Synthesis and antiviral activity of novel anti-VZV 5-substituted uracil nucleosides with a cyclopropane sugar moiety

Article abstract of DOI:10.1021/jm9904194

A series of 5-substituted uracil nucleoside derivatives with a 1(1'S,2'R)-[1',2'-bis(hydroxymethyl)cyclopropyl]methyl group as an acyclosugar moiety were synthesized and evaluated for their anti-herpetic activities. Among the compounds synthesized, (E)-5-

Full text of DOI:10.1021/jm9904194

278
J . Med. Chem. 2000, 43, 278-282
Syn th esis a n d An tivir a l Activity of Novel An ti-VZV 5-Su bstitu ted Ur a cil
Nu cleosid es w ith a Cyclop r op a n e Su ga r Moiety
Tomoyuki Onishi, Chika Mukai, Ryusuke Nakagawa, Takaaki Sekiyama, Miho Aoki, Katsuya Suzuki,
Harumi Nakazawa, Nobukazu Ono, Yuko Ohmura, Satoshi Iwayama, Masahiko Okunishi, and Takashi Tsuji*
Pharmaceutical Research Laboratories, Ajinomoto Company, Inc., 1-1 Suzuki-cho, Kawasaki 210-8681, J apan
Received August 19, 1999
A series of 5-substituted uracil nucleoside derivatives with a 1(1′S,2′R)-[1′,2′-bis(hydroxymethyl)-
cyclopropyl]methyl group as an acyclosugar moiety were synthesized and evaluated for their
anti-herpetic activities. Among the compounds synthesized, (E)-5-halovinyluracil derivatives
showed superior anti-varicella zoster virus (VZV) activity over acyclovir (ACV) but were less
potent than ACV against herpes symplex virus type-1 (HSV-1). IC50 values for the VZV
Kawaguchi strain were 0.027 for Br, 0.070 for Cl, and 0.054 µg/mL for I derivatives and 3.4
µg/mL for ACV. The most potent compound, (1′S,2′R)-5-[(E)-2-bromoethenyl]-1-[[1′,2′-bis-
(hydroxymethyl)cycloprop-1′-yl]methyl]-2,4-(1H,3H)-pyrimidinedione (3a ), was 40-60-fold more
potent than ACV against clinical isolates of VZV. It showed good oral bioavailability in rats
(68.5%) and, unlike (E)-5-(2-bromovinyl)-1-â-D-arabinofuranosyluracil (BVaraU), did not result
in the release of (E)-5-(2-bromovinyl)uracil (BVU), a potent dihydropyrimidine dehydrogenase
inhibitor, in plasma after oral administration.
Ch a r t 1
In tr od u ction
Since the discovery of acyclovir (ACV) as a potent
antiherpetic agent,1 acyclic nucleosides have attracted
the interest of both medicinal chemists and virologists.
The search for a new agent having superior activity to
ACV has resulted in the discovery of ganciclovir (GCV),2
which shows broader antiviral activity, and penciclovir
(PCV)3 as new therapeutic agents. As represented by
these two drugs, one of the approaches to improve
antiherpetic activity is to design a compound with two
hydroxyl groups mimicking the 3′- and 5′-hydroxyl
groups of the 2′-deoxyribose moiety of nucleosides. In
the search for new acyclonucleosides based on this
hypothesis, we previously found that (1′S,2′R)-9-[[1′,2′-
bis(hydroxymethyl)cycloprop-1′-yl]methyl]guanine (A-
5021, 1) (Chart 1) showed extremely potent antiherpetic
activity.4 Another important chemical class of antiher-
petic nucleosides is a series of 5-substituted uracil
nucleosidesssuch as (E)-5-(2-bromovinyl)-2′-deoxyuri-
dine (BVdU)5 (2a )sthat show specific anti-varicella
zoster virus (VZV) activity. Among these uracil nucleo-
sides (E)-5-(2-bromovinyl)-1-â-D-arabinofuranosyluracil
(BVaraU)6 (2b) shows extremely potent anti-VZV activ-
ity; however, potentiation of the toxicity of 5-fluorouracil
(5-FU) by its metabolite, (E)-5-(2-bromovinyl)uracil
(BVU),7 has limited its use as a therapeutic agent.
