Note: Descriptions are shown in the official language in which they were submitted.
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DESCRIPTION
PRODRUGS OF A 7-ACYLAMINO-3-HETEROARYLTHIO-3-CEPHEM
CARBOXYLIC ACID ANTIBIOTIC
FIELD OF THE INVENTION
The present invention relates to organic chemistry, medicinal chemistry,
biochemistry and medicine. In particular it relates to prodrugs of a
cephalosporin
antibiotic wherein the prodrugs are substantially more water soluble than the
parent antibiotic which, among other benefits, aids parenteral administration.
The
prodrugs convert readily under physiological conditions to provide the parent
antibiotic.
BACKGROUND OF THE INVENTION
The following is provided to help understand of present invention. Nothing
in this section is admitted, nor should be construed to be, prior art to the
present
invention.
Over the past three decades a variety of antibiotics has become available
for clinical use. However, the indiscriminant use of these antibiotics has
given
rise to resistance among a number of clinically important bacterial strains
such as
Salmonella, S. pneumonia?, Enterobacteriacea?, Staphylococcus aureus, and
Pseudomonas. The rate of development of resistance has increased alarmingly
in recent years. Among the various classes of antibiotics that have
encountered
this rise in development of resistance, the cephalosporins have been
particularly
hard hit.
Since 1965, over 70 cephalosporins have become available for clinical use
in the treatment of bacterial infections. Their mode of action involves
inhibition of
the biosynthesis of bacterial peptidoglycan biosynthesis, an important step in
cell
wall manufacture. Resistance to cephalosporins occurs primarily by three
mechanisms: (a) the development of (i-lactamases, which cleave a-lactam rings
thereby deactivating the antibiotic; (b) changes in cell wall composition
resulting in
decreased penetration by the antibiotic; and, (c) changes in penicillin-
binding
proteins (PBPs) resulting in reduced binding of the PBPs with ~3-lactams, the
binding being essential to the inhibition of cell-_wall biosynthesis by (i-
lactams.
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Examples of bacteria whose resistant is due to poor PBP binding are
methicillin-
resistant Staphylococcus aureus ("MRSA") and the Enterococci. Resistance in
MRSA is due to the presence of high levels of an altered PBP, PBP2a, which has
been shown to bind very poorly to [i-lactams. Attempts to circumvent this
mechanism of resistance has led to the discovery of a host of new
antibacterial
compounds.
Among the compounds shown to be effective against bacteria whose
resistance has been shown to be related to poor PBP binding are those
described
in commonly owned International Application No. PCT/US95/03976 and U.S.
patent applications Serial Nos. 081222,262, filed April 1, 1994; 08/369,798,
filed
January 6, 1995; 08/413,713, 08/413,714, 08/415,065, 08/413,712, 08/415,064,
and 08/415,069, all of which were filed on March 29, 1995; 08/455,969, filed
May
31, 1995; 08/457,673, fil~,d June 1, 1995; 08/940,508 and 08/937,812, both of
which were filed September 29, 1997; 08/730,041, 08/730,039, 08/728,232,
081430,042, 08/728,233, and 08/730,040, all of which were filed October 11,
1996; and 08/842,915, filed April 17, 1997; all of which are incorporated
herein by
reference in their entirety, including any drawings.
A class of compounds which have demonstrated activity against ~-lactam,
in particular, cephalosporin resistant, bacteria is the 7-acylamino-3-
heteroarylthio-
3-eephem carboxylic acids, described in U.S. Patent No. 6,025,352, which is
likewise incorporated by reference, includign any drawings, as if fully set
forth
herein. Of the 7-acylamino-3-heteroarylthio-3-cephem carboxylic acids, a
particularly active compound is (7R)-7-[(Z)-2-(2-amino-5-chlorothiazol-4-yl)-2-
(hydroxyimino)acetamido]-3-{3-(2-aminoethylthiomethyl]-pyrid-4-ylthio~-3-
cephem-
4-carboxylic acid (1 ):
N~OH
H
i w
~(N I N ~S ~ N
H2N S I O ~N \ I
Cl O ~ ~S
O p- S ~ NH3+
1
However, while exhibiting a high level of activity against (3-lactam resistant
bacterial strains in vitro, the utility of 1 in vivo is limited due to its
relatively low
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water solubility which limits the available modes of administration. That is,
the
water solubility of 1 at or near neutral pH, i.e., from about pH 5 to about pH
7, is
insufficient for parental administration.
What is needed is a version of 1, which is more water soluble at or near
neutral pH but which has the same high bactericidal activity as 1 or which
readily
reverts to 1 itself in vivo. The present invention provides such a version of
1.
SUMMARY OF THE INVENTION
The present invention relates to prodrugs of 1 that exhibit surprising water
solubility and which are readily bioconverted in vivo to the parent compound.
Thus, in one aspect, the present invention relates to compounds having
the chemical structure:
N~OHH
w
R~~HN N I Nw. S wN
~S ~ O /~--~ / I
CI O ~S
C02H ~S~NHR' 2
wherein:
R'' is selected from the group consisting of hydrogen and -C(O)CH(NH~)CH3;
and,
R'2 is selected from the group consisting of hydrogen and an acyl group that
is
cleaved by an enzyme found in mammals.
In another aspect, the present invention relates to the above compound
wherein:
R'2 is selected from the group consisting of hydrogen, -C(O)-R88, -C(O)-OR89,
0
o"o
-C(O)-CH(NHR'~)-alk4, and -oco~-o-oH2~
wherein
0
R8$ is ''~ or '''~
R'3 is selected from the group consisting of hydrogen, -C(O)-OR89, and
-C(O)-CH(NHZ)-alk4;
alk4 is selected from the group consisting of hydrogen, and
optionally substituted alkyl, wherein said alkyl is optionally
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substituted with one or more substituents selected from the group
consisting of hydrogen, phenyl, -COOH, -C(O)-OR89, -C(O)NH2,
NH
-OH, -SH, -NHS, and ~~, ;and,
R89 is selected from the group consisting of benzhydryl, t-butyl, allyl,
p-nitrobenzyl, benzyl, p- or o-nitrobenzyl, 2,2,2-trichloroethyl,
cinnamyl, 2-chloroallyl, t-amyl, trityl, 4-methoxytrityl,
4,4'-dimethoxytrityl, trimethylsilyl, t-butyldimefihylsilyl,
~-(trimethylsilyl)ethyl, 4- or 2-methoxybenzyl, 2,4-dimethoxybenzyl,
3,4-dimethoxybenzyl, 2,4,6-trimethoxybenzyl, methoxymethyl, and
3,3-dimethylallyl.
It is a further aspect of this invention that, in the above compound,
R'3 is selected from the group consisting of hydrogen, methyl, and
-C(O)CH(NH2)CH3.
Furhermore, it is an aspect of this invention that, in the above compounds,
alk4 is selected from the group consisting of hydrogen, -CH3,
-CH(CH3)2, -CH20H, -CH2NH2, -CH2CH2NH2, -CHZCH2CHZNH~,
-CH2CH2CH2CH2NH~, -CH2COOH, -CHZCH~COOH, -CHZ C(O)NH2, -CHZCH~
C(O)NH~, and -~HZ N ,
Pharmaceutically acceptable salts of any of the above compounds are
likewise an aspect of this invention.
