Synthesis and in vitro antifungal activities of novel triazole antifungal agent CS-758

Article abstract of DOI:10.1248/cpb.49.1647

Synthesis and in vitro antifungal activities of a novel triazole antifungal agent CS-758 (former name, R120758) are described. The minimum inhibitory concentrations (MICs) of a series of dioxane-triazole compounds related to R-102557 were examined. Variat

Full text of DOI:10.1248/cpb.49.1647

December 2001
Notes
Chem. Pharm. Bull. 49(12) 1647—1650 (2001)
1647
Synthesis and in Vitro Antifungal Activities of Novel Triazole Antifungal
Agent CS-758
Toshiyuki KONOSU, ,a Sadao OIDA,a Yoshie NAKAMURA,a Shinobu SEKI,a Takuya UCHIDA,a
*
Atsushi SOMADA,a Makoto MORI,a Yoshiko HARADA,a Yasuki KAMAI,b Tamako HARASAKI,b
Takashi FUKUOKA,b Satoshi OHYA,b Hiroshi YASUDA,b Takahiro SHIBAYAMA,c Shin-ichi INOUE,c
d
Akihiko NAKAGAWA,c and Yasuo SETA
Medicinal Chemistry Research Laboratories,a Biological Research Laboratories,b Pharmacokinetics and Drug Delivery
Research Laboratories,c and Product Development Laboratories,d Sankyo Co., Ltd., 1–2–58 Hiromachi, Shinagawa-ku,
Tokyo 140–8710, Japan. Received July 9, 2001; accepted September 17, 2001
Synthesis and in vitro antifungal activities of a novel triazole antifungal agent CS-758 (former name, R-
120758) are described. The minimum inhibitory concentrations (MICs) of a series of dioxane–triazole com-
pounds related to R-102557 were examined. Variation of the length of the chain between the dioxane ring and the
phenyl ring revealed that the linkage with two double bonds is the most preferable. When a cyano group was in-
troduced to the C4 position on the benzene ring, MICs improved further. A fluorine atom was introduced to ob-
tain CS-758. The MICs of CS-758 surpassed those of fluconazole and itraconazole against Candida, Aspergillus
and Cryptococcus species. The precursor (E,E)-aldehyde was synthesized stereoselectively from 3-fluoro-4-
methylbenzonitrile using the Horner–Wadsworth–Emmons reaction.
Key words CS-758; R-120758; antifungal; triazole; Horner–Wadsworth–Emmons reaction
Recently we synthesized a series of dioxane–triazole anti- long in humans to exhibit reasonable therapeutic effects. On
fungal agents, which are effective against systemic my- this assumption, some of the previous compounds, such as
coses.1) From such compounds, R-102557 (3d) was chosen 3b—g,1) were re-evaluated on the basis of MICs. Their pre-
as a candidate compound for development on the basis of its cursor 1a was also submitted for MIC determination. Some
in vivo activities in mice. Since it was found that R-102557’s additional compounds, such as 2a, 3a, 3h—j, were prepared.
high in vivo activities were caused by its excessively long
Preparation of the compounds 2a, 3a, 3h—j were done in
elimination half-life in plasma,2) we determined to search for acetalization reactions of 4 with aldehydes 5a, 6a, 6h—j, re-
a similar compound but with a shorter half-life. In this paper, spectively (Chart 2). Previously, molecular sieves were then
we will describe the synthesis and in vitro antifungal activi- used to remove water,1) but this time we conducted the reac-
ties of our new compound CS-758 (3j; former name, R- tion by concentrating a tetrahydrofuran (THF) solution con-
120758),3) which is currently under development as an anti- taining 4, the aldehydes, and p-toluenesulfonic acid in a ro-
fungal agent against systemic mycoses.
tary evaporator. Aldehyde 6j, a precursor of CS-758, was
Starting our search, our attention was focused on minimun
inhibitory concentrations (MICs) because as the elimination
half-life in plasma gets shorter, the requirements for MICs
become severer. We reasoned that, even if a compound with
good MICs were to exhibit only fair in vivo activities in
mice, the compound might still be able to remain sufficiently
Chart 2
Chart 1
Chart 3
To whom correspondence should be addressed. e-mail: kohnos@shina.sankyo.co.jp
© 2001 Pharmaceutical Society of Japan

1648
Vol. 49, No. 12
prepared stereoselectively using the Horner–Wadsworth–Em- The difference was most clear in the activity against Crypto-
mons reaction of fumaraldehyde monoacetal 10 as depicted coccus neoformans.
in Chart 3.
