Synthesis and antibacterial evaluation of 1 β-methyl-2-(5-substituted heterocyclic carbamoyl)pyrrolidin-3-ylthio)carbapenem derivatives

Article abstract of DOI:10.1002/ardp.200400867

The synthesis of a new series of 1 β-methylcarbapenems having a substituted heterocyclic carbamoyl pyrrolidine moiety is described. Their in vitro antibacterial activity against both gram-positive and gram-negative bacteria was tested, and the effect of h

Full text of DOI:10.1002/ardp.200400867

Arch. Pharm. Pharm. Med. Chem. 2004, 337, 391−397
Synthesis and Antibacterial Evaluation of Carbapenem Derivatives 391
Joo-Shin Leea,
Synthesis and Antibacterial Evaluation of
1β-Methyl-2-(5-substituted heterocyclic
carbamoyl)pyrrolidin-3-ylthio)carbapenem
Derivatives
Jung-Hyuck Choa,
Heeyeong Chob,
Chang-Hyun Oha
a Medicinal Chemistry
Research Center,
Korea Institute of Science
and Technology,
The synthesis of a new series of 1β-methylcarbapenems having a substituted
heterocyclic carbamoyl pyrrolidine moiety is described. Their in vitro antibacterial
activity against both gram-positive and gram-negative bacteria was tested, and
the effect of heterocyclic substituents on the pyrrolidine was investigated. One
particular compound (IIId) having a substituted oxadiazole moiety showed the
most potent antibacterial activity.
Seoul, Korea
b Pharmaceutical Screening
Lab, Korea Research
Institute of Chemical
Technology,
Keywords: β-Methylcarbapenem; Antibacterial activity; Substituent effect
Taejon, Korea
Received: January 8, 2004; Accepted: March 12, 2004 [FP867]
DOI 10.1002/ardp.200400867
Introduction
Results and discussion
Chemistry
Carbapenem compounds that have a (3S)-pyrrolidin-
3-ylthio group at the C-2 position in the carbapenem
skeleton are noted for their broad and potent antibac-
terial activity [1], and a large number of derivatives
have been synthesized and investigated. Among
these compounds, panipenem [2] and meropenem [3]
were the first to be successfully launched in the mar-
ket, and clinical evaluations are in progress for S-4661
[4], BO-2727 [5] and DX-8739 [6], which show en-
hanced metabolic stability to renal dehydropeptidase-
1 (DHP-1) due to the introduction of a 1b-methyl group
in the carbapenem skeleton for high antibacterial po-
tency. We were also interested in this pyrroldin-3-ylthio
group and reported that the carbapenem compounds
having a pyrrolidine-3-ylthio group at the C-2 position
in the carbapenem skeleton are noted for their broad
and potent antibacterial activity, and a large number of
derivatives have been synthesized and investigated
[7Ϫ15].
Our synthetic route leading to the new carbapenems
commences with preparation of appropriately substi-
tuted pyrrolidine carrying a thiol group at the 3-posi-
tion. The intermediates thus prepared were then cou-
pled with carbapenem diphenylphosphates, and the
protecting groups were removed by the usual tech-
niques.
The thiol compounds Ia and Ib were prepared by the
sequence shown in Scheme 1. The hydroxyethyl car-
bamoyl compound 1 [15] was converted to the alde-
hyde compound 2 by Swern oxidation. The formation
of thiazolidine (3) and 2Ј-ester substituted thiazolidine
(4) were accomplished by the reaction of aldehyde 2
with L-cysteamine and L-cysteine ethyl ester in 90%
aqueous ethanol. Deprotection of the trityl group to
thiol compounds (Ia and Ib) was achieved by treatment
of 3 and 4 with trifluoroacetic acid in the presence of
triethylsilane (Scheme 1). N-Protected proline car-
boxylic acid (5) [15] was converted to cyanomethyl
carbamoyl 6 by treatment with ethyl chloroformate and
aminoacetonitrile and subsequently hydrolyzed with
sulfuric acid in THF to provide amide 7. The synthesis
of 4Ј-ester substituted thiazole (9) was accomplished
by the reaction of thioamide 8 with ethyl bromopyru-
vate in ethanol (Scheme 2). The formation of 5Ј-ester
substituted oxadiazole (12) was accomplished by the
reaction of N-hydroxyacetamidine with ethyl oxalyl
chloride in THF. The 4Ј-ester substituted oxadiazole
(12) was converted to the amide 13 by treatment with
ammonium hydroxide in ethanol (Scheme 3). N-Pro-
tected acetimidate 16 was allowed to react with L-cys-
teine ethyl ester to give 4Ј-ester substituted thiazoline
In this paper, we describe the synthesis and structure-
activity relationships of the 1β-methylcarbapenems
having a substituted heterocyclic carbamoyl pyrrolidin-
3Ј-ylthio group as C-2 side chain, and our approach
for the improvement of antibacterial activity of the car-
bapenems is discussed.
Correspondence: Chang-Hyun Oh, Medicinal Chemistry
Research Center, Korea Institute of Science and Technology,
Seoul 130-650, Korea. e-mail: choh@kist.re.kr
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392 Oh et al.
Arch. Pharm. Pharm. Med. Chem. 2004, 337, 391−397
Scheme 1. i) Oxalyl chloride, DMSO, TEA, CH2Cl2; ii) Cysteamine hydrochloride, 90% EtOH; iii) Cysteine ethyl
ester, 90% EtOH; iv) Trifluoroacetic acid, triethyl silane, CH2Cl2.