Several uracil nucleosides with 5-substituents other
than the 5-halovinyl group have been developed to
overcome this problem.8 Among this class of compounds,
however, only those with cyclic sugar moieties have thus
far been demonstrated to show specific anti-VZV activ-
ity. Though the sugar moiety of 1 has a cyclopropane
ring, its overall feature is acyclic because of its flex-
ibility. Thus, it would be of interest to determine
whether 5-substituted uracil nucleosides with a sugar
moiety of 1 show VZV-specific antiviral activity. In this
paper, we report the synthesis and antiviral activity of
these compounds. Some of the compounds showed
potent anti-VZV activity, and preliminary results on the
pharmacokinetics of the most active compound, (1′S,2′R)-
5-[(E)-2-bromoethenyl]-1-[[1′,2′-bis(hydroxymethyl)cyclo-
prop-1′-yl]methyl]-2,4-(1H,3H)-pyrimidinedione (3a), are
also presented.
Ch em istr y
In Scheme 1, the syntheses of 5-substituted uracil
derivatives with a 1(1′S,2′R)-[1′,2′-bis(hydroxymethyl)-
cyclopropyl]methyl group are represented by the prepa-
ration of 3a . To prepare a series of analogues, the sugar
moiety was attached to 5-substituted uracil bases10,11
by alkylation reaction. The chiral trisubstituted cyclo-
propane 4 was prepared from chiral epichlorohydrin and
diethyl malonate in >97% ee as described previously.4
* To whom correspondence should be addressed. Tel: 44 210 5822.
Fax: 44 210 5871. E-mail: takashi_tsuji@ajinomoto.com.
10.1021/jm9904194 CCC: $19.00 © 2000 American Chemical Society
Published on Web 12/30/1999

Novel Anti-VZV 5-Substituted Uracil Nucleosides
J ournal of Medicinal Chemistry, 2000, Vol. 43, No. 2 279
Sch em e 1a
Ta ble 1. Anti-HSV-1 Activity (Tomioka in Vero Cells) by
Quantitative CPE Assay and Anti-VZV Activity (Kawaguchi in
HEL Cells) by Plaque Reduction Assay of the Compounds
HSV-1
VZV
IC50
a
b
compd
ACV
1 (A-5021)
9
10
11
12
13
14c
15
3a
3bd
16
17
18
X
IC50
CC50
0.81
0.020
>500
>500
295
820
240
3.4
0.67
>100
>100
>100
97
H
F
Cl
Br
I
>500
>500
>500
>500
>500
>500
>500
>500
>500
330
215
90
9.3
Me
>500
4.30
14.5
>500
24.6
310
>100
0.070
0.027
7.4
0.054
>100
19.8
(E)-2-chloroethenyl
(E)-2-bromoethenyl
(E)-2-bromoethenyl
(E)-2-iodoethenyl
ethynyl
Because of high reactivity of halomethylcyclopropanes
such as 7, the cis-hydroxymethyl groups were protected
with diphenylketal 5, which is more stable under acidic
conditions than the previously reported dimethyketal
derivative.4 6 was converted to bromide 7 by triph-
enylphosphine/CBr4 in the presence of triethylamine to
avoid decomposition. The alkylation of unprotected
5-substituted uracils occurred mainly at the 1-position,
but limited amounts of 3-alkylated and 1,3-dialkylated
products were also obtained. These byproducts were
separated by C18 reversed-phase chromatography after
removal of the ketal protective group with 1 M HCl
treatment. The yield of the alkylation products varies
from 16% to 72% depending on the type of the uracil
base. The other enantiomer of 3a was prepared by the
same procedure using the enantiomer of 4.
>500
>500
1-propynyl
325
a
b
Concentrations in µg/mL. Cytotoxicity in Vero cells. c Race-
mate.4 With (1′R,2′S)-configuration in the sugar portion.
d
Despite its potent activity, BVaraU generates BVU,
a potent inhibitor of dihydropyrimidine dehydrogenase,
after oral administration. Since 3a has no glycosidic
linkage, 3a is expected to be more metabolically stable
than BVaraU. When 0.1 mmol/kg of the compounds was
given to rats, 3a showed oral bioavailability of 68.5%,
versus 47.5% for BVaraU, as shown in Table 3. It is
noted that, unlike BVaraU, BVU was not detected in
the plasma of the rats given 3a orally.
