0us1y.l~ Male CD rata, 180-250 g, were fed Purina certified rodent
`chow (5002) and water ad libitum. 20,25-Diazacholesterol was
`given intragastrically as a suspension (0.1% Tween 80/saline) at
`a daily dose of 5 mg/kg for 7 days. Test compounds were ad-
`ministered, as suspensions, intragastrically over the last 4 days
`of the test. Rata were killed 2 h after the last treatment, the livers
`were removed, the microsomal fraction was prepared (6 X loe
`G/min), and HMG CoA reductase activity was determined for
`control and treat group rats on the basis of conversion of [14C]-
`HMG GOA to [14C]mevalonate.13 All results are presented as
`percent reduction from concurrent controls. Means were com-
`pared to respective controls by Student's t test.
`
`(13) M. S. Brown, S. E. Dana, and J. L. Goldstein, J. Biol. Chem.,
`249, 789 (1974).
`
`J. Med. Chem. 1985,28, 601-606
`60 1
`Acknowledgment. We are grateful to A. J. Damascus,
`E. Zielinski, and their staff for the spectroscopic and
`analytical results. We are indebted to K. Williams and T.
`Lindberg for their assistance in the preparation of addi-
`tional amounts of compounds.
`Registry No.
`Id, 97-62-1; If, 627-90-7; lj, 628-97-7; 2d,
`52939-56-7; 2f, 52939-58-9; 2j, 52939-55-6; 3b, 52939-72-7; 3c,
`52939-71-6; 3d, 52939-65-8; 3e, 95249-30-2; 3f, 52939-68-1; 3g,
`95249-31-3; 3h, 95249-32-4; 3j, 52939-64-7; 3k, 95249-33-5; 31,
`95249-34-6; 3m, 95249-35-7; 4a, 73489-84-6; 4b, 72060-93-6; 4c,
`95249-36-8; 4d, 95249-37-9; 4e, 95249-38-0; 4f, 95249-39-1; 4g,
`95249-40-4; 5a, 34695-32-4; 5b, 95249-41-5; 5c, 95249-42-6; 5d,
`95249-43-7; 6, 95249-29-9; 7a, 95249-44-8; 7b, 95249-45-9; 8a,
`95249-46-0; Sb, 95249-47-1; SC, 95249-48-2; HMGR, 9028-35-7; aUyl
`bromide, 106-95-6.
`
`Effect of Structural Modification of the Hydantoin Ring on Anticonvulsant
`Activity
`
`Sergio Cortes,la Zeng-Kun Liao, Darrell Watson,lb and Harold Kohn*lc
`Department of Chemistry, University of Houston-University Park, Houston, Texas 77004. Received February 15, 1984
`
`Selectively substituted hydantoins 1 (15 examples), 4-hydroxy-2-imidazolidinones 2 (13 examples), 2-imidazolones
`3 (10 examples), 2-imidazolidinones 4 (four examples), vicinal diamines 5 (two examples), and simple amino acid
`derivatives 6 (four examples) have been prepared and evaluated in the maximal electroshock seizure (MES),
`subcutaneous pentylenetetrazole seizure threshold (sc Met), and rotorod (Tox) tests. The medium effective doses
`(ED50) and the medium toxic dose (TD50) for the most active compounds are reported. In general, the most
`pronounced activity was observed for hydantoins 1 and protected amino acids 6. Within each series of compounds,
`enhanced anticonvulsant activity was often noted for compounds containing an aromatic group one carbon removed
`from a nitrogen atom. Among the most active compounds observed were the amino acid derivative N-aCetyl-D,L-danine
`benzylamide (6d) and the two 2-imidazolones 4-methyl-l-(phenylmethyl)-l,3-dihydro-2H-imidazol-2-one
`(3e) and
`l-phenyl-l,3-dihydro-2H-imidazol-2-one (3g). Compound 6d proved to be slightly more potent in the MES test
`than phenacemide.
`
`Vicinal diamine based substrates form an important set
`of CNS-active medicinal agentsa2 Among the most im-
`portant members of this class of compounds are the hy-
`dantoins 1. The effect of structural modification of the
`hydantoin ring system on biological activity has been a
`subject of considerable i n t e r e ~ t . ~ Attention has been
`focused on the select replacement of the ring atoms and
`the alteration of the hydrogen bonding properties of the
`heter~cycle.~
`
`a
`
`R3-t
`
`N-R,
`
`In this report, we describe the syntheses, physical
`properties, and anticonvulsant activities of a select series
`of hydantoins 1, 4-hydroxy-2-imidazolidinones 2, 2-
`imidazolones 3, 2-imidazolidinones 4, vicinal diamines 5,
`and amino acid derivatives 6. This study differed con-
`siderably from previous reports in that the basic sequence
`present in hydantoins 1 has been
`of atoms (N-C-C-N-C)
`retained in almost all the substrates examined. Differen-
`tiation among the classes of compounds (1-6) evaluated,
`however, was achieved by altering the oxidation state,
`basicity, and lipophilicity of the compounds.
`
`(a) Abstracted from Ph.D dissertation of this author. Addi-
`tional structure proof, discussion, and experimental and spec-
`tral data may be found in this reference. (b) On leave from the
`University of Mary Hardin-Baylor, Belton, TX 76513, 1982.
`(c) Camille and Henry Dreyfus Teacher-Scholar Grant Re-
`cipient, 1977-1982.
`For previous studies, see: Kohn, H.; Kohn, B. A.; Steenberg,
`M. L.; Buckley, J. P. J. Med. Chem. 1977,20, 158-160. Ar-
`ceneaux, J. H.; Kohn, H.; Steenberg, M. L.; Buckley, J. P. J.
`Pharm. Sci. 1978,67,600-602.
`For a general discussion, see: Jones, G. L.; Woodbury, D. M.
`Drug Dev. Res. 1982,2, 333-355.
`Poupaert, J. H.; Vandervorst, D.; Guiot, P.; Moustafa, M. M.
`M.; Dumont, P. J. Med. Chem. 1984,27', 76-78 and references
`therein.
`
`2
`
`3
`
`4
`
`RsNHCHzCHNHCH,
`I
`
`0 I1
`R N H ~ C H N H R"
`I
`A '
`k S
`5
`6
`Selection of Compounds. Hydantoins la-i served as
`the parent compounds in this study (Table I). Within this
`class of compounds we have systematically varied the R3
`substituent from methyl to benzyl to phenyl and the R5
`group from hydrogen to methyl to phenyl.
`Identical
`substituent patterns were incorporated into the 4-
`
`0022-2623/85/ 1828-0601$01.50/0
`
`0 1985 American Chemical Society
`
`IPR2014-01126- Exhibit 1009, p. 1
`
`

`
`602 Journal of Medicinal Chemistry, 1985, Vol. 28, No. 5
`
`Cortes et al.
`
`Table I. Pharmacological Evaluation of 2,4-Imidazolidinediones (Hydantoins) I
`
`results"
`
`compound
`R3
`
`sc
`R1
`R6,
`ASP"
`Toxd
`MetC
`MESb
`no.
`R6
`I11
`H
`H
`CH3
`H
`l a
`0
`0
`0
`H
`I11
`CH3
`H
`0
`0
`0
`l b
`CH3
`Ph
`3
`3
`H
`I
`CH3
`H
`1
`I C
`I
`3
`H
`H
`Bnf
`H
`Id
`2
`2
`I
`H
`CH3
`Bnf
`H
`le
`4
`2
`1
`I11
`H
`Ph
`Bnf
`H
`If
`0
`0
`0
`I11
`H
`H
`Ph
`H
`0
`0
`1g
`1
`Ph
`H
`I11
`H
`CH3
`l h
`1
`0
`0
`I11
`H
`Ph
`Ph
`H
`li
`0
`0
`0
`I11
`CH3
`CH3
`CHZPh(3-OCH3)
`H
`0
`0
`1j
`1
`I
`3
`CH3
`CH3
`(CHz)zPh
`H
`2
`2
`l k
`I1
`CH3
`CH3
`(CHZ),Ph(3-OCH,)
`H
`11
`2
`2
`1
`H
`H
`I11
`H
`CH3
`lm
`0
`0
`0
`I
`3
`H
`Ph
`H
`H
`In
`1
`2
`I1
`H
`CH3
`0
`CH3
`CH3
`0
`lo
`2
`4The following code has been adopted: 0 = no activity at dose levels of 600 mg/kg; 1 = noticeable activity at dose levels of 600 mg/kg; 2
`= noticeable activity at dose levels of 300 mg/kg; 3 = noticeable activity at dose levels of 100 mg/kg; 4 = noticeable activity at dose levels
`of 30 mg/kg. bMES = maximal electroshock seizure test. 'SC Met = subcutaneous pentylenetetrazole (Metrazol) seizure test. d T o ~ =
`neurologic toxicity (the rotorod test). e ASP Results Classification. f Bn = benzyl.
`
`Table 11. Pharmacological Evaluation of 3-Substituted 4-Hydroxy-2-imidazolidinones 2
`
`R3-N il N-R,
`
`H*R5
`no
`
`R,,
`
`2
`
`results"
`
`compound
`R3
`
`
`
`~
`
`sc
`ASP'
`Toxd
`Metc
`MESb
`R5
`R1
`no.
`R6'
`I11
`H
`H
`CH3
`H
`0
`0
`0
`2a
`I11
`H
`0
`0
`0
`CH3
`CH3
`H
`2b
`Ph
`I1
`H
`2
`0
`1
`CH3
`H
`2c
`H
`I11
`H
`Bnf
`H
`0
`0
`2d
`1
`H
`CH3
`Bnf
`H
`2e
`I1
`1
`1
`2 '
`I11
`H
`Ph
`Bnf
`H
`0
`0
`2f
`0
`H
`H
`Ph
`H
`2g
`111
`0
`0
`0
`H
`111
`1
`1
`1
`CH3
`Ph
`H
`2h
`111
`H
`Ph
`Ph
`H
`2i
`0
`0
`0
`111
`CH3
`CH3
`CHZPh(3-OCH3)
`0
`0
`H
`1
`2j
`I11
`CH3
`CH3
`(CHJzPh
`H
`1
`2k
`1
`1
`I1
`CH3
`CH3
`(CH2)3Ph(3-OCH3)
`H
`21
`1
`2
`2
`I11
`H
`CH,
`CH,
`CH,
`20
`0
`0
`0
`"The following code has been adopted: 0 = no activity at dose levels of 600 mg/kg; 1 = noticeable activity at dose levels of 600 mg/kg; 2
`= noticeable activity at dose levels of 300 mg/kg; 3 = noticeable activity at dose levels of 100 mg/kg; 4 = noticeable activity at dose levels
`of 30 mg/kg. bMES = maximal electroshock seizure test. c~~ Met = subcutaneous pentylenetetrazole (Metrazol) seizure test. d T o ~ =
`neurologic toxicity (the rotorod test). e ASP Results Classification. f Bn = benzyl.
`hydroxy-2-imidazolidinone (2a-i) (Table 11) and 2-
`imidazolone (3a-i) (Table 111) series. We have also ex-
`amined the pharmacological activity of two carbon-5 mo-
`nosubstituted hydantoins (lm and n) (Table I), the more
`complex N1,N3,C5- and N3,C5,C5-trisubstituted hydantoins
`lo and lj-I, respectively (Table I), and the corresponding
`4-hydroxy adducts (20 and 2j-1) (Table 11) as well as 2-
`imidazolone 30 (Table 111). Included in our survey were
`the substituted imidazolidinones 4a-e, the vicinal diamines
`5a and 5b, and the amino acid derivatives 6a-d (Table IV).
`Of note, the substituent patterns present in 1 have been
`preserved in these structural derivatives.
`
`Chemistry. The synthetic procedures as well as
`physical and spectral properties of hydantoins la-^,^!^
`4-hydroxy-2-imidazolidinones 2a-1 and
`2-
`imidazolidinones 4b-d,6 and vicinal diamines 5a and 5b5
`have been previously reported. All the carbon-5 mono-
`substituted hydantoins 1 as well as diamines 5a and 5b
`were racemic. Pharmacological evaluation of 4-hydroxy-
`2-imidazolidinones 2b, 2c, 2e, 2f, 2h, and 2i was conducted
`on the synthetic diastereomeric mixture.
`
`(5) Cortes, S.; Kohn, H. J. Org. Chem. 1983, 48, 2246-2254.
`(6) Kohn, H.; Liao, Z. K. J. Org. Chem. 1982, 47, 2787-2789.
`
`IPR2014-01126- Exhibit 1009, p. 2
`
`

`
`Anticonvulsant Activity of Hydantoins
`
`Journal of Medicinal Chemistry, 1985, Vol. 28, No. 5 603
`
`Table 111. Pharmacological Evaluation of 3-Substituted 2-Imidazolones 3 1
`R3-H-R'
`
`H
`
`R 5
`
`3
`
`'
`
`results4
`compound
`M E S ~
`ASP'
`Toxd
`sc MetC
`R6
`R3
`R,
`no.
`I11
`CH3
` 0
`0
`H
`H
`3a
`0
`I11
`CH3
`CH3
`H
`0
`0
`0
`3b
`I11
`Ph
`CH3
`0
`H
`1
`1
`3c
`I
`2
`3
`Bnf
`H
`H
`3d
`2
`I1
`H
`2
`CH3
`3e
`Bnf
`1
`2
`I11
`Ph
`Bnf
`H
`0
`3f
`0
`0
`I
`3
`H
`Ph
`H
`2
`2
`3f3
`H
`I11
`CH3
`3h
`0
`Ph
`1
`1
`Ph
`Ph
`H
`I1
`3i
`0
`2
`0
`I11
`CH3
`CH3
`CH3
`0
`0
`30
`0
`"The following code has been adopted: 0 = no activity at dose levels of 600 mg/kg; 1 = noticeable activity at dose levels of 600 mg/kg; 2
`= noticeable activity at dose levels of 300 mg/kg; 3 = noticeable activity at dose levels of 100 mg/kg; 4 = noticeable activity at dose levels
`of 30 mg/kg. *MES = maximal electroshock seizure test. 'sc Met = subcutaneous pentylenetetrazole (Metrazol) seizure test. d T o ~ =
`neurologic toxicity (the rotorod test). 'ASP Results Classification. f Bn = benzyl.
`
`,
`
`The 2-imida~olones'-~~ 3 were prepared by the acid-
`promoted dehydration of the 4-hydroxy-2-imidazolidinones
`2. Key physical and spectral properties for these com-
`pounds are listed in Table V.
`Imidazolone 3c was selectively hydrogenated to give 4a
`by using palladium on activated carbon (H2, 40 psi, 40 h)
`in glacial acetic acid.12 The methodologies employed for
`the preparation of each of the racemic amino acid deriv-
`atives 6a-d were patterned after procedures common to
`peptide synthesis.13 D,L-Phenylglycine methylamide (6a)
`and D,L-alanine benzylamide (6c) were synthesized by
`treatment of the hydrochloride salt of the corresponding
`methyl ester14 with excess methylamine or benzylamine,
`respectively. Acetylation of 6a and 6c with a slight excess
`of acetic anhydride gave 6b and 6d, respectively, as crys-
`talline solids.
`Pharmacological Evaluation. The 48 substrates
`prepared in this study were submitted to the National
`Institutes of Health Antiepileptic Drug Development
`Program for pharmacological evaluation. Each compound
`was tested for anticonvulsant activity in mice by using the
`procedure described by Krall et al.15
`The phase I test results are summarized in Tables I-IV.
`All compounds were administered in four dose levels (30,
`100, 300, and 600 mg). The smallest dose that produced
`activity was noted for separate tests involving maximal
`electroshock-induced convulsions (MES), subcutaneous
`Metrazol-induced convulsions (sc Met), and a rotorod
`toxicity test (Tox). The overall effect of the drug in these
`
`(7) Leonard, N. J.; Wiemer, D. F. J. Am. Chem. SOC. 1976, 98,
`8218-8221.
`(8) Wilk,-I. J.; Close, W. J. J. Org. Chem. 1950, 15, 1020-1022.
`(9) Novak, J. J. K. Collect. Czech. Chem. Commun. 1978, 43,
`1511-1519.
`(10) Chupp, J. P. J. Heterocycl. Chem. 1971, 8, 557-563.
`(11) Forrest. T. P.: DauDhinee. G. A.: Chen, F. M. F. Can. J. Chem.
`1974, 52, 2725-2729.
`.
`.
`(12) Duschinskv. R.: Dolan. L. A.: Randall. L. 0.: Lehmann. G. J.
`.
`
`.
`Am. Chem: Soc. 1947,'69, 3150.
`(13) Bodanszky, M.; Klausner, Y. S.; Ondetti, M. A. "Peptide
`Synthesis", 2nd ed.; Wiley: New York, 1976.
`(14) Barfield, M.; Al-Obeidi, F. A.; Hruby, V. J.; Walter, S. R. J.
`Am. Chem. SOC. 1982, 104, 3302-3306.
`(15) Krall, R. L.; Penry, J. K.; White, B. G.; Kupferberg, H. J.;
`Swinyard, E. A. Epilepsia 1978,19, 409-428.
`
`three tests was then given by one of four different ratings
`(ASP Results Classification I-IV). Compounds with rat-
`ings of I or I1 are considered promissory and were con-
`sidered for phase I1 (quantification) testing (Table VI).
`This stage involved the same tests previously described,
`except under a more strict monitoring of dosages and ac-
`tivity time spans. It also included an evaluation of the
`median effective dose (ED50) and the median toxic dose
`(TD50).
`Evaluation of the composite set of results revealed sig-
`nificant trends. First, the level of CNS activity decreased
`as the overall state of oxidation of the molecule was re-
`duced. For the six classes of compounds evaluated, hy-
`dantoins 1 and amino acid derivatives 6 were the most
`active, followed by 4-hydroxy-2-imidazolidinones 2, 2-
`imidazolones 3, and 2-imidazolidinones 4, followed by
`vicinal diamines 5. Second, enhanced anticonvulsant ac-
`tivity was often noted for compounds containing an aro-
`matic group one carbon removed from an amino residue
`(Le., lc-e, In, 2c, 2e, 3d, 3e, 3g, 3i, 4a, 4b, 6c, and 6d).
`Exceptions were observed (i.e., lk, 11, lo, 21). Ample
`precedence exists for this structural pattern. Many com-
`pounds which exhibit pronounced CNS depressant activity
`contain an aromatic group one carbon removed from a
`diamine linkage.3,16
`In view of these trends, it was of interest to trace the
`biological activities of two series of compounds. In the first
`set (le, 2e, 3e, 5b, 6c and 6d) each compound contained
`both a N-benzyl moiety and a methyl group attached to
`the vicinal diamine linkage. In the second group (IC, 2c,
`3c, 4a, 5a, 6a, and 6b) the common'structural features were
`a N-methyl group and a phenyl moiety attached to the
`diamine moiety. All the compounds in the former set other
`than the basic diamine 5b exhibited significant activity.
`Compounds IC and 6d were both assigned an ASP clas-
`sification rating of I. Protected amino acid 6d can be
`viewed as the open-chain analogue of hydantoin 1e.l' The
`
`(16) For representative examples, see: Troupin, A. S.; Friel, P.;
`Wilensky, A. J.; Moretti-Ojemann, L.; Levy, R. H.; Feigl, P.
`Neurology 1979,29,458-460. Congdon, P. J.; Forsythe, W. I.
`Epilepsia 1980,21, 97-102. Griffith, P. A.; Karp, H. R. Ann.
`Neurol. 1980, 7,493. Pinder, R. M.; Brogden, R. N.; Speight,
`T. M.; Avery, G. S. Drugs 1976, 12, 321-361. Ogata, M.;
`Matsumoto, H.; Hirose, K. J. Med. Chem. 1977,20, 776-781.
`
`IPR2014-01126- Exhibit 1009, p. 3
`
`

`
`604 Journal of Medicinal Chemistry, 1985, Vol. 28, No. 5
`
`Table IV. Pharmacological Evaluation of Additional Vicinal
`Diamine Based Substratesa
`no.
`compd
`4a
`
`MESb sc MetC Toxd ASPe
`I1
`2
`2
`1
`
`4b rnN
`xQo
`cH30)qy
`\ Tk0
`
`c H 3 - - J N -
`
`n
`
`\
`\ Ph
`
`H
`
`4c
`
`CH30
`
`4d
`
`CH30
`
`CH3 H
`
`CH3 \
`
`2
`
`0
`
`0
`
`2
`
`0
`
`0
`
`2
`
`I1
`
`1
`
`I11
`
`0
`
`I11
`
`5a
`
`CH3NHCHZCHNHCH3
`
`I
`
`Ph
`
`0
`
`0
`
`2
`
`I11
`
`0
`
`0
`
`0
`
`2
`
`3
`
`0
`
`0
`
`0
`
`0
`
`0
`
`2
`
`0
`
`0
`
`2
`
`1
`
`I11
`
`I11
`
`IV
`
`I1
`
`1
`
`
`
`5b
`
`6a
`
`6b
`
`6c
`
`6d
`
`i
`
`CH3NHCCHIPhlNHCCH3 ( U i )
`
`BnNHCCH(CH3)NHz (dl)'
`
`R
`
`I
`B~NHCH~CHNHCH,'
`c H3
`I/
`0
`CH3NHCCH(Ph)NHZ ( U l I
`A
`ii
`A
`BnNHCCH(CH3)NHCCH3 (dll'
`"The following code has been adopted: 0 = no activity at dose
`levels of 600 mg/kg; 1 = noticeable activity at dose levels of 600
`mg/kg; 2 = noticeable activity at dose levels of 300 mg/kg; 3 =
`noticeable activity at dose levels of 100 mg/kg; 4 = noticeable ac-
`tivity at dose levels of 30 mg/kg. bMES = maximal electroshock
`seizure test.
`sc Met = subcutaneous pentylenetetrazole (Metra-
`zol) seizure test. d T o ~ = neurologic toxicity (the rotorod test).
`Results Classification. fBn = benzyl.
`results observed in the latter set were less straightforward.
`Significant pharmacological activity was detected for IC,
`2c, and 4a, while 3c, 5a, and 6a were inactive, and the fully
`protected amino acid 6b gave inconsistent test results.
`The pharmacological activities observed for compounds
`IC, Id, lk, In, 3d, 3e, 3g, and 6d warranted their further
`evaluation in phase I1 trails. These data are summarized
`in Table VI along with similar information for several
`proven antiepileptic drugs.15Js Promising results were
`obtained for compounds 3e, 3g, and 6d. Compound 6d was
`found to be slightly more potent in the MES test than
`phenacemide and equally as toxic. Compounds 3e, 3g, and
`6d are slated for additional screening at the National In-
`stitutes of Health.
`Experimental Section
`General Methods. Melting points were determined with a
`Thomas-Hoover melting point apparatus and are uncorrected.
`
`(17) Although amino acid derivatives 6a-d structurally resemble
`phenacemide analogue^,^ the sequence of atoms in these two
`classes of compounds differ.
`(18) Results obtained by Dr. Gill D. Gladding (ASP Project) of the
`National Institute of Neurological and Communicative Disor-
`ders and Stroke at the National Institutes of Health (private
`communication).
`
`Cortes et al.
`
`Infrared spectra (IR) were rur on a Beckman IR-4250 spectro-
`photometer and calibrated against the 1601-cm-' band of poly-
`styrene. Absorption values are expressed in wavenumbers (cm-').
`Proton nuclear magnetic resonance (lH NMR) spectra were re-
`corded on Varian Associates Models T-60 and FT-BOA NMR
`spectrometers. Carbon nuclear magnetic resonance (13C NMR)
`spectra were run on a Varian Associates Models FT-80A instru-
`ment. Chemical shifts are in parts per million (6 values) relative
`to Me,Si, and coupling constants (.I values) are in hertz. Mass
`spectral data were obtained at an 'onizing voltage of 70 eV on
`a Hewlett-Packard 5930 gas chromatograph-mass spectrometer.
`High-resolution (E1 mode) mass spectra were performed by Dr.
`James Hudson at the Department of Chemistry, University of
`Texas a t Austin, on a CEC21-11OB double-focusing magnetic-
`sector spectrometer at 70 eV. Elemental analyses were obtained
`at Spang Microanalytical Laboratories, Eagle Harbor, MI.
`The solvents and reactants were of the best commercial grade
`available and were used without further purification unless noted.
`AU anhydrous reactions were run under nitrogen, and all glassware
`was dried before use.
`Preparation of 2-Imidazolones (3). General Procedure.
`To a suspension of the 4-hydroxy-2-imidazolidinone 2 (6.1-15.8
`mmol) in CH2C12 (200 mL) or CH2C12-MeOH (200 mL, 10-100/1,
`v/v) was added two drops of TFA and the mixture stirred (30
`min) at room temperature. During this time interval, the initially
`heterogeneous system became a clear solution. Evaporation of
`the solvent in vacuo afforded the desired 2-imidazolone. Spectral
`('H and I3C NMR) analyses indicated that the material was
`essentially pure.
`Purification was accomplished in the case of 3a by recrystal-
`lization from dichloromethane-hexanes, 3b by sublimation (70
`"C, 0.1 torr), 3c by recrystallization from EtOH, 3d by recrys-
`tallization from dichloromethane-hexanes, 3e by recrystallization
`from benzene-methanol, 3f by recrystallization from EtOH-
`CH2C12 or sublimation (168 "C, 0.14 torr), and 3g and 3h by
`recrystallization from benzene.
`Preparation of l-Methyl-4-phenyl-2-imidazolidinone (4a).
`To a glacial HOAc solution (40 mL) of 3c (1.70 g, 98 mmol) in
`a thick-wall glass bottle was added Pd-C (Pd content 1%, 1.00
`9). The container was connected to a medium-pressure hydro-
`genation apparatus and the resulting mixture stirred under H2
`(40 psi) for 40 h. The catalyst was filtered with the aid of a Celite
`pad, and the filtrate was neutralized (pH -8) with aqueous 5 N
`NaOH and then extracted with CHC13 (3 X 50 mL). The organic
`layers were combined, dried (Na2S04), and concentrated in vacuo.
`Recrystallization from CH2C12-hexanes gave 1.00 g (58%) of 4a:
`mp 134.5-136.0 "C; IR (CH2C1,) 1715 cm-l; 'H NMR (CDC13) 6
`2.72 (8, 3 H), 3.12 (d, d, J = 7.4, 8.6 Hz, 1 H), 3.71 (d, d, J = 8.6,
`8.8 Hz, 1 H), 4.69 (d, d, J = 7.4, 8.8 Hz, 1 H), 6.08 (br s, 1 H),
`7.31 (s, 5 H); 13C NMR (CDCl,) 30.5, 53.6, 56.1, 126.0, 128.0, 128.8,
`141.9, 162.5 ppm; mass spectrum, m / e (relative intensity) 176
`(loo), 175 (37), 104 (28). Anal. (CloH12N20) C, H, N.
`D,L-Phenylglycine Methylamide (6a). A 40% aqueous so-
`lution of methylamine (60 mL, 0.70 mol) was slowly added to
`D,L-phenylglyche methyl ester hydr~chloride'~ (9.00 g, 44.7 mmol).
`The resulting solution was heated to reflux (3 h) and then ex-
`tracted with CHC1, (3 X 50 mL). The organic layers were com-
`bined, dried (Na2S04), and concentrated in vacuo. Purification
`of the oily residue by short-path distillation (100 "C, 0.5 torr) gave
`4.60 g (63%) of 6a: IR (neat, NaC1) 3310, 1665, 1550 cm-'; 'H
`NMR (CDC13) 6 1.85 (s, 2 H), 2.64 (d, J = 5.0 Hz, 3 H), 4.35 (s,
`1 H), 7.26 (s, 5 H), 7.35-7.60 (br s, 1 H); 13C NMR (CDCl,) 25.9,
`59.6, 126.8, 127.6, 128.6, 141.6, 173.9 ppm; mass spectrum (CI
`mode), m / e 165 (P -I- 1). Anal. (CgH12N20) C, H, N.
`N-Acetyl-D,L-phenylglycine Methylamide (6b). Acetic
`anhydride (2.90 g, 28 mmol) was added dropwise to 6a (3.40 g,
`20 mmol) and the mixture allowed to stir at room temperature
`(1.5 h). During this time, a copious white precipitate formed. This
`material was collected by filtration, dried in vacuo, and recrys-
`tallized from absolute alcohol to give 2.00 g (49%) of 6b: mp
`232-235 "C dec; IR (KBr) 3310,1645 cm-'; 'H NMR (Me2SO-d6)
`6 1.89 (s, 3 H), 2.58 (d, J = 4.6 Hz, 3 H), 5.42 (d, J = 8.1 Hz, 1
`H), 7.35 (8, 5 H), 8.18 (br q, J = 4.2 Hz, 1 H), 8.47 (d, J = 8.1 Hz,
`1 H); 13C NMR (Me2SO-d,) 22.4, 25.5, 56.3, 127.1,127.3, 128.1,
`139.0, 168.9, 170.3 ppm; mass spectrum (CI mode), m / e 207 (P
`+ 1). Anal. (CllH14N202) C, H, N.
`
`IPR2014-01126- Exhibit 1009, p. 4
`
`

`
`Anticonvulsant Activity of Hydantoins
`
`Journal of Medicinal Chemistry, 1985, Vol. 28, No. 5 605
`
`Table V. Summary of Selected Physical and Spectral Properties of 2-Imidazolone Derivatives 38
`fi
`
`NMR datac
`'H NMR data,c
`IR data,b
`yield,
`c=o
`c2=0
`c4
`mp, "C
`R3
`C4 H
`no.
`%
`R6
`c5
`11 2.6
`6.16
`1670
`108.3
`155.0
`141-142*
`28
`H
`CH3
`3a
`e, f
`117.9
`108.2
`155.1
`5.84
`1680
`CH3
`3b
`CH3
`24
`120.3
`6.98
`1690
`109.5
`153.8
`268-278 de@
`38
`Ph
`CH
`3c
`6.09
`108.8
`155.0
`1680
`134-136'
`51
`H
`Bnh3
`3d
`111.2
`118.4
`106.9
`154.9
`5.77
`1670
`158-16 1'
`68
`CH3
`Bnh
`3e
`7.05
`120.9
`108.4
`153.7
`1690
`247-254 decf
`32
`Ph
`Bnh
`3f
`3g
`109.7
`153.8
`6.41
`1680
`136-13gk
`59
`H
`Ph
`111.0
`6.23
`119.5
`106.5
`153.7
`1680
`169-172l
`CH3
`17
`Ph
`3h
`6.86
`1690
`124.0
`106.3
`153.9
`180-1 82fgm
`15
`Ph
`Ph
`3i
`See reference 5 for a detail description of the physical properties of 3m.
`Infrared were taken in KBr disks (in cm-'). CNMR spectra
`Lit.' mp 139-140 O C . e Hygroscopic sample. f Elemental composition verified by high-resolution
`were taken in CDCI3 or MezSO-d6 (in 6).
`mass spectroscopy. gLit.* mp 275-278 O C . hBn = benzyl. 'Lit.v mp 133-135 O C . 'Lit.'O mp 162-165 "C. kLit.ll mp 123 "C.
`mp 170
`mp 215-216 O C .
`O C .
`
`~~
`
`no.
`
`Table VI. Summary of Phase I1 Evaluation
`sc Met
`Tox
`MES
`ED50"
`ED50a
`TD50a
`271 (223-326)
`IC
`75 (60-88)
`26 (16-36)
`224 (179-288)
`Id
`65 (53-82)
`114 (88-149)
`l k
`243 (212-268)
`130 (101-154)
`110 (90-131)
`399 (341-472)
`109 (85-137)
`156 (129-183)
`In
`83 (71-94)
`3d
`190 (176-203)
`90 (53-158)
`268 (229-309)
`90 (83-98)
`3e
`b
`211 (194-239)
`173 (156-195)
`124 (103-141)
`3g
`77 (67-89)
`6d
`454 (417-501)
`b
`phenytoinC
`66
`d
`10
`mephenytoinC
`154
`31
`61
`421 (337-549)
`116 (71-150)
`87 (74-100)
`phenacemidee
`aNumbers in parentheses are 95% confidence intervals. bThe
`ED50 value was not computed for this substrate. CReference 18.
`Not effective. e Reference 15.
`n,L-Alanine Benzylamide (6c). Benzylamine (30.68 g, 0.29
`mol) waa added dropwise to a stirred solution of D,L-alanine methyl
`ester hydrochloride (20.00 g, 0.14 mol) in methanol (50 mL). The
`mixture was heated to reflux (3 h) and concentrated in vacuo,
`and the residue was triturated with CHC13 (3 X 50 mL). The
`remaining solid was dissolved in aqueous 5% NaOH and extracted
`with CHC1, (3 X 50 mL). All the organic layers were combined,
`dried (NazS04), concentrated in vacuo, and distilled (twice) by
`using a shorbpath distillation apparatus (100 OC, 0.5 torr) to yield
`5.50 g (22%) of product: IR (neat, NaCl) 3300,1655,1525 cm-l;
`'H NMR (CDClJ 6 1.34 (d, J 7.0 Hz, 3 H), 1.58 (9, 2 H), 3.51
`(9, J = 7.0 Hz, 1 H), 4.42 (d, J = 5.9 Hz, 2 H), 7.27 (8, 5 H), 7.39
`(br s, 1 H); 13C NMR (CDC13) 21.8, 43.1, 50.8, 127.4, 127.7, 128.7,
`138.6, 175.6 ppm; mass spectrum (CI mode), m / e 179 (P + 1);
`mass spectrum, m / e (relative intensity) 179 (5), 178 (3), 177 (6),
`106 (29), 91 (loo), 65 (20). Anal. (C10H14N20) C, H, N.
`N-Acetyl-D&-alanine Benzylamide (6d). Acetic anhydride
`(2.20 g, 0.022 mol) waa slowly added to a CHzClz solution (30 mL)
`of 6c (3.80 g, 0.021 mol) and allowed to stir at room temperature
`(3 h). The mixture was then successively washed with HzO (15
`mL), 1% aqueous NaOH (15 mL), and HzO (15 mL), dried
`(Na2S04), and concentrated in vacuo. The residue was recrys-
`tallized from CHzClz to yield 2.50 g (54%) of 6d: mp 239-241
`"C; IR (CHCl,) 3440, 3300, 3005, 1660, 1515 cm-l; lH NMR
`(MezSO-d6) 6 1.22 (d, J = 7.1 Hz, 3 H), 1.84 (8, 3 H), 4.04-4.50
`(m, 3 H), 7.26 (8, 5 H), 8.11 (br d, J = 7.3 Hz, 1 H), 8.42 (br t,
`J = 6 Hz, 1 H); 13C NMR (MezSO-d6) 18.2, 22.4, 41.9, 48.2, 126.5,
`126.9, 128.1, 139.4, 168.9, 172.4 ppm; mass spectrum (CI mode),
`m / e 221 (P + 1); M, 220.1208 (calcd for Cl2HlaNzO2, 220.1212).
`Pharmacology. Each compound listed in Tables I-IV was
`tested for anticonvulsant activity (phase I evaluation) with use
`of male Carworth Farms No. 1 mice. All compounds were given
`in four dose levels (30,100,300, and 600 mg). Seizures were then
`artificially induced by either electroshock or pentylenetetrazole.
`
`Maximal electroshock seizures (MES) are elicited with a 60-cycle
`alternating current of 50-mA intensity (5-7 times that necessary
`to elicit minimal electroshock seizures) delivered for 0.2 s via
`corneal electrodes. A drop of 0.9% saline is instilled in the eye
`prior to application of the electrodes so as to prevent the death
`of the animal. Protection in this test is defined as the abolition
`of the hind limb tonic extension component of the seizure. The
`subcutaneous pentylenetetrazole (Metrazol) seizure threshold test
`(sc Met) entailed the administration of 85 mg/kg of pentylene-
`tetrazole as a 0.5% solution subcutaneously in the posterior
`midline. This amount of pentylenetetrazole is expected to produce
`seizures in greater than 95% of mice. The animal is observed
`for 30 min. Protection is defined as the failure to observe even
`a threshold seizure (a single episode of clonic spasms of at least
`5-s duration). The effects of the compounds on forced and
`spontaneous motor activity were evaluated in mice by the rotorod
`test (Tox). The animal is placed on an 1-in.-diameter knurled
`plastic rod rotating at 6 rpm after the administration of the drug.
`Normal mice can remain on a rod rotating at this speed indefi-
`nitely. Neurologic toxicity is defined as the failure of the animal
`to remain on the rod for 1 min. The MES and sc Met tests were
`conducted on single animals while four mice were utilized for the
`Tox test.
`The overall effect of the drug in these three tests is then given
`by one of four different ratings (ASP Results Classification I-IV).
`The number I indicated anticonvulsant activity at 100 mg/kg or
`less, I1 designated activity at doses greater than 100 mg/kg, I11
`denoted no anticonvulsant activity at doses up to and including
`300 mg/kg, and IV indicated that anticonvulsant activity and
`toxicity or toxicity alone was demonstrated at 30 mg/kg or that
`anticonvulsant activity was displayed at 100 mg/kg or less, but
`that the test results were not consistent.
`Compounds with ratings of I and I1 are considered promissory
`and were considered for phase I1 (quantification) testing. The
`dose-effect behavior of the eight substrates listed in Table VI
`was evaluated by using the previously described procedures by
`the administration of varying dose levels of each compound,
`treating normally eight mice at each dose.
`Acknowledgment. We are grateful to Dr. Gill D.
`Gladding and t h e Anticonvulsant Screening Project (ASP)
`of the National Institute of Neurological a n d Communi-
`cative Disorders and Stroke at the National Institutes of
`H e a l t h for kindly performing all t h e pharmacological
`studies. F u n d s for this project were provided by t h e Na-
`tional Institutes of Health.
`Registry No. la, 6843-45-4; lb, 74310-97-7; IC, 93860-68-5;
`ld, 2301-40-8; le, 93781-89-6; If, 93781-90-9; lg, 2221-13-8; l h ,
`93781-91-0; li, 93781-92-1; lj, 81572-14-7; l k , 93781-93-2; 11,
`81572-15-8; lm, 67337-69-3; In, 27534-86-7; lo, 93781-94-3; 2a,
`85369-76-2; 2b, 93781-95-4; 2c, 93781-96-5; 2d, 85369-80-8; 2e,
`92764-01-7; 2f, 93781-97-6; 2g, 85369-84-2; 2h, 93781-98-7; 2i,
`
`IPR2014-01126- Exhibit 1009, p. 5
`
`

`
`J. Med. Chem. 1985,28,606-612
`606
`93781-99-8; 2j, 81572-18-1; 2k, 93782-00-4; 21, 81572-19-2; 20,
`93782-01-5; 3a, 39799-77-4; 3b, 93782-02-6; 3c, 93782-03-7; 3d,
`67909-04-0; 3e, 33542-53-9; 3f, 93782-04-8; 3g, 53995-06-5; 3h,
`24631-04-7; 3i, 2032-07-7; 30, 24138-94-1; 4a, 93782-05-9; 4b,
`
`81572-20-5; 4c, 81583-49-5; 4d, 81572-22-7; 5a, 93860-69-6; 5b,
`93782-06-0; 6a, 93782-08-2; 6b, 93782-08-2; 6c, 93860-70-9; 6d,
`93782-09-3; D,L-phenylglycine methyl ester hydrochloride,
`15028-40-7; D,L-alanine methyl ester hydrochloride, 13515-97-4.
`
`I-[ 3-(Diarylamino)propyl]piperidines and Related Compounds, Potential
`Antipsychotic Agents with Low Cataleptogenic Profiles
`
`Lawrence D. Wise,*’ Ian C. Pattison,? Donald E. Butler,’ Horace A. DeWald,t Edward P. Lewis,t
`Sandra J. Lobbestael,’ Ivan C. Nordin,+ B. P, H. Posche1,f and Linda L. Coughenourt
`Departments of Chemistry and Pharmacology, Warner-LambertlParke-Davis Pharmaceutical Research, Ann Arbor,
`Michigan 48105. Received June 21, 1984
`
`On the basis of a structural model of the postsynaptic dopaminergic antagonist pharmacophore, a series of 1-[3-
`(diarylamino)propyl]piperidines and related compounds was synthesized and evaluated for potential antipsychotic
`activity. For a rapid measure of activity, the target compounds were initially screened in vitro for inhibition of
`[3H]haloperidol binding and in vivo in a test of locomotor activity. Behavioral efficacy of compounds identified
`from the initial screens was more accurately measured in rats by using a suppression of high base-line medial forebrain
`bundle self-stimulation test model. The propensity of these compounds for causing extrapyramidal side effects
`was evaluated by using a rat catalepsy method. On the basis of these test models, we have shown that the methine
`carbon of the 1-(4,4-diarylbutyl)piperidines can be advantageously replaced with a nitrogen atom. The 1-[3-(di-
`ary1amino)propyllpiperidines were less cataleptic than the corresponding 1-(4,4-diarylbutyl)piperidines. The compounds
`with the widest separation between efficacious dose and cataleptic dose are 8-[3-[bis(4-fluorophenyl)amino]-
`
`propyl]-l-phenyl-1,3,8-triazaspiro[4.5]decan-4-one (6), 1-[1-[3-[bis(4-fluorophenyl)amino]propyl]-4-piperidinyl]-
`1,3-dihydro-2H-benzimidazol-2-one (ll), l-[l-[3-[bis(4-fluorophenyl)amino]propyl]-l,2,3,6-tetrahydro-4-
`pyridinyl]-1,3-dihydro-2H-benzimidazol-2-one (22), and l-[3-[bis(4-fluorophenyl)amino]propyl]-4-(2-methoxy-
`pheny1)piperazine (26).
`
`In the past 25 years, the advent of antipsychotic drugs
`has resulted in a virtual revolution in the treatment of
`schiz0phrenia.l Although these agents have proven ben-
`eficial, their therapeutic effects are accompanied by dis-
`tinct disadvantages including extrapyramidal side effects
`(EPS) and tardive dyskinesia (TD).2 At one time, in fact,
`EPS was actually considered by many investigators as
`evidence of therapeutic efficacy. With the discovery of
`newer agents, sometimes described as atypica