Another aspect of this invention is a compound selected from the group
consisting of:
(7R)-7-[(Z)-2-(2-amino-5-chlorothiazol-4-yl)-2-(hydroxyimino)acetamido]-3-
{3-[2-N-(L)-ornithylaminoethylthiomethyl]pyrid-4-ylthio)-3-cephem-4-carboxylic
acid: N~OH
H
HZN~N~N
O' O ~ S \ H NH
O OH g~N~~NH2
I~~O
(7R)-7-[(Z)-2-(2-amino-5-chlorothiazol-4-yl)-2-(hydroxyimino)acetamido]-3-
~3-[2-N-(L)-prolylaminoethylthiomethyl]pyrid-4-ylthio}-3-cephem-4-carboxylic
acid:
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N~OH
H
HzN~N~N S / I
--~S~CI O~ O~ / S \ H HN
O OH ~S~N~
O
(7R)-7-[(Z)-2-(2-N-(L)-alanylamino-5-chlorothiazol-4-yl)-2-
(hydroxyimino)acetamido]-3-~3-[2-aminoethylthiomethyl]pyrid-4-ylthio}-3-cephem-
4-carboxylic acid:
,OH
O N H
t o ~H~N~N~S
I /
N~Hz - -~/S~CI ~ O ~~''''~ / S \
O OH S~~z
(7R)-7-[(Z)-2-(2-amino-5-chlorothiazol-4-yl)-2-(hydroxyimino)acetamido]-
3-~3-[2-N-(L,L)-alanylalanylaminoethylthiomethyl]pyrid-4-ylthio)-3-cephem-
15 4-carboxylic acid:
N~OH
H
HzN \ N I I N S / I O
i
S~ N \
CI O~ / S H HN _
0 OH S~N~ ~z
I'O
20 (7R)-7-[(Z)-2-(2-amino-5-chlorothiazol-4-yl)-2-(hydroxyimino)acetamido]-3-
(3-[2-N-glycylaminoethylthiomethyl]pyrid-4-ylthio)-3-cephem-4-carboxylic acid:
N~OH
H
HZN~N I I N S / I
S~ N \
CI O~ / S H
25 O OH S~N~NHz
O
(7R)-7-[(Z)-2-(2-amino-5-chlorothiazol-4-yl)-2-(hydroxyimino)acetamido]-3-
~3-[2-N-(L)-aspartylaminoethylthiomethyl]pyrid-4-ylthio)-3-cephem-4-carboxylic
acid: N~OH
H
HzN~N~N ~S / N
S CI O O' N / S \ H NHz O
O OH S~''N~OH
O
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(7R)-7-[(Z)-2-(2-amino-5-chlorothiazol-4-yl)-2-(hydroxyimino)acetamido]-3-
{3-[2-N-(L)-alanylaminoethylthiomethyl]pyrid-4-ylthio}-3-cephem-4-carboxylic
acid:
N,OH
H
N~N S / N
~i
H N ICI O O / S \ I H NHz
O OH S~''N
O
(7R)-7-[(Z)-2-(2-amino-5-chlorothiazol-4-yl)-2-(hydroxyimino)acetamido]-3-
~3-[2-N-(L)-(Na methyl)alanylaminoethylthiomethyl]pyrid-4-ylthio~-3-cephem-4-
carboxylic acid: N,oH
H
N~N S / N
~i
H N--< ICl O O~ / S \ I H
0 OH SAN
O
1S (7R)-7-[(Z)-2-(2-amino-5-chlorothiazol-4-yl)-2-(hydroxyimino)acetamido]-3-
{3-[2-N-(L)-histidylaminoethylthiomethyl]pyrid-4-ylthio}-3-cephem-4-carboxylic
acid:
N,OH
H
N~N S / N
,~ ~i ~
HzN s ICI O O~ / S \ I H NHz N
O OH S~'N~~~
O
(7R)-7-[(Z)-2-(2-amino-5-chlorothiazol-4-yl)-2-(hydroxyimino)acetamido]-3-
(3-[2-N-(L)-valylaminoethylthiomethyl]pyrid-4-ylthio}-3-cephem-4-carboxylic
acid:
N~OH
H
ZS N N S / N
H N ICI O O / S \ I H NHz
O OH SAN
IO
(7R)-7-[(Z)-2-(2-amino-5-chlorothiazol-4-yl)-2-(hydroxyimino)acetamido]-3-
{3-[2-N-(L)-asparagylaminoethylthiomethyl]pyrid-4-ylthio~-3-cephem-4-
carboxylic
N,OH
H
N~N S / N
--~ ~i
HzN s I Cl O O~ / S \ I H NHz O
O OH S'~N~NHz
O
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acid:
(7R)-7-[(Z)-2-(2-amino-5-chlorothiazol-4-yl)-2-(hydroxyimino)acetamido]-3-
~3-[2-N-(L)-lysylaminoethylthiomethyl]pyrid-4-ylthio]-3-cephem-4-carboxylic
acid:
N,OH
H
N~N S / N
i~ ~ w
H ' CI O O / S \ I H NHz
O OH SAN NHz
O
(7R)-7-[(Z)-2-(2-amino-5-chlorothiazol-4-yl)-2-(hydroxyimino)acetamido]-3-
~3-[2-N-(L)-serylaminoethylthiomethyl]pyrid-4-ylthio~-3-cephem-4-carboxylic
acid:
N,OH
H
~N~N s / N
HzN~ ICI ~O O?'"' / S \ I H NH2
O OH S~N~OH
IIO
(7R)-7-[(Z)-2-(2-amino-5-chlorothiazol-4-yl)-2-(hydroxyimino)acetamido]-3-
~3-[2-N-(L)-glutamylaminoethylthiomethyl]pyrid-4-ylthio}-3-cephem-4-carboxylic
acid N~OH
H
N~N ~S / N
i ~ ~ ''
HzN~S ' Cl O O' N / S \ I H NHz
O OH S~N'~~OH
IOI 'I0
(7R)-7-[(Z)-2-(2-amino-5-chlorothiazol-4-yl)-2-(hydroxyimino)acetamido]-3-
~3-[2-N-(L)-glutaminylaminoethylthiomethyl]pyrid-4-ylthio}-3-cephem-4-
carboxylic
acid: N~OH
H
ZS N N N S
w
S CI O O~N / S \ H NHz
O OH S~N'~NHz
IOI IIO
and,
(7R)-7-[(Z)-2-(2-amino-5-chlorothiazol-4-yl)-2-(hydroxyimino)acetamido]-3-
30 ~3-[2-N-((5-methyl-1,3-dioxolan-4-en-2-on-4-yl)methoxycarbonyl)aminoethyl-
thiomethyl]pyrid-4-ylthio}-3-cephem-4-carboxylic acid:
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N,OH
H
I
, ~i N S ~ N
HzN s I O N \ I O
C1 O~ ~ S H 0
O OH S~N~O~O
IO
A still further aspect of this invention is a compound selected from the
group consisting of:
(7R)-7-[(Z)-2-(2-amino-5-chlorothiazol-4-yl)-2-(hydroxyimino)acetamido]-3-
{3-[2-N-(L)-ornithylaminoethylthiomethyl]pyrid-4-ylthio)-3-cephem-4-carboxylic
acid,
(7R)-7-[(Z)-2-(2-amino-5-chlorothiazol-4-yl)-2-(hydroxyimino)acetamido]-3-
~3-[2-N-(L,L)-alanylalanylaminoethylthiomethyl]pyrid-4-ylthio}-3-cephem-4-
carboxylic acid,
(7R)-7-[(Z)-2-(2-amino-5-chlorothiazol-4-yl)-2-(hydroxyimino)acetamido]-3-
{3-[2-N-(L)-aspartylaminoethylthiomethyl]pyrid-4-ylthio)-3-cephem-4-carboxylic
acid,
(7R)-7-[(Z)-2-(2-amino-5-chlorothiazol-4-yl)-2-(hydroxyimino)acetamido]-3-
~3-[2-N-(L)-alanylaminoethylthiomethyl]pyrid-4-ylthio}-3-cephem-4-carboxylic
acid,
(7R)-7-[(Z)-2-(2-amino-5-chlorothiazol-4-yl)-2-(hydroxyimino)acetamido]-3-
~3-[2-N-(L)-lysylaminoethylthiomethyl]pyrid-4-ylthio)-3-cephem-4-carboxylic
acid,
(7R)-7-((Z)-2-(2-amino-5-chlorothiazol-4-yl)-2-(hydroxyimino)acetamido]-3-
{3-[2-N-(L)-glutamylaminoethylthiomethyl]pyrid-4-ylthio)-3-cephem-4-carboxylic
acid; and,
(7R)-7-[(Z)-2-(2-amino-5-chlorothiazol-4-yl)-2-(hydroxyimino)acetamido]-3-
~3-[2-N-((5-methyl-1,3-dioxolan-4-en-2-on-4-yl)methoxycarbonyl)aminoethyl-
thiomethyl]pyrid-4-ylthio)-3-cephem-4-carboxylic acid.
Finally, an aspect of this invention is the compound (7R)-7-[(Z)-2-(2-
amino-5-chlorothiazol-4-yl)-2-(hydroxyimino)acetamido]-3-~3-[2-N-(L)-
aspartylaminoethylthiomethyl]pyrid-4-ylthio)-3-cephem-4-carboxylic acid:
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N.OHH
N ~ N~ S ~N
w
NCH g I C~ O ~ / S I / NH3+
O H
COz S~N~COzH
'O
In a further aspect, this invention relates to a pharmaceutically acceptable
salt of any of the compounds of this invention.