Discu ssion
Biologica l Stu d ies
Series of 5-substituted uracil nucleosides are known
as antivirals with specific activity against VZV. These
nucleosides include 5-bromovinyluracil derivatives such
as BVdU, its carbocyclic analogue GR-95168,13 BVaraU,
and a 5-alkynyluracil derivative, Netivudine.8 5-Iodo
derivatives such as 5-iodo-2′-deoxyuridine (IDU) and its
hexitol analogue show some antiherpetic activity,14 and
compounds with even more bulky 5-substituents, such
as heteroaromatics, have also been reported.15 These
nucleosides have cyclic sugar moieties similar to 2′-
deoxyribose. Even an isoribose derivative of BVdU is
active against VZV.16 In contrast, the ACV and GCV
type compounds with 5-bromovinyluracil as a base
moiety have been reported to show no antiherpetic
activities.17 A 5-bromovinyluracil derivative with a
carbocyclic oxetane moiety has recently been reported
as a potent anti-VZV agent.18 This compound is struc-
turally similar to 3a ; however, because of the structural
constraint, it belongs to a class of nucleosides with cyclic
sugar moieties. Though 3a has a cyclopropane ring, this
ring is connected via a methylene linkage, so that the
pseudo-sugar moiety of 3a has an overall flexibility like
that of the acyclonucleosides. Thus, 3a is the first
example of a 5-substituted uracil acyclonucleoside with
potent anti-VZV activity. The reason some 5-substituted
uracil derivatives show specific activity against VZV is
The antiherpetic activities of this series of compounds
were measured by quantitative CPE reduction assay4
against herpes simplex virus type 1 (HSV-1) Tomioka
strain and plaque reduction assay against Kawaguchi
strain.12 The results are summarized in Table 1. Among
the compounds tested, 5-halovinyl derivatives (3a , 15,
16) showed the most potent activity against VZV. 3a
was the most potent compound and was more than 100
times as potent as ACV. It showed no cytotoxic effect
up to 500 µg/mL in Vero cells. Unlike ACV and 1, 3a
showed only marginal activity against HSV-1. The
enantiomer (3b) of 3a showed weak activity against
VZV, and even this activity may have been due not to
3b but to 3a in the preparation. Among the other
compounds, only 5-iodo (13) and 5-propynyl (18) deriva-
tives showed anti-VZV activity, and this activity was
weak.
The antiviral activities of 3a were further evaluated
against several strains of herpes viruses, including
clinical isolates of VZV, by plaque reduction assay. 3a
was extremely potent against clinical isolates of VZVs
more potent than ACV, PCV, or 1swhile BVaraU was
about 100 times more potent than 3a . Like other
nucleosides of this chemical class, 3a showed no activity
against HSV-2, and its activity was specific to VZV.

280 J ournal of Medicinal Chemistry, 2000, Vol. 43, No. 2
Onishi et al.
Ta ble 2. Antiherpetic Activity of 3a and Reference Compounds against Various Strains by Plaque Reduction Assay
a
IC50
virus
strain
Tomioka
cells
3a
1
ACV
0.29
0.25
3.4
1.3 ( 0.40
5.4 ( 1.5
PCV
0.54
1.2
5.6
ND
10 ( 3.8
BVaraU
HSV-1
HSV-2
VZV
VZV
VZV
MRC-5
MRC-5
HEL
MRC-5
HEL
0.77
>100
0.027
0.0093
0.12
0.14
NDb
ND
186
Kawaguchi
clinical isolatesc
clinical isolatesd
0.67
0.035 ( 0.021
0.097 ( 0.029
0.21 ( 0.096
0.00031 ( 0.000072
ND
ND
a
b
d
Concentrations in µg/mL. Not determined. c Average of 6 isolates. Average of 11 isolates.
Ta ble 3. Oral Bioavailability of 3a and BVaraU in Rats
MRC-5 cells were purchased from Dainippon Pharmaceu-
ticals (Osaka, J apan). HEL cells and clinical isolates of VZV
were provided by Dr. Koichi Yamanishi of Osaka University
Medical School. ACV, PCV, and BVaraU were synthesized in
the Central Research Laboratories of Ajinomoto Co.
