed.8 In brief, AVP regulates a
water-selective channel membrane protein aquaporin-2
(also labeled AQP2 or AQP-CD) to control osmotic water
permeability of water channels in the kidney.9-11
The blockade of V2 receptors may be useful in treating
diseases characterized by excess renal reabsorption of
free water. V2 antagonists may correct the fluid reten-
tion in congestive heart failure, liver cirrhosis, nephrotic
syndrome, central nervous system injuries, lung disease,
and hyponatremia. Thus, antagonizing AVP actions at
the receptor level with orally active, non-peptide agents
may be the treatment of choice for edematous states.
In 1991 the first non-peptide AVP antagonist 1 (OPC-
21268) with selectivity for rat V1a receptor (V2/V1a g 100)
was reported.12 Structure-activity relationships among
analogues have been published.13,14 The non-peptide 2
(OPC-31260) with selectivity for rat V2 receptors (V1a/
V2 ) 86) and oral activity as an aquaretic was disclosed
in 1992.15 Clinical studies have demonstrated oral
efficacy for the hydrochloride as an aquaretic in hu-
mans.16,17 The synthesis and structure-activity rela-
tionships of 1-[4-(benzoylamino)benzoyl]-2,3,4,5-tetrahy-
dro-1H-benzazepines and 1-[4-(benzoylamino)benzoyl]-
2,3,4,5-tetrahydro-1H-1,5-benzodiazepines have been
disclosed.18,19
pyrrolo[2,1-c][1,4]benzodiazepin-10(11H)-ylcarbonyl)-3-
chlorophenyl]benzamide 9 (VPA-985), and related ana-
logues as a new class of compounds with potent binding
affinity for human AVP V2 receptors and potent aqu-
aretic activity.
The tricyclic 10,11-dihydro-5H-pyrrolo[2,1-c][1,4]benzo-
diazepine 3 was synthesized according to the literature
procedure20 by reductive ring closure of 1-(2-nitroben-
zyl)-2-pyrrolecarboxaldehyde.20,21 Two procedures (A
and B) were used to synthesize derivatives 9-31.
Reaction of 3 with unsubstituted or substituted 4-ni-
trobenzoyl chlorides 4 afforded the 4-nitrobenzoyl de-
rivatives 5. Reduction of the nitro group was carried
out by one of three procedures: (1) with Pd/C-H2, (2)
with 10% Pd/C-H2NNH2 in refluxing ethanol,22 or (3)
with SnCl2‚2H2O in refluxing ethanol to give intermedi-
ates 6 in high yields. In derivatives 5 where R is a
chloro group, partial dechlorination was observed with
Pd/C and hydrazine. In procedure B, methyl esters of
unsubstituted or substituted 4-aminobenzoates were
reacted with substituted benzoyl chlorides to give
intermediate amide esters. The esters were hydrolyzed
and converted to the acid chlorides 8. Reaction of the
10,11-dihydro-5H-pyrrolo[2,1-c][1,4]benzodiazepine 3 with
intermediates 8 gave target compounds 9-31 (Tables
1 and 2).24
Initial binding studies were carried out with receptor
membrane preparations isolated from rat liver (V1a) and
rat kidney (V2). Binding affinities were determined by
measuring the inhibition of (Phe-3,4,5-3H)-AVP binding
to isolated rat hepatic V1a receptors or inhibition of
binding of 3H-AVP to isolated kidney medullary V2
receptors.24 For binding studies with human receptors,
As part of a project to develop nonpeptide vasopressin
antagonists, we report on 5-fluoro-2-methyl-N-[4-(5H-
† Pearl River.
‡ Princeton.