Scheme 2. i) Ethyl chloroformate NH2CH2CN, TEA, CH2Cl2; ii) H2SO4, 4N-NaOH, THF; iii) Lawessen’s reagent,
THF; iv) Ethyl bromopyruvate, EtOH; v) Trifluoroacetic acid, triethyl silane, CH2Cl2.
Scheme 3. i) Hydroxyl amine, EtOH; ii) Ethyloxaly chloride, THF; iii) NH4OH, EtOH; iv) Trifluoroacetic acid,
triethyl silane, CH2Cl2.
(17); the following deprotection with palladium in meth-
anol led to the amino compound 18. Synthesis of 19
was accomplished by the reaction of N-protected pro-
line carboxylic acid (5) with ethyl chloroformate in
CH2Cl2 (Scheme 4). Also, the thiols IcϪf were prepared
by a method similar to that described for the prep-
aration of Ia.
Finally, the reaction of 20 [16] with thiols (Ia؊f) in the
presence of diisopropylethylamine provided the 2-sub-
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Arch. Pharm. Pharm. Med. Chem. 2004, 337, 391−397
Synthesis and Antibacterial Evaluation of Carbapenem Derivatives 393
Scheme 4. i) 4-Nitrobenzyl chloroformate, TEA, CH2Cl2CN; ii) HCl gas, EtOH; iii) L-Cysteine ethyl ester HCl,
TEA, EtOH; iv) Pd/C, MeOH:THF = 1:1; v) 5, Ethyl chloroformate, TEA, CH2Cl2; vi) Trifluoroacetic acid, triethyl
silane, CH2Cl2.
Scheme 5. i) N,N-Diisopropylethyl amine, CH3CN; ii) Pd(OH)2, THF, H2O.
stituted carbapenem (IIa؊f). Deprotection of these
compounds by catalytic hydrogenation gave the crude
products that were purified by HP-20 column to give
the pure carbapenems (IIIa؊f) (Scheme 5).
Antibacterial activity studies
The in vitro antibacterial activities of the new carba-
penems (IIIa؊f), prepared as described above, against
gram-positive and gram-negative bacteria are listed in
Table 1. For comparison, the MIC values of Imipenem
and Meropenem are also listed. One particular com-
pound (IIId) having a substituted oxadiazole moiety
displayed superior or similar antibacterial activities
against gram-positive bacteria compared to Mero-
penem, and against gram-negative bacteria compared
to Imipenem.
Biological assay
Measurement of in vitro antibacterial activity
MIC were determined by the agar dilution method
using test agar. An overnight culture of bacteria in tryp-
tosoy broth was diluted to about 106 cells/mL with the
same broth and inoculated with an inoculating device
onto agar containing serial twofold dilutions of the test
compounds. Organisms were incubated at 37°C for
18Ϫ20 h. The MIC of a compound was defined as the
lowest concentration that visibly inhibited growth.
The non-substituted thiazolidine compound (IIIa)
showed better antibacterial activities against gram-
positive and gram-negative bacteria than the ester
substituted compounds (IIIb). Comparing the com-
pounds (IIIb؊d, IIIf) containing an ester substituted
heterocyclic carbamoyl moiety at CЈ-5 of pyrrolidine,
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394 Oh et al.
Arch. Pharm. Pharm. Med. Chem. 2004, 337, 391−397
Table 1. In vitro antibacterial activities of carbapenem derivatives.
R =
Imipenem Meropenem
Organism
IIIa
IIIb
IIIc
IIId
IIIe
IIIf
Streptococcusp.
0.05
0.10
0.01
0.03
0.10
0.05
< 0.01
< 0.01
0.01
0.01
0.01
0.10
0.03
0.03
0.40
0.04
308Aa
Streptococcus p. 0.03
0.10
0.80
0.20
0.40
3.10
0.80
0.01
0.10
0.10
0.40
3.10
0.40
0.01
0.10
0.05
0.05
0.80
0.10
0.05
0.20
0.20
0.40
1.56
0.20
0.03
0.10
0.10
0.20
1.56
0.10
77Ab
Streptococcusa.
0.20
0.10
0.20
SG511c
Escherichia c.
0.10
DC2d
Escherichia c.
0.20
TEMe
Pseudomonas a. 1.56
0.80
9027f
Enterobacter c.
0.10
0.10
1321Eg
MIC (µg/mL) determined by agar dilution method. a: Streptococcus pyogenes 308A; b: Streptococcus pyogenes
77A; c: Streptococcus aureus SG511; d: Escherichia coli DC2; e: Escherichia coli TEM; f: Pseudomonas
aeruginosa 9027; g: Enterobacter cloacae 1321E.
1
matography to give 2 (3.7 g, 73.4%) as a pale yellow oil. H-
similar activity was observed against all bacteria
tested. Among these compounds, IIId having a substi-
tuted oxadiazole moiety exhibited the most potent and
well balanced activity.