route
3a
BVaraU
AUC0-12h (µM‚h)
AUC0-12h (µM‚h)
oral bioavailability (%)a
BVDb
iv
po
86.9
59.5
68.5
100.5
47.7
47.5
Eth yl (1R,7R)-3,5-Dioxa -4,4-d ip h en ylbicyclo[5.1.0]oc-
t a n e-1-ca r b oxyla t e (5). Ethyl (1R,2R)-1,2-bis(hydroxy-
methyl)-1-cyclopropanecarboxylate4 (4) (5.23 g, 30 mmol, >97%
ee) and diphenyldiazomethane (5.83 g, 30 mmol) in 130 mL of
1,2-dichloroethane were slowly added to a solution of 2,3-
dichloro-5,6-dicyano-1,4-benzoquinone (6.81 g, 30 mmol) in 250
mL of 1,2-dichloroethane at room temperature. The mixture
was stirred for 1 h and the reaction mixture was concentrated
in vacuo. The concentrate was dissolved in toluene and the
solution was washed with saturated NaHCO3. The organic
layer was concentrated in vacuo and the residue was chro-
matographed on silica gel eluting with CH2Cl2 to yield 5 as a
yellow oil (8.72 g, 85%): 1H NMR (CDCl3) δ 1.22 (t, J ) 7.0
Hz, 3H), 1.33 (dd, J ) 3.6, 7.1 Hz, 1H), 1.43 (dd, J ) 3.6, 9.3
Hz, 1H), 1.80 (m, 1H), 3.68 (d, J ) 13.3 Hz, 1H), 3.76 (dd, J )
3.1, 12.9 Hz, 1H), 4.1 (m, 3H), 4.65 (d, J ) 13.0 Hz, 1H), 7.20-
7.60 (m, 10H); FD MASS m/z 338 (M+).
not detectedc
detectedd
a
AUC0-12h(po)/AUC0-12h(iv) × 100. b Presence of BVU in plasma
after oral dosage. c Detection limit > 0.5 µM. 9.38 ( 3.02 µM at
12 h.
d
not clear. One possible explanation is that the thymidine
kinase of VZV may have a large binding pocket to
accommodate these derivatives.19 The sugar moiety of
3a may take a conformation resembling that of 2′-
deoxyribose in terms of the position of the two hydroxyl
groups in the binding site of the thymidine kinase, and
3a may exhibit potent anti-VZV activity through ef-
ficient phosphorylation.
Among the series of 5-substituted uracil nucleosides,
BVaraU shows the most potent anti-VZV activity.
Despite this potent activity, however, its clinical use is
limited because of the metabolic formation of BVU. BVU
is known to be a potent inhibitor of dihydropyrimidine
dehydrogenase, and use of BVaraU in combination with
5-FU delays the degradation of 5-FU and potentiates
its toxicity. The release of BVU is catalyzed by pyrimi-
dine phosphorylase of the enterobacteria.7a Since 3a has
no glycosidic linkage, it is expected that 3a is more
metabolically stable than BVaraU. Our preliminary
experiment revealed the good oral bioavailability and
stability of 3a . There may be other pathways of me-
tabolism, such as oxidative degradation at the liver, and
thus additional studies will be needed on the metabolic
stability of 3a . However, 3a in combination with 5-FU
is expected to be a safer drug than BVaraU or BVdU.
Further studies on the pharmacology and pharmacoki-
netics of 3a are currently in progress.
(1S,7R)-3,5-Dioxa -4,4-d ip h en ylb icyclo[5.1.0]oct a n e-1-
m eth a n ol (6). To a solution of 5 (7.01 g, 20.7 mmol) in 10 mL
of dry THF was added 12 mL of a 2 M solution of LiBH4 in
THF, and the mixture was heated at 72 °C for 16 h. Saturated
NH4Cl was added to the mixture at 0 °C and the product was
extracted with EtOAc. The organic layer was washed with H2O
and concentrated in vacuo. The residue was chromatographed
on silica gel eluting with CH2Cl2-MeOH (19:1) to yield 6 as a
1
white solid (5.54 g, 90%): mp 93 °C; H NMR (CDCl3) δ 0.67
(dd, J ) 4.4, 8.9 Hz, 1H), 0.96 (dd, J ) 4.4, 5.8 Hz, 1H), 1.08
(m, 1H), 3.42 (dd, J ) 11.0, 27.9 Hz, 2H), 3.65 (dd, J ) 3.9,
12.9 Hz, 1H), 3.76 (d, J ) 12.7 Hz, 2H), 4.1 (m, 3H), 7.20-
7.60 (m, 10H); FD MASS m/z 296 (M+).
(1R,7R)-1-Br om om eth yl-3,5-d ioxa -4,4-d ip h en ylbicyclo-
[5.1.0]octa n e (7). To a solution of 6 (5.00 g, 16.9 mmol) in
100 mL of CH2Cl2 were added Et3N (1.2 mL, 8.4 mmol),
triphenylphosphine (7.97 g, 30.4 mmol), and CBr4 (10.1 g, 30.4
mmol). After the mixture stirred for 20 min at room temper-
ature, saturated NaHCO3 was added and the product was
extracted with hexane. The organic layer was washed with
H2O and the solvent was removed in vacuo. The residue was
chromatographed on silica gel eluting with a gradient of
0-25% EtOAc in hexane to yield 7 as a yellow oil (5.45 g,
90%): 1H NMR (CDCl3) δ 0.83 (dd, J ) 4.2, 8.5 Hz, 1H), 1.16-
1.28 (m, 2H), 3.13 (d, J ) 10.2 Hz, 1H), 3.60 (dd, J ) 3.5, 12.9
Hz, 2H), 3.80 (d, J ) 12.9 Hz, 2H), 4.07 (dd, J ) 4.8, 13.0 Hz,
2H), 7.20-7.60 (m, 10H); FD MASS m/z 358 (M+).