Another aspect of this invention is a composition for use in the treatment of
a bacterial infection in a patient comprising one or more compounds of this
invention.
A still further aspect of this invention is a composition comprising a
compound of this invention and a pharmaceutically acceptable carrier or
excipient.
An aspect of this invention is a composition for use in the treatment of a
bacterial infection in a human being comprising one or more compounds of this
invention
It is likewise an aspect of this invention that the composition for use in
treatment of a bacterial infection in a human being further comprises a
pharmaceutically acceptable carrier or excipient.
An aspect of this invention is that the above compositions are useful in the
treatment of a ~i-lactam antibiotic resistant bacterial infection.
The (i-lactam antibiotic resistant bacterial infection is a methicillin,
ampicillin
or vancomycin resistant bacterial infection in another aspect of this
invention.
Furthermore, the bacterial infection is caused by a Staphylococcus or
Entercoccus species bacteria in a further aspect of this invention.
The Staphylococcus or Enterococcus species are resistant to some, or all,
other ~i-lactam antibiotics in a still further aspect of this invention.
The resistant Staphylococcus species is S. aureus Col (MethR)(bla-), S.
aureus 76 (MethR) (bla+), S. aureus ATCC 29213, S. Aureus ATCC 25913, S.
Aureus ATCC 32432 or S. Aureus CoIBA in another aspect of this invention.
The resistant Enterococcus species is E, f~cium ATCC 35667 or E.
fa?calis ATCC 29212 in an aspect of this invention.
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Finally, a composition for use in the prophylactic treatment of a patient for
the prevention of a bacterial infection is an aspect of this invention.
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DETAILED DESCRIPTION OF THE INVENTION
Brief description of the Figures.
Figure 1 shows the water solubility of the parent antibiotic, compound 1, in
its zwitterionic form (2) compared to that of a prodrug of this invention,
compound
3:
N~O H N~OH
N~N S
/ N N I N' S
HZN~S 'C1 O ~ / ~ I i O ~~ I ~ +
O S CI O ~S + H NH3
O O- S~NH3 COZ Na S~N~COZ
I0
2 3
Definitions
As used herein, the term "alkyl" refers to a saturated aliphatic hydrocarbon
including straight chain and branched chain groups. Preferably, the alkyl
group
has 1 to 20 carbon atoms (whenever a numerical range; e.g. "1-20", is stated
herein, it means that the group, in this case the alkyl group, may contain 1
carbon
atom, 2 carbon atoms, 3 carbon atoms, etc., up to and including 20 carbon
atoms). More preferably, it is a medium size alkyl having 1 to 10 carbon
atoms.
Most preferably, it is a lower alkyl having 1 to 4 carbon atoms. The alkyl
group
may be substituted or unsubstituted. Examples, without limitation, of
unsubstituted alkyl groups are methyl, ethyl, n-propyl, iso-propyl, n-butyl,
sec-butyl, iso-butyl, tent-butyl, and 2-methylpentyl. When substituted, the
substituent groups) may be, without limitation, one or more independently
selected from the group consisting of halo, hydroxy, cyano, nitro, lower
alkoxy,
carboxy, carbonyl, alkylcarbonyl, alkoxycarbonyl, mercapto, alkylthio, amino,
amido, isothioureido, amidino, guanidino, optionally substituted aryl,
optionally
substituted aryloxy, optionally substituted arylthio, optionally substituted 6-
member heteroaryl having from 1 to 3 nitrogen atoms in the ring, optionally
substituted 5-member heteroaryl having from 1 to 3 heteroatoms in the ring
selected from the group consisting of nitrogen, oxygen and sulfur, and
optionally
substituted 5- or 6-member heteroalicyclic group having from 1 to 3
heteroatoms
in the ring selected from the group consisting of nitrogen, oxygen and sulfur.
Examples, without limitation of substituted alkyl groups include
trifluoromethyl,
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3-hydroxyhexyl, 2-carboxypropyl, 2-fluoroethyl, carboxymethyl, 4-cyanobutyl,
2-guanidinoethyl and 3-N,N'-dimethylisothiouroniumpropyl.
A "cycloalkyl" group refers to a 3 to 8 member all-carbon monocyclic ring,
an all-carbon 5-member/6-member or 6-member/6-member fused bicyclic ring or
a multicyclic fused ring (a "fused" ring system means that each ring in the
system
shares an adjacent pair of carbon atoms with each other ring in the system)
group
wherein one or more of the rings may contain one or more double bonds but none
of the rings has a completely conjugated pi-electron system. Examples, without
limitation, of cycloalkyl groups are cyclopropane, cyclobutane, cyclopentane,
cyclopentene, cyclohexane, cyclohexadiene, adamantane, cycloheptane and,
cycloheptatriene. A cycloalkyl group may be substituted or unsubstituted. When
substituted, the substituent groups) may be, without limitation, one or more
independently selected from the group consisting of halo, hydroxy, alkoxy,
mercapto, alkylthio, cyano, nitro, optionally substituted aryl, optionally
substituted
aryloxy, mercapto, alkylthio, optionally substituted arylthio, amino, amido,
carboxy, carbonyl, alkylcarbonyl, alkoxycarbonyl, optionally substituted 6-
member heteroaryl having from 1 to 3 nitrogen atoms in the ring, optionally
substituted 5-member heteroaryl having from 1 to 3 heteroatoms in the ring
selected from the group consisting of nitrogen, oxygen and sulfur, and
optionally
substituted 5- or 6-member heteroalicyclic group having from 1 to 3
heteroatoms
in the ring selected from the group consisting of nitrogen, oxygen and sulfur.
An "alkenyl" group refers to an alkyl group, as defined herein, consisting of
at least two carbon atoms and at least one carbon-carbon double bond.
An "alkynyl" group refers to an alkyl group, as defined herein, consisting of
at least two carbon atoms and at least one carbon-carbon triple bond.
An "aryl" group refers to an all-carbon monocyclic or fused-ring polycyclic
(i.e., rings which share adjacent pairs of carbon atoms) groups having a
completely conjugated pi-electron system. Examples, without limitation, of
aryl
groups are phenyl, naphthalenyl and anthracenyl. The aryl group may be
substituted or unsubstituted. When substituted, the substituting groups) may
be,
without limitation, one or more independently selected from the group
consisting
of alkyl, (halo)3C-, halo, hydroxy, alkoxy, mercapto, alkylthio, cyano, nitro,
amino,
amido, carboxy, carbonyl, alkylcarbonyl, alkoxycarbonyl, optionally
substituted 6-
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member heteroaryl having from 1 to 3 nitrogen atoms in the ring, optionally
substituted 5-member heteroaryl having from 1 to 3 heteroatoms in the ring
selected from the group consisting of nitrogen, oxygen and sulfur, and
optionally
substituted 5- or 6-member heteroalicyclic group having from 1 to 3
heteroatoms
in the ring selected from the group consisting of nitrogen, oxygen and sulfur.
Examples, without limitation, of substituted aryl groups are biphenyl,
iodobiphenyl,
methoxybiphenyl, anthryl, bromophenyl, iodophenyl, chlorophenyl,
hydroxyphenyl, methoxyphenyl, formylphenyl, acetylphenyl,
trifluoromethylthiophenyl, trifluoromethoxyphenyl, alkylthiophenyl,
trialkylammoniumphenyl, amidophenyl, thiazolylphenyl, oxazolylphenyl,
imidazolylphenyl, imidazolylmethylphenyl, cyanophenyl, pyridylphenyl,
pyrrolylphenyl, pyrazolylphenyl, triazolylphenyl and tetrazolylphenyl.
As used herein, a "heteroaryl" group refers to a monocyclic or fused ring
(i.e., rings which share an adjacent pair of atoms) group having in the rings)
one
or more atoms selected from the group consisting of nitrogen, oxygen and
sulfur
and, in addition, having a conjugated pi-electron system. Examples, without
limitation, of heteroaryl groups are pyrrole, furan, thiophene, imidazole,
oxazole,
thiazole, pyrazole, pyridine, pyrimidine, quinoline, isoquinoline, purine and
carbazole. A heteroaryl group may be substituted or unsubstituted. When
substituted, the substituted groups) may be, without limitation, one or more
independently selected from the group consisting of alkyl, (halo)3C-, halo,
hydroxy, lower alkoxy, mercapto, alkylthio, arylthio, cyano, nitro, amino,
amido,
carboxy, carbonyl, alkylcarbonyl and alkoxycarbonyl. Examples of substituted
heteroaryl groups are, without limitation, 2-aminothiazol-4-yl, 2-amino-5-
chlorothiazol-4-yl, 5-amino-1,2,4-thiadiazol-3-yl, 2,3-dioxopiperazinyl,
4-alkylpiperazinyl, 2-iodo-3-dibenzfuranyl and 3-hydroxy-4-dibenzthienyl.