NMR (300 MHz, CDCl3) δ 2.05Ϫ2.27 (m, 2H), 2.95 (m, 1H),
3.12 (bs, 2H), 4.07 (d, 2H, J = 1.6 Hz), 4.45 (m, 2H), 5.32 (d,
2H, J = 7.6 Hz), 5.90 (bs, 1H), 7.29 (m, 9H), 7.55 (d, 6H, J =
8.1 Hz), 9.60 (s, 1H).
(2S,4S)-1-Allyloxycarbonyl-2-[N-(thiazolidin-2Ј-yl)methyl]-
carbamoyl-4-tritylthiopyrrolidine (3)
Experimental
A solution of 2 (6.2 g, 12.0 mmol) in 90% aqueous ethanol
(60 mL) was added slowly to a solution of cysteamine hydro-
chloride (1.3 g, 12.0 mmol) in water (20 mL) and NaHCO3
(0.9 g, 12.0 mmol) at Ϫ5°C. The reaction mixture was stirred
for 24 h at room temperature and then concentrated in vacuo
to give a white solid, which was diluted in ethyl acetate and
water. The organic layer was dried over anhydrous MgSO4.
Evaporation of the solvent in vacuo gave a crude residue
which was purified by silica gel column chromatography to
give 3 (3.0 g, 43.3%) as a light yellowish oil. 1H-NMR (300
MHz, CDCl3) δ 2.20 (m, 2H), 2.80 (m, 1H), 2.93 (bs, 2H), 3.21
(m, 2H), 3.46 (m, 2H), 3.72 (m, 2H), 3.94 (m, 2H), 4.48 (d,
2H, J = 6.2 Hz), 5.21 (d, 2H, J = 3.2 Hz), 5.82 (m, 1H), 7.29
(m, 9H), 7.32 (d, 6H, J = 7.8 Hz).
Melting point (mp): Thomas Hoover apparatus, uncorrected.
UV spectra: Hewlett Packard 8451A UV-VIS spectrophoto-
meter. IR spectra: Perkin Elmer 16F-PC FT-IR. NMR spectra:
Varian Gemini 300 spectrometer, tetramethylsilane (TMS) as
an internal standard. The mass spectrometry system was
based on a HP5989A MS Engine (Palo Alto, CA, USA) mass
spectrometer with an HP Model 59987A.
(2S,4S)-1-Allyloxycarbonyl-2-N-(formylmethyl)carbamoyl-4-
tritylthiopyrrolidine (2)
Dry DMSO (1.6 mL, 9.8 mmol) in dry CH2Cl2 (10 mL) was
added dropwise over 20 min to a stirred solution of oxalyl
chloride (1.2 g, 13.7 mmol) in dry CH2Cl2 (20 mL), under an
argon atmosphere at Ϫ45°C. After stirring for an additional
15 min, compound 1 (5.1 g, 9.8 mmol) in dry CH2Cl2 (15 mL)
was added dropwise over 45 min. The mixture was stirred for
a further 45 min at Ϫ45°C, and triethylamine was then added
dropwise over 30 min, followed by stirring for a further 2 h at
Ϫ45°C. The mixture was washed with brine and dried over
anhydrous MgSO4. Evaporation of the solvent in vacuo gave
a crude residue which was purified by silica gel column chro-
(2S,4S)-1-Allyloxycarbonyl-2-[N-(4Ј-ethoxycarbonylthiazol-
idin-2Ј-yl)methyl]carbamoyl-4-trityl thiopyrrolidine (4)
A solution of 2 (2.7 g, 5.3 mmol) in 90% aqueous ethanol (30
mL) was added slowly to a solution of cysteine ethyl ester
hydrochloride (1.0 g, 5.3 mmol) in water (10 mL) and 10%
NaHCO3 (0.4 g, 5.3 mmol) at Ϫ5°C. The reaction mixture
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Arch. Pharm. Pharm. Med. Chem. 2004, 337, 391−397
Synthesis and Antibacterial Evaluation of Carbapenem Derivatives 395
was stirred for 24 h at room temperature and then concen-
trated in vacuo to give a white solid, which was diluted in
ethyl acetate and water. The organic layer was dried over
anhydrous NaSO4. Evaporation of the solvent in vacuo gave
a crude residue which was purified by silica gel column chro-
matography to give 4 (1.7 g, 50.4%) as a light yellowish oil.
1H-NMR (300 MHz, CDCl3) δ 1.27Ϫ1.34 (t, 3H, J = 3.6 Hz),
2.21Ϫ2.37 (bs, 2H), 2.70 (bs, 1H), 2.80 (d, 2H, J = 8.6 Hz),
3.12 (m, 2H), 3.26 (m, 1H), 3.27Ϫ3.36 (bs, 1H), 4.01 (bs,
2H), 4.19 (q, 2H, J = 3.6 Hz), 4.44 (d, 2H, J = 4.2 Hz),
5.21Ϫ5.26 (d, 2H, J = 5.2 Hz), 5.81 (m, 2H), 7.30 (m, 9H),
7.44 (d, 6H, J = 7.6 Hz).
vacuo gave a crude residue which was purified by silica gel
column chromatography to give 8 (0.6 g, 48.8%) as a pale
yellow oil. 1H-NMR (300 MHz, CDCl3) δ 2.14Ϫ2.18 (d, 2H,
J = 7.2 Hz), 2.86 (m, 2H), 3.03 (d, 1H, J = 4.2 Hz), 4.36 (s,
2H), 4.53 (t, 2H, J = 3.6 Hz), 4.93 (d, 1H, J = 6.2 Hz), 5.22
(q, 2H), 5.77 (m, 1H), 7.22 (m, 9H), 7.42 (d, 6H, J = 7.2 Hz).
