Synthesis and anti-influenza virus activity of tricyclic compounds with a unique amine moiety

Article abstract of DOI:10.1248/cpb.49.379

Several novel tricyclic compounds with a unique amine moiety (1, 2a - i) were designed and prepared based on the structure of triperiden for the development of anti-influenza virus agents. An in vitro antiviral assay showed that 1-(1-azabicyclo[3.3.)]octa

Full text of DOI:10.1248/cpb.49.379

April 2001
Chem. Pharm. Bull. 49(4) 379—383 (2001)
379
Synthesis and Anti-influenza Virus Activity of Tricyclic Compounds with
a Unique Amine Moiety
Mitsuru OKA,* Yoshiro ISHIWATA, Noriyuki IWATA, Naoki HONDA, and Takuji KAKIGAMI
Central Research Laboratory, Sanwa Kagaku Kenkyusho, Co., Ltd., 363 Shiosaki, Hokusei-cho, Inabe-gun, Mie 511–0406,
Japan. Received September 21, 2000; accepted December 20, 2000
Several novel tricyclic compounds with a unique amine moiety (1, 2a—i) were designed and prepared based
on the structure of triperiden for the development of anti-influenza virus agents. An in vitro antiviral assay
showed that 1-(1-azabicyclo[3.3.0]octan-5-yl)-1-(4-fluorophenyl)-1-(2-tricyclo[3.3.1.13,7]decyl)methan-1-ol hy-
drochloride (2f) has a potent anti-influenza A virus activity. Furthermore, since 2f was well tolerated in mice, 2f
is promising as a novel anti-influenza virus agent for humans.
Key words anti-influenza virus agent; 1-azabicyclo[3.3.0]octane; triperiden; adamantane
An epidemic of influenza, which is one of the infections of noethyl group of triperiden with a 1-azabicyclo[3.3.0]octyl
most concern for humans, occurs almost every year and oc- group, which is an effective amine moiety for various biolog-
casionally on a global scale. Infections of the elderly, infants ically active substances.8) Secondly, we introduced a 2-tricy-
and chronic invalids with the virus can cause severe diseases clo[3.3.1.13,7]decyl group instead of the tricyclo[2.2.1.02,6]-
such as pneumonia and encephalitis, and in some cases, can heptyl group as a bulky and hydrophobic moiety. Thirdly,
bring about the death of the patient.
various functional groups were introduced into the benzene
Amantadine,1) a well-known chemotherapeutic agent for in- ring (Chart 1).
fection, inhibits viral replications by acting on the membrane
In this paper, we describe the syntheses and in vitro anti-
protein M2, which is located on the surface of the influenza influenza A virus activities of these compounds. We also
A virus particle. This agent is not effective against the in- mention the cytotoxicity tests of the most active compound
fluenza B virus which does not have the M2 protein, and it 2f.
has an adverse effect on the central nervous system. Rib-
Chemistry Diastereomixture 1 was prepared from 5-
avirin,2) which is also a well-known antiviral agent, inhibits cyano-1-azabicyclo[3.3.0]octane (3)9) via two addition reac-
RNA synthesis in cells. Rationally designed neuraminidase tions involving an initial addition of phenyllithium followed
(NA) inhibitors, zanamivir3) and oseltamivir,4) inhibit the re- by treatment with Grignard reagent from 3-chlorotricy-
lease of the virus from cells by acting on NA, which is a clo[2.2.1.02,6]heptane,10) as shown in Chart 2. Each diastere-
membrane protein on the viral envelope. Meanwhile Presber omer was separated by silicagel column chromatography, and
et al.5) reported that triperiden, one of the anti-parkinsonism their chemical shifts were assigned by H/C shift correlated
agents, inhibits the replication of the influenza A virus. spectroscopy. The stereochemistry of each diastereomer was
Ghendon et al.6) suggested that it acts directly on hemagglu- estimated by observations of the nuclear Overhauser effect
tinin (HA), which is another membrane protein of the viral (NOE) and shielding effect. The NOE difference spectrum
particle. On the other hand, Ott and Wunderli-Allenspach7) showed that irradiation of the hydrogen atom of the hydroxy
proposed that the antiviral effect is caused by increase in the group in a major product led to an increase in the signal of
prelysosomal pH.