A "heteroalicyclic" group refers to a monocyclic or fused ring group having
in the rings) one or more atoms selected from the group consisting of
nitrogen,
oxygen and sulfur. The rings may also have one or more double bonds.
However, the rings do not have a completely conjugated pi-electron system. The
heteroalicyclic ring may be substituted or unsubstituted. When substituted,
the
substituting groups) may be, without limitation, one or more independently
selected from the group consisting of alkyl, (halo)3C-, halo, hydroxy, alkoxy,
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mercapto, alkylthio, cyano, nitro, amino, amido, carboxy, carbonyl,
alkylcarbonyl
and alkoxycarbonyl.
A "hydroxy" group refers to an -OH group.
An "alkoxy" group refers to both an -O-(unsubstituted alkyl) and an -O-
(unsubstituted cycloalkyl) group.
An "aryloxy" group refers to both an -O-aryl and an -O-heteroaryl group, as
defined herein.
A "mercapto" group refers to an -SH group.
A "alkylthio" group refers to both an (unsubstituted alkyl)S- and an
(unsubstituted cycloalkyl)S- group.
A "arylthio" group refers to both an -S(aryl) and an -S(heteroaryl group), as
defined herein.
A "halo" group refers to fluorine, chlorine, bromine or iodine.
A "cyano" group refers to a -C---N group.
A "nitro" group refers to a -NO~ group.
An "amino" group refers to an NRR' group wherein R and R' are
independently selected from the group consisting of hydrogen, alkyl,
cycloalkyl,
aryl, heteroaryl and heteroalicyclic.
An "amido" group refers to a -C(O)NRR', wherein R and R' have the above
meaning.
A "carboxy" group refers to a -CO(O)H group.
A "carbonyl" group refers to a -C(O)H group.
An "acyl" group refers to a -C(O)R group, in which R is hydrogen or alkyl as
defined above, such as formyl, acetyl, propionyl, or butyryl.
An "alkylcarbonyl" group refers to a -C(O)(alkyl) group.
An "alkoxycarbonyl" group refers to an -C(O)(O-alkyl) group.
A "trialkylsilyl" groups refers to an RR'R"Si- group, where R, R' and R" are
alkyl as defined above.
A "trialkylammonium" group refers to a [RR'R"N-]+, where R, R' and R" are
alkyl as defined above.
The term "method" refers to manners, means, techniques and procedures for
accomplishing a given task including, but not limited to, those manners,
means,
techniques and procedures either known to, or readily developed from those
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manners, means, techniques and procedures known to practitioners of the
chemical,
pharmaceutical, biological, biochemical and medical arts.
A "pharmaceutical composition" refers toga mixture of one or more of the
compounds described herein, or physiologically acceptable salts thereof, with
other chemical components, such as physiologically acceptable carriers and
excipients. The purpose of a pharmaceutical composition is to facilitate
administration of a compound to an organism.
As used herein, a pharmaceutically acceptable salt refers to any of the
compounds of this invention in its cationic or anionic form together with an
appropriate counterion. A compound of this invention may exist as a singly or
a
doubly charged species, in the latter instance it will form a salt with two
counterions, which may be the same or different. Preferred pharmaceutically
acceptable salts include (1 ) inorganic salts such as sodium, potassium,
chloride,
bromide, iodide, nitrate, phosphate or sulfate; (2) carboxylate salts such as
acetate, trifluoroacetate, propionate, butyrate, maleate, or fumarate; (3)
alkylsulfonates such as methanesulfonate, ethanesulfonate,
2-hydroxyethylsulfonate, n-propylsulfonate or isopropylsulfonate; and (4)
hydroxycarboxylates such as lactate, malate, and citrate. Salts in which a
compound of this invention is the cationic species are prepared by reacting
the
compound with an organic or inorganic acid, such as hydrochloric acid,
hydrobromic acid, sulfuric acid, nitric acid, phosphoric acid, methanesulfonic
acid,
ethanesulfonic acid, p-toluenesulfonic acid, salicylic acid, and the like. The
acid
used provides the anionic counterion. Salts in which a compound herein is the
anionic species of the pair are prepared by reacting any one of the compounds
of
the invention with an organic or inorganic base, such as benzathene,
chloroprocaine, choline, diethanolamine, ethylenediamine, meglumine, procain,
and the hydroxide, alkoxide, carbonate, bicarbonate, sulfate, bisulfate,
amide,
alkylamide, or the dialkylamide salts of lithium, sodium, potassium,
magnesium,
calcium, aluminum, and zinc. The base supplies the cation.
A "prodrug" refers to an compound which is converted into the parent drug
in vivo. Prodrugs are often useful because, in some situations, they may be
easier to administer than the parent drug. They may, for instance, be
bioavailable
by oral administration whereas the parent drug is not. The prodrug may also
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have improved solubility in pharmaceutical compositions over the parent drug.
An
example, without limitation, of a prodrug would be a compound of the present
invention which is administered as an ester (the "prodrug") to facilitate
transmittal
across a cell membrane where water solubility is detrimental to mobility but
then
is metabolically hydrolyzed to the carboxylic acid, the active entity, once
inside
the cell where water solubility is beneficial.
A further example of a prodrug might be a single amino acid or a short
polypeptide, for example, without limitation, a 2 - 10 amino acid polypeptide,
bonded through a terminal amino group to a carboxy group of a compound or
through a carboxy group of the amino acid to an amino group of a compound, as
is the case with the compounds of this invention. The compound thus formed is
then converted in vivo to release the active molecule.
As used herein, a "physiologically acceptable carrier" refers to a carrier or
diluent that does not cause significant irritation to an organism and does not
abrogate the biological activity and properties of the administered compound.
An "excipient" refers to an inert substance added to a pharmaceutical
composition to further facilitate administration of a compound. Examples,
without
limitation, of excipients include calcium carbonate, calcium phosphate,
various
sugars and types of starch, cellulose derivatives, gelatin, vegetable oils and
polyethylene glycols.
"In vitro" refers to procedures performed in an artificial environment such
as, e.g., without limitation, a test tube or a petri dish containing a culture
medium.
"In vivo" refers to procedures performed in a living organism such as,
without limitation, a mouse, rat, dog, cat, rabbit, cow, pig, horse or a
human.
As used herein, a "bacterial infection" refers to the establishment of a
sufficient population of a pathogenic bacteria in a patient to have a
deleterious
effect on the health and well-being of the patient and/or to give rise to
discernable
symptoms associated with the particular bacteria.
As used herein, the terms "prevent", "preventing" and "prevention" refer to
a method for barring an organism from acquiring a bacterial infection in the
first
place.
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As used herein, the terms "treat", "treating" and "treatment" refer to a
method of alleviating or abrogating a bacterial infection and/or its attendant
symptoms.
As used herein, "administer," administering," or "administration" refers to
the delivery of a compound, or salt thereof, or a pharmaceutical composition
containing a compound or salt thereof to an organism for the purpose of
treating
or preventing a bacterial infection.
The term "patient" refers to any living entity capable of being infected by
bacteria. In particular, a "patient" refers to a mammal such as a dog, cat,
horse,
cow, pig, rabbit, goat or sheep. Most particularly, a patient herein refers to
a
human being.
The term "therapeutically effective amount" as used herein refers to that
amount of a compound being administered that will relieve, to some extent, one
or more of the symptoms of the disorder being treated. In reference to the
treatment of a bacterial infection, a therapeutically effective amount refers
to that
amount of a compound that (1 ) reduces, preferably eliminates, the population
of
the bacteria in the patient's body, (2) inhibits (that is, slows to some
extent,
preferably stops) proliferation of the bacteria, (3) inhibits to some extent
(that is,
slows to some extent, preferably stops) spread of the infection caused by the
bacteria, and/or, (4) relieves to some extent (preferably, eliminates) one or
more
symptoms associated with the bacterial infection.
The term "prophylactically effective amount" refers to that amount of a
compound that (1 ) maintains a reduced level of a population of a bacteria;
(2)
maintains the level of inhibition of proliferation of the bacteria; (3)
maintains the
level of inhibition of spread of the infection and/or (4) maintains the level
of relief
of one or more symptoms associated with the baterial infection, achieved by
the
adminstration of a therapeutically effective amount of the compound.