(2S,4S)-1-Allyloxycarbonyl-2-[N-(4Ј-ethoxycarbonylmethyl-
thiazol-2Ј-yl)methyl]carbamoyl-4-tritylthiopyrrolidine (9)
Ethyl bromopyruvate (0.5 g, 2.2 mmol) was added dropwise
to a stirred solution of 8 (1.0 g, 1.8 mmol) in ethanol (30 mL),
and the mixture was stirred for 20 h at room temperature.
The resulting solution was evaporated and diluted with ethyl
acetate and washed with brine. The organic layer was dried
over anhydrous MgSO4. Evaporation of the resulting solution
in vacuo gave a crude residue which was purified by silica
gel column chromatography to give 9 (0.6 g, 51.0%) as a
(2S,4S)-1-Allyloxycarbonyl-2-[N-(thiazolidine-2Ј-yl)methyl]-
carbamoyl-4-mercaptanpyrrolidine (Ia)
To a solution of 3 (1.3 g, 2.3 mmol) in CH2Cl2 was added
dropwise trifluoroacetic acid (2 mL) at 0°C, then triethylsilane
(0.4 mL, 2.6 mmol). After stirring for 30 min at room tempera-
ture, the mixture was evaporated under reduced pressure.
The residue was washed with 10% NaHCO3 and brine. The
organic layer was concentrated in vacuo to give a residue
which was used without further purification.
1
pale yellow oil. H-NMR (300 MHz, CDCl3) δ 1.35 (t, 3H, J =
3.7 Hz), 2.03 (bs, 2H), 2.57 (m, 1H), 2.91 (t, 2H, J = 5.7 Hz),
4.30 (q, 5H), 4.55 (t, 2H, J = 6.2 Hz), 5.26 (bs, 2H), 5.81 (bs,
1H), 7.22 (m, 9H), 7.40 (d, 6H, J = 7.2 Hz), 8.03 (s, 1H).
(2S,4S)-1-Allyloxycarbonyl-2-[N-(4Ј-ethoxycarbonylmethyl-
thiazol-2Ј-yl)methyl]carbamoyl-4-mercaptanpyrrolidine (Ic)
(2S,4S)-1-Allyloxycarbonyl-2-[N-(4Ј-ethoxycarbonythiazol-
xidin-2Ј-yl)methyl]carbamoyl-4-mercaptanpyrrolidine (Ib)
Ic was prepared from 9 by a method similar to that described
for the preparation of Ia. The above compound was used with-
out further purification.
Ib was prepared from 4 by a method similar to that described
for the preparation of Ia.
(2S,4S)-1-Allyloxycarbonyl-2-(N-cyanomethyl)carbamoyl-4-
tritylthiopyrrolidine (6)
(2S,4S)-1-Allyloxycarbonyl-2-(N-hydroxyacetamidine)-
carbamoyl-4-tritylthiopyrrolidine (11)
A solution of 5 (20.0 g, 42.3 mmol) and triethylamine (6.5 mL,
46.5 mmol) in dry CH2Cl2 (150 mL) was cooled to 0°C under
nitrogen and treated with ethyl chloroformate (4.5 mL, 46.5
mol). After stirring for 30 min at 0°C, aminoacetonitrile (5.2
mL, 84.6 mmol) was added, and the mixture was stirred for
1 h at 0°C. The mixture was washed with 10% NaHCO3 and
brine and dried over anhydrous MgSO4. Evaporation of the
solvent in vacuo gave a crude residue which was purified by
silica gel column chromatography to give 6 (20.1 g, 93.0%)
as a yellow oil. 1H-NMR (300 MHz, CDCl3) δ 2.21 (s, 2H),
2.94 (d, 2H, J = 7.5 Hz), 3.31 (bs, 1H), 4.02 (s, 3H), 4.54 (d,
2H, J = 6.8 Hz), 5.28 (d, 2H, J = 5.2 Hz), 5.89 (s, 1H), 7.23
(m, 9H), 7.50 (d, 6H, J = 8.2 Hz).
Hydroxylamine hydrochloride (1.7 g, 23.5 mmol) was added
slowly to a solution of 6 (10.0 g, 19.6 mmol) in ethanol at
room temperature, and the mixture was stirred for 20 h at
60°C. The resulting solution was evaporated, diluted with
ethyl acetate and washed with brine. The organic layer was
dried over anhydrous MgSO4. Evaporation of the resulting
solution in vacuo gave a crude residue which was purified by
silica gel column chromatography to give 11 (8.5 g, 79.6%)
1
as a pale yellow oil. H-NMR (300 MHz, CDCl3) δ 2.20Ϫ2.24
(m, 2H), 2.78 (m, 1H), 3.02Ϫ3.14 (m, 2H), 3.85 (bs, 2H), 4.08
(t, 1H, J = 6.2 Hz), 4.49 (m, 2H), 5.26 (d, 2H, J = 5.4 Hz),
5.80 (m, 1H), 7.25 (m, 9H), 7.43 (d, 6H, J = 7.2 Hz).