We then fixed n to 2, and compared the MICs of the deriv-
The MICs of the compounds with various side chain atives 3b—f having various substituents at the C4 position on
lengths were determined against clinically important patho- the benzene ring Ar (Table 2). The compound with a cyano
genic fungi (Table 1). An unsubstituted phenyl group was group (3f) showed remarkable effect with excellent MICs.
first selected as the Ar group and compounds 1a (nϭ0), 2a The difference was the most clear in the activity against As-
(nϭ1), and 3a (nϭ2) were compared. Compound 3a with pergillus fumigatus.
two olefinic double bonds (nϭ2) showed the best MICs.4)
We finally introduced a fluorine atom to the C2 position on
Table 1. In Vitro Antifungal Activities of Compounds 1a, 2a, 3a
MIC (mg/ml)
Compound
n
Candida albicans
Cryptococcus neoformans
Aspergillus fumigatus
Aspergillus flavus
SANK 51486
TIMM 1855
SANK 10569
SANK 18497
1a
2a
3a
0
1
2
Ϲ0.008
Ϲ0.008
Ϲ0.008
0.25
0.031
0.016
4
0.25
0.25
Ͼ4
2
1
Table 2. In Vitro Antifungal Activites of Compounds 3a—j
MIC (mg/ml)
Compound
Ar
Candida albicans
Cryptococcus neoformans
Aspergillus fumigatus
Aspergillus flavus
SANK 51486
TIMM 1855
SANK 10569
SANK 18497
3a
Ϲ0.008
0.016
0.25
1
2
3b
3c
0.016
0.016
0.25
0.031
0.016
0.031
0.031
0.5
1
3d
0.125
0.25
(R-102557)
3e
3f
Ϲ0.008
Ϲ0.008
0.016
0.016
0.125
0.063
0.25
0.25
3g
3h
3i
0.016
0.016
Ϲ0.008
0.25
0.25
0.5
0.5
0.016
0.016
0.031
0.016
0.25
1
3j
Ϲ0.008
0.063
0.25
(CS-758)

December 2001
1649
Table 3. In Vitro Antifungal Activites of CS-758, Fluconazole, and Itra- 474.1663. Found: 474.1672.
conazole
Compounds 3a, 3h, and 3i were prepared similarly from aldehydes 6a,
6h, and 6i, respectively.
MIC (mg/ml)
3a: Amorphous solid, 69%. [a]D25 Ϫ80.3° (cϭ1.13, CHCl3). 1H-NMR
(400 MHz, CDCl3) d: 1.18 (3H, d), 3.33 (1H, q, Jϭ7 Hz), 3.39 (1H, tt,
Jϭ11, 5 Hz), 3.62 (1H, t, Jϭ11 Hz), 3.64 (1H, t, Jϭ11 Hz), 4.30 (1H, ddd,
Jϭ11, 4, 2 Hz), 4.41 (1H, ddd, Jϭ11, 4, 2 Hz), 4.83 (1H, d, Jϭ14 Hz), 5.00
(1H, d, Jϭ1 Hz), 5.03 (1H, d, Jϭ14 Hz), 5.05 (1H, d, Jϭ4 Hz), 5.77 (1H, dd,
Jϭ15, 4 Hz), 6.59 (1H, dd, Jϭ15, 11 Hz), 6.63 (1H, d, Jϭ15 Hz), 6.7—6.8
(2H, m), 6.78 (1H, dd, Jϭ15, 11 Hz), 7.20—7.25 (1H, m), 7.3—7.4 (3H, m),
7.41 (2H, d, Jϭ5 Hz), 7.79 (2H, s). IR (KBr) cmϪ1: 1617, 1597, 1499, 1450,
1420, 1388, 1275, 1140, 1050, 966, 899, 852. HR-MS (FAB) m/z: Calcd for
C26H28F2N3O3S (MϩH)ϩ: 500.1819. Found: 500.1814.