The term "beta-lactam resistant bacteria" refers to bacteria against which a
beta-lactam antibiotic has a minimum inhibitory concentration (MIC) of greater
than 32 ~,g/mL.
Synthesis
Compound 1 is synthesized using well-known organic chemistry reactions
and procedures from readily available materials. Texts such as, without
limitation,
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March, Advanced Organic Chemistry: Reactions, Mechanisms and Structure
(McGraw-Hill, latest edition); Larock, Comprehensive Organic Transformations
(VCH Publishers, latest edition); Greene and Wuts, Protective Groups in
Organic
Synthesis (John Wiley & Sons, latest edition) and G.I. Georg, The Organic
Chemistsry of,l~Lactams (VCH Publishers, latest edition) provide ample
direction
for the synthesis of 1. A method for the preparation of 1 can also be found in
U.S.
Patent No. 6,025,352, which is incorporated, including any drawings, as if
fully set
forth herein. The following is representative of that synthesis:
A. (Z)-2-(2-Amino-5-chlorothiazol-4-yl)-2-(triphenylmethoxyimino)- acetic
acid.
To a solution of (Z)-2-(2-aminothiazol-4-yl)-2-(triphenylmethoxy-
imino)acetic acid (5.81 g, 13.47 mmol) in DMF (30 mL) at room temperature was
added N-chloro- succinimide (1.80 g, 13.47 mmol). After stirring overnight,
the
reaction mixture was poured into water (500 mL) and the resulting precipitate
was
filtered, washed with water and ethyl acetate, and dried under vacuum to
afford
4.43 g (71 %) of the title compound: '3C NMR (CDCI3) 8 108.5, 125.6, 126.2,
126.6, 127.3, 134.7, 141.8, 146.5, 162.1, 163.3.
B. (7R)-7-[(Z)-2-(2-Amino-5-chlorothiazol-4-yl)-2-(triphenylmethoxy-
imino)-acetamido]-3-chloro-3-cephem-4-carboxylate diphenylmethyl ester.
To a solution of 7-amino-3-chlorocephalosporanic acid diphenylmethyl
ester toluenesulfonic acid salt (5.0 g, 8.72 mmol) in dry THF (100m1) at room
temperature was added pyridine (0.63 g, 10.0 mmol), followed by (Z)-2-(2-amino-
5-chlorothiazol-4-yl)-2-(triphenylmethoxyimino)acetic acid (5.81 g, 13.47
mmol).
The resulting slurry was cooled to -15° C and additional pyridine (1.42
g, 22.5
mmol) was added followed by dropwise addition of phosphorous oxychloride
(1.64 g, 17.5 mmol), while maintaining reaction temperature below -10°
C. After
min, ethyl acetate (200 mL) was added followed by water (150 mL). The
aqueous layer was thoroughly extracted with ethyl acetate and the combined
organic extracts were dried over sodium sulfate and concentrated under vacuum
30 to yield the crude product, which was purified by flash column
chromatography on
silica gel (ethyl acetate/hexane 3:1 ) to afford the title compound (5.37 g,
65%):
'H NMR (CDCI3 /CD30D) 8 3.35 (d, 1 H, J=18), 3.68 (d, 1 H, J=18), 5.07 (d,
18
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1 H, J=5), 5.80 (br s, 2H), 6.04 (dd, 1 H, J=9, 5), 7.03 (s, 1 H), 7.06 (d, 1
H, J=9),
7.22-7-50 (m, 25H).
C. (7R)-7-[(Z)-2-(2-Amino-5-chlorothiazol-4-yl)-2-(triphenylmethoxy
imino)-acetamido]-3-mercapto-3-cephem-4-carboxylate diphenylmethyl
ester.
To a solution of (7R)-7-[(Z)-2-(2-amino-5-chlorothiazol-4-yl)-2-(triphenyl-
methoxyimino)acetamido]-3-chloro-3-cephem-4-carboxylate diphenylmethyl ester
(4.0 g, 4.72 mmol) in DMF (30 mL) at -20° C was added, in one portion,
powdered sodium hydrogen sulfide hydrate (1.10 g, 19.6 mmol). After 15 min the
reaction mixture was poured into 0.5 M monosodium phosphate (about 100 mL).
The mixture was extracted with ethyl acetate, and the organic layer was washed
thoroughly with water. After concentrating under vacuum, the crude title
product
was obtained as a yellow foam 3.8 g (95%):
' H NMR (CDCI3 / CD30D) 8 3.38 (d, 1 H, J=15), 4.43 (d, 1 H, J=15), 5.03 (d,
1 H, J=5), 5.80 (d, 1 H, J=5), 5.99 (br s, 1 H), 6.80 (s, 1 H), 7.05-7.50 (m,
25H).
D. 3-Chtoromethyl-4-chloropyridine hydrochloride
Thionyl chloride (0.714 mL, 9.78 mmol) was added at room temperature to
dry DMF (7 mL). After 30 min, the solution was cannulated into a solution of 3-
hydroxymethyl-4-chloropyridine (700 mg, 4.89 mmol) in DMF (3 mL). After 45
min, the product was precipitated by addition of dry ether (100 ml), washed
with
ether, and dried under vacuum to yield 813 mg (84%) of the title compound:
'H NMR (CD30D) 8 5.00 (s, 2H), 8.31 (d, 1 H, J=5), 8.99 (d, 1 H, J=5), 9.18
(s, 1 H).
E. 3-(N-tert-Butoxycarbonylaminoethylthiomethyl)-4-chloropyridine.
To a solution of 3-chloromethyl-4-chloropyridine hydrochloride (513 mg,
2.59 mmol) in DMF (6 mL) at room temperature were added sodium iodide (386
mg, 2.59 mmol), diisopropylethyl- amine (1.12 mL, 6.47 mmol) and 2-(N-tert-
butoxycarbonylamino)ethanethiol (458 mg, 2.59 mmol). After 2 h, the reaction
mixture was partitioned between dilute HCI and ethyl acetate. The organic
layer
was washed with water, dried over sodium sulfate, and concentrated to yield
750
mg of the oily product (96%), which was used in the next step without further
purification:
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'H NMR (CDCI3) s 1.43 (s, 9H), 2.61 (m, 2H), 3.35 (m, 2H), 3.81 (s, 2H),
4.90 (br s, 1 H), 7.35 (d, 1 H, J=4), 8.40 (d, 1 H, J=4), 8.57 (s, 1 H).
F. (7R)-7-[(Z)-2-(2-Amino-5-chlorothiazol-4-yl)-2-(triphenylmethoxy-
imino)-acetamido]-3-[3-(N-tent-butoxycarbonylaminoethylthiomethyl)pyrid-4-
ylthio]-3-cephem-4-carboxylate diphenylmethyl ester.
To a solution of (7R)-7-[(Z)-2-(2-amino-5-chlorothiazol-4-yl)-2-
(triphenylmethoxy- imino)acetamido]-3-mercapto-3-cephem-4-carboxylate
diphenylmethyl ester (650 mg, 0.777 mmol) in DMF (3 mL) was added 3-(N-tert-
butoxycarbonylaminoethylthiomethyl)-4-chloropyridine (242 mg, 0.80 mmol) at
room temperature. After stirring overnight, the reaction mixture was
partitioned
between water and ethyl acetate. The organic layer was thoroughly washed with
water, dried over sodium sulfate, and concentrated to yield the crude product
which was purified by radial chromatography on silica gel (dichloromethane /
methanol; v/v, 50/1 ) to afford 220 mg of the title compound (26%):
'H NMR (CDCI3/CD30D) 8 1.23 (s, 9H), 2.32 (t, 2H, J=6), 2.98 (d, 1 H,
J=18), 3.06 (m, 2H), 3.40 (d, 1 H, J=18), 3.46 (s, 2H), 5.03 (d, 1 H, J=5),
5.52 (br s,
1 H), 5.94 (d, 1 H, J= 5), 6.80 (s, 1 H), 6.90 (d, 1 H, J=6), 7.00-7.22 (m,
25H), 8.01
(d, 1 H, J=6), 8.08 (s, 1 H).
G. (7R)-7-[(Z)-2-(2-Amino-5-chlorothiazol-4-yl)-2-(hydroxyimino)
acetamido]-3-[3-(aminoethylthiomethyl)pyrid-4-ylthio]-3-cephem-4
carboxylate, methanesulfonic acid salt.