S0022-2623(98)00179-4 CCC: $15.00 © 1998 American Chemical Society
Published on Web 06/16/1998

Communications to the Editor
J ournal of Medicinal Chemistry, 1998, Vol. 41, No. 14 2443
Ta ble 1. Affinity for Human Vasopressin Receptors (IC50, nMa)
Ta ble 3. Vasopressin V2 Antagonistic Effects in Rats
compd
R
R1
V1a
V2
V1a /V2 procedure
compd dose,a no. of urine vol, osmolality,b AVP (ip), water (po),
no.
mg/kg rats
mL/4 h
mOsm/kg 0.4 µg/kg 30 mL/kg
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
3-Cl
2-CH3,5-F
2-CH3,5-F
2-CH3,5-F
230
1.2 ( 0.1 192
1.5 ( 0.2
B
A
B
B
A
A
A
B
A
A
A
B
A
B
B
9
1*
3*
6
15
13
22
8
24
38
43
8
393
222
188
785
629
366
302
850
352
635
557
507
473
1308
-
-
-
-
+
+
+
+
+
+
+
+
+
+
-
-
-
-
+
+
+
+
+
+
+
+
+
+
H
20 ( 2
25 ( 5
15 ( 1
120
13
6
8
2-Cl
4
2
10*
3-OCH3 2-CH3,5-F
3-CH3 2-CH3,5-F
3-Cl
3-Cl
3-Cl
H
3-Cl
H
3-Cl
control
9
-*
1**
2.1 ( 0.2
8.3 ( 0.4 530
80
14
30
37
10
23
10
13
14
17
5
2-F,3-CF3
2-CH3,3-CH3 430
2-CH3,5-CH3 340
2-Cl,4-F
2-Cl,4-F
2-Cl,4-Cl
2-Cl,4-Cl
4400
3**
10**
3**
10**
10**
10**
10**
10**
10
6
2
2
2
2
4
3
10
0.5
860
81
2
53
5
4.2 ( 0.3
2
6.3 ( 0.3 4.0 ( 0.4
37 ( 6
15 ( 2
640
0.7
14
15
20
22
3.2 ( 0.5
2
320
17
2-OCH3 2-Cl,4-Cl
3-Cl
3-Cl
32 ( 5
540 ( 20 1.9 ( 0.3 284
1.9 ( 0.2
2-CH3,3-F
2-CH3
control -**
59
1
59
a
Displacement of H-AVP or 3H-[d(CH2)51Tyr(Me)2-Arg8)-AVP
from specific binding sites in membrane preparations from human
platelets (V1a column): Displacement of 3H-AVP from specific
binding sites in membrane preparations from a murine fibroblast
cell line (LV2) which express human V2 receptors25,26 (V2 column).
IC50’s are reported as group means ( SEM for compounds for
which there were two or three separate determinations.
a
3
The vehicle for administration was 20% dimethyl sulfoxide
(DMSO) in aqueous 2.5% preboiled starch (test compounds were
first dissolved in DMSO). *Conscious rats with free access to water
before and during the experiment. **Conscious rats with free
access to water before (but not during) the experiment dosed (ip)
with 0.4 µg/kg of AVP (in peanut oil): 20 min later given orally
(by gavage) 30 mL/kg of deionized water and another 20 min later
b
given vehicle or test compound. Urinary osmolality from urine
collected (normotensive Sprague-Dawley rats).