Gen er a l Meth od for P r ep a r a tion of 3a , 3b, a n d 9-18.
To a solution of 8 (358 mg, 1.0 mmol) in dry DMF (20 mL)
were added the corresponding 5-substituted uracil10,11 (1.2
mmol), K2CO3 (138 mg, 1.0 mmol), and 18-crown-6 (264 mg,
1.0 mmol). After stirring for 2 h at 60 °C, the mixture was
cooled to room temperature and insoluble substances were
removed by filtration. The filtrate was concentrated in vacuo
and the residue was dissolved in 10 mL of MeOH and 2.5 mL
of HCl. After the mixture stirred for 30 min at room temper-
ature, MeOH was removed in vacuo. The concentrate was
brought to pH ) 4 by adding K2CO3 and was chromatographed
on reversed-phase C18 silica gel eluting with 0-30% MeOH/
Exp er im en ta l Section
Gen er a l. Reagents used were the highest quality available
commercially. Unless otherwise noted, organic extracts were
dried over anhydrous MgSO4 or Na2SO4 and temperature
refers to the temperature of the bath. 1H and 13C NMR spectra
were recorded with a Varian XL-300 300-MHz or a J EOL
J NM-GX-400 400-MHz spectrometer, using tetramethylsilane
as an internal standard. Mass spectra were recorded on a
J EOL J MS-DX300 spectrophotometer, and accurate masses
were measured on a J EOL J MS-HX110 spectrometer. Optical
rotations were recorded on a J ASCO DIP-370 polarimeter.
Thin-layer chromatography was carried out on silica gel
60F254 precoated plates (Merck art. no. 5715) and silica gel
column chromatography was conducted on silica gel 60 (70-
230 mesh; Merck art. no. 7734). Preparative reversed-phase
column chromatography was conducted on a Merck LiChro-
prep RP-18 column (40-63 µm). Elemental combustion analy-
ses, where indicated only by the elements, were within (0.4%
of the theoretical values.

Novel Anti-VZV 5-Substituted Uracil Nucleosides
J ournal of Medicinal Chemistry, 2000, Vol. 43, No. 2 281
13C NMR (CD3OD) δ 15.0, 25.6, 27.6, 54.4, 62.8, 63.2, 147.1,
H2O. Evaporation of the desired fractions gave 3a , 3b, 9-13,
and 15-18. 14 was prepared as a racemate as described
previously.4
152.2, 153.3, 163.4; HRMS calcd for
C
10H14IN2O4 (MH+)
352.9998, found 353.0007. Anal. (C10H13IN2O4‚0.2H2O) C, H,
N.
1-[(1′S,2′R)-1′,2′-Bis(h yd r oxym et h yl)cyclop r op -1′-yl]-
m eth yl-5-[(E)-2-br om oeth en yl]-2,4(1H,3H)-p yr im id in ed i-
on e (3a ): colorless needles from water; yield 20%; mp 99-
102 °C; [R]26D ) +14.7 (c ) 0.689%, MeOH); 1H NMR (DMSO-
d6) δ 0.42 (t, J ) 5.4 Hz, 1H), 0.80 (dd, J ) 4.8, 8.7 Hz, 1H),
1.20-1.30 (m, 1H), 3.24-3.37 (m, 2H), 3.50 (dd, J ) 6.0, 12.0
Hz, 1H), 3.61 (dt, J ) 12.0, 6.0 Hz, 1H), 3.61 (d, J ) 14.1 Hz,
1H), 3.77 (d, J ) 14.1 Hz, 1H), 4.50-4.59 (m, 2H), 6.81 (d, J
) 13.5 Hz, 1H), 7.23 (d, J ) 13.5 Hz, 1H), 7.91 (s, 1H); 13C
NMR (CD3OD) δ 14.9, 25.7, 27.5, 54.3, 62.8, 63.2, 108.6, 111.5,
130.2, 145.6, 152.5, 164.1; HRMS calcd for C12H16BrN2O4
(MH+) 331.0293, found 331.0298. Anal. (C12H15BrN2O4) C, H,
N.