We noticed that the action of triperiden is different from
the actions of amantadine, ribavirin and neuraminidase in-
hibitors, since it is expected that derivatives of triperiden
having a different action mechanism would be effective
against a virus acquiring drug tolerance. Combination ther-
apy with already-known drugs would also be useful in
chemotherapy. Thus, we designed novel derivatives based on
triperiden to decrease the neurotoxicity of this agent and to
increase its antiviral potency. First, we replaced the piperidi-
Chart 1
Chart 2
To whom correspondence should be addressed. e-mail: m_oka@mb6.skk-net.com
© 2001 Pharmaceutical Society of Japan

380
Vol. 49, No. 4
hydrogen atoms at the 1-, 2- and 7-positions of the tricyclo- two addition reactions. The first was an addition of 2-tricy-
heptane ring. Further, the upfield shift of the hydrogen atom clo[3.3.1.13,7]decyllithium11) to 3 to yield 1-(1-azabicyclo-
at the 4-position of the ring was observed, and this shift can [3.3.0]octan-5-yl)-1-(2-tricyclo[3.3.1.13,7]decyl)methan-1-
be caused by the shielding effect of the phenyl group. The one (5); the second was an addition of the appropriate aryl
chemical shifts of the hydrogen atom at the 4-position of the Grignard or aryllithium reagent12) derived from aryl bromide
major product were 1.20—1.34 ppm, and that of the minor to 5, respectively (Chart 3). Compound 2e was prepared by
product was 2.35 ppm. In the minor product, however, NOE the deprotection of the oxathiolane group13) to the carbonyl
interactions of the hydrogen atom of the hydroxy group with group after the addition of 4-(2-methyl-1,3-oxathiolane-2-
the hydrogen atoms at the 3- and 4-positions of the tricyclo- yl)phenyllithium12) to 5.
heptane ring were observed in the NOE difference spectrum.
Further, the upfield shifts of the hydrogen atoms at the 1- and Pharmacological Results and Discussion
7-positions of the ring were observed. These shifts can also
The anti-influenza virus activities of 1, 2a—i, ribavirin
be caused by the shielding effect of the phenyl group. The and triperiden were evaluated in vitro at doses of 5 mg and
chemical shift on the hydrogen atom at the 1-position of the 10 mg/ml. The tissue culture infectious doses (TCID50) of in-
major product was 1.50—1.58 ppm, and that of the minor fluenza A virus in the presence or absence of test compounds
product was 0.81—0.84 ppm. The chemical shifts at the 7- were calculated by microscopic observations of the cyto-
position of the major product were 0.84 and 1.62 ppm, while pathic effect (CPE) induced by the virus on Madin–Darby
those of the minor product were 0.46 and 0.70 ppm. These canine kidney (MDCK) cells. The activity values, DTCID50
data showed that the relative configuration of the major prod- (log10), shown in Table 1 indicate the differences between the
uct was (1R*,3ЈS*) and that of the minor product was TCID50 (log10) of the test compound-treated group and that
(1R*,3ЈR*), as shown in Chart 2.
of the untreated group. Compound (1R*,3ЈS*)-1 showed a
Compounds 2a—i (except 2e) were prepared from 3 via higher activity than triperiden; the replacement of piperidine
with 1-azabicyclo[3.3.0]octane enhanced the activity. The
following hydrophobic group modification, namely, the sub-
stitution of tricyclo[3.3.1.13,7]decane for tricyclo[2.2.1.02,6]-
heptane, led to a higher activity at a dose of 10 mg/ml;
DTCID50 (log10) values showed that the activity of 2a in-
creased approximately five-fold over that of triperiden. In the
modification of the phenyl group of 2a, the introduction of a
fluoro group to the para position produced the remarkably
potent compound 2f. Compound 2f was approximately thirty
times as active as triperiden at a dose of 10 mg/ml. The activ-
Chart 3
ity of ribavirin in this assay was slightly lower than that of
Table 1. Anti-influenza A Virus Activities in Vitro of Tricyclic Compounds
DTCID50 (log10)b)
CC50
Compd.
R
mp (°C)
Formulaa)
(mg/ml)c)
5 mg/ml
10 mg/ml
Ribavirin
0.33
0.00
0.17
1.83
0.50
0.83
0.00
1.17
1.34
0.33
Ͼ100
Triperidend)
(1R*,3ЈS*)-1
(1R*,3ЈR*)-1
203—206
192—195
238—242
220—225
235—238
187—190
218—220
232—235
146—148
210—213
195—200
C21H27NO·HCl
C21H27NO·HCl
C24H33NO·HCl
C25H35NO·HCl
C25H32F3NO·HCl
C30H37NO·HCl
C26H35NO2·HCl
C24H32FNO·HCl
C26H38N2O·2HCl
C25H32F3NO·HCl
C25H35NO·HCl
2a
2b
2c
2d
2e
2f
2g
2h
2i
H
p-CH3
p-CF3
p-C6H5
p-COCH3
p-F
p-N(CH3)2
m-CF3
o-CH3
0.00
0.17
0.33
2.17
0.50
1.00
32.5
36.9
Ϫ
e) (ϩ)f )
1.00
2.00
53.9
0.17 (ϩ)f )
0.00
0.33
Ϫ
e) (ϩ)f )
a) All compounds had elemental analyses (C, H, N) within Ϯ0.3% of the theoretical values. b) The difference between the log reduction of TCID50 of test compound-
treated group and that of untreated group. c) 50% cytotoxic concentration. d) A diastereomeric mixture. e) Not determined. f ) Cytotoxicity.