Strain
CS-758
Fluconazole Itraconazole
C. albicans ATCC 24433
C. albicans SANK 51486
C. albicans TIMM 3164
C. albicans ATCC 64550
C. parapsilosis ATCC 90018
C. glabrata ATCC 90030
C. krusei ATCC 6258
C. tropicalis ATCC 750
C. neoformans TIMM 1855
A. fumigatus ATCC 26430
A. fumigatus SANK 10569
A. flavus SANK 18497
0.016
Ϲ0.008
0.063
0.5
0.016
1
0.25
0.25
0.016
0.063
0.063
0.25
0.5
0.25
0.125
0.031
0.25
1
0.125
1
0.5
0.5
0.25
0.25
0.25
0.5
Ͼ4
Ͼ4
0.5
Ͼ4
Ͼ4
2
Ͼ4
Ͼ4
Ͼ4
Ͼ4
3h: Amorphous solid, 83%. [a]D25 Ϫ73.6° (cϭ0.96, CHCl3). IR (KBr)
cmϪ1: 1617, 1602, 1499, 1488, 1416, 1388, 1275, 1141, 1050, 967, 900,
854. 1H-NMR (400 MHz, CDCl3) d: 1.18 (3H, d, Jϭ7 Hz), 3.33 (1H, q,
Jϭ7 Hz), 3.39 (1H, tt, Jϭ11, 5 Hz), 3.62 (1H, t, Jϭ11 Hz), 3.64 (1H, t,
Jϭ11 Hz), 4.30 (1H, ddd, Jϭ11, 5, 2 Hz), 4.41 (1H, ddd, Jϭ11, 5, 2 Hz),
4.83 (1H, d, Jϭ14 Hz), 5.01 (1H, s), 5.03 (1H, d, Jϭ14 Hz), 5.05 (1H, d,
Jϭ4 Hz), 5.81 (1H, dd, Jϭ15, 4 Hz), 6.58 (1H, dd, Jϭ15, 11 Hz), 6.7—6.8
(2H, m), 6.70 (1H, d, Jϭ15 Hz), 6.82 (1H, dd, Jϭ15, 11 Hz), 7.05—7.12
(2H, m), 7.3—7.45 (2H, m), 7.79 (2H, s). HR-MS (FAB) m/z: Calcd for
C26H26ClF3N3O3S (MϩH)ϩ: 552.1335. Found: 552.1328.
the benzene ring to obtain CS-758 (3j). The aim of the fluo-
rine atom was to improve the solubility and chemical/meta-
bolic stability.5) CS-758 (3j) showed comparable MICs to
those of 3f. Analogs 3g—i, with a fluorine atom at the C2
position but without a cyano group at the C4 position,
showed lower activities. The excellent MIC of 3g against
Cryptococcus neoformans was an exception.
The MICs of CS-758, fluconazole, and itraconazole
against 12 fungal strains are listed in Table 3. The MICs of
CS-758 were excellent and surpassed those of the reference
drugs. Further evaluations are under way.