To a cold solution (0° C) of (7R)-7-[(Z)-2-(2-amino-5-chlorothiazol-4-
yl)-2-
(triphenylmethoxyimino)acetamido]-3-[3-(N-tert-butoxycarbonylaminoethylthio
methyl)-pyrid-4-ylthio]-3-cephem-4-carboxylate diphenylmethyl ester (1.00 g,
0.907 mmol) in dichloromethane (10 mL) and anisole (1.0 mL) was added
trifluoroacetic acid (13 mL). After 1.5 hr, the reaction mixture was
concentrated
under vacuum at room temperature, and the oily residue was dissolved in 98%
formic acid (20 mL). After 4 hr at room temperature, formic acid was removed
under vacuum, and the residue was dissolved in water (25 mL). Insoluble
material
was removed by centrifugation. The supernatant was purified on an HP20
column by elution with water, then 0.1 M aqueous ammonium acetate, then
finally
eluting the product with 1:4 acetonitrile/water. The eluate was concentrated
to
about 1/10 original volume, and the resulting precipitate was filtered, washed
with
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water and dried in vacuum to yield a zwitterionic product (260 mg). The
methanesulfonate salt was prepared by suspending the zwitterionic product in
water (15 mL) followed by addition of methanesulfonic acid (1.0 M in water,
0.98
eq) and acetonitrile (5 mL). After evaporation of the resulting solution to
dryness,
the residue was dissolved in wafer (30 mL) and centrifuged to remove insoluble
material, and the supernatant was lyophilized to give the title compound (274
mg,
44%).
'H NMR (D20) 8 3.11 (s, 3H), 3.19 (m, 2H), 3.52 (m, 2H), 3.67 (d, 1 H,
J=17), 4.22 (d, 1 H, J=17), 4.33 (s, 2H), 5.76 (d, 1 H, J=4), 6.29 (d, 1 H,
J=4), 7.93
(d, 1 H, J=4), 8.78 (d, 1 H, J=4), 8.87 (s, 1 H).
Prodrugs of 1, which are the subject of this invention, can also be prepared
by standard organic synthetic procedures found in the above-referenced texts.
The following are examples of such preparations. The syntheses shown are not
to be construed as limiting the scope of this invention in any manner
whatsoever.
That is, other prodrugs and other approaches to sythesizing them will become
apparent to those skilled in the art based on the disclosures herein; all such
prodrugs and syntheses are within the scope of this invention.
1. (7R)-7-[(Z)-2-(2-amino-5-chlorothiazol-4-yl)-2-(hydroxyimino)-
acetamido]-3-~3-[2-N-(L)-a-glutamylaminoethyl thiomethyl] pyrid-4-ylthio~-3-
cephem-4-carboxylate, bis trifluoroacetic acid salt
N,OH
I H
N N~ S ~ NH+ CF3C02
HZN~~ ~
CI O OAe N / S I / H NH3+ CF3C0z
COZH S~N~COZH
I I0
A solution of (7R)-7-[(Z)-2-(2-amino-5-chlorothiazol-4-yl)-2-
(triphenylmethoxyimino)acetamido]-3-mercapto-3-cephem-4-carboxylate,
diphenylmethyl ester (354 mg, 0.41 mmol) and 4-chloro-3-(2-[N-(L)-a-(N-t-
butoxycarbonyl)-(y-t-butoxy)-glutamyl]-aminoethylthiomethyl)pyridine (183 mg,
0.41 mmol) in DMF (2.5 mL) was stirred under nitrogen for 3 h., and was
diluted
with ethyl acetate (25 mL). The reaction mixture was thoroughly washed with
water and dried over anhydrous sodium sulfate. The mixture was subjected to
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column chromatography on silica gel (eluting with 2:1 hexane/ethyl acetate,
followed by 1:3) to afford the desired coupling product as an oily solid (107
mg).
Standard deprotection (trifluoroacetic acid, dichloromethane, triethylsilane)
was
conducted, and the title product was precipitated by addition of diethyl
ether. The
precipitate was filtered, washed thoroughly with diethyl ether and dried to
afford
the title compound (48 mg).
'H NMR (CD30D): ~ 2.25-2.37 (m, 2H), 2.65 (t, 2H, J = 8), 2.80-2.96 (m, 2H),
3.58-3.78 (m, 3H), 4.08-4..20 (m, 4H), 5.58 (d, 1 H, J = 8), 6.20 (d, 1 H, J =
8), 7.80 (d,
1 H, J = 8), 8.62 (d, 1 H, J = 8), 8.91 (s, 1 H).
2. (7R)-7-((Z)-2-(2-amino-5-chlorothiazol-4-yl)-2-(hydroxyimino)
acetamido]-3-~3-(2-N-(L)-a-(N-t-butoxycarbonyl)-(y-t-butoxy)aspartyl-
aminoethyl-thiomethyl]pyrid-4-ylthio~-3-cephem-4-carboxylic acid
N~OH
H
N I I N~~S I ~N
H~N-<~
S I O O~N ~ S ~ H NHCOZt-Bu
COZH S~N~~COZt-Bu
O
To a stirred suspension of (7R)-7-[(Z)-2-(2-amino-5-chlorothiazol-4-yl)-2-
(hydroxyimino)acetamido]-3-{3-[2-aminoethylthiomethyl]pyrid-4-ylthio}-3-cephem-
4-carboxylic acid (8.6 g, 14.28 mmol) in DMF (25 mL) at room temperature was
added triethylamine (2.0 mL, 14.5 mmol), followed by addition of a solution of
aspartic acid, N-t-butoxycarbonyl-[a-(N-hydroxysuccinimide)-ester]-y-t-butyl
ester
(5.5 g, 14.28 mmol) in DMF (25 ml). After 30 min., ice cold water (200 mL) was
added to the reaction mixture followed by addition of hydrochloric acid (1.0
M,
14.3 mL). A precipitate formed, which was filtered, washed thoroughly with
water
and dried under reduced pressure to yield the crude product as a yellowish
solid
(10.0 g).
3. (7R)-7-((Z)-2-(2-amino-5-chlorothiazol-4-yl)-2-(hydroxyimino)
acetamido]-3-~3-[2-N-(L)-~y-aspartylaminoethylthiomethyl]pyrid-4-ylthio~-3-
cephem-4-carboxylate, sodium salt
,OH
N H
N N~~S ~ N
H2N~/ I CI O 'i N ~ S I ~ NH
S O H 3
COZ Na+~S~N COZ
O
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To a stirred suspension of crude (7R)-7-[(Z)-2-(2-amino-5-chlorothiazol-4-yl)-
2-(hydroxyimino)acetamido]-3-{3-[2-N-(L)-a-(N-t-butoxycarbonyl)-(y-t-butoxy)-
aspartyl-aminoethylthiomethyl]pyrid-4-ylthio}-3-cephem-4-carboxylic acid (11.8
g,
13.52 mmol) in dichloromethane (200 mL) at room temperature was added
triethylsilane (66 mL) followed by trifluoroacetic acid (200 mL). The
resulting clear
solution was stirred for 2.5 hr. After removing the solvents under reduced
pressure,
the oily residue was re-dissolved in ethyl acetate (50 mL), and the
trifluoroacetate
salt of the product was precipitated with addition of diisopropyl ether (100
mL). The
precipitate was filtered, thoroughly washed with diisopropyl ether, and dried
under
reduced pressure to produce the crude trifluoroacetate salt as a yellow solid
(15.0
g). A solution of the crude product (in 600 mL water, adjusted with aqueous
sodium
bicarbonate to pH 6.0) was loaded onto a reverse phase preparative column,
which
was eluted with an acetonitrile/phosphate buffer mixture. The fractions
containing
pure product (800 mL) were combined, the acetonitrile was removed by
evaporation
under reduced pressure, and the aqueous solution of the product was desalted
by
loading it onto a column containing HP20 resin and washing thoroughly with
water.
The product was eluted with 20°l° aqueous acetonitrile, and the
fractions containing
pure desalted product were concentrated under reduced pressure to remove the
acetonitrile. The remaining water was removed from the resulting cloudy
solution by
lyophilization. The lyophilized material was redissolved in water and the
cloudy
solution was adjusted to pH 6.1 with addition of sodium bicarbonate solution.
The
resulting clear solution was lyophilized to yield the pure title product as a
pale yellow
solid (3.99 g.).