April 2001
381
1
and 1.84 g (14.3%) of (1R*,3ЈR*)-1 as colorless prisms. (1R*,3ЈS*)-1: H-
2f; the DTCID50 (log10) of ribavirin was 1.83 at a dose of
10 mg/ml. The 50% cytotoxic concentration (CC50) of 2f was
53.9 mg/ml in MDCK cells, and that of ribavirin was
Ͼ100 mg/ml (Table 1).
We were anxious about a cholinolytic action of 2f, because
triperiden is an anti-parkinsonism drug. Thus, in vivo toxicity
tests for triperiden and 2f were performed using BALB/c
mice. The administration of triperiden (i.p. 80 mg/kg) caused
a transient convulsion and a lateral turning in one of two
NMR (CDCl3) d: 0.84 (1H, d, Jϭ10.7 Hz, 7-tricycloheptane H), 1.08 (1H, d,
Jϭ10.3 Hz, 5-tricycloheptane H), 1.20—1.34 (4H, m, 4,5,6-tricycloheptane
H, 4,6-azabicylooctane H), 1.50—1.58 (2H, m, 1,2-tricycloheptane H), 1.62
(1H, d, Jϭ10.7 Hz, 7-tricycloheptane H), 1.72—1.92 (3H, m, one proton of
4,6-azabicylooctane H, two protons of 3,7-azabicylooctane H), 2.10—2.25
(3H, m, one proton of 4,6-azabicylooctane H, two protons of 3,7-azabicy-
looctane H), 2.30 (1H, s, 3-tricycloheptane H), 2.93—3.00 (2H, m, one pro-
ton of 4,6-azabicylooctane H, one proton of 2,8-azabicylooctane H), 3.23-
3.28 (1H, m, 2,8-azabicylooctane H), 3.70—3.79 (1H, m, 2,8-azabicyclo-
octane H), 4.14—4.20 (1H, m, 2,8-azabicylooctane H), 4.47 (1H, br s, OH),
mice after eight minutes thirty seconds; these were probably 7.28—7.40 (4H, m aromatic H), 7.83-7.94 (1H, m, aromatic H), 10.9 (1H, br
s, NϩH). 13C-NMR (CDCl3) d: 12.46 (1-tricycloheptane C), 13.18 (6-tri-
from side-effects relating to the nervous system. In addition,
a deficiency phenomenon was observed after thirteen min-
utes and ten seconds. The administration of 2f in the same
cycloheptane C), 13.24 (2-tricycloheptane C), 22.19, 25.37 (3,7-azabicyclo-
octane C), 29.79 (7-tricycloheptane C), 34.43 (5-tricycloheptane C), 34.54
(4-tricycloheptane C), 35.91, 37.64 (4,6-azabicyclooctane C), 50.23 (3-tricy-
manner, however, did not induce any abnormalities for up to
seventy minutes in two cases. No abnormal anatomical find-
ings were observed with either of the administrations.
cloheptane C), 55.85, 58.80 (2,8-azabicyclooctane C), 79.02 (1-C), 89.80 (5-
azabicyclooctane C), 127.07, 125.00, 128.50, 142.61 (aromatic C). IR (KBr)
cmϪ1: 3209 (O–H), 2990 (C–H). MS (CI) m/z: 310 (MϩH)ϩ. (1R*,3ЈR*)-1:
1H-NMR (CDCl3) d: 0.46 (1H, d, Jϭ10.7 Hz, 7-tricycloheptane H), 0.70
(1H, d, Jϭ10.7 Hz, 7-tricycloheptane H), 0.81—0.84 (1H, m, 1-tricyclohep-
tane H), 1.14—1.26 (4H, m, 2,6-tricycloheptane H, 5-tricycloheptane H,
4,6-azabicyclooctane), 1.47 (1H, d, Jϭ10.3 Hz, 5-tricycloheptane H), 1.83—
2.38 (6H, m, 3,7-azabicyclooctane H, two protons of 4,6-azabicyclooctane
H), 2.35 (1H, s, 4-tricycloheptane H), 2.51 (1H, s, 3-tricycloheptane H),
2.97—3.22 (3H, m, one proton of 4,6-azabicyclooctane H, two protons of
2,8-azabicyclooctane H), 3.66—3.75 (1H, m, 2,8-azabicyclooctane H),
3.95—4.01 (1H, m, 2,8-azabicyclooctane H), 4.99 (1H, s, OH), 7.22—7.53
(4H, m, aromatic H), 7.90—7.93 (1H, m, aromatic H), 11.6 (1H, br s, NϩH).