(2S,4S)-1-Allyloxycarbonyl-2-(N-carbamoylmethyl)car-
bamoyl-4-tritylthiopyrrolidine (7)
(2S,4S)-1-Allyloxycarbonyl-2-[N-(5Ј-ethoxycarbonyl-1Ј,2Ј,4Ј-
oxadiazol-3Ј-yl)methyl]carbamoyl-4-tritylthiopyrrolidine (12)
At 0°C H2SO4 (20 mL) was added slowly to a solution of 6
(4.4 g, 8.5 mmol) in THF (50.0 mL), and the mixture was
stirred for 1 h at 0°C. The mixture was neutralized with 1 N
NaOH, diluted with ethyl acetate (60 mL) and washed with
brine. The organic layer was dried over anhydrous MgSO4.
Evaporation of the solvent in vacuo gave a crude residue
which was purified by silica gel column chromatography to
give 7 (3.8 g, 83.1%) as a pale yellow oil. 1H-NMR (300 MHz,
CDCl3) δ 1.92Ϫ2.16 (m, 2H), 2.87 (m, 1H), 3.07 (bs, 2H),
3.89 (m, 1H), 4.04 (bs, 2H), 4.52 (t, 2H, J = 6.3 Hz), 5.26 (d,
2H, J = 7.6 Hz), 5.91 (m, 1H), 7.28 (m, 9H), 7.44 (d, 6H, J =
4.2 Hz).
Ethyl oxalylchloride (0.6 mL, 5.5 mmol) was added dropwise
to a solution of 11 (3.0 g, 5.5 mmol) in THF (40 mL), and the
resulting solution was refluxed for 12 h. The reaction mixture
was poured into 10% NaHCO3 and extracted with ethyl acet-
ate (60 mL). Evaporation of the solvent in vacuo gave a crude
residue which was purified by silica gel column chromatogra-
phy to give 12 (1.6 g, 46.2%) as a pale yellow oil. 1H-NMR
(300 MHz, CDCl3) δ 1.44 (t, 3H, J = 6.2 Hz), 2.01 (m, 2H),
2.42 (bs, 1H), 2.98 (bs, 2H), 4.11 (bs, 1H), 4.49 (m, 4H), 4.65
(m, 2H), 5.28 (bs, 2H), 5.82 (bs, 1H), 7.26 (m, 9H), 7.43 (d,
6H, J = 7.2 Hz).
(2S,4S)-1-Allyloxycarbonyl-2-[N-(5Ј-ethoxycarbonyl-1Ј,2Ј,4Ј-
oxadiazole-3Ј-yl)methyl]carbamoyl-4-thiopyrrolidine (Id)
(2S,4S)-1-Allyloxycarbonyl-2-(N-thiocarbamoylmethyl)-
carbamoyl-4-tritylthiopyrrolidine (8)
A mixture of 7 (1.2 g, 2.2 mmol) and Lawesson’s reagent (1.8
g, 4.4 mmol) was dissolved in THF (30 mL), and the solution
was refluxed for 2 h. Evaporation of the resulting solution in
Id was prepared from 12 by a method similar to that described
for the preparation of Ia. The above compound was used with-
out further purification.
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396 Oh et al.
Arch. Pharm. Pharm. Med. Chem. 2004, 337, 391−397
(2S,4S)-1-Allyloxycarbonyl-2-[N-(5Ј-carbamoyl-1Ј,2Ј,4Ј-
oxadiazole-3Ј-yl)methyl]carbamoyl-4-tritylthiopyrrolidine (13)
filtered through celite. The combined filtrates were dried over
anhydrous MgSO4. Evaporation of the solvent in vacuo gave
18 as a brown oil. The above compound was used without
further purification.
Ammonium hydroxide (28%, 10 mL) was added to a stirred
solution of 12 (1.5 g, 2.4 mmol) in ethanol (20 mL), and the
mixture was stirred for 3 h at 60°C. The mixture was neu-
tralized with 6 N HCl, diluted with ethyl acetate (50 mL) and
washed with brine. The organic layer was dried over anhy-
drous MgSO4. Evaporation of the solvent in vacuo gave a
crude residue which was purified by silica gel column chro-
matography to give 13 (1.1 g, 77.9%) as a pale yellow oil.
1H-NMR (300 MHz, CDCl3) δ 2.13 (bs, 2H), 2.43 (m, 1H),
3.00 (bs, 2H), 4.12 (t, 1H, J = 5.2 Hz), 4.46 (s, 2H), 4.60 (d,
2H, J = 6.5 Hz), 5.24 (d, 2H, J = 7.4 Hz), 5.81 (bs, 1H), 7.25
(m, 9H), 7.46 (d, 6H, J = 4.6 Hz).
(2S,4S)-1-Allyloxycarbonyl-2-{[N-(4Ј-ethoxycarbonyl)thi-
azolin-2Ј-yl]methyl}carbamoyl-4-trityl thiopyrrolidine (19)
A solution of 5 (3.0 g, 6.3 mmol) and triethylamine (0.9 mL,
6.9 mmol) in dry CH2Cl2 (50 mL) was cooled to 0°C under
nitrogen and treated with ethyl chloroformate (0.7 mL, 6.9
mmol). The mixture was stirred at 0°C for 30 min, compound
18 (1.2 g, 6.3 mmol) was added, and the resulting mixture
was stirred at 0°C for 1 h. The mixture was washed with 10%
NaHCO3 and brine and dried over anhydrous MgSO4. Evap-
oration of the solvent in vacuo gave a crude residue which
was purified by silica gel column chromatography to give 19
(2.1 g, 52.8%) as a pale yellowish oil. 1H-NMR (300 MHz,
CDCl3) δ 1.31 (m, 3H), 1.62 (bs, 2H), 2.62 (bs, 2H), 2.90 (d,
2H, J = 6.2 Hz), 3.20 (bs, 2H), 3.55 (m, 2H), 4.29 (d, 1H, J =
7.2 Hz), 4.48 (m, 2H), 5.20 (m, 2H), 5.92 (bs, 1H), 7.26 (m,
9H), 7.46 (d, 6H, J = 8.4 Hz).