3i: Amorphous solid, 63%. [a]D25 Ϫ70.3° (cϭ1.00, CHCl3). IR (KBr)
cmϪ1: 1618, 1500, 1429, 1331, 1276, 1171, 1138, 1050, 993. 1H-NMR
(400 MHz, CDCl3) d: 1.19 (3H, d, Jϭ7 Hz), 3.33 (1H, q, Jϭ7 Hz), 3.40 (1H,
tt, Jϭ11, 5 Hz), 3.62 (1H, t, Jϭ11 Hz), 3.64 (1H, t, Jϭ11 Hz), 4.31 (1H,
ddd, Jϭ11, 5, 2 Hz), 4.42 (1H, ddd, Jϭ11, 5, 2 Hz), 4.83 (1H, d, Jϭ14 Hz),
5.00 (1H, s), 5.03 (1H, d, Jϭ14 Hz), 5.07 (1H, d, Jϭ4 Hz), 5.87 (1H, dd,
Jϭ15, 4 Hz), 6.62 (1H, dd, Jϭ15, 11 Hz), 6.7—6.8 (2H, m), 6.77 (1H, d,
Jϭ16 Hz), 6.93 (1H, dd, Jϭ16, 11 Hz), 7.31 (1H, d, Jϭ10 Hz), 7.33—7.39
(2H, m), 7.59 (1H, t, Jϭ8 Hz), 7.79 (2H, s). HR-MS (FAB) m/z: Calcd for
C27H26F6N3O3S (MϩH)ϩ: 586.1599. Found: 586.1602.
4-(Bromomethyl)-3-fluorobenzonitrile (8)6) In a 2000 ml round-bot-
tomed Pyrex glass flask fitted with a condenser, a mixture of 3-fluoro-4-
methylbenzonitrile (7; 96 g, 710 mmol), N-bromosuccinimide (NBS; 126 g,
708 mmol), 2,2Ј-azobis(isobutyronitrile) (AIBN; 1.2 g, 7 mmol) and 1,2-
dichloroethane (1000 ml) was stirred with a magnetic stirrer and irradiated
with a tungsten lamp (375 W). The mixture was allowed to warm by the light
of the lamp. When the mixture started to reflux, the lamp was occasionally
turned off to prevent violent refluxing. After 20 min of refluxing, the red-
brown color of the bromine disappeared and the solution became yellow.
The mixture was irradiated for 5 min further, and then allowed to cool to
room temperature. The mixture was then cooled with ice, and the precipi-
tated succinimide was removed by filtration. The filtrate was partitioned be-
tween EtOAc and 10% (w/w) NaCl. The organic layer was dried over
MgSO4 and solvents were removed in vacuo to afford a crude solid, which
was recrystallized from hexane–EtOAc to afford 8 (96 g, 63% yield) as col-
orless needles, mp 71—74 °C. Anal. Calcd for C8H5BrFN: C, 44.89; H,
2.36; N, 6.54. Found: C, 45.01; H, 2.36; N, 6.67. IR (KBr) cmϪ1: 2238,
1573, 1502, 1417, 1264, 954, 895, 841. 1H-NMR (270 MHz, CDCl3) d: 4.49
(2H, s), 7.38 (1H, dd, Jϭ9, 1 Hz), 7.45 (1H, dd, Jϭ8, 1 Hz), 7.54 (1H, t,
Jϭ8 Hz). MS [electron impact (EI)] m/z: 215, 213 (Mϩ), 134 (100%), 107.
HR-MS (EI) m/z: Calcd for C8H5BrFN (Mϩ): 214.9569. Found: 214.9542.
Diethyl 4-Cyano-2-fluorobenzylphosphonate (9) A mixture of 8 (1.5
g, 7.0 mmol) and triethyl phosphite (1.4 g, 8.4 mmol) was heated at 150 °C
for 2 h. The mixture was then concentrated under reduced pressure, and the
residue was heated at 100 °C while being suctioned with a vacuum pump to
remove volatile materials. The crude oil thus obtained (1.97 g, quantitative
yield) was used for the next reaction without further purification. IR (CHCl3)
Experimental
Melting points were determined with a Yanagimoto micro melting point
apparatus and are uncorrected. IR spectra were recorded on a Nic 5SCX
spectrometer. 1H-NMR spectra were recorded either on a JEOL GX-270
(270 MHz), on a Varian Mercury 400 (400 MHz), or on a JNM GSX-400
(400 MHz) spectrometer using tetramethylsilane as an internal standard. The
abbreviations are as follows: s, singlet; d, doublet; dd, doublet of doublets;
ddd, doublet of doublets of doublets; t, triplet; dt, doublet of triplets; td,
triplet of doublets; tt, triplet of triplets; q, quartet; m, multiplet; br, broad.