Ta ble 2. Affinity for Rat Vasopressin Receptors (IC50, nM)a
compd
R
R1
V1a
V2
V1a/V2 procedure
Differences in binding to human versus rat AVP V1a
receptors have been reported.28-30
9
19
20
23
24
25
26
27
28
29
30
31
3-Cl
H
3-Cl
3-Cl
H
2-CH3,5-F
2-Cl,4-Cl
2-Cl,4-Cl
2-CH3
340
2.3
148
7
5
12
9
2
3
2
2
6
B
A
B
B
B
A
A
A
A
A
A
A
23 ( 2
45 ( 3
54 ( 2
38 ( 1.3 4.1 ( 0.2
10 ( 0.6 4.6 ( 0.3
26 ( 1
31 ( 3
3.1 ( 1
8.3 ( 0.3
4.5 ( 0.2
On the basis of its selectivity for human V2 receptors
and its in vivo aquaretic activity (Table 3), the derivative
9 (VPA-985) was selected for advanced in vivo studies
and clinical trials. Compared to 2 (OPC-31260), the
analogue 9 is 3 times more active (in vivo) in rats (Table
3). In conscious dogs, water-loaded with 30 mL/kg (po)
and AVP-treated (0.4 µg/kg in oil, sc), 9 (1, 3, and 10
mg/kg po) increased Uvol over the AVP-treated vehicle
group by 438, 1018, and 1133%, respectively, while Uosm
decreased from 1222 mOsm/kg (water-loaded and AVP-
treated vehicle) to 307, 221, and 175 mOsm/kg, respec-
tively. In homozygous Brattleboro rats lacking AVP,
compound 9 at 10 mg/kg po (i.e., 10 times the dose
producing V2 antagonist activity) b.i.d. for 5 days,
showed a sustained antagonist action without evidence
of agonist effects, while desGlyd(CH2)5D-Tyr(Et)VAVP
(SK&F 10192631) (1-30 µg/kg, ip), a peptide AVP V2
receptor antagonist in normal rats, demonstrated strong
agonist effects.
In a randomized double-blind placebo-controlled as-
cending single dose study, patients (deprived of fluids
overnight before dosing) were dosed orally with 30, 75,
or 150 mg of 9. All three doses increased urine flow
and serum sodium concentrations and produced signifi-
cant dose-related decreases in urinary osmolality.32
In conclusion, 9 (VPA-985) is a potent, orally active
V2 antagonist in rats and humans and may be useful
for the treatment of conditions characterized by water
retention and inappropriate secretion of AVP.33
2-CH3
H
H
H
H
2-Cl
2-CF3
2-OCH3
2-OCH3,4-Cl 33 ( 5
2-CH3,3-CH3 31 ( 2
10.2 ( 0.7
14 ( 1
16 ( 1
5.0 ( 0.2
8 ( 1
H
2-CH3 2-Cl,4-Cl
2-CH3,3-F
33 ( 3
26 ( 4
4
7
H
4 ( 1
a
Displacement of (Phe-3,4,5-3H)vasopressin from specific bind-
ing sites in membrane preparations isolated from rat liver (V1a
column): Displacement of 3H-AVP from specific binding sites in
rat kidney medulla (V2 column). IC50 values are reported as group
means ( SEM for compounds for which there were two or three
separate determinations.
3
the compounds were evaluated by displacement of H-
AVP in membrane preparations from a murine fibro-
blast cell line (LV2) which express human V2 recep-
tors25,26 or the inhibition of 3H-AVP or 3H-[d(CH2)5-
1Tyr(Me)2,Arg8)-AVP binding to V1a receptors from
human platelet membranes.27
In a search for structural parameters which might
enhance selectivity for binding to V2 receptors over V1a
receptors, we introduced chloro, fluoro, methoxy, and
methyl substituents (R and R1 in compounds 9-31) in
the phenyl rings of the 4-(benzoylamino)benzoyl “tail
unit”. Introduction of a chloro or a methyl group (R) at
the C-3 position enhanced the selectivity for binding to
human AVP V2 receptors while substituents (R ) Cl or
CH3O) at the C-2 position (compounds 11 and 21) had
little effect on potency and selectivity compared to their
unsubstitued analogues, compounds 10 and 19 (Table
1). This general trend, which showed that a 3-chloro
group (R) increased selectivity for human V2 receptors,
was less obvious in binding affinities for rat receptors
(Table 2). Derivatives 20 and 23, which contain a 3-Cl
substituent (R), showed no significant selectivity for rat
V2 receptors, while exhibiting selectivity for human V2
receptors. Analogues 13-16, 20, 22, and 23 all exhibit
selectivity for human V2 receptors, due mainly to
decreased binding affinities for the human V1a receptors.
Ack n ow led gm en t. The authors thank the following
people for their technical support: C. F. Howell for early
project discovery studies (synthetic), S. J eyaseelan, J .