1-[(1′R,2′S)-1′,2′-Bis(h yd r oxym et h yl)cyclop r op -1′-yl]-
m eth yl-5-[(E)-2-br om oeth en yl]-2,4(1H,3H)-p yr im id in ed i-
on e (3b): enatiomer of 8 was used instead of 8 in this
preparation; colorless needles from water; yield 14%; 1H NMR
was identical to that of 3a ; mp 97-100 °C; [R]26D ) -16.7 (c )
0.563%, MeOH); HRMS calcd for C12H16BrN2O4 (MH+) 331.0293,
found 331.0295. Anal. (C12H15BrN2O4) C, H, N.
1-[(1′S,2′R)-1′,2′-Bis(h yd r oxym et h yl)cyclop r op -1′-yl]-
m eth yl-5-[(E)-2-ch lor oeth en yl]-2,4(1H,3H)-p yr im id in ed i-
on e (15): colorless needles from water; yield 51%; mp 74-77
°C; [R]25 ) +21.7 (c ) 2.56%, MeOH); 1H NMR (CD3OD) δ
D
0.56 (t, J ) 5.4 Hz, 1H), 1.01 (dd, J ) 5.4, 8.7 Hz, 1H), 1.38-
1.49 (m, 1H), 3.45 (dd, J ) 9.3, 12.2 Hz, 1H), 3.51 (d, J ) 12.3
Hz, 1H), 3.76 (d, J ) 12.3 Hz, 1H), 3.81 (d, J ) 14.4 Hz), 3.88
(dd, J ) 5.9, 12.2 Hz, 1H), 3.92 (d, J ) 14.4 Hz, 1H), 6.56 (d,
J ) 13.4 Hz, 1H), 7.26 (d, J ) 13.4 Hz, 1H), 7.78 (s, 1H); 13C
NMR (CD3OD) δ 15.7, 26.4, 28.3, 55.1, 63.6, 64.0, 111.2, 121.5,
127.3, 146.1, 153.2, 164.9; HRMS calcd for C12H16ClN2O4
(MH+) 287.0799, found 287.0812. Anal. (C12H15ClN2O4‚0.1H2O)
C, H, N.
1-[(1′S,2′R)-1′,2′-Bis(h yd r oxym et h yl)cyclop r op -1′-yl]-
m et h yl-5-[(E)-2-iod oet h en yl]-2,4(1H ,3H )-p yr im id in ed i-
on e (16): colorless solid; yield 39%; mp 105-107 °C; [R]23
)
D
1
+12.4 (c ) 0.105%, MeOH); H NMR (CD3OD) δ 0.56 (t, J )
5.4 Hz, 1H), 1.00 (dd, J ) 5.4, 8.7 Hz, 1H), 1.38-1.48 (m, 1H),
3.45 (dd, J ) 9.6, 12.3 Hz, 1H), 3.5 (d, J ) 12.3 Hz, 1H), 3.76
(d, J ) 12.3 Hz, 1H), 3.81 (d, J ) 14.6 Hz), 3.88 (dd, J ) 5.6,
12.3 Hz, 1H), 3.92 (d, J ) 14.6 Hz, 1H), 7.16 (d, J ) 14.7 Hz,
d), 7.34 (d, J ) 14.7 Hz, 1H), 7.80 (s, 1H); 13C NMR (CD3OD)
δ 14.9, 25.7, 27.5, 54.3, 62.8, 63.2, 78.3, 113.1, 137.7, 145.5,
152.5, 164.2; HRMS calcd for C12H16IN2O4 (MH+) 379.0155,
found 379.0156. Anal. (C12H15IN2O4‚0.1H2O) C, H, N.
1-[(1′S,2′R)-1′,2′-Bis(h yd r oxym et h yl)cyclop r op -1′-yl]-
m eth yl-2,4(1H,3H)-p yr im id in ed ion e (9): colorless solid;
yield 22%; mp 129-132 °C; [R]25 ) +21.1 (c ) 0.885%,
D
MeOH); 1H NMR (CD3OD) δ 0.55 (t, J ) 5.4 Hz, 1H), 1.00 (dd,
J ) 5.4, 9.0 Hz, 1H), 1.35-1.46 (m, 1H), 3.46 (dd, J ) 9.3,
12.0 Hz, 1H), 3.49 (d, J ) 12.3 Hz, 1H), 3.77 (d, J ) 12.3 Hz,
1H), 3.83-3.92 (m, 3H), 5.68 (d, J ) 7.8 Hz, 1H), 7.69 (d, J )
7.8 Hz, 1H); 13C NMR (CD3OD) δ 15.0, 25.5, 27.7, 54.1, 62.8,
63.1, 101.8, 147.8, 153.4, 166.8; HRMS calcd for C10H15N2O4
(MH+) 227.1032, found 227.1008. Anal. (C10H14N2O4) C, H, N.