13C-NMR (CDCl3) d: 12.18 (1-tricycloheptane C), 12.97 (6-tricycloheptane
C), 14.82 (2-tricycloheptane C), 23.53, 25.61 (3,7-azabicyclooctane C),
29.58 (7-tricycloheptane C), 33.21 (4-tricycloheptane C), 34.28 (5-tricyclo-
heptane C), 35.78, 37.03 (4,6-azabicyclooctane C), 52.56 (3-tricycloheptane
C), 55.84, 57.77 (2,8-azabicyclooctane C), 79.42 (1-C), 91.47 (5-azabicyclo-
In conclusion, through the structure modification of
triperiden we developed a novel and potent anti-influenza
virus agent, 2f, which had no adverse effects. Interactions of
the agent with a biopolymer might be improved favorably by
the modification. In the toxicity test of triperiden, however,
we observed adverse effects, i.e., transient convulsion, lateral
turning and deficiency phenomenon, which might have been
induced by a cholinolytic action caused by the anti-parkin-
sonism drug, while no side-effect was observed in the test of
2f (i.p. 80 mg/kg). In addition, since the action mechanism of
2f may be the same as that of triperiden, and may differ from
those of amantadine and neuraminidase inhibitors, this agent
is expected to be effective on variants of the influenza virus octane C), 125.87, 126.62, 127.15, 128.01, 128.29, 141.05 (aromatic C). IR
(KBr) cmϪ1: 3320 (O–H), 2878 (C–H). MS (CI) m/z: 310 (MϩH)ϩ.
1-(1-Azabicyclo[3.3.0]octan-5-yl)-1-(2-tricyclo[3.3.1.13,7]decyl)methan-
which are resistant toward these drugs.
1-one (5) To a solution of 3 (5.45 g, 40.0 mmol) in ether (200 ml), a solu-
Experimental
tion of 2-tricyclo[3.3.1.13,7]decyllithium (64.8 mmol) in ether (600 ml) was
Melting points were measured on a Yanagimoto micromelting point appa- added dropwise over a period of 2 h at Ϫ50 °C. The mixture was stirred at
ratus and were uncorrected. Infrared (IR) spectra were obtained on a JASCO Ϫ50 °C for 1 h, followed by stirring at room temperature for 18 h, and was
FT/IR-8000; 1H-NMR spectra were obtained on a JEOL JNM-GSX 270 then poured into ice water (500 ml). The solution was adjusted to pH 3 with
1
spectrometer (270 MHz for H and 68 MHz for 13C) using tetramethylsilane
3 N HCl, stirred at 5 °C for 1.5 h, and extracted with ether (3ϫ500 ml). The
as an internal standard; mass spectra were obtained on a JEOL JMS-DX 300 aqueous layer was adjusted to pH 9 with NaHCO3 and extracted with ether
spectrometer; and elemental analyses for C, H, and N were obtained on a (4ϫ500 ml). The organic layers were combined, dried over Na2SO4, and con-
1
Yanaco CHN Analyzer MT-5.
centrated to afford 9.02 g (82.5%) of 5 as colorless prisms. mp: 75 °C. H-
5-Benzoyl-1-azabicyclo[3.3.0]octane (4) To a solution of 3 (4.09 g, NMR (CDCl3) d: 1.45—1.92 (16H, m, 4,6,8,9,10-tricyclodecane H, 3,7-aza-
30.0 mmol) in ether (30 ml), 1.8 M phenyllithium ether solution (20.0 ml, bicyclooctane H, two protons of 4,6-azabicycloocatane H), 2.03—2.13 (4H,
36.0 mmol) was added dropwise over a period of 45 min at Ϫ50 to Ϫ60 °C. m, 5,7-tricyclodecane H, two protons of 4,6-azabicycloocatane H), 2.22 and
The mixture was stirred at 0 °C for 30 min, and water (20 ml) was added fol- 2.27 (2H, s, 1,3-tricyclodecane H), 2.59—2.69 (2H, m, 2,8-azabicyclooctane
lowed by the addition of 10% sulfuric acid (50 ml). After stirring at 0—5 °C H), 3.07—3.15 (2H, m, 2,8-azabicyclooctane H), 3.23 (1H, s, 2-tricyclode-
for 2 h, the mixture was neutralized with NaHCO3 and made basic with 20% cane H). IR (KBr) cmϪ1: 2903 (C–H), 1696 (CϭO). MS (CI) m/z: 274
NaOH. The aqueous layer was extracted with CH2Cl2 (3ϫ100 ml). The com- (MϩH)ϩ.