(2S,4S)-1-Allyloxycarbonyl-2-[N-(5Ј-carbamoyl-1Ј,2Ј,4Ј-
oxadiazole-3Ј-yl)-methyl]carbamoyl-4-mercaptanpyrrolidine
(Ie)
Ie was prepared from 12 by a method similar to that described
for the preparation of Ia. The above compound was used with-
out further purification.
(2S,4S)-1-Allyloxycarbonyl-2-{[N-(4Ј-ethoxycarbonyl)thi-
azolin-2Ј-yl]methyl}carbamoyl-4-mercaptanpyrrolidine (If)
p-Nitrobenzyloxycarbonyl)aminoacetonitrile (15)
A solution of 14 (2.9 g, 51.1 mmol) and triethylamine (7.1
mL, 51.1 mmol) in CH2Cl2 (80 mL) was cooled to 0°C under
nitrogen and treated with p-nitrobenzyl chloroformate (13.5 g,
61.3 mmol). The mixture was stirred for 1 h at 0°C, diluted
with ethyl acetate (50 mL) and washed with aqueous 10%
NaHCO3 and brine. The organic layer was dried over anhy-
drous MgSO4. Evaporation of the resulting solution in vacuo
gave a crude residue which was purified by silica gel column
chromatography to give 15 (8.6 g, 71.3%) as a pale yellow
oil. 1H-NMR (300 MHz, CDCl3) δ 2.72 (s, 2H), 4.08 (s, 2H),
7.52 (d, 2H, J = 7.2 Hz), 8.17 (d, 2H, J = 8.5 Hz).
If was prepared from 19 by a method similar to that described
for the preparation of Ia. The above compound was used with-
out further purification.
Allyl(1R,5S,6S)-6-[(1R)-1-hydroxyethyl]-2-{(3S,5S)-5-[N-
(thiazolidin-2-yl)methyl]carbamoyl-1-(allyloxycarbonyl)-
pyrrolidin-3-ylthio}-1-methylcarbapen-2-em-3-carboxylate (IIa)
A solution of allyl(1R,5S,6S)-2-(diphenylphosphoryloxy)-6-
[(1R)-1-hydroxymethyl]-1-methylcarbapen-2-em-3-car-
boxylate (20) (0.5 g, 1.0 mmol) in CH3CN (10 mL) was cooled
to 0°C under nitrogen. This solution was added to diisopropy-
lethylamine (0.2 g, 1.0 mmol) and a solution of the thiol com-
pound Ia in CH3CN (5 mL). After stirring for 6 h, the mixture
was diluted with ethyl acetate, washed with 10% NaHCO3
and brine and dried over anhydrous MgSO4. Evaporation of
the solvents in vacuo gave a residue which was purified by
silica gel column chromatography to give IIa (0.3 g, 43.2%)
as a yellow oil. 1H-NMR (300 MHz, CDCl3) δ 0.9Ϫ1.26 (m,
6H), 1.53 (m, 2H), 2.32 (bs, 3H), 2.74 (bs, 3H), 3.12 (bs, 3H),
3.40 (m, 1H), 3.62 (bs, 2H), 3.84 (m, 2H), 4.21 (m, 1H), 4.60
(m, 6H), 5.25 (bs, 6H), 5.92 (m, 3H).
Ethyl(p-nitrobenzyloxycarbonyl)aminoacetimidate (16)
Gaseous HCl was bubbled into a solution of 15 (12.0 g, 51.0
mmol) in ethanol (40 mL) and stirred for 1 h at 0°C. The
resulting solution was evaporated to give 16 (13.3 g, 82.2%)
as a white powder. Mp = 95Ϫ99°C (dec.). 1H-NMR (300
MHz, CDCl3) δ 1.30 (bs, 3H), 3.24 (s, 2H), 4.00 (d, 2H, J =
6.8 Hz), 4.25 (m, 2H), 7.54 (d, 2H, J = 14.2 Hz), 8.24 (d, 2H,
J = 12.3 Hz).
2-(p-Nitrobenzyloxycarbonyl)aminomethyl-4-ethoxycarbonyl-
thiazoline (17)
Synthesis of compounds IIbϪIIf was carried out by the same
procedure as described for the preparation of IIa.
L-cysteine ethyl ester hydrochloride (2.1 g, 11.1 mmol) was
added to a solution of 16 (3.3 g, 11.1 mmol) and triethylamine
(1.5 mL, 11.1 mmol) in dry methanol (50 mL), and the mixture
was stirred for 2 h at room temperature. The resulting solution
was evaporated, diluted with ethyl acetate and washed with
brine. The organic layer was dried over anhydrous MgSO4.