MS and high-resolution MS (HR-MS) were recorded either on a JEOL JMS
D300, on a JEOL BU30, or on a JEOL JMS-700 spectrometer. Column
chromatography was carried out on silica gel (Kieselgel 60, 0.040—0.063
mm, Merck). The amounts of silica gel used are shown in parentheses.
(2R,3R)-2-(2,4-Difluorophenyl)-3-[[trans-2-[(E)-styryl]-1,3-dioxan-5-
yl]thio]-1-(1H-1,2,4-triazol-1-yl)-2-butanol (2a) and (2R,3R)-2-(2,4-Di-
fluorophenyl)-3-[[trans-2-[(2E,4E)-5-aryl-2,4-pentadienyl]-1,3-dioxan-5-
yl]thio]-1-(1H-1,2,4-triazol-1-yl)-2-butanols (3a, 3h, 3i) As a typical ex-
ample, the preparation of 2a is described. A solution of (2R,3R)-2-(2,4-diflu-
orophenyl)-3-[[2-hydroxy-1-(hydroxymethyl)ethyl]thio]-1-(1H-1,2,4-triazol-
1-yl)-2-butanol (4; 1.10 g, 2.78 mmol),1) (E)-cinnamaldehyde (5a; 404 mg,
3.06 mmol), and p-toluenesulfonic acid monohydrate (581 mg, 3.05 mmol)
in THF (10 ml) was allowed to stand at room temperature for 5 min, and then
concentrated in vacuo using a rotary evaporator to remove water azeotropi-
cally. Similar processes (addition of THF and concentration) were repeated
two more times. The residual oil was dissolved in THF and cautiously
poured into a stirred aqueous solution of NaHCO3 at 0 °C. The mixture was
partitioned between EtOAc and water. The organic layer was washed with
brine and dried over MgSO4. Evaporation of the solvent afforded an oily
residue, which was chromatographed on silica gel (60 g). Elution with a
mixture of EtOAc and hexane (1 : 1 then 4 : 1, v/v) afforded 2a (796.5 mg,
61%) as a colorless, amorphous solid. [a]D25 Ϫ86.1° (cϭ1.64, CHCl3). IR
1
cmϪ1: 2237, 1262, 1054, 1029. H-NMR (270 MHz, CDCl3) d: 1.27 (6H, t,
Jϭ7.1 Hz), 3.24 (2H, d, Jϭ22.3 Hz), 4.00—4.05 (4H, m), 7.37 (1H, d,
Jϭ9.2 Hz), 7.43 (1H, d, Jϭ7.9 Hz), 7.51 (1H, td, Jϭ9.2, 2.6 Hz). MS (EI)
m/z: 271 (Mϩ) 139, 109, 93.
3-Fluoro-4-[(1E,3E)-5-oxo-1,3-pentadienyl]benzonitrile (6j) A solu-
tion of butyllithium (1.53 N in hexane, 0.5 ml, 0.77 mmol) was added in
drops to a stirred solution of 9 (209 mg, 0.77 mmol) in dry THF (4 ml) at
Ϫ78 °C. After the solution was stirred at Ϫ78 °C for 30 min, a solution of
fumaraldehyde mono(dimethylacetal) (10; 100 mg, 0.77 mmol) in dry THF
(2 ml) was added in drops. The whole was stirred for 2 h at Ϫ78 °C, and then
stirred in an ice bath for 15 min. Then, the reaction was quenched by adding
an aqueous solution of 0.1 N HCl (3.9 ml). The mixture was stirred again in
the ice bath for 30 min, and then at room temperature for 1 h. Then the mix-
ture was cooled with ice and treated with a saturated NaHCO3 solution. The
(KBr) cmϪ1: 1617, 1499, 1388, 1274, 1137, 1050, 966, 852. H-NMR (400
1
MHz, CDCl3) d: 1.19 (3H, d, Jϭ7 Hz), 3.34 (1H, q, Jϭ7 Hz), 3.42 (1H, tt,
Jϭ11, 5 Hz), 3.65 (1H, t, Jϭ11 Hz), 3.67 (1H, t, Jϭ11 Hz), 4.35 (1H, ddd,
Jϭ11, 5, 2 Hz), 4.44 (1H, ddd, Jϭ11, 5, 2 Hz), 4.83 (1H, d, Jϭ14 Hz), 5.02
(1H, s, Jϭ14 Hz), 5.04 (1H, d, Jϭ14 Hz), 5.13 (1H, d, Jϭ5 Hz), 6.18 (1H,
dd, Jϭ16, 5 Hz), 6.7-6.8 (2H, m), 6.80 (1H, d, Jϭ16 Hz), 7.25-7.42 (6H, m),
7.79 (2H, s). HR-MS (FAB) m/z: Calcd for C24H26F2N3O3S (MϩH)ϩ:

1650
Vol. 49, No. 12
cells/ml for Candida species, ca. 1ϫ104 cells/ml for C. neoformans, and
2.5ϫ104 spores/ml for Aspergillus species, and incubated at 35 °C (for As-
pergillus species: 30 °C). The MICs were read when obvious growth was ob-
served in compound-free control wells. The MICs were defined as the lowest
compound concentrations causing at least 80% growth inhibition compared
with the control.