'H NMR (D20): 8 2.50-2.70 (m, 3H), 3.21 (d, 1 H, J =16), 3.30 (t, 2H, J = 8),
3.70
(d, 1 H, J = 16), 3.78 (s, 2H), 4.04-4.10 (m, 1 H), 5.27 (d, 1 H, J = 8), 5.80
(d, 1 H, J =
8), 7.18 (d, 1 H, J = 8), 8.19 (d, 1 H, J = 8), 8.23 (s, 1 H).
Pharmaceutical Applications and Preparations
A prodrug of the present invention or a physiologically acceptable salt
thereof can be administered as such to a patient or can be administered in
pharmaceutical compositions in which the foregoing materials are mixed with
suitable carriers or excipient(s). Techniques for formulation and
administration of
drugs may be found in Remington's Pharmacological Sciences (Mack Publishing
Co., Easton, PA, latest edition).
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Routes of Administration.
Suitable routes of administration may include, without limitation, oral,
rectal, transmucosal, intramuscular, subcutaneous, intramedullary,
intrathecal,
intraventricular, intravenous, intravitreal, intraperitoneal, intranasal, or
intraocular.
The preferred routes of administration are oral and intravenous.
Alternatively, one may administer the compound in a local rather than
systemic fashion, for example, topical application onto or injection directly
into an
infected area of a patient's body.
Compositions/Formulations
Pharmaceutical compositions of the present invention may be
manufactured by processes well known in the art, e.g., by means of
conventional
mixing, dissolving, granulating, dragee-making, levigating, emulsifying,
encapsulating, entrapping or lyophilizing processes.
Pharmaceutical composifiions may be formulated in conventional manner
using one or more physiologically acceptable carriers comprising excipients
and
auxiliaries which facilitate processing of the active compounds into
preparations
which can be used pharmaceutically. Proper formulation is dependent upon the
route of administration chosen; such formulations are well-known to those
skilled
in the art and include, without limitation, the following:
For injection, compounds may be formulated in aqueous solutions,
preferably in physiologically compatible buffers such as Hanks' solution,
Ringer's
solution, or physiological saline buffer. For transmucosal administration,
penetrants appropriate to the barrier to be permeated are used in the
formulation.
Such penetrants are generally known in the art.
For oral administration, the compounds can be formulated by combining
the active compounds with pharmaceutically acceptable carriers well known in
the
art. Such carriers enable the compounds of the invention to be formulated as
tablets, pills, lozenges, dragees, capsules, liquids, gels, syrups, slurries,
suspensions and the like, for oral ingestion by a patient. Pharmaceutical
preparations for oral use can be made using a solid excipient, optionally
grinding
the resulting mixture, and processing the mixture of granules, after adding
other
suitable auxiliaries, if desired, to obtain tablets or dragee cores. Some
useful
excipients, without limitation, are fillers such as sugars such as lactose,
sucrose,
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mannitol, or sorbitol, cellulose preparations such as maize starch, wheat
starch,
rice starch and potato starch and other materials such as gelatin, gum
tragacanth,
methyl cellulose, hydroxypropylmethylcellulose, sodium carboxymethylcellulose
and polyvinylpyrrolidone (PVP). If desired, disintegrating agents may be
added,
such as cross-linked polyvinyl pyrrolidone, agar, or alginic acid. Salts such
as
sodium alginate may also be used.
Dragee cores are normally provided with suitable coatings. For this
purpose, concentrated sugar solutions may be used which may optionally contain
gum arabic, talc, polyvinyl pyrrolidone, carbopol gel, polyethylene glycol,
and/or
titanium dioxide, lacquer solutions, and suitable organic solvents or solvent
mixtures. Dyestuffs or pigments may be added to the tablets or dragee coatings
for identification or to characterize different combinations of active
compound
doses.
Pharmaceutical compositions which can be used orally include push-fit
capsules made of gelatin, soft, sealed capsules made of gelatin and a
plasticizer,
such as glycerol or sorbitol, and the like. Push-fit capsules may contain the
active
ingredients in admixture with a filler such as lactose, a binder such as
starch,
and/or a lubricant such as talc or magnesium stearate and, optionally,
stabilizers.
In soft capsules, the active compounds may be dissolved or suspended in
suitable liquids, such as fatty oils, liquid paraffin, or liquid polyethylene
glycols.
Stabilizers may be added in these formulations, also. .
For administration by inhalation, the compounds are conveniently delivered
in the form of an aerosol spray using a pressurized pack or a nebulizer and a
suitable propellant, e.g., without limitation, dichlorodifluoromethane,
trichlorofluoromethane, dichlorotetrafluoroethane or carbon dioxide. In the
case
of a pressurized aerosol, the dosage unit may be controlled by providing a
valve
to deliver a metered amount. Capsules and cartridges of, for example, gelatin
for
use in an inhaler or insufflator may be formulated containing a powder mix of
the
compound and a suitable powder base such as lactose or starch.
The compounds may also be formulated for parenteral administration, e.g.,
by bolus injection or continuous infusion. Formulations for injection may be
presented in unit dosage form, e.g., in ampoules or in multi-dose containers,
with
an added preservative. The compositions may take such forms as suspensions,
CA 02423334 2003-03-20
WO 02/24708 PCT/USO1/08980
solutions or emulsions in oily or aqueous vehicles, and may contain
formulating
materials such as suspending, stabilizing and/or dispersing agents.
Pharmaceutical compositions for parenteral administration include aqueous
solutions of a water soluble form, such as, without limitation, a salt, of the
active
compound. Additionally, suspensions of the active compounds may be prepared
in a lipophilic vehicle. Suitable lipophilic vehicles include fatty oils such
as
sesame oil, synthetic fatty acid esters such as ethyl oleate and
triglycerides, or
materials such as liposomes. Aqueous injection suspensions may contain
substances which increase the viscosity of the suspension, such as sodium
carboxymethyl cellulose, sorbitol, or dextran. Optionally, the suspension may
also
contain suitable stabilizers and/or agents that increase the solubility of the
compounds to allow for the preparation of highly concentrated solutions.
Alternatively, the active ingredient may be in powder form for constitution
with a suitable vehicle, e.g., sterile, pyrogen-free water, before use.
The compounds may also be formulated in rectal compositions such as
suppositories or retention enemas, using, e.g., conventional suppository bases
such as cocoa butter or other glycerides.
In addition, compounds may also be formulated as depot preparations.
Such long acting formulations may be administered by implantation (for
example,
subcutaneously or intramuscularly) or by intramuscular injection. A compound
may be formulated for this route of administration with suitable polymeric or
hydrophobic materials (for instance, in an emulsion with a pharmacologically
acceptable oil), with ion exchange resins, or as a sparingly soluble
derivative such
as, without limitation, a sparingly soluble salt.
The pharmaceutical compositions herein also may comprise suitable solid
or gel phase carriers or excipients. Examples of such carriers or excipients
include, but are not limited to, calcium carbonate, calcium phosphate, various
sugars, starches, cellulose derivatives, gelatin, and polymers such as
polyethylene glycols.
The compounds of the invention may be provided as physiologically
acceptable salts wherein the claimed compound may form the negatively or the
positively charged species. Examples of salts in which the compound forms the
positively charged entity include, without limitation, quaternary ammonium
salts
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WO 02/24708 PCT/USO1/08980
such as the hydrochloride, sulfate, carbonate, lactate, tartrate, maleate,
succinate
wherein the nitrogen atom of the quaternary ammonium group is a nitrogen of
the
compound herein which has reacted with the appropriate acid. Salts in which a
compound of this invention forms the negatively charged species include,
without
limitation, the sodium, potassium, calcium and magnesium salts formed by the
reaction of a carboxylic acid group of a compound herein with an appropriate
base, e.g., sodium hydroxide (NaOH), potassium hydroxide (KOH), Calcium
hydroxide (Ca(OH)2), etc.
A therapeutically effective amount of a (3-lactam antibiotic compound of this
invention can be administered to a patient to ameliorate or eliminate a
methicillin
or other ~-lactam, such as vancomycin or ampicillin, resistant bacterial
infection.
In particular, infections caused by resistant S. aureus species, such as,
without
limitation, S. aureus Col (MethR)(bla-), S, aureus 76 (MethR) (bla+), S.
aureus
ATCC 29213, S. Aureus ATCC 25913, S. Aureus ATCC 32432 and S. Aureus
CoIBA or resistant Enterococcus species such as E. fa?cium ATCC 35667, or E.
f~calis ATCC 29212, may be treated using a therapeutically effective amount of
a
compound of this invention. Of course, the compounds of the present invention
may be used against bacteria which are susceptible or sensitive to
methicillin,
vancomycin, ampicillin or other antibiotic, also.