bined organic layer was dried over Na2SO4, concentrated in vacuo, and dis-
1-(1-Azabicyclo[3.3.0]octan-5-yl)-1-phenyl-1-(2-tricyclo[3.3.1.13,7]-
tilled to afford 5.17 g (80.2%) of 4 as a colorless oil. bp: 126—129 °C decyl)methan-1-ol Hydrochloride (2a) To
a solution of 5 (1.50 g,
(1.4 mmHg). 1H-NMR (CDCl3) d: 1.64—1.98 (6H, m, 3,7-H, two protons of 5.49 mmol) in THF (15 ml), a solution of phenylmagnesium bromide
4,6-H), 2.31—2.41 (2H, m, 4,6-H), 2.70—2.79 (2H, m, 2,8-H), 3.11—3.20 (16.5 mmol) prepared from bromobenzene and magnesium turnings in THF
(2H, m, 2,8-H), 7.37—7.51 (3H, m, aromatic H), 8.01—8.04 (2H, m, aro-
matic H). IR (neat) cmϪ1: 2963 (C–H), 1672 (CϪO). MS (CI) m/z: 216
(MϩH)ϩ.
(15 ml) was added dropwise at Ϫ30 to Ϫ40 °C. The mixture was stirred at
20 °C for 18 h and poured into a saturated ammonium chloride solution in an
ice bath. The solution was adjusted to pH 10 with 10% NaOH and extracted
with ether (2ϫ300 ml). The organic layers were combined, dried over
(1R*)-1-(1-Azabicyclo[3.3.0]octan-5-yl)-1-phenyl-1-((3S*)-3-tricyclo-
[2.2.1.02,6]heptyl)methan-1-ol Hydrochloride ((1R*,3؅S*)-1) and (1R*)-1- Na2SO4, concentrated in vacuo, and recrystallized from CH2Cl2/MeOH. The
(1-Azabicyclo[3.3.0]octan-5-yl)-1-phenyl-1-((3R*)-3-tricyclo[2.2.1.02,6]- resulting prisms were converted to hydrochloride with hydrochloric acid and
1
heptyl)methan-1-ol Hydrochloride ((1R*,3؅R*)-1) To a solution of 4 lyophilized to afford 1.50 g (70.5%) of 2a as a colorless powder. H-NMR
(8.00 g, 37.2 mmol) in ether (60 ml), a solution of 3-tricyclo[2.2.1.02,6]- (CDCl3) d: 1.60—2.49 (22H, m, tricyclodecane H, 3,7-azabicyclooctane H,
heptylmagnesium chloride (81.8 mmol) in ether (80 ml) was added dropwise three protons of 4,6-azabicyclooctane H), 3.01—3.35 (4H, m, three protons
over a period of 30 min at Ϫ5 to 0 °C. The mixture was stirred at 20 °C for of 2,8-azabicyclooctane H, one proton of 4,6-azabicyclooctane H), 4.18—
2 h and poured into a saturated ammonium chloride solution (100 ml) in an 4.29 (1H, m, 2,8-azabicyclooctane H), 5.18 (1H, br s, OH), 7.23—7.50 (4H,
ice bath. The ether layer was separated, and the aqueous layer was extracted m, aromatic H), 7.97—8.00 (1H, m, aromatic H), 9.76 (1H, br s, NϩH). IR
with ether (3ϫ150 ml). The organic layers were combined, dried over (KBr) cmϪ1: 3376 (O–H), 2907 (C–H). MS (CI) m/z: 352 (MϩH)ϩ.
MgSO4, concentrated in vacuo, and separated into each diastereomer by sil-
1-(1-Azabicyclo[3.3.0]octan-5-yl)-1-(4-methylphenyl)-1-(2-tricyclo-
icagel column chromatography (toluene/tetrahydrofuran (THF)). Each di- [3.3.1.13,7]decyl)methan-1-ol Hydrochloride (2b): By a procedure similar
astereomer was converted to hydrochloride with hydrogen chloride in ether to that described for 2a, compound 2b was prepared as colorless powders
and recrystallized from isopropanol to afford 3.51 g (27.2%) of (1R*,3ЈS*)-1 from 5 and 4-methylphenylmagnesium bromide in an 81.8% yield. 1H-NMR

382
Vol. 49, No. 4
matic H), 10.3 (2H, br s, NϩH). IR (KBr) cmϪ1: 3421 (OH). MS (CI) m/z:
395 (MϩH)ϩ.