1-[(1′S,2′R)-1′,2′-Bis(h yd r oxym et h yl)cyclop r op -1′-yl]-
m eth yl-5-flu or o-2,4(1H,3H)-p yr im id in ed ion e (10): color-
1-[(1′S,2′R)-1′,2′-Bis(h yd r oxym et h yl)cyclop r op -1′-yl]-
m eth yl-5-eth yn yl-2,4(1H,3H)-p yr im id in ed ion e (17): color-
less solid; yield 23%; mp 155-158 °C; [R]25 ) +19.9 (c )
D
0.269%, MeOH); 1H NMR (CD3OD) δ 0.56 (t, J ) 5.6 Hz, 1H),
1.01 (dd, J ) 5.6, 8.7 Hz, 1H), 1.38-1.48 (m, 1H), 3.46 (dd, J
) 9.2, 12.3 Hz, 1H), 3.51 (d, J ) 12.3 Hz, 1H), 3.59 (s, 1H),
3.77 (d, J ) 12.3 Hz, 1H), 3.86 (dd, J ) 5.7, 12.3 Hz, 1H), 3.87
(s, 2H), 8.05 (s, 1H); 13C NMR (CD3OD) δ 15.0, 25.6, 27.6, 54.6,
62.8, 63.2, 76.0, 82.8, 98.9, 151.3, 152.7, 165.2; HRMS calcd
less solid; yield 16%; mp 138-141 °C; [R]25 ) +22.1 (c )
D
1
1.48%, MeOH); H NMR (CD3OD) δ 0.56 (t, J ) 5.3 Hz, 1H),
0.99 (dd, J ) 5.3, 8.7 Hz, 1H), 1.37-1.47 (m, 1H), 3.46 (dd, J
) 9.3, 11.8 Hz, 1H), 3.52 (d, J ) 12.0 Hz, 1H), 3.78 (d, J )
12.0 Hz, 1H), 3.80 (d, J ) 15.0 Hz, 1H), 3.84 (d, J ) 15.0 Hz,
1H), 3.87 (dd, J ) 6.2, 11.8 Hz, 1H), 7.89 (d, J ) 14.4 Hz, 1H);
13C NMR (CD3OD) δ 14.9, 25.5, 27.5, 54.5, 62.8, 63.2, 131.6
(d, J ) 32.8 Hz), 141.4 (d, J ) 230.4 Hz), 152.1, 159.9 (d, J )
25.5 Hz); HRMS calcd for C10H14FN2O4 (MH+) 245.0938, found
245.0941. Anal. (C10H13FN2O4) C, H, N.
for
C
12H15N2O4 (MH+) 251.1032, found 251.1027. Anal.
(C12H14N2O4) C, H, N.
1-[(1′S,2′R)-1′,2′-Bis(h yd r oxym et h yl)cyclop r op -1′-yl]-
m eth yl-5-(1-p r op yn yl)-2,4(1H,3H)-p yr im id in ed ion e (18):
colorless solid; yield 61%; mp 156-159 °C; [R]25D ) +20.7 (c )
0.453%, MeOH); 1H NMR (CD3OD) δ 0.55 (t, J ) 5.4 Hz, 1H),
1.00 (dd, J ) 5.4, 8.6 Hz, 1H), 1.36-1.46 (m, 1H), 2.03 (s, 3H),
3.46 (dd, J ) 9.3, 12.0 Hz, 1H), 3.50 (d, J ) 12.3 Hz, 1H), 3.76
(d, J ) 12.3 Hz, 1H), 3.80 (d, J ) 14.3 Hz, 1H), 3.86 (dd, J )
6.2, 12.0 Hz, 1H), 3.90 (d, J ) 14.3 Hz, 1H), 7.87 (s, 1H); 13C
NMR (CD3OD) δ 4.0, 15.0, 25.5, 27.6, 54.4, 62.8, 63.1, 71.5,
90.7, 100.5, 149.4, 152.5, 165.4; HRMS calcd for C13H17N2O4
(MH+) 265.1188, found 265.1190. Anal. (C13H16N2O4‚0.3H2O)
C, H, N.