mixture was partitioned between water and EtOAc. The organic layer was
dried over MgSO4 and the solvents were removed in vacuo to afford a crys-
talline residue, which was recrystallized from hexane–AcOEt to afford
6j (127 mg, 82%) as a yellow solid, mp 174—177 °C. Anal. Calcd for
C12H8FNO: C, 71.64; H, 4.01; N, 6.96. Found: C, 71.84; H, 4.27; N, 6.83.
IR (KBr) cmϪ1: 2230, 1681, 1672, 1621, 1421, 1159, 1124. 1H-NMR
(270 MHz, CDCl3) d: 6.36 (1H, dd, Jϭ15, 8 Hz), 7.14 (1H, d-like, Jϭ3 Hz),
7.16 (1H, d, Jϭ8 Hz), 7.28 (1H, ddd, Jϭ15, 8, 3 Hz), 7.40 (1H, dd, Jϭ10, 1
Hz), 7.47 (1H, dd, Jϭ8, 1 Hz), 7.67 (1H, t, Jϭ8 Hz), 9.68 (1H, d, Jϭ8 Hz).
MS m/z 201 (Mϩ), 172 (100%), 158, 145.
Acknowlegement We acknowledge the contribution of Dr. Yasuhiro Ito
of Planning & Coordination Department of our company for the coordina-
tion of the project and active discussions.
4-[(1E,3E)-4-[trans-5-[[(1R,2R)-2-(2,4-Difluorophenyl)-2-hydroxy-1-
methyl-3-(1H-1,2,4-triazol-1-yl)propyl]thio]-1,3-dioxan-2-yl]-1,3-butadi-
enyl]-3-fluorobenzonitrile (CS-758, 3j) A mixture of 4 (8.73 g, 24.3
mmol), 6j (4.63 g, 23.0 mmol) and p-toluenesulfonic acid monohydrate
(5.07 g, 26.7 mmol) in dry THF (200 ml) was allowed to stand at room tem-
perature for 30 min. Then the solvent was removed using a rotary evaporator.