(CDCl3) d: 1.17—1.22 (1H, m, 6-tricyclodecane H), 1.57—2.50 (21H, m,
tricyclodecane H, 3,7-azabicyclooctane H, three protons of 4,6-azabicyclo-
octane), 2.33 (3H, s, CH3), 2.83—3.15 (4H, m, three protons of 2,8-azabi-
cyclooctane, one proton of 4,6-azabicyclooctane), 4.10—4.18 (1H, m, 2,8-
azabicyclooctane H), 4.95 (1H, br s, OH), 7.06 (1H, dd, Jϭ8.3, 2.0 Hz, 3-
aromatic H), 7.16 (1H, dd, Jϭ8.3, 2.0 Hz, 3-aromatic H), 7.30 (1H, dd, Jϭ
8.3, 2.0 Hz, 2-aromatic H), 8.11 (1H, dd, Jϭ8.3, 2.0 Hz, 2-aromatic H), 10.1
(1H, br s, NϩH). IR (KBr) cmϪ1: 3386 (O–H), 2903 (C–H). MS (CI) m/z:
366 (MϩH)ϩ.
1-(1-Azabicyclo[3.3.0]octan-5-yl)-1-(2-tricyclo[3.3.1.13,7]decyl)-1-(3-tri-
fluoromethylphenyl)methan-1-ol Hydrochloride (2h): By a procedure simi-
lar to that described for 2a, compound 2h was prepared as colorless powders
from 5 and 3-trifluoromethylphenylmagnesium bromide in an 80.2% yield.
1H-NMR (CDCl3) d: 1.05—1.19 (1H, m, 6-tricyclodecane H), 1.39—2.64
(21H, m, tricyclodecane H, 3,7-azabicyclooctane H, three protons of 4,6-
azabicyclooctane), 2.87—3.30 (4H, m, three protons of 2,8-azabicyclo-
octane, one proton of 4,6-azabicyclooctane), 4.02—4.19 (1H, m, 2,8-azabi-
cyclooctane H), 5.56 (1H, br s, OH), 7.28—7.64 (3H, m, aromatic H),
8.35—8.43 (1H, m, aromatic H), 10.8 (1H, br s, NϩH). IR (KBr) cmϪ1: 3370
(O–H), 2901 (C–H). MS (CI) m/z: 420 (MϩH)ϩ.
1-(1-Azabicyclo[3.3.0]octan-5-yl)-1-(2-methylphenyl)-1-(2-tricyclo-
[3.3.1.13,7]decyl)methan-1-ol Hydrochloride (2i): By a procedure similar to
that described for 2a, compound 2i was prepared as colorless powders from
5 and 2-methylphenylmagnesium bromide in a 55.1% yield. 1H-NMR
(CDCl3) d: 1.18—3.16 (26H, m, tricyclodecane H, azabicyclooctane H),
2.39 (3H, s, CH3), 3.74—4.22 (1H, m, 2,8-azabicyclooctane H), 4.51 (1H, br
s, OH), 7.08—7.31 (3H, m, aromatic H), 8.09—8.13 (1H, m, aromatic H),
10.3 (NϩH). IR (KBr) cmϪ1: 3384 (OH), 2903 (C–H). MS (CI) m/z: 366
(MϩH)ϩ.
Reference Compounds Triperiden was synthesized at our laboratory by
a known procedure,14) and ribavirin was purchased from Sigma-Aldrich.
Tests for the Anti-influenza Virus Activities Confluent monolayers of
MDCK cells in 96-well plates were infected with the influenza virus
(A/PR/8 strain) in the presence or absence of the test compounds. After in-
cubation at 37 °C for 2 d, the CPE of the virus-infected culture were micro-
scopically observed. The virus titer, TCID50, was determined by microscopic
observations of CPE at concentrations of 5 mg and 10 mg/ml of the test com-
pounds. The DTCID50 (log10) values were calculated as described in Table 1.
Cytotoxicitity Tests in Vitro A confluent monolayer of MDCK cells in
a 96-well plate was incubated with the test compounds (ribavirin, 2a, 2b, 2f)
at 37 °C for 2 d. After the incubation, the cells were stained with a 0.1% neu-
tral red solution and the dye incorporated into live cells was extracted with a
mixture of 0.1 M NaH2PO4 and ethanol. The absorbance at 546 nm was de-
termined. The cytotoxicity was calculated from the absorbance and ex-
pressed as CC50.
1-(1-Azabicyclo[3.3.0]octan-5-yl)-1-(2-tricyclo[3.3.1.13,7]decyl)-1-(4-tri-
fluoromethylphenyl)methan-1-ol Hydrochloride (2c): By a procedure similar
to that described for 2a, compound 2c was prepared as colorless powders
from 5 and 4-trifluoromethylphenylmagnesium bromide in a 37.8% yield.