1-[(1′S,2′R)-1′,2′-Bis(h yd r oxym et h yl)cyclop r op -1′-yl]-
m eth yl-5-ch lor o-2,4(1H,3H)-p yr im id in ed ion e (11): color-
less solid; yield 31%; mp 122-124 °C; [R]25 ) +18.2 (c )
D
0.955%, MeOH); 1H NMR (CD3OD) δ 0.56 (t, J ) 5.5 Hz, 1H),
1.00 (dd, J ) 5.5, 8.7 Hz, 1H), 1.38-1.48 (m, 1H), 3.46 (dd, J
) 9.3, 11.4 Hz, 1H), 3.52 (d, J ) 12.2 Hz, 1H), 3.78 (d, J )
12.2 Hz, 1H), 3.85 (d, J ) 14.6 Hz, 1H), 3.87 (dd, J ) 6.9, 11.4
Hz, 1H), 3.87 (d, J ) 14.6 Hz, 1H), 8.02 (s, 1H); 13C NMR (CD3-
OD) δ 15.0, 25.6, 27.5, 54.6, 62.8, 63.2, 108.4, 144.6, 152.6,
162.0; HRMS calcd for C10H14ClN2O4 (MH+) 261.0642, found
261.0638. Anal. (C10H13ClN2O4‚0.2H2O) C, H, N.
An tivir a l Activity. Quantitative CPE reduction assay
against HSV-1 was performed using the neutral red dye
uptake method as described previously.4 Plaque reduction
assay for HSV-1,2 and VZV was carried out as described in
the previous report.12 All antiviral titrations were done in
either triplicate or quadruplicate.
1-[(1′S,2′R)-1′,2′-Bis(h yd r oxym et h yl)cyclop r op -1′-yl]-
m eth yl-5-br om o-2,4(1H,3H)-p yr im id in ed ion e (12): color-
less solid; yield 72%; mp 141-143 °C; [R]25 ) +11.3 (c )
D
1
3.13%, MeOH); H NMR (CD3OD) δ 0.56 (t, J ) 5.3 Hz, 1H),
P h a r m a cok in etics in Ra ts. Drugs were dissolved in PBS
by addition of an equimolar amount of NaOH and were given
to male SD rats of 5 weeks of age. Blood samples were collected
by cardiac puncture at 1, 5, 10, 30, 60, 120, 240, 480, and 720
min after injection and at 15, 30, 60, 120, 240, 480, and 720
min after oral administration from 3 ether-anesthetized rats
at each time point. Plasma was recovered by centrifugation
and mixed with an equal volume of 20% TCA to remove
protein. The drug concentrations in plasma were determined
by reversed-phase HPLC analysis using a YMCpack AM-302
column with a linear gradient of 0.1% TFA and CH3CN,
monitoring of UV absorbance at 254 and 295 nm. The elimina-
tion portion of the semilogarithmic plasma concentration was
analyzed by linear regression. AUC values were determined
by the linear trapezoidal method and extrapolated to 12 h.
1.00 (dd, J ) 5.3, 9.0 Hz, 1H), 1.38-1.48 (m, 1H), 3.45 (dd, J
) 9.2, 11.8 Hz, 1H), 3.52 (d, J ) 12.2 Hz, 1H), 3.77 (d, J )
12.2 Hz, 1H), 3.86 (s, 2H), 3.87 (dd, J ) 6.3, 11.8 Hz, 1H),
8.11 (s, 1H); 13C NMR (CD3OD) δ 15.0, 25.6, 27.5, 54.6, 62.8,
63.2, 96.1, 147.1, 152.8, 162.1; HRMS calcd for C10H14BrN2O4
(MH+) 307.0117, found 307.0110. Anal. (C10H13BrN2O4) C, H,
N.
1-[(1′S,2′R)-1′,2′-Bis(h yd r oxym et h yl)cyclop r op -1′-yl]-
m eth yl-5-iod o-2,4(1H,3H)-p yr im id in ed ion e (13): colorless
solid; yield 39%; mp 148-150 °C; [R]25 ) +7.6 (c ) 0.841%,
D
MeOH); 1H NMR (CD3OD) δ 0.55 (t, J ) 5.4 Hz, 1H), 1.00 (dd,
J ) 5.4, 8.7 Hz, 1H), 1.36-1.47 (m, 1H), 3.45 (dd, J ) 9.0,
11.7 Hz, 1H), 3.51 (d, J ) 12.0 Hz, 1H), 3.76 (d, J ) 12.0 Hz,
1H), 3.86 (dd, J ) 6.3, 11.7 Hz, 1H), 3.86 (2H, s), 8.17 (s, 1H);

282 J ournal of Medicinal Chemistry, 2000, Vol. 43, No. 2
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