Evaporation of the resulting solution in vacuo gave a crude
residue which was purified by silica gel column chromatogra-
phy to give 17 (1.8 g, 45.0%) as a pale yellow oil. 1H-NMR
(300 MHz, CDCl3) δ 1.33 (t, 3H, J = 9.3 Hz), 1.71 (s, 3H),
3.57 (bs, 2H), 4.29 (m, 2H), 5.09 (s, 2H), 7.44 (d, 2H, J =
14.6 Hz), 8.24 (d, 2H, J = 12.4 Hz).
IIb: Yield 53.4%. 1H-NMR (300 MHz, CDCl3) δ 1.21Ϫ1.43 (m,
9H), 2.40 (bs, 2H), 2.42 (bs, 3H), 2.88 (bs, 3H), 3.22 (m, 1H),
3.29 (m, 3H), 3.52 (bs, 3H), 3.93 (bs, 1H), 4.24 (m, 2H), 4.60
(m, 4H), 5.27 (m, 4H), 5.93 (m, 2H).
IIc: Yield 49.6%. 1H NMR (300 MHz, CDCl3) δ 1.30 (m, 9H),
2.81 (m, 2H), 2.90 (bs, 2H), 3.31 (bs, 2H), 3.74 (bs, 2H), 4.13
(m, 1H), 4.36 (bs, 2H), 4.47 (bs, 2H), 4.50 (m, 1H), 4.89 (m,
4H), 5.30 (m, 4H), 5.89 (m, 2H), 8.09 (t, 1H, J = 7.6 Hz).
IId: Yield 57.2%. 1H-NMR (300 MHz, CDCl3) δ 1.23Ϫ1.32 (m,
6H), 1.43 (t, 3H, J = 7.2 Hz), 2.17 (bs, 2H), 2.78 (bs, 2H),
3.24 (d, 2H, J = 6.4 Hz), 3.27 (m, 2H), 3.74 (t, 1H, J = 6.6
Hz), 4.12 (m, 2H), 4.45 (m, 2H), 4.57 (m, 4H), 4.92 (m, 1H),
5.45 (m, 4H), 5.93 (m, 2H).
2-Aminomethyl-(4Ј-ethoxycarbonyl)thiazoline (18)
IIe: Yield 52.2%. 1H-NMR (300 MHz, CDCl3) δ 1.20Ϫ1.63 (m,
6H), 2.06 (m, 1H), 2.62 (m, 2H), 3.22 (m, 2H), 3.54 (bs, 1H),
3.84 (bs, 3H), 4.12 (bs, 1H), 4.27 (d, 2H, J = 3.8 Hz), 4.62
(d, 4H, J = 7.8 Hz), 5.25Ϫ5.47 (m, 4H), 5.91 (m, 2H).
Compound 17 (1.44 g, 4.5 mmol) and 0.5 g of Pd/C (10%
[wt/wt]) were dissolved in THF:MeOH (1:1) (10 mL each). The
mixture was hydrogenated at 45 psi for 2 h and subsequently
© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Arch. Pharm. Pharm. Med. Chem. 2004, 337, 391−397
Synthesis and Antibacterial Evaluation of Carbapenem Derivatives 397
1
IIf: Yield 45.6%. H-NMR (300 MHz, CDCl3) δ 1.24Ϫ1.38 (m,
(m, 2H). IR (KBr): 3490 (OH), 1705, 1660 (C=O) cmϪ1. MS
9H), 1.86 (bs, 2H), 2.32 (m, 2H), 2.98 (bs, 2H), 3.21 (m, 4H),
3.30 (m, 4H), 4.23Ϫ4.27 (m, 2H), 4.64Ϫ4.87 (m, 4H),
5.24Ϫ5.41 (m, 4H), 5.91 (m, 2H).
m/z 527 (M+).
References
(1R,5S,6S)-6-[(1R)-1-Hydroxyethyl]-2-[(3S,5S)-5-(N-thiazol-
idin-2-ylmethyl)carbamoylpyrrolidin-3-ylthio]-1-methylcar-
bapen-2-em-3-carboxylic acid (IIIa)
[1] M. Sato, M. Takemura, S. Atarashi, K. Higashi, T. Naga-
hara, M. Furukawa, T. Ikeuchi, Y. Osada, J. Antibiot.
1987, 40, 1292Ϫ1302.
Compound IIa (0.31 g, 0.5 mmol) and 0.1 g of Pd(OH)2 (10%)
were dissolved in THF-phosphate buffer (pH 7) (1:1; 10 mL
each). The mixture was hydrogenated at 50 psi for 2 h. The
solution was filtered through celite and washed with water (2
ϫ 10 mL). The combined filtrates were washed with ethyl
ether (2 ϫ 20 mL) and lyophilized to give a yellow powder,
which was purified on a Diaion HP-20 column and eluted with
2% THF in water. Fractions showing UV absorption at 298
nm were collected and lyophilized again to give the title com-
pound IIIa (27 mg, 18.0%) as a white powder. Mp =
155Ϫ159°C (dec.). 1H-NMR (300 MHz, D2O) δ 0.90Ϫ1.26
(m, 6H), 1.53 (m, 2H), 2.32 (bs, 3H), 2.74 (bs, 3H), 3.12 (bs,
3H), 3.40 (m, 1H), 3.62 (bs, 2H), 3.84 (m, 2H), 4.21 (m, 1H).
IR (KBr): 3480 (OH), 1670 (C=O) cmϪ1. MS m/z 457 (M+).
[2] T. Miyadera, T. Sugimura, T. Hasimoto, T. Tanaka, K.
Iino, S. Sugawara, J. Antibiot. 1983, 36, 1034Ϫ1039.