1H-NMR (CDCl3) d: 1.13—1.18 (1H, m, 6-tricyclodecane H), 1.53—2.47
(21H, m, tricyclodecane H, 3,7-azabicyclooctane H, three protons of 4,6-
azabicyclooctane), 2.90—3.48 (4H, m, three protons of 2,8-azabicyclo-
octane, one proton of 4,6-azabicyclooctane), 4.20—4.26 (1H, m, 2,8-azabi-
cyclooctane H), 5.60 (1H, br s, OH), 7.40 (1H, d, Jϭ8.3 Hz, 3-aromatic H),
7.52 (1H, d, Jϭ8.3 Hz, 3-aromatic H), 7.73 (1H, d, Jϭ8.3 Hz, 2-aromatic H),
8.34 (1H, d, Jϭ8.3 Hz, 2-aromatic H), 10.7 (1H, br, NϩH). IR (KBr) cmϪ1
3393 (O–H), 2916 (C–H). MS (CI) m/z: 420 (MϩH)ϩ.
:
1-(1-Azabicyclo[3.3.0]octan-5-yl)-1-(4-biphenyl)-1-(2-tricyclo-
[3.3.1.13,7]decyl)methan-1-ol Hydrochloride (2d): By a procedure similar
to that described for 2a, compound 2d was prepared as colorless powders
1
from 5 and biphenyllithium in a 76.1% yield. H-NMR (CDCl3) d: 1.14—
1.22 (1H, m, 6-tricyclodecane H), 1.55—2.47 (21H, m, tricyclodecane H,
3,7-azabicyclooctane H, three protons of 4,6-azabicyclooctane), 2.82—3.18
(4H, m, three protons of 2,8-azabicyclooctane, one proton of 4,6-azabicyclo-
octane), 4.01—4.13 (1H, m, 2,8-azabicyclooctane H), 5.04 (1H, m, OH),
7.32—7.76 (8H, m, aromatic H), 8.29 (1H, d, Jϭ7.3 Hz, aromatic H), 10.5
(1H, br s, NϩH). IR (KBr) cmϪ1: 3422 (O–H). 749, 699 (Ar–H). MS (CI)
m/z: 428 (MϩH)ϩ.
1-(4-Acetylphenyl)-1-azabicyclo[3.3.0]octan-5-yl)-1-(2-tricyclo-
[3.3.1.13,7]decyl)methan-1-ol Hydrochloride (2e): By a procedure similar to
that described for 2a, 1-(1-azabicyclo[3.3.0]octan-5-yl)-1-(4-(2-methyl-1,3-
oxathiolane-2-yl)phenyl)-1-(2-tricyclo[3.3.1.13,7]decyl)methan-1-ol was pre-
pared from
5 and 4-(2-methyl-1,3-oxathiolane-2-yl)phenyllithium in a
47.3% yield. The mixture of oxathiolane (1.00 g, 2.20 mmol) and HgCl2
(598 mg, 2.20 mmol) in THF (50 ml) was stirred at room temperature for
5 min. After the addition of 0.1 N NaOH (2.20 ml), the mixture was stirred
for 10 min and extracted with CH2Cl2. The organic layer was dried over
Na2SO4, concentrated in vacuo, and purified by silicagel column chromatog-
raphy. The resulting prisms were recrystallized from CH2Cl2/MeOH, con-
verted to hydrochloride with hydrochloric acid, and lyophilized to afford
401 mg (46.2%) of 2e as a colorless powder. 1H-NMR (CDCl3) d: 1.14—
1.18 (1H, m, 6-tricyclodecane H), 1.58—2.48 (21H, m, tricyclodecane H,
3,7-azabicyclooctane H, three protons of 4,6-azabicyclooctane), 2.62 (3H, s,
COCH3), 2.85—3.13 (4H, m, three protons of 2,8-azabicyclooctane, one
proton of 4,6-azabicyclooctane), 4.09—4.17 (1H, m, 2,8-azabicyclooctane
H), 5.42 (1H, br s, OH), 7.40 (1H, dd, Jϭ8.3, 2.0 Hz, aromatic H), 7.89 (1H,
dd, Jϭ8.3, 2.0 Hz, aromatic H), 8.04 (1H, dd, Jϭ8.3, 2.0 Hz, aromatic H),
8.34 (1H, dd, Jϭ8.3, 2.0 Hz, aromatic H), 10.7 (NϩH). IR (KBr) cmϪ1: 3424
(O–H). 1680 (CϭO). MS (CI) m/z: 394 (MϩH)ϩ.
1-(1-Azabicyclo[3.3.0]octan-5-yl)-1-(4-fluorophenyl)-1-(2-tricyclo-
[3.3.1.13,7]decyl)methan-1-ol Hydrochloride (2f): By a procedure similar to
that described for 2a, compound 2f was prepared as colorless powders from
5 and 4-fluorophenylmagnesium bromide in a 65.9% yield. 1H-NMR
(CDCl3) d: 1.12—1.21 (1H, m, 6-tricyclodecane H), 1.52—2.44 (21H, m,
tricyclodecane H, 3,7-azabicyclooctane H, three protons of 4,6-azabicyclo-
octane), 2.87—3.27 (4H, m, three protons of 2,8-azabicyclooctane, one pro-
ton of 4,6-azabicyclooctane), 4.10—4.21 (1H, m, 2,8-azabicyclooctane H),
5.33 (1H, br s, OH), 6.92—7.28 (3H, m, aromatic H), 8.16—8.23 (1H, m,
aromatic H), 10.4 (1H, br s, NϩH). IR (KBr) cmϪ1: 3420 (OH), 2911 (C–H).