The compositions containing a compound or compounds of the invention
can be administered for prophylactic or therapeutic treatment. In therapeutic
applications, the compositions are administered to a patient already suffering
from
an infection, as described above, in an amount sufficient to cure or at least
partially arrest the symptoms of the infection. An amount adequate to
accomplish
this is defined as "therapeutically effective amount or dose" and will depend
on
the severity and course of the infection, previous therapy, the patient's
overall
health status and response to the drugs, and the judgment of the treating
physician. In prophylactic applications, compositions containing a compound or
compounds of the invention are administered to a patient who is who has
previously been treated with a therapeutically effective amount of a compound
to
prevent recurrence of the infection, or they may be adminstered to a patient
who,
for one reason or another, may be susceptible to infection but is not yet
infected
such as the case of presurgical adminstration an antibiotics. Such an amount
is
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WO 02/24708 PCT/USO1/08980
defined to be a "prophylactically effective amount or dose." The precise
amounts
again depend on factors such as those described above.
Dosage
The proper dosage will depend on the severity and course of the infection,
previous therapy, the patient's general health status, his or her response to
the
drugs, etc., all of which are within the knowledge, expertise and judgment of
the
treating physician.
In general, a suitable effective dose of the compound of the invention will
be in the range of 0.1 to 10000 milligram (mg) per recipient per day,
preferably in
the range of 20 to 2000 mg per day. The desired dosage is preferably presented
in one, two, three, four or more subdoses administered at appropriate
intervals
throughout the day. These subdoses can be administered as unit dosage forms,
for example, containing 5 to 1000 mg, preferably 10 to 100 mg of active
ingredient
per unit dosage form. Preferably, the compounds of the invention will be
administered in amounts of between about 2.0 mg/kg to 250 mg/kg of patient
body weight, between about one to four times per day.
Once improvement of the patient's condition is observed, a maintenance
dose may be administered if desired by the treating physician. The dosage,
frequency, or both, can be reduced as a function of the patient's response to
a
level at which the improvement persists. When the symptoms have been
alleviated to the desired level, treatment may be stopped although some
patients
may require intermittant treatment on a long-term basis should flare-ups of
the
symptoms reccur.
Biological Evaluation
The biological activity of compound 1 was previously reported as
compound 16 in U.S. Patent No. 6,025,352, which is incorporated by reference,
including any drawings, as if fully set forth herein. Thus, the biological
activity of
the prodrugs described herein are expected to be the same since they hydrolyze
readily to the parent compound in vivo. However, the prodrugs and salts
thereof
described in the present invention are substantially more water soluble at or
near
neutral pH that the parent compound of its salts. It is this surprisingly
enhanced
solubility that is the focus of this invention. The solubility of any of the
prodrugs
herein can be determined using the following procedure:
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WO 02/24708 PCT/USO1/08980
A small amount (5-8 mg) of a salt of a compound of this invention is
weighed into a screw cap vial. Water is added to dissolve the salt at a high
concentration (50-75 mg/mL). To this~solution is added small amounts (1-5 pL
increments) of 0.1 N aqueous sodium hydroxide until a faint precipitate
remains
after mixing. The suspension is maintained at room temperature for 15 minutes
with periodic vortexing. An aliquot of the suspension is then transferred to
an
Eppendorf tube and centrifuged at 14000 rpm for 1.5 minutes. A portion of the
supernatant is diluted with water, filtered and quantified by HPLC against a
standard calibration curve. The pH of the supernatant is measured using a fine
needle probe. For each subsequent determination, using a new sample, more
0.1 N sodium hydroxide is added to increase the pH just slightly, and the rest
of
the procedure is repeated. Five to seven determinations are used to prepare
the
pH vs. concentration curve.
When starting with a zwitterion, the zwitterion is suspended in water and
0.1 N sodium hydroxide or 0.1 N hydrochloric acid is added to begin to
dissolve
the solid. The suspensions are held at room temperature for 15 minutes with
frequent stirring and then are subjected to the same treatment described above
(centrifugation, dilution and quantitation).
An example of the vastly greater water solubility at or near neutral pH of
the compounds of this invention compared to that of 1 is shown in Figure 1. In
Fig. 1, the water solubility of 1, in its zwitterionic form (2) is compared to
that of its
L-aspartyl prodrug (3):
,OH ,OH
N H N H
N ~ N S / N N ~ N~ S ~N
HN
HN S \ ~ 2 ~ I O ~/ I / +
Cl p / S CI O ~S ~ H NH3
~Ng3+ OZ Na+ S~N~C02
O O- ~ -S
O
2 3
Determination of prodrug cleavage in serum
Of course, the key to the utility of the prodrugs of this invention is their
ready conversion to the parent active compound, 1, under physiological
conditions. The ability of a prodrug herein to revert to 1 can be evaluated
using
the following protocol:
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WO 02/24708 PCT/USO1/08980
Fresh control human serum, fresh control rat serum, and rhesus monkey
plasma (heparinized and stored frozen) are preincubated at 37 °C for 15
min in a
shaking water bath. The pH of the serum or plasma is measured using test
strips.
Then 25 p,L aliquots of a solution in water of a prodrug of this invention (2
mg/mL)
are added to each matrix resulting in a final solution volumn of 1 mL. The
solutions are incubated at 37° C for 1 hr, removing 100 p,L aliquotes
at 0, 15, 30,
and 60 min post dosing. The aliquotes are added to 200 p,L 4% trichloroacetic
acid, vortexed, and centrifuged for 10 min at 14,000 rpm in an Eppendorf
microcentrifuge. Then 25 p,L of each supernatant is analyzed via HPLC
(Beckman Ultrasphere C18 column, 5 micron, 4.6mm x 25cm and 1 mL/min of
95% 0.1 M ammonium acetate, pH = 6, 5% acetonitrile ramping to 25%
acetonitrile over 20 min with peak detection at 254 and 280 nM).
CONCLUSION
One skilled in the art would readily appreciate that the present invention is
well adapted to carry out the objects and obtain the ends and advantages
mentioned, as well as those inherent therein. The molecular complexes and the
methods, procedures, treatments, molecules, specific compounds described
herein
are presently representative of preferred embodiments are exemplary and are
not
intended as limitations on the scope of the invention. Changes therein and
other
uses will occur to those skilled in the art which are encompassed within the
spirit of
the invention are defined by the scope of the claims.
It will be readily apparent to one skilled in the art that varying
substitutions
and modifications may be made to the invention disclosed herein without
departing from the scope and spirit of the invention.
All patents and publications mentioned in the specification are indicative of
the levels of those skilled in the art to which the invention pertains. All
patents
and publications are herein incorporated by reference to the same extent as if
each individual publication was specifically and individually indicated to be
incorporated by reference.
The invention illustratively described herein suitably may be practiced in the
absence of any element or elements, limitation or limitations which is not
specifically
disclosed herein. Thus, for example, in each instance herein any of the terms
CA 02423334 2003-03-20
WO 02/24708 PCT/USO1/08980
"comprising", "consisting essentially of and "consisting of may be replaced
with
either of the other two terms. The terms and expressions which have been
employed are used as terms of description and.not of limitation, and there is
no
intention that in the use of such terms and expressions of excluding any
equivalents
of the features shown and described or portions thereof, but it is recognized
that
various modifications are possible within the scope of the invention claimed.
Thus,
it should be understood that although the present invention has been
specifically
disclosed by preferred embodiments and optional features, modification and
variation of the concepts herein disclosed may be resorted to by those skilled
in the
art, and that such modifications and variations are considered to be within
the
scope of this invention as defined by the appended claims.
In addition, where features or aspects of the invention are described in
terms of Markush groups, those skilled in the art will recognize that the
invention
is also thereby described in terms of any individual member or subgroup of
members of the Markush group. For example, if X is described as selected from
the group consisting of bromine, chlorine, and iodine, claims for X being
bromine
and claims for X being bromine and chlorine are fully described.
The invention has been described broadly and generically herein. Each of
the narrower species and subgeneric groupings falling within the generic
disclosure also form part of the invention. This includes the generic
description of
the invention with a proviso or negative limitation removing any subject
matter
from the genus, regardless of whether or not the excised material is
specifically
recited herein.
Other embodiments are contained within the following claims.
31