[3] M. Sunagawa, H. Matsumure, T. Inoue, M. Fukasawa,
M. Kato, J. Antibiot. 1990, 43, 519Ϫ532.
[4] Y. Iso, T. Irie, Y. Nishino, K. Motokawa, Y. Nishitani, J.
Antibiot. 1996, 46, 199Ϫ209.
[5] K. Inoue, Y. Hamana, T. Inoue, M. Fukasawa, M. Kato,
Abstracts of Papers of 34th Intersci. Conf. on Antimicro.
Agents Chemother., No. 1, Orlando, 1994.
[6] G. Bourboulis, P. Grecka, M. Grammatikou, H. Giama-
rellou, Abstracts of Papers of 34th Intersci. Conf. on Anti-
micro. Agents Chemother., No. 68, Orlando, 1994.
[7] C.-H. Oh, S.-Y. Hong, K.-H. Nam, J.-H. Cho, Korean J.
Med. Chem. 1993, 3, 82Ϫ92.
Synthesis of compounds IIIbϪIIIf was carried out by the same
procedure as described for the preparation of IIIa.
IIIb: Yield 15.2%. λmax: 298 nm. Mp = 160Ϫ163°C (dec.). 1H-
NMR (300 MHz, D2O) δ 0.93Ϫ1.20 (bs, 9H), 2.10 (bs, 2H),
2.54 (m, 1H), 3.22 (m, 3H), 3.52 (m, 2H), 3.84 (bs, 4H), 3.97
(bs, 3H), 4.23 (bs, 3H). IR (KBr): 3480 (OH), 1710, 1670 (C=
O) cmϪ1. MS m/z 529 (M+).
[8] C.-H. Oh, E.-R. Woo, S.-Y. Hong, K.-H. Nam, D. Y. Kim,
J.-H. Cho, Korean J. Med. Chem. 1994, 4, 26Ϫ34.
[9] C.-H. Oh, J.-H. Cho, J. Antibiot. 1994, 47, 126Ϫ128.
[10] C. B. Jin, I. S. Jung, H.-J. Ku, J. W. Yook, D.-H. Kim,
J.-H. Cho, M. S. Kim, C.-H. Oh., Toxicology 1999, 138,
59Ϫ67.
IIIc: Yield 9.4%. λmax: 298 nm. Mp = 140Ϫ143°C (dec.). 1H-
NMR (300 MHz, D2O) δ 1.02 (bs, 3H), 1.13 (bs, 3H), 1.22
(bs, 2H), 1.89 (t, 2H, J = 7.2 Hz), 2.32 (m, 1H), 2.84 (bs, 1H),
3.02Ϫ3.24 (bs, 3H), 3.50 (m, 1H), 3.81 (m, 2H), 4.02 (bs, 2H)
4.21 (bs, 2H), 8.23 (s, 1H). IR (KBr): 3480 (OH), 1730, 1670
(C=O) cmϪ1. MS m/z 525 (M+).
[11] C.-H. Oh, H.-W. Cho, I.-K. Lee, J.-Y. Gong, J.-H. Choi,
J.-H. Cho, Arch. Pharm. Pharm. Med. Chem. 2002,
335, 152Ϫ158.
IIId: Yield 21.4%. λmax: 298 nm. Mp = 175Ϫ179°C (dec.). 1H-
NMR (300 MHz, D2O) δ 1.07Ϫ1.20 (m, 9H), 1.54 (m, 2H),
2.70 (m, 1H), 3.12 (bs, 3H), 3.45 (bs, 2H), 3.92 (m, 2H),
4.02Ϫ4.21 (m, 4H). IR (KBr): 3440 (OH), 1700, 1670 (C=O)
cmϪ1. MS m/z 510 (M+).
[12] C.-H. Oh, H.-G. Dong, H.-W. Cho, S. J. Park, J. H. Hong,
J.-H. Cho, Arch. Pharm. Pharm. Med. Chem. 2002,
335, 200Ϫ206.
[13] C.-H. Oh, H.-W. Cho, J.-H. Cho, Eur. J. Med. Chem.
2002, 37, 743Ϫ754.
IIIe: Yield 15.2%. λmax: 298 nm. Mp = 120Ϫ125°C (dec.). 1H-
NMR (300 MHz, D2O) δ 1.17Ϫ1.26 (m, 6H), 1.79 (m, 2H),
2.59Ϫ2.71 (m, 2H), 3.31 (m, 4H), 3.80 (m, 2H), 4.12 (m, 2H).
IR (KBr): 3480 (OH), 1690, 1660 (C=O) cmϪ1. MS m/z 481
(M+).
[14] C.-H. Oh, S.-C. Lee, J.-H. Cho, Eur. J. Med. Chem.
2003, 38, 751Ϫ758.
[15] C.-H. Oh, S.-C. Lee, J.-H. Cho, Eur. J. Med. Chem.
2003, 38, 841Ϫ850.
1
IIIf: Yield 10.6%. λmax: 298 nm. Mp = 140Ϫ146°C (dec.). H-
NMR (300 MHz, D2O) δ 1.09Ϫ1.21 (m, 6H), 2.21 (bs, 2H),
[16] D. H. Shih, F. L. Baker, B. G. Christensen, Heterocycles
1984, 21, 29Ϫ40.
2.59 (m, 2H), 3.02 (m, 5H), 3.20 (m, 3H), 3.73 (bs, 3H), 4.48
© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim