J. Med. Chem. 1996, 39, 673-679
`J. Med. Chem. 1996, 39, 673-679 (cid:9)
`
`673
`673
`
`Synthesis and Antibacterial Activity of U-100592 and U-100766, Two
`Synthesis and Antibacterial Activity of U-100592 and U-100766, Two
`Oxazolidinone Antibacterial Agents for the Potential Treatment of
`Oxazolidinone Antibacterial Agents for the Potential Treatment of
`Multidrug-Resistant Gram-Positive Bacterial Infections
`Multidrug-Resistant Gram-Positive Bacterial Infections
`
`Steven J. Brickner,* Douglas K. Hutchinson, Michael R. Barbachyn, Peter R. Manninen, Debra A. Ulanowicz,
`Steven J. Brickner,* Douglas K. Hutchinson, Michael R. Barbachyn, Peter R. Manninen, Debra A. Ulanowicz,
`Stuart A. Garmon, Kevin C. Grega, Susan K. Hendges, Dana S. Toops, Charles W. Ford, and Gary E. Zurenko
`Stuart A. Garmon, Kevin C. Grega, Susan K. Hendges, Dana S. Toops, Charles W. Ford, and Gary E. Zurenko
`Upjohn Laboratories, The Upjohn Company, Kalamazoo, Michigan 49001
`Upjohn Laboratories, The Upjohn Company, Kalamazoo, Michigan 49001
`
`Received December 22, 1995®
`Received December 22, 1995X
`
`Bacterial resistance development has become a very serious clinical problem for many classes
`Bacterial resistance development has become a very serious clinical problem for many classes
`of antibiotics. The 3-aryl-2-oxazolidinones are a relatively new class of synthetic antibacterial
`of antibiotics. The 3-aryl-2-oxazolidinones are a relatively new class of synthetic antibacterial
`agents, having a new mechanism of action which involves very early inhibition of bacterial
`agents, having a new mechanism of action which involves very early inhibition of bacterial
`protein synthesis. We have prepared two potent, synthetic oxazolidinones, U-100592 and
`protein synthesis. We have prepared two potent, synthetic oxazolidinones, U-100592 and
`U-100766, which are currently in clinical development for the treatment of serious multidrug-
`U-100766, which are currently in clinical development for the treatment of serious multidrug-
`resistant Gram-positive bacterial infections caused by strains of staphylococci, streptococci,
`resistant Gram-positive bacterial infections caused by strains of staphylococci, streptococci,
`and enterococci. The in vitro and in vivo (po and iv) activities of U-100592 and U-100766
`and enterococci. The in vitro and in vivo (po and iv) activities of U-100592 and U-100766
`against representative strains are similar to those of vancomycin. U-100592 and U-100766
`against representative strains are similar to those of vancomycin. U-100592 and U-100766
`demonstrate potent in vitro activity against Mycobacterium tuberculosis. A novel and practical
`demonstrate potent in vitro activity against Mycobacterium tuberculosis. A novel and practical
`asymmetric synthesis of (5S)-(acetamidomethyl)-2-oxazolidinones has been developed and is
`asymmetric synthesis of (5S)-(acetamidomethyl)-2-oxazolidinones has been developed and is
`employed for the synthesis of U-100592 and U-100766. This involves the reaction of
`employed for the synthesis of U-100592 and U-100766. This involves the reaction of
`N-lithioarylcarbamates with (R)-glycidyl butyrate, resulting in excellent yields and high
`N-lithioarylcarbamates with (R)-glycidyl butyrate, resulting in excellent yields and high
`enantiomeric purity of the intermediate (R)-5-(hydroxymethyl)-2-oxazolidinones.
`enantiomeric purity of the intermediate (R)-5-(hydroxymethyl)-2-oxazolidinones.
`
`Introduction
`against the emerging and currently problematic Gram-
`Introduction
`against the emerging and currently problematic Gram-
`positive pathogens MRSA, methicillin-resistant coagu-
`positive pathogens MRSA, methicillin-resistant coagu-
`The increasing incidence of multidrug resistance
`The increasing incidence of multidrug resistance
`lase-negative staphylococci, VRE, and penicillin-resis-
`lase-negative staphylococci, VRE, and penicillin-resis-
`among Gram-positive bacterial pathogens represents
`among Gram-positive bacterial pathogens represents
`tant pneumococci,16 as well as the perceived looming
`tant pneumococci,16 as well as the perceived looming
`one of the major challenges in the 1990’s for health care
`one of the major challenges in the 1990's for health care
`threat of a vancomycin-resistant S. aureus.
`threat of a vancomycin-resistant S. aureus.
`practitioners.1-3 One particularly unsettling milestone
`practitioners." One particularly unsettling milestone
`In a 1978 patent17 issued to the EI DuPont de
`In a 1978 patent12 issued to the EI DuPont de
`has been the acquisition of resistance to vancomycin,4
`
`has been the acquisition of resistance to vancomycin,4
`Nemours & Co., Inc., a series of 5-(halomethyl)-3-aryl-
`Nemours & Co., Inc., a series of 5-(halomethyl)-3-aryl-
`an antibiotic generally regarded as the agent of last
`an antibiotic generally regarded as the agent of last
`2-oxazolidinones were claimed to have activity against
`2-oxazolidinones were claimed to have activity against
`resort for serious Gram-positive infections.
`Isolated
`resort for serious Gram-positive infections. Isolated
`certain plant pathogens. Subsequent reports detailed
`reports from U.S. and U.K. hospitals have begun
`certain plant pathogens. Subsequent reports detailed
`reports from U.S. and U.K. hospitals have begun
`a (5R)-(hydroxymethyl)-3-aryl-2-oxazolidinone, S-6123,18
`describing what is an alarming escalation in the per-
`
`a (5R)-(hydroxymethyl)-3-aryl-2-oxazolidinone, S-6123,18
`describing what is an alarming escalation in the per-
`centage of vancomycin-resistant enterococcal (VRE)
`which demonstrated weak in vitro antibacterial activity
`
`centage of vancomycin-resistant enterococcal (VRE) which demonstrated weak in vitro antibacterial activity
`
`clinical isolates.5,6 Since VRE strains also carry resis-
`against human pathogens.19 Further optimization20,21
`clinical isolates.5,6 Since VRE strains also carry resis-
`19 Further optimization29,21
`against human pathogens.
`tance to virtually all other known antibiotics,7 the
`led to the description in 1987 of two drug candidates,
`
`tance to virtually all other known antibiotics,2 the
`led to the description in 1987 of two drug candidates,
`prognosis for patients with such refractory infections
`prognosis for patients with such refractory infections
`DuP 721 and DuP 105, members of a new class of
`DuP 721 and DuP 105, members of a new class of
`is grim; associated mortality rates above 35% have been
`is grim; associated mortality rates above 35% have been
`parenterally and orally active, totally synthetic (5S)-
`
`parenterally and orally active, totally synthetic (5S)-
`reported.8
`reported.8
`(acetamidomethyl)-3-aryl-2-oxazolidinone antibacterial
`(acetamidomethyl)-3-aryl-2-oxazolidinone antibacterial
`A problem of much larger dimension is the escalating
`A problem of much larger dimension is the escalating
`agents.22
`agent 5.22
`incidence of the more virulent, methicillin-resistant
`incidence of the more virulent, methicillin-resistant
`The oxazolidinones have a novel mechanism of action
`The oxazolidinones have a novel mechanism of action
`Staphylococcus aureus (MRSA) among clinical isolates
`
`Staphylococcus aureus (MRSA) among clinical isolates
`that involves the inhibition of bacterial protein synthesis
`that involves the inhibition ofbacterial protein synthesis
`found throughout centers worldwide.9 As with the VRE,
`found throughout centers worldwide.9 As with the VRE,
`at a very early stage, prior to chain initiation.23 DuP
`23 DuP
`at a very early stage, prior to chain initiation.
`many MRSA strains are resistant to most other anti-
`many MRSA strains are resistant to most other anti-
`721 demonstrated potent activity vs Gram-positive
`721 demonstrated potent activity vs Gram-positive
`biotics;10,11 however, as yet, MRSA strains have re-
`biotics;19,11 however, as yet, MRSA strains have re-
`pathogens (including MRSA),24 Gram-negative anaer-
`pathogens (including MRSA),24 Gram-negative anaer-
`mained susceptible to vancomycin. The sobering emer-
`mained susceptible to vancomycin. The sobering emer-
`obes, and Mycobacterium tuberculosis.25 The in vitro
`
`obes, and Mycobacterium tuberculosis.25 The in vitro
`gence of VRE pales in the face of projections from
`gence of VRE pales in the face of projections from
`development of bacterial resistance to either DuP 721
`development of bacterial resistance to either DuP 721
`numerous infectious diseases experts,12,13 who are of the
`
`numerous infectious diseases experts,12,13 who are of the
`or DuP 105 could not be demonstrated.26 While both
`
`or DuP 105 could not be demonstrated.26 While both
`opinion there is high likelihood S. aureus will, in time,
`opinion there is high likelihood S. aureus will, in time,
`DuP 721 and DuP 105 were entered into phase I clinical
`DuP 721 and DuP 105 were entered into phase I clinical
`also naturally acquire vancomycin resistance. Noble et
`
`also naturally acquire vancomycin resistance. Noble et
`trials, the development of each was subsequently dis-
`trials, the development of each was subsequently dis-
`al.14 have observed transposon-mediated transmission
`al." have observed transposon-mediated transmission
`continued.27 In drug safety studies conducted at The
`continued.27 In drug safety studies conducted at The
`of the vancomycin resistance genes to S. aureus, from
`of the vancomycin resistance genes to S. aureus, from
`Upjohn Co.,28 it was demonstrated that (()-DuP 721
`Upjohn Co.,28 it was demonstrated that (±)-DuP 721
`a VRE (Enterococcus faecalis), in an experiment con-
`
`a VRE (Enterococcus faecalis), in an experiment con-
`exhibited lethal toxicity in the rat, when dosed orally
`exhibited lethal toxicity in the rat, when dosed orally
`ducted on the skin of a mouse.
`ducted on the skin of a mouse.
`at 100 mg/kg b.i.d. for 30 days.
`at 100 mg/kg b.i.d. for 30 days.
`This growing problem of multidrug resistance has
`This growing problem of multidrug resistance has
`recently rekindled interest in the search for new anti-
`recently rekindled interest in the search for new anti-
`biotic structural classes that inhibit or kill by novel
`biotic structural classes that inhibit or kill by novel
`mechanisms.15 Clearly there is an urgent need for the
`mechanisms.15 Clearly there is an urgent need for the
`discovery and development of new agents effective
`discovery and development of new agents effective
`
`
`0 (cid:9)0
`A
`A
`N
`0
`0 (cid:9)
`N
`\__OH
`\—OH (cid:9)
`14
`A (cid:9)
`
`0
`0
`0
`A o
`A
`N 0 ,g,
`0
`N
`
`\-1,..N"CH3 CH3
`
`H NH
`: (cid:9)
`DuP 721 R . MeCO (cid:9)DuP 721 R . MeCO \--( (cid:9)
`
`
`DuP 105 R . MeS0 H DuP 105 R . MeS0 H
`
`O
`0
`H2N'S
`ii
`0 (cid:9)
`
`
`
`S-6123 (cid:9)S-6123
`
`0022-2623/96/1839-0673$12.00/0 © 1996 American Chemical Society
`
`0022-2623/96/1839-0673$12.00/0 © 1996 American Chemical Society
`
`MYLAN - EXHIBIT 1023
`
`

`
`0
`0
`o
`n
`AND 0
`NAO
`N
`c
`\_/ H' -CH3
`-CH3
`A
`A
`
`Brickner et al.
`674 (cid:9) Journal of Medicinal Chemistry, 1996, Vol. 39, No. 3
`674 Journal of Medicinal Chemistry, 1996, Vol. 39, No. 3
`Brickner et al.
`method, employing a high-temperature isocyanate-
`Realizing that oxazolidinones had promising potential
`Realizing that oxazolidinones had promising potential
`method, employing a high-temperature isocyanate—
`to address the imminent critical need for new antibacte-
`epoxide cyclization, was deemed incompatible with our
`
`to address the imminent critical need for new antibacte-epoxide cyclization, was deemed incompatible with our
`rial agents, we instituted a program to improve upon
`choices of phenyl substituents. There were also con-
`
`rial agents, we instituted a program to improve upon choices of phenyl substituents. There were also con-
`the properties of DuP 721. Herein we describe U-100592
`cerns regarding the hazards of phosgene use, which
`
`the properties of DuP 721. Herein we describe U-100592 cerns regarding the hazards of phosgene use, which
`and U-100766, two novel oxazolidinones currently in
`would be required for construction of noncommercially
`and U-100766, two novel oxazolidinones currently in
`would be required for construction of noncommercially
`clinical trials.
`available isocyanates.
`clinical trials.
`available isocyanates.
`The syntheses of U-100592 and U-100766 share a
`The syntheses of U-100592 and U-100766 share a
`common route, detailed in Scheme 1. Commencing with
`common route, detailed in Scheme 1. Commencing with
`3,4-difluoronitrobenzene, nucleophilic aromatic displace-
`3,4-difluoronitrobenzene, nucleophilic aromatic displace-
`ment, with excess piperazine (1a) or morpholine (1b),
`ment, with excess piperazine (la) or morpholine (lb),
`selectively gave the p-substituted nitrobenzene 2. Re-
`
`selectively gave the p-substituted nitrobenzene 2. Re-
`duction of 2a or 2b was followed by attachment of a
`duction of 2a or 2b was followed by attachment of a
`carbobenzoxy (CBZ) activating group to the arylamines
`
`carbobenzoxy (CBZ) activating group to the arylamines
`3 (for 3a, concomitant protection of the piperazine gave
`3 (for 3a, concomitant protection of the piperazine gave
`4a). Carbamate 4a or 4b was deprotonated with n-BuLi
`4a). Carbamate 4a or 4b was deprotonated with n-BuLi
`(THF, -78 °C), and then (R)-glycidyl butyrate [96-98%
`(THF, —78 °C), and then (R)-glycidyl butyrate [96-98%
`enantiomeric excess (ee); Lonza] was added and the
`enantiomeric excess (ee); Lonza] was added and the
`mixture slowly allowed to warm to room temperature.36
`
`mixture slowly allowed to warm to room temperature.36
`This sequence provided directly the (5R)-(hydroxy-
`This sequence provided directly the (5R)-(hydroxy-
`methyl)-2-oxazolidinone 5a or 5b in >80% yield, thus
`methyl)-2-oxazolidinone 5a or 5b in >80% yield, thus
`realizing a greater overall economy of chemical steps
`realizing a greater overall economy of chemical steps
`than the DuPont approach. As will be detailed else-
`than the DuPont approach. As will be detailed else-
`where, crucial to the success of this new approach37 was
`
`where, crucial to the success of this new approach37 was
`Results and Discussion
`the selection of lithium as the base counterion.
`the selection of lithium as the base counterion.
`Results and Discussion
`In prior disclosures, we have described (S)-3-(5¢ -
`With the alcohols 5 in hand, conversion to the (5S)-
`With the alcohols 5 in hand, conversion to the (5S)-
`In prior disclosures, we have described (S)-3-(5'-
`(acetamidomethyl)-2-oxazolidinones U-100592
`and
`(acet amidomethyl)-2-oxazolidinones U-100592 and
`indolinyl)-5-(acetamidomethyl)-2-oxazolidinones,29
`in d olin y1)-5 -(a cet a m idom et hyl)-2-oxa zolidin on es
`,29
`U-100766 was straightforward.35 Activation as the
`U-100766 was straightforward.35 Activation as the
`wherein one of the more potent analogues, U-97456, was
`wherein one of the more potent analogues, U-97456, was
`mesylate 6 and then displacement with either potas-
`mesylate 6 and then displacement with either potas-
`substituted with a hydroxyacetyl moiety on the indoline
`substituted with a hydroxyacetyl moiety on the indoline
`nitrogen. E-370930 is an extremely active [4-(4¢ -pyridyl)-
`sium phthalimide to give 7 or with NaN3 (on laboratory
`sium phthalimide to give 7 or with NaN3 (on laboratory
`nitrogen. E-37093° is an extremely active [4-(4'-pyridyl)-
`scale) to give 8b was followed by formation of the
`scale) to give 8b was followed by formation of the
`phenyl]oxazolidinone described by DuPont. We ulti-
`phenyl]oxazolidinone described by DuPont. We ulti-
`intermediate 5-(aminomethyl)-2-oxazolidinones. This
`intermediate 5-(aminomethyl)-2-oxazolidinones. This
`mately came to focus on exploring the (S)-3-(4-piper-
`mately came to focus on exploring the (S)-3-(4-piper-
`was accomplished by deblocking of the phthalimide 7a
`7a
`was accomplished by deblocking of the phthalimide
`azinylphenyl)-5-(acetamidomethyl)-2-oxazolidinones,31
`azinylpheny1)-5-(acetamidomethyl)-2-oxazolidinones,
`31
`with aqueous MeNH2 or reduction of the azide 8b.
`with aqueous MeNH2 or reduction of the azide 8b.
`based on considerations that the piperazine heterocycle
`based on considerations that the piperazine heterocycle
`Treatment of the amines with Ac2O and pyridine
`Treatment of the amines with Ac20 and pyridine
`would position the two nitrogens in similar loci to those
`would position the two nitrogens in similar loci to those
`provided U-100766 (69% overall yield from 5b, >99.8%
`found in both the 5¢ -indolinyl and the 4-(4¢ -pyridyl)-
`provided U-100766 (69% overall yield from 5b, >99.8%
`found in both the 5'-indolinyl and the 4-(4'-pyridyl)-
`ee38) and the CBZ-piperazine 9. Catalytic hydrogenoly-
`ee38) and the CBZ-piperazine 9. Catalytic hydrogenoly-
`phenyl congeners. In the piperazinyl series, we again
`phenyl congeners. In the piperazinyl series, we again
`sis of 9 provided the piperazine HCl salt 10, which was
`sis of 9 provided the piperazine HC1 salt 10, which was
`observed that an appendant hydroxyacetyl on the
`observed that an appendant hydroxyacetyl on the
`acylated with (benzyloxy)acetyl chloride. Finally, ben-
`acylated with (benzyloxy)acetyl chloride. Finally, ben-
`heterocyclic nitrogen afforded favorable antibacterial
`heterocyclic nitrogen afforded favorable antibacterial
`zylic hydrogenolytic cleavage of 11 gave U-100592 (37%
`zylic hydrogenolytic cleavage of 11 gave U-100592 (37%
`activity. Additional enhancements in in vitro and in
`activity. Additional enhancements in in vitro and in
`overall yield from 5a, >99.7% ee38).
`overall yield from 5a, >99.7% ee38).
`vivo potency were attained by fluorine substitution at
`vivo potency were attained by fluorine substitution at
`the phenyl 3-position, leading to U-100592.32 A bioi-
`U-100592 and U-100766 demonstrated excellent in
`
`U-100592 and U-100766 demonstrated excellent in
`
`the phenyl 3-position, leading to U-100592.32 A bioi-
`sostere of the piperazine, the morpholinyl analogue
`vitro activity, at potency levels similar to that of
`
`sostere of the piperazine, the morpholinyl analogue vitro activity, at potency levels similar to that of
`U-100766, contemporaneously emerged from our exten-
`vancomycin,againstmoststaphylococci(includingMRSA)
`U-100766, contemporaneously emerged from our exten-
`vancomycin, against most staphylococci (in clu din g MRS A)
`sive structure-activity relationship (SAR) studies.
`and all streptococci and enterococci strains tested
`sive structure—activity relationship (SAR) studies.
`and all streptococci and enterococci strains tested
`(selected strains, Table 1), without evidence of cross-
`(selected strains, Table 1), without evidence of cross-
`resistance to any known antibiotic in the strains tested.39
`
`resistance to any known antibiotic in the strains tested.39
`U-100766 was slightly less active than U-100592 in vitro
`
`U-100766 was slightly less active than U-100592 in vitro
`against some organisms; neither drug demonstrated
`against some organisms; neither drug demonstrated
`significant in vitro activity against Gram-negative
`significant in vitro activity against Gram-negative
`aerobes. Both drugs had good anaerobe activity and
`aerobes. Both drugs had good anaerobe activity and
`demonstrated very potent in vitro activity against M.
`demonstrated very potent in vitro activity against M.
`tuberculosis.40
`to
`
`U-100592 and U-100766 dosed orally (po) or subcu-
`U-100592 and U-100766 dosed orally (po) or subcu-
`taneously (sq) were equipotent with vancomycin admin-
`taneously (sq) were equipotent with vancomycin admin-
`istered sq vs S. aureus UC 9213 in a lethal systemic
`istered sq vs S. aureus UC 9213 in a lethal systemic
`mouse model (Table 2). Exceptional activity was also
`mouse model (Table 2). Exceptional activity was also
`seen vs aminoglycoside-resistant E. faecalis and van-
`seen vs aminoglycoside-resistant E. faecalis and van-
`comycin-resistant E. faecium in lethal systemic mouse
`comycin-resistant E. faecium in lethal systemic mouse
`models.
`models.
`Only the oxazolidinone enantiomer with a (5S)-
`Our new asymmetric synthesis of (5S)-(acetamidom-
`Only the oxazolidinone enantiomer with a (5S)-
`Our new asymmetric synthesis of (5S)-(acetamidom-
`acetamidomethyl configuration possesses antibacterial
`ethyl)-2-oxazolidinones involving the reaction of an
`ethyl)-2-oxazolidinones involving the reaction of an
`acetamidomethyl configuration possesses antibacterial
`activity.33 We desired a more viable approach to the
`N-lithioarylcarbamate with (R)-glycidyl butyrate (1) is
`
`activity.33 We desired a more viable approach to the N-lithioarylcarbamate with (R)-glycidyl butyrate (1) is
`asymmetric synthesis of these oxazolidinones than that
`applicable to the synthesis of widely divergent 3-(4-
`
`asymmetric synthesis of these oxazolidinones than that applicable to the synthesis of widely divergent 3-(4-
`afforded by the Herweh-Kauffmann procedure,34 which
`substituted-aryl)-2-oxazolidinones, (2) proceeds with
`
`afforded by the Herweh—Kauffmann procedure,34 which
`substituted-aryl)-2-oxazolidinones, (2) proceeds with
`Wang et al.35 had employed in a chiral fashion. This
`high efficiency from commercially available reagents,
`Wang et al.35 had employed in a chiral fashion. This
`high efficiency from commercially available reagents,
`
`O
`0
`II
`II
`HO
`fioo,
`
`0
`0
`0
`0
`AO
`n
`A
`,c.,
`O
`N
`N
`c
`cH3
`\__1,111-, ., cH3
`
`U-100592
`U-100592
`
`A
`FI
`
`O
`0
`0 n
`A 0 n
`A
`c
`
`c.....
`N 0 (cid:9)
`N 0
`,
`\_._L N,
` CH3
`\ (cid:9)
`H CH3
`
`HN
`
`HO
`HO
`
`0
`0
`
`0
`n
`c,
` c,
`NA()
`NAo
`-cH3
`\_4,..,r
` -cH3
`•
`H
`•
`A
`
`He
`
`U-100766 (cid:9)
`U-100766 (cid:9)
`
`U-97456
`U-97456
`
`E-3709 (cid:9)
`E-3709 (cid:9)
`
`
`(cid:9)
`(cid:9)
`

`
`Two Oxazolidinone Antibacterial Agents
`Two Oxazolidinone Antibacterial Agents
`
`Journal of Medicinal Chemistry, 1996, Vol. 39, No. 3 675
`
`Journal of Medicinal Chemistry, 1996, Vol. 39, No. 3 675
`
`Scheme 1a
`Scheme la
`
`X NH +
`X NH +
`
`
`
`NO2 NO2
`
`(a or a')
`(a or a')
`
`X N
`X N
`
`NO2 (cid:9)
`NO2 (cid:9)
`
`(b or U)
`(b or U)
`
`X= NH
`X= NH
`X= 0
`X= 0
`
`X N
`X N
`
`0
`0
`,C
`N (cid:9)
`N
`
`H H
`
`o
`o
`
`(75%) 4a X= CbzN
`(75%) 4a X= CbzN
`(91%) 4b X= 0
`(91%) 4b X= 0
`
`
`F F
`(method a, 81%) 2a X= NH
`(method a, 81%) 2a X= NH
`(method a', 98%) 2b X= 0
`(method a', 98%) 2b X= 0
`
`(c)
`(c)
`
`X - N
`X - N
`
`
`
`NH2 NH2
`
`
`F F
`method (b) 3a X= NH
`method (b) 3a X= NH
`method (IA 3b X= 0
`method (U) 3b X= 0
`
`(d,e)
`(d,e)
`
`/—\
`/—\
`X N
`X N
`
`
`
`F F
`
`yL
`yL
`
`N 0
`N 0
`\—c0H
`
`(f)
`(f)
`
`/—\
`/—\
`X N
`X N
`
`
`
`O O
`
`N 0
`N 0
`\-O-SO2CH3
`\—c0--802CH3
`
`(83%) 5a X= CbzN
`(83%) 5a X= CbzN
`(85%) 5b X= 0
`(85%) 5b X= 0
`
`6a X= CbzN
`6a X= CbzN
`6b X= 0
`6b X= 0
`
`X N
`X N
`
`X - N
`X - N
`
`0
`
`0
`0
`N0 (cid:9)
`N0 (cid:9)
`C,
`-CH3
`\-14-,
`01-13
`
`(9)
`(9)
`
`
`0 0
`(80%) 7a X= CbzN Y= N
`Y= N
`(80%) 7a X= CbzN
`0
`0
`
`
`
`(I) (i)
`
`(k)
`(k)
`
`(h)
`(h)
`—I.- (93%) 8b X= 0 (cid:9)
`--N.-
`(93%) 8b X= 0
`
`Y= N3
`Y= N3
`
`(j)
`
`X= Nebz
`9 (cid:9)
`(61%) (cid:9)
`X= Nebz
`9 (cid:9)
`(61%) (cid:9)
`(I)
`X= NH•HC-TD
`10 (cid:9)
`(94%) (cid:9)
`X= NH•HC-T
`10 (cid:9)
`(94%) (cid:9)
`X= NCOCH2OCH2Ph—J(m)
`X= NCOCH2OCH2Ph—J(m)
`11 (cid:9)
`(100%) (cid:9)
`11 (cid:9)
`(100%) (cid:9)
`(n)
`--3 (n)
`(81%) U-100592 X= NCOCH2OH
`(81%) U-100592 X= NCOCH2OH (cid:9)
`(68%) U-100766 X= 0
`(68%) U-100766 X= 0
`a (a) CH3CN, reflux or (a¢ ) (i-Pr)2EtN, EtOAc; (b) H2, 5% Pd/C, THF or (b¢ ) HCO2NH4, 10% Pd/C, THF/MeOH; (c) CBZ-Cl, NaHCO3 (or
`a (a) CH3CN, reflux or (a') (i-Pr)2EtN, EtOAc; (b) H2, 5% Pd/C, THF or (b') HCO2NH4, 10% Pd/C, THF/MeOH; (c) CBZ-Cl, NaHCO3 (or
`Na2CO3), acetone-H2O; (d) n-BuLi, THF -78 °C; (e) (R)-glycidyl butyrate; (f) MsCl, Et3N, CH2Cl2; (g) potassium phthalimide, CH3CN,
`Na2CO3), acetone—H20; (d) n-BuLi, THF —78 °C; (e) (R)-glycidyl butyrate; (f) MsCI, Et3N, CH2C12; (g) potassium phthalimide, CH3CN,
`H2O, reflux; (h) NaN3, DMF, 75 °C; (i) aqueous MeNH2, EtOH, reflux; (j) 10% Pd/C, H2, EtOAc; (k) Ac2O, pyr; (l) Pd/C, H2, MeOH-
`H2O, reflux; (h) NaN3, DMF, 75 °C; (i) aqueous MeNH2, EtOH, reflux; (j) 10% Pd/C, H2, EtOAc; (k) Ac20, pyr; (1) Pd/C, H2, Me0H—
`CH2Cl2; (m) ClCOCH2OCH2Ph, Et3N, CH2Cl2, 0 °C; (n) 10% Pd/C, H2, MeOH-CH2Cl2.
`(n) 10% Pd/C, H2, Me0H—CH2C12.
`CH2C12; (m) C1COCH2OCH2Ph, Et3N, CH2C12, 0 °C;
`
`Table 1. In Vitro Antibacterial Activity, Minimum Inhibitory Concentration ((cid:237)g/mL)
`Table 1. In Vitro Antibacterial Activity, Minimum Inhibitory Concentration (Atg/mL)
`vancomycin
`organism
`strain number
`U-100592
`U-100766
`organism
`strain number
`vancomycin
`U-100592
`U-100766
`1
`UCa 9213
`4
`4
`Staphylococcus aureus
`Staphylococcus aureus
`1
`4
`4
`UCa 9213
`Staphylococcus aureusb
`1
`UC 12673
`2
`4
`1
`2
`4
`Staphylococcus aureusc
`UC 12673
`Staphylococcus aureus
`1
`ATCCb 29213
`4
`4
`ATCCb 29213
`1
`4
`4
`Staphylococcus aureus
`Staphylococcus epidermidis
`1
`1
`1
`1
`UC 30031
`1
`1
`Staphylococcus epidermidis
`UC 30031
`4
`ATCC 29212
`2
`4
`Enterococcus faecalis
`Enterococcus faecalis
`4
`ATCC 29212
`2
`4
`Enterococcus faecium
`UC 12712
`1
`2
`0.5
`UC 12712
`1
`2
`Enterococcus faecium
`0.5
`Streptococcus pneum on iae
`1
`0.5
`UC 9912
`0.5
`1
`Streptococcus pneumoniae
`0.5
`UC 9912
`0.5
`0.5
`UC 152
`1
`2
`Streptococcus pyogenes
`Streptococcus pyogenes
`1
`2
`0.5
`UC 152
`>64
`>64
`>64
`Escherichia coli
`ATCC 25922
`ATCC 25922
`Escherichia coli
`>64
`>64
`>64
`>64
`>64
`>64
`Klebsiella pneum on iae
`UC 12081
`Klebsiella pneumoniae
`>64
`UC 12081
`>64
`>64
`>64
`>64
`>64
`Pseudomonas aeruginosa
`ATCC 27853
`Pseudomonas aeruginosa
`>64
`ATCC 27853
`>64
`>64
`>16d
`ATCC 25285
`1
`1
`Bacteroides fragilis
`Bacteroides fragilis
`>16d
`1
`1
`ATCC 25285
`Clostridium perfringens
`ATCC 13124
`1
`1
`1e
`ATCC 13124
`1
`1
`Clostridium perfringens
`le
`Mycobacterium tuberculosis
`H37Rv
`e0.125
`e0.125
`f
`Mycobacterium tuberculosis
`H37Rv
`f
`
`a Upjohn Culture (registered trademark of The Upjohn Co.). b American Type Culture Collection. a MRSA. d Comparative control value
`a Upjohn Culture (registered trademark of The Upjohn Co.). b American Type Culture Collection. c MRSA. d Comparative control value
`for clindamycin was 0.5 (cid:237)g/mL. e Comparative control value for clindamycin was 0.06 (cid:237)g/mL. f Comparative control value for isoniazid
`for clindamycin was 0.5 itg/mL. e Comparative control value for clindamycin was 0.06 itg/mL. f Comparative control value for isoniazid
`was 0.20 (cid:237)g/mL.
`was 0.20 itg/mL.
`
`Table 2. In Vivo Antibacterial Activity ED50
`Table 2. In Vivo Antibacterial Activity ED50a (mg/kg)
`a (mg/kg)
`organism (cid:9)
`strain number
`vancomycine
`U-100766
`U-100592
`organism
`strain number
`vancomycine
`U-100766 (cid:9)
`U-100592
`Staphylococcus aureusb
`3.9
`5.6 (po)
`1.9 (po)
`UC 9213
`Staphylococcus aureusb
`5.6 (po)
`1.9 (po)
`UC 9213
`3.9
`Staphylococcus aureusb
`3.9
`2.0 (sq)
`0.9 (sq)
`UC 9213
`Staphylococcus aureusb
`2.0 (sq)
`0.9 (sq)
`UC 9213
`3.9
`<0.6
`10 (po)
`1.3 (po)
`UC 12379
`Enterococcus faecalisc
`Enterococcus faecalisb
`<0.6
`10 (po)
`1.3 (po)
`UC 12379
`>100
`
`En terococcus faecium d
`24 (po)
`12.5 (po)
`UC 15090
`Enterococcus faeciumd
`24 (po)
`12.5 (po)
`>100
`UC 15090
`
`
`a Dose that protects 50% of the animals. b Organism demonstrates intermediate in vivo resistance to methicillin. a Gentamycin resistant.
`a Dose that protects 50% of the animals. b Organism demonstrates intermediate in vivo resistance to methicillin. c Gentamycin resistant.
`d Vancomycin resistant. e Control was dosed subcutaneously.
`d Vancomycin resistant. e Control was dosed subcutaneously.
`
`Experimental Section
`and (3) following side-chain manipulation, provides the
`Experimental Section
`and (3) following side-chain manipulation, provides the
`targeted antibacterial oxazolidinones in extremely high
`targeted antibacterial oxazolidinones in extremely high
`Chemistry. Melting points were determined on a Fisher-
`Chemistry. Melting points were determined on a Fisher-
`ee. On the basis of their antibacterial potency, and
`ee. On the basis of their antibacterial potency, and
`Johns apparatus and are uncorrected. 1H NMR spectra were
`Johns apparatus and are uncorrected. 'H NMR spectra were
`acceptable pharmacokinetic41 and drug safety profiles42
`acceptable pharmacokinetic41 and drug safety profiles42
`recorded on either a Bruker AM-300 or ARX-400 spectrometer.
`recorded on either a Bruker AM-300 or ARX-400 spectrometer.
`in the rat and dog, U-100592 and U-100766 were
`Chemical shifts are reported in (cid:228) units (ppm) relative to TMS
`in the rat and dog, U-100592 and U-100766 were
`Chemical shifts are reported in 6 units (ppm) relative to TMS
`as internal standard. Coupling constants (J) are reported in
`
`as internal standard. Coupling constants (J) are reported in
`selected for development as clinical candidates. These
`selected for development as clinical candidates. These
`hertz (Hz). Electron impact (EI) mass spectra were obtained
`hertz (Hz). Electron impact (EI) mass spectra were obtained
`oxazolidinones are targeted as potential therapies for
`oxazolidinones are targeted as potential therapies for
`with an ionization voltage of 70 eV. Data are reported in the
`with an ionization voltage of 70 eV. Data are reported in the
`treating human infections caused by staphylococci,
`treating human infections caused by staphylococci,
`form m/z (rel intensity). All moisture-sensitive reactions were
`form m/z (rel intensity). All moisture-sensitive reactions were
`streptococci, and enterococci,
`including multidrug-
`streptococci, and enterococci, including multidrug-
`conducted under a nitrogen atmosphere in oven- or flame-dried
`conducted under a nitrogen atmosphere in oven- or flame-dried
`resistant strains.
`resistant strains.
`glassware. Unless specified, all commercially available sol-
`glassware. Unless specified, all commercially available sol-
`
`(cid:9)
`(cid:9)
`(cid:9)
`(cid:9)
`(cid:9)
`(cid:9)
`(cid:9)
`(cid:9)
`(cid:9)
`(cid:9)
`(cid:9)
`(cid:9)
`(cid:9)
`(cid:9)
`(cid:9)
`(cid:9)
`(cid:9)
`(cid:9)
`(cid:9)
`(cid:9)
`

`
`676 Journal of Medicinal Chemistry, 1996, Vol. 39, No. 3
`676 (cid:9)
`Journal of Medicinal Chemistry, 1996, Vol. 39, No. 3 (cid:9)
`
`Brickner et al.
`Brickner et al.
`
`vents and reagents were used without further purification.
`vents and reagents were used without further purification.
`THF was distilled under argon from sodium benzophenone
`THE was distilled under argon from sodium benzophenone
`ketyl prior to use. Solvent removal was accomplished by a
`ketyl prior to use. Solvent removal was accomplished by a
`rotary evaporator operating at house vacuum (40-50 Torr).
`rotary evaporator operating at house vacuum (40-50 Torr).
`Crude products were purified by medium pressure column
`Crude products were purified by medium pressure column
`chromatography over silica gel (EM Science; 230-400 mesh
`chromatography over silica gel (EM Science; 230-400 mesh
`ASTM). Alternatively, smaller scale purifications were ac-
`ASTM). Alternatively, smaller scale purifications were ac-
`complished by preparative TLC (Analtech silica gel GF plates,
`complished by preparative TLC (Analtech silica gel GF plates,
`20 (cid:2) 20 cm, 1000 (cid:237)m). Silica gel (Analtech silica gel GF, 1 (cid:2)
`20 x 20 cm, 1000 gm). Silica gel (Analtech silica gel GF, 1 x
`3 in., 250 (cid:237)m thickness) plates were utilized for TLC analyses.
`3 in., 250 gm thickness) plates were utilized for TLC analyses.
`Elemental analyses were within (0.4% of the calculated
`Elemental analyses were within ±0.4% of the calculated
`values.
`values.
`1-(2-Fluoro-4-nitrophenyl)piperazine, 2a. A solution of
`1-(2-Fluoro-4-nitrophenyl)piperazine, 2a. A solution of
`12.0 g (75.42 mmol) of 3,4-difluoronitrobenzene in 150 mL of
`12.0 g (75.42 mmol) of 3,4-difluoronitrobenzene in 150 mL of
`acetonitrile was treated with 16.24 g (188.6 mmol) of pipera-
`acetonitrile was treated with 16.24 g (188.6 mmol) of pipera-
`zine followed by warming at reflux for 3 h. The solution was
`zine followed by warming at reflux for 3 h. The solution was
`cooled to ambient temperature and concentrated in vacuo. The
`cooled to ambient temperature and concentrated in vacuo. The
`resulting residue was diluted with 200 mL of water and
`resulting residue was diluted with 200 mL of water and
`extracted with ethyl acetate (3 (cid:2) 250 mL). The combined
`extracted with ethyl acetate (3 x 250 mL). The combined
`organic layers were extracted with water (200 mL) and
`organic layers were extracted with water (200 mL) and
`saturated sodium chloride solution (200 mL) followed by drying
`saturated sodium chloride solution (200 mL) followed by drying
`(Na2SO4). The solution was concentrated in vacuo to afford
`(Na2504). The solution was concentrated in vacuo to afford
`an orange oil which was chromatographed over 450 g of silica
`an orange oil which was chromatographed over 450 g of silica
`gel eluting initially with dichloromethane until the least polar
`gel eluting initially with dichloromethane until the least polar
`fractions had eluted, and then elution was continued with 2%
`fractions had eluted, and then elution was co