L. Considine, and D. M. Blum (scale-up work), A. Berks
(literature support), and Annette McMonegal (manu-
script preparation).
Su p p or tin g In for m a tion Ava ila ble: Experimental pro-
cedures, analytical data, and melting points for intermediates
and derivatives (Tables 1 and 2) (8 pages). Ordering informa-
tion is given on any current masthead page.

2444 J ournal of Medicinal Chemistry, 1998, Vol. 41, No. 14
Communications to the Editor
(19) Ogawa, H.; Miyamoto, H.; Kondo, K.; Yamashita, H.; Nakaya,
K.; Komatsu, H.; Tanaka, M.; Kora, S.; Tominaga, M.; Yabuuchi,
Y. Benzoheterocyclic Compounds. U.S. Patent 5,559,230, Sept
24, 1996.
(20) Artico, M.; de Martino, G.; Filacchioni, G.; Giuliano, R. Ricerche
su Sostanze ad Attivita Antiblastica, Parte I.; Sintesi Della 10,-
11-Diidro-5H-pirrolo[2,1-c][1,4]benzodiazepine. Farmaco, Ed.
Sci. 1969, 24, 276-284.
(21) Wright, W. B., J r.; Greenblatt, E. M.; Day, I. P.; Quinones, N.
Q.; Hardy, R. A. Derivatives of 11-(1-Piperazinyl)-5H-pyrrolo-
[2,1-c][1,4]benzodiazepine as Central Nervous System Agents.
J . Med. Chem. 1980, 23, 462-465.
(22) Adger, B. M.; Young, R. G. Selective Reduction of Nitroaryl-
alkylnitriles with Hydrazine and a Metal Catalyst. Tetrahedron
Lett. 1984, 25, 5219-5222.
(23) Bellamy, F. D., Ou, K. Selective Reduction of Aromatic Nitro
Compounds with Stannous Chloride in Nonacidic and Nonaque-
ous Medium. Tetrahedron Lett. 1984, 25, 839-842. Errata.
Tetrahedron Lett. 1985, 26, 1362.
(24) Albright, J . D.; Reich, M. F.; Sum, F. W.; Delos Santos, E. G.
Tricyclic Diazepine Vasopressin Antagonists and Oxytocin An-
tagonists. U.S. Patent 5,516,774, May 14, 1996.
(25) Birnbaumer, M.; Seibold, A.; Gilbert, S.; Ishido, M.; Barberis,
C.; Antaramian, A.; Brobet, P.; Rosenthal, W. Molecular Cloning
of the Receptor for Human Antidiuretic Hormone. Nature 1992,
357, 333-335.
(26) Seibold, A.; Rosenthal, W.; Barberis, C.; Birnbaumer, M. Cloning
of the Human Type-2 Vasopressin Receptor Gene. Ann. N.Y.
Acad. Sci. 1993, 689, 570-573.
(27) Kruszyki, M.; Lammek, B.; Manning, M. [1-(â-Mercapto-â,â-
cyclopentamethlenepropionic acid), 2-(O-Methyl)tyrosine]argi-
nine-vasopressin and [1-(â-Mercapto-â,â-cyclopentamethyle-
nepropionic acid)]-arginine-vasopressin, Two Highly Potent
Antagonists of the Vasopressor Response to Arginine-vaso-
pressin. J . Med. Chem. 1980, 23, 364-368.
(28) Pettibone, D. J .; Kishel, M. T.; Woyden, C. J .; Clineschmidt, B.
V.; Bock, M. G.; Freidinger, R. M.; Veber, D. F.; Williams, P. D.
Radioligand Binding Studies Reveal Marked Species Differences
in the Vasopressin V1 Receptor of Rat, Rhesus, and Human
Tissues. Life Sci. 1992, 50, 1953-1958.
(29) Serradeil-Le Gal, C.; Wagnon, J .; Garcia, C.; Lacour, C.; Guirau-
dou, P.; Christophe, B.; Villanova, G.; Nisato, D.; Maffrand, J .
P.; LeFur, G.; Guillon, G.; Cantau, B.; Barberis, C.; Trueba, M.;
Ala, Y.; J ard, S. Biomedical and Pharmacological Properties of
SR 49059, a New, Potent, Nonpeptide Antagonist of Rat and
Human Vasopressin V1a Receptors. J . Clin. Invest. 1993, 92,
224-231.
(30) Serradeil-Le Gal, C.; Raufaste, D.; Marty, E.; Garcia, C.;
Maffrand, J . P.; Le Fur, G. Binding of [3H] SR-49059, a Potent
Nonpeptide Vasopressin V1a Antagonist, to Rat and Human
Liver Membranes. Biochem. Biophys. Res. Commun. 1994, 199,
353-360.
Refer en ces
(1) Laszlo, F. A.; Laszlo, F., J r.; De Wied, D. Pharmacology and
Clinical Perspectives of Vasopressin Antagonists. Pharmacol.
Rev. 1991, 43, 73-108.
(2) Thibonnier, M. Signal Transduction of V1- Vascular Vasopressin
Receptors. Regulatory Pept. 1992, 38, 1-11.
(3) Laszlo, F. A.; Laszlo, F., J r. Clinical Perspectives for Vasopressin
Antagonists. Drug News Perspect. 1993, 6, 591-599.
(4) Nielsen, S.; Knepper, M. A. Vasopressin Activates Collecting
Duct Urea Transporters and Water Channels by Distinct Physi-
cal Processes. Am. J . Physiol. 1993, 265, F204-F213.
(5) Knepper, M. A.; Nielsen, S. Kinetic Model of Water and Urea
Permeability Regulation by Vasopressin in Collecting Duct. Am.
J . Physiol. 1993, 265, F214-F224.
(6) Nielsen, S.; Muller, J .; Knepper, M. A. Vasopressin and cAMP-
induced Changes in Ultrastructure of Isolated Perfused Inner
Medullary Collecting Ducts. Am. J . Physiol. 1993, 265, F225-
338.
(7) Nonoquchi, H.; Owada, A.; Kobayashi, N.; Takayama, M.;
Teroda, Y.; Koike, J .; Ujue, K.; Marumo, F.; Sakai, T.; Tomita,
K. Immunohistochemical Localization of V2 Vasopressin Recep-
tor Along the Nephron and Functional Role of Luminal V2
Receptor in Terminal Inner Medullary Collecting Ducts. J . Clin.
Invest. 1995, 96, 1768-1778.
(8) Knepper, M. A.; Nielson, S.; Chou, C.-L.; DiGiovanni, S. R.
Mechanism of Vasopressin Action in the Renal Collecting Duct.
Semin. Nephrol. 1994, 14, 302-321.
(9) Knepper, M. A. The Aquaporin Family of Molecular Water
Channels. Proc. Natl. Acad. Sci. U.S.A. 1994, 91, 6255-6258.
(10) Kishore, B. K.; Mandon, B.; Oza, N. B.; DiGiovanni, S. R.;
Coleman, R. A.; Ostrowski, N. L.; Wade, J . B.; Knepper, M. A.
Rat Renal Arcade Segment Expresses Vasopressin-regulated
Water Channel and Vasopressin V2 Receptor. J . Clin. Invest.
1996, 97, 2763-2771.
(11) Hayashi, M.; Sasaki, S.; Tsuganezawa, H.; Monkawa, T.; Kita-
jima, W.; Konishi, K.; Fushimi, K.; Marumo, F.; Saruta, T.
Expression and Distribution of Aquaporin of Collecting Duct are
Regulated by Vasopressin V2 Receptor in Rat Kidney. J . Clin.
Invest. 1994, 94, 1778-1783.
(12) Yamamura, Y.; Ogawa, H.; Chihara, T.; Kondo, K.; Onogawa,
T.; Nakamura, S.; Mori, T.; Tominaga, M.; Yabuuchi, Y. OPC-
21268, an Orally Effective, Nonpeptide Vasopressin V1 Receptor
Antagonist. Science 1991, 252, 572-574.
(13) Ogawa, H.; Yamamura, Y.; Miyamoto, H.; Kondo, K.; Yamashita,
H.; Nakaya, K.; Chihara, T.; Mori, T.; Tominaga, M.; Yabuuchi,
Y. Orally Active, Nonpeptide Vasopressin V1 Antagonists. A
Novel Series of 1-(1-Substituted 4-piperidyl)-3,4-dihydro-2(1H)-
quinolinone. J . Med. Chem. 1993, 36, 2011-2017.
(14) Kondo, K.; Ogawa, H,; Nakaya, K.; Tominaga, M.; Yabuuchi, Y.
Structure-activity Relationships of Nonpeptide Vasopressin V1a
Antagonists: 1-(1-Multi-substituted Benzoyl 4-Piperidyl)-3,4-
dihydro -2(1H)-quinolinones. Chem. Pharm. Bull. 1996, 44, 725-
733.
(15) Yamamura, Y.; Ogawa, H.; Yamashita, H.; Chihara, T.; Miya-
moto, H.; Nakamura, S.; Onogawa, T.; Yamashita, T.; Hosokawa,
T.; Mori, T.; Tominaga, M.; Yabuuchi, Y. Characterization of a
Novel Aquaretic Agent, OPC-31260, as an Orally Effective, Non-
peptide Vasopressin V2 Receptor Antagonist. Br. J . Pharmacol.
1992, 105, 787-791.
(16) Ohnishi, A.; Orita, Y.; Okahara, R.; Fujihara, H.; Inoue, T.;
Yamamura, Y.; Yabuuchi, Y.; Tanaka, T. Potent Aquaretic
Agent. J . Clin. Invest. 1993, 92, 2653-2659.
(17) Ohnishi, A.; Orita, Y.; Takagi, N.; Fujita, T.; Toyoki, T.; Ihara,
Y.; Yamamura, Y.; Inou, T.; Tanaka, T. Aquaretic Effect of a
Potent, Orally Active, Nonpeptide V2 Antagonist in Men. J .
Pharmacol. Exp. Ther. 1995, 272, 546-551.
(18) Ogawa, H.; Yamashita, H.; Kondo, K.; Yamamura, Y.; Miyamoto,
H.; Kan, K.; Kitano, K.; Tanaka, M.; Nakaya, K.; Nakamura,
S.; Mori, T.; Tominaga, M.; Yakuuchi, Y. Orally Active, Non-
peptide Vasopressin V2 Receptor Antagonists: a Novel Series
of 1-[(4-Benzoylamino)benzoyl]-2,3,4,5-tetrahydro-1H-benza-
zepine and Related Compounds. J . Med. Chem. 1996, 39, 3547-
3555.
(31) Kinter, L. B.; Caltabiano, S.; Huffman, W. F. Anomalous
Antidiuretic Activity of Antidiuretic Hormone Antagonists.
Biochem. Pharm. 1993, 45, 1731-1737.
(32) Abraham, W.T.; Oren , R. M.; Crisman , T.S.; Robertson, A. D.;
Shaker, S.; Lowes, B. D.; Panther, L.; Kelley, P.; Pies, C. J .;
Schrier, R. W. Effects of an Oral,Nonpeptide, Selective V2
Receptor Vasopressin Antagonist in Patients with Chronic Heart
Failure. J . Am. Coll. Cardiol. 1997, 29 (2 Suppl. A): 169A.
(33) Albright, J . D.; Chan, P. S. Recent Advances in the Discovery
and Development of Vasopressin Antagonists: Peptide and
Nonpeptide V1a and V2 Receptor Antagonists. Curr. Pharm. Des.
1997, 3, 615-632.
J M980179C