MS (CI) m/z: 370 (MϩH)ϩ.
Toxicity Tests in Vivo The toxicity tests were performed using two mice
per group; male BALB/c mice weighing 30—35 g were used for the test.
Triperiden and 2f suspended in 5% gum arabic saline were injected in-
traperitoneally into mice at a dosage of 80 mg/kg (0.1 ml/10 g). The behav-
iors of mice were observed, and finally autopsies were performed.
Acknowledgments We would like to thank Dr. T. Ikami and Mr. H.
Hamajima for their assistance with the mass spectral measurements and the
elemental analyses.
References and Notes
1) Davies W. L., Grunert R. R., Haff R. F., McGahen J. W., Neumayer E.
M., Paulshock M., Watts J. C., Wood T. R., Hermann E. C., Hoffmann
C. E., Science, 144, 862—863 (1964).
2) Sidwell R. W., Robins R. K., Hillyard I. W., Pharmac. Ther., 6, 123—
146 (1979).
3) von Itzstein M., Wu W.-Y., Kok G. B., Pegg M. S., Dyason J. C., Jin
B., Phan T. V., Smythe M. L., White H. F., Oliver S. W., Colman P. M.,
Varghese J. N., Ryan D. M., Woods J. M., Bethell R. C., Hotham V. J.,
Cameron J. M., Penn C. R., Nature (London), 363, 418—423 (1993).
4) Kim C. U., Lew W., Williams M. A., Liu H., Zhang L., Swaminathan
S., Bischofberger N., Chen M. S., Mendel D. B., Tai C. Y., Laver W.
G., Stevens R. C., J. Am. Chem. Soc., 119, 681—690 (1997).
5) Presber H. W., Schroeder C., Hegenscheid B., Heider H., Reefschläger
J., Rosenthal H. A., Acta Virol., 28, 501—507 (1984).
6) Ghendon Y., Markushin S., Heider H., Melnikov S., Lotte V., J. Gen.
Virol., 67, 1115—1122 (1986).
1-(1-Azabicyclo[3.3.0]octan-5-yl)-1-(4-(dimethylamino)phenyl)-1-(2-tri-
cyclo[3.3.1.13,7]decyl)methan-1-ol Dihydrochloride (2g): By a procedure
similar to that described for 2a, compound 2g was prepared as colorless
7) Ott S., Wunderli-Allenspach H., Antiviral Res., 24, 37—42 (1994).
8) Miyano S., Shima K, Hayashimatsu M., Satoh F, Sumoto K., J. Pharm.
Sci., 76, 416—418 (1987); Kakigami T., Usui T., Ikami T., Tsukamoto
K., Miwa Y., Taga T., Kataoka T., Chem. Pharm, Bull., 46, 1039—
1043 (1998); Suzuki T., Oka M., Maeda K., Furusawa K., Uesaka H.,
Kataoka T., ibid., 47, 28—36 (1999).
9) Oka M., Matsumoto Y., Unno R., Heterocycles, 45, 1447—1450
(1997).
10) Reetz M. T., Sauerwald M., Chem. Ber., 114, 2355—2356 (1981).
1
powders from 5 and 4-(dimethylamino)phenyllithium in a 75.5% yield. H-
NMR (CDCl3) d: 1.17—1.23 (1H, m, 6-tricyclodecane H), 1.41—2.43
(21H, m, tricyclodecane H, 3,7-azabicyclooctane H, three protons of 4,6-
azabicyclooctane), 2.86—3.20 (4H, m, three protons of 2,8-azabicyclo-
octane, one proton of 4,6-azabicyclooctane), 3.19 (6H, s, N(CH3)2), 4.11—
4.20 (1H, m, 2,8-azabicyclooctane H), 5.42 (1H, br s, OH), 7.36—65 (2H,
m, aromatic H), 7.92—7.98 (1H, m, aromatic H), 8.43—8.49 (1H, m, aro-

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11) Molle G., Bauer P., Dubois J. E., J. Org. Chem., 48, 2975—2981
(1983).
12) Jones R. G., Gilman H., Org. React., 6, 339—366 (1975).
13) Djerassi C, Gorman M., J. Am. Chem. Soc., 75, 3704—3708 (1953);
Djerassi C., Shamma M., Kan T. Y., ibid., 80, 4723—4732 (1958).
14) Lueche L., Runge H. J., Ger. (East) 124521 (1977) [Chem. Abstr., 88,
89350b (1978)].