The residue was suctioned using a vacuum pump at room temperature to af-
ford an oily residue. Similar evaporation cycles (addition of THF, allowing
the mixture to stand, and evaporation) were repeated two more times. To the
residue, THF (150 ml) was added, and the solution was poured slowly into a
stirred aqueous solution of saturated NaHCO3 at 0 °C. The product was ex-
tracted with EtOAc. The organic layer was washed with brine. The extract
was dried over MgSO4 and solvents were removed in vacuo to afford a pale
yellow oil, which was chromatographed on silica gel (500 g, hexane–AcOEt,
2 : 1, v/v) to afford CS-758 (3j) (9.35 g, 74%) as a yellow amorphous
solid. An analytical sample, mp 127—128 °C, was obtained by recrystalliza-
tion from EtOAc–hexane. [a]D25 Ϫ78.3° (cϭ1.8, CHCl3). Anal. Calcd for
C27H25F3N4O3S: C, 59.77; H, 4.64; F, 10.50; N, 10.33; S, 5.91. Found: C,
59.66; H, 4.62; F, 10.38; N, 10.24; S, 5.92. IR (KBr) cmϪ1: 2232, 1616,
1499, 1140. 1H-NMR (400 MHz, CDCl3) d: 1.19 (3H, d, Jϭ7 Hz), 3.33 (1H,
q, Jϭ7 Hz), 3.40 (1H, tt, Jϭ11, 5 Hz), 3.62 (1H, t, Jϭ11 Hz), 3.64 (1H, t,
Jϭ11 Hz), 4.30 (1H, ddd, Jϭ11, 5, 2 Hz), 4.43 (1H, ddd, Jϭ11, 5, 2 Hz),
4.83 (1H, d, Jϭ14 Hz), 5.01 (1H, s), 5.03 (1H, d, Jϭ14 Hz), 5.07 (1H, d,
Jϭ4 Hz), 5.90 (1H, dd, Jϭ15, 4 Hz), 6.62 (1H, dd, Jϭ15, 11 Hz), 6.7—6.8
(2H, m), 6.73 (1H, d, Jϭ16 Hz), 6.95 (1H, dd, Jϭ16, 11 Hz), 7.3—7.4 (1H,
m), 7.34 (1H, d, Jϭ9 Hz), 7.40 (1H, d, Jϭ8 Hz), 7.58 (1H, t, Jϭ8 Hz), 7.79
(2H, s). MS (FAB) m/z 543 (MϩH)ϩ.
References and Notes
1) Oida S., Tajima Y., Konosu T., Nakamura Y., Somada A., Tanaka T.,
Habuki S., Harasaki T., Kamai Y., Fukuoka T., Ohya S., Yasuda H.,
Chem. Pharm. Bull., 48, 694—707 (2000).
2) The elimination half-life of R-102557 in plasma was 37.4 h in rats.
3) A part of this work was presented by the authors at the 40th Inter-
science Conference on Antimicrobial Agents and Chemotherapy,
American Society for Microbiology, Poster No. 1087, Sep. 17—20,
2000, Toronto.
4) We did not investigate derivatives with longer (nм3) side chains be-
cause their syntheses would require more steps. A separate experiment
we carried out showed that a compound having three double bonds
(nϭ3) with a 4-(trifluoromethyl)phenyl group (Arϭ4-(CF3)C6H4) had
lower activities than 3b (nϭ2) in vivo in mice (unpublished data).
5) The effects of the fluorine atom can be seen in the results of the pre-
liminary experiments. The concentration of CS-758 reached 13 mg/ml
when a capsule (No. 2) containing CS-758 (50 mg) and polysorbate 80
(300 mg) was stirred in a JP-2 solution (900 ml) at 37 °C. For 4f, the
maximum concentration was 4—5 mg/ml. The half-life of CS-758 in
HCl (0.007 mol/l) solution in CH3CN–H2O (3 : 7, v/v) at 37 °C was
6.40 min, whereas that of 3f was 3.12 min. The absolute bioavailability
(BA) of CS-758 in rats after oral administration (20 mg/kg) of its
poly(ethylene glycol) 400 solution was 113%, whereas that of 3f was
50.7%. The elimination half-life of CS-758 in plasma was 9.1 h in rats,
whereas that of 3f was 5.7 h.
6) Xue C.-B., Wityak J., Sielecki T. M., Pinto. D. J., Batt D. G., Cain G.
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Determination of MICs MICs were determined by the broth microdilu-
tion method according to the guidelines in National Committee for Clinical
Laboratory Standard (NCCLS) documents 1997 M27-A, 1995 M27-T, and
1998 M38-P, Wayne, PA. Roswell Park Memorial Institute (RPMI) 1640
medium (GIBCO) (for C. neoformans: yeast nitrogen base) buffered with
0.165 M 3-(morpholino)propanesulfonic acid (MOPS) (pH 7.0) was used.
Microplates (96 wells) were inoculated at a concentration of 1—5ϫ103