AU729634B2 - Certain fused pyrrolecarboxanilides: A new class of GABA brain receptor ligands - Google Patents

Description

P/00/01i1 Regulation 3.2

AUSTRALIA

Patents Act 1990

ORIGINAL

COMPLETE SPECIFICATION a a. a.

e, a. a..

S. a STANDARD PATENT Invention Title: Receptor Ligands Certain Fused PyrrolecarboxanilIides: A New Class of GABA Brain The following statement is a full description of this invention, including the best method of performing it known to me/us: a FHPMELC699099008.8 Certain Fused Pyrrolecarboxanilides; A New Class of GABA Brain Receptor Ligands Field of the Invention This invention relates' to certain fused pyrrolecarboxanilides which selectively bind to GABAa receptors. This invention also relates to pharmaceutical compositions comprising such compounds. It further relates to the use of such compounds in treating anxiety, sleep and seizure disorders, and overdoses of benzodiazepine-type drugs, and enhancing alertness. The interaction of fused pyrrolecarboxanilides of the invention 10 with a GABA binding site, the benzodiazepines (BDZ) receptor, is described.

This interaction results in. the pharmacological activities of these compounds.

Description of the Related Art -y-Aminobutyric acid (GABA) is regarded as one of the major inhibitory amino acid transmitters in the mammalian brain. Over 30 years have elapsed since its presence in the brain was demonstrated (Roberts Frankel, J. Biol. Chem 187: 55-63. 1950; Udenfriend, J. Biol. Chem. 1.8: 65-69.

1950). Since that time, an enormous amount of effort has been devoted to -23 implicating GABA in the etiology of seizure disorders. sleep, anxiety and cognition (Tallman and Gallager, Ann. Rev. Neuroscience 8: 21-44, 1985).

Widely, although unequally, distributed through the mammalian brain.

GABA is said to be a transmitter at approximately 30% of the synapses in the brain. In most regions of the brain. GABA is associated with local inhibitory neurons and only in two regions is GABA associated with longer projections.

GABA mediates many of its actions through a complex of proteins localized both on cell bodies and nerve endings; these are called GABAa receptors.

Postsynaptic responses to GABA are mediated through alterations in chloride conductance that generally, although not invariably, lead to hyperpolarization of the cell. Recent investigations have indicated that the complex of proteins associated with postsynaptic GABA responses is a major site of action for a number of structurally unrelated compounds capable of modifying postsynaptic responses to GABA. Depending on the mode of interaction, these compounds are capable of producing a spectrum of activities (either sedative, anxiolytic, and anticonvulsant, or wakefulness, seizures, and anxiety).

1,4-Benzodiazepines continue to be among the most widely used drugs in the world. Principal among the benzodiazepines marketed are chlordiazepoxide, diazepam, flurazepam, and triazolam. These compounds are widely used as anxiolytics, sedative-hypnotics, muscle relaxants, and anticonvulsants. A number of these compounds are extremely potent drugs; such potency indicates a site of action with a high affinity and specificity for individual receptors. Early electrophysiological studies indicated that a major action of benzodiazepines was enhancement of GABAergic inhibition.

The benzodiazepines were capable of enhancing presynaptic inhibition of a monosynaptic ventral root reflex, a GABA-mediated event (Schmidt et al., S' 1967, Arch. Exp. Path. Pharmakol. 258 69-82). All subsequent electrophysiological studies (reviewed in Tallman et al. 1980, Science 207: 274-81, Haefley et al., 1981, Handb. Exptl. Pharmacol. 11: 95-102) have generally confirmed this finding, and by the mid-1970s, there 20 was a general consensus among electrophysiologists that the benzodiazepines could enhance the actions of GABA.

S* With the discovery of the "receptor" for the benzodiazepines and the subsequent definition of the nature of the interaction between GABA and the benzodiazepines, it appears that the behaviorally important interactions 25 of the benzodiazepines with different neurotransmitter systems are due in a large part to the enhanced ability of GABA itself to modify these systems.

Each modified system, in turn, may be associated with the expression of a behavior.

Studies on the mechanistic nature of these interactions depended on the demonstration of a high-affinity benzodiazepine binding site (receptor).

Such a receptor is present in the CNS of all vertebrates phylogenetically newer than the boney fishes (Squires Braestrup 1977, Nature 166: 732-34, Mohler Okada, 1977. Science 198: 854-51, Mohler Okada, 1977, Br. J.

Psychiatry 133: 261-68). By using tritiated diazepam, and a variety of other compounds, it has been demonstrated that these benzodiazepine binding sites fulfill many of the criteria of pharmacological receptors; binding to these sites in vitro is rapid, reversible, stereospecific, and saturable. More importantly, highly significant correlations have been shown between the ability of benzodiazepines to displace diazepam from its binding site and activity in a number of animal behavioral tests predictive of benzodiazepine .3 potency (Braestrup Squires 1978, Br. J. Psychiatry 133: 249-60, Mohler Okada. 1977. Science 198: 854-51. Mohler Okada, 1977, Br. J. Psychiatry 133: 261-68). The average therapeutic doses of these drugs in man also correlate with receptor potency (Tallman et al. 1980, Science 207: 274-281).

In 1978, it became clear that GABA and related analogs could interact at the low affinity (1 mM) GABA binding site to enhance the binding of benzodiazepines to the clonazepam-sensitive site (Tallman et al. 1978, Nature.

274: 383-85). This enhancement was caused by an increase in the affinity of the benzodiazepine binding site due to occupancy of the GABA site. The data were interpreted to mean that both GABA and benzodiazepine sites were allosterically linked in the membrane as part of a complex of proteins. For a number of GABA analogs, the ability to enhance diazepam binding by 50% of maximum and the ability to inhibit the binding of GABA to brain membranes by 50% could be directly correlated. Enhancement of benzodiazepine binding by GABA agonists is blocked by the GABA receptor antagonist S°bicuculline; the stereoisomer bicuculline is much less active (Tallman et al., 1978, Nature, 274: 383-85).

Soon after the discovery of high affinity binding sites for the benzodiazepines, it was discovered that a triazolopyridazine could interact with benzodiazepine receptors in a number of regions of the brain in a manner consistent with receptor heterogeneity or negative cooperativity.

;In these studies. Hill coefficients significantly less than one were observed in a number of brain regions, including cortex, hippocampus, and striatum.

In cerebellum, triazolopyridazine interacted with benzodiazepine sites with 25 a Hill coefficient of I (Squires et al., 1979, Pharma. Biochem. Behav. 10_Q.: 825- Klepner et al. 1979, Pharmacol. Biochem. Behav. 1 1: 457-62). Thus, multiple benzodiazepine receptors were predicted in the cortex, hippocampus, striatum, but not in the cerebellum.

Based on these studies, extensive receptor autoradiographic localization studies were carried out at a light microscopic level. Although receptor heterogeneity has been demonstrated (Young Kuhar 1980, J.

Pharmacol. Exp. Ther. 212: 337-46, Young et al., 1981 J. Pharmacol Exp. ther 216: 425-430, Niehoff et al. 1982, J. Pharmacol. Exp. Ther. 221: 670-75), no simple correlation between localization of receptor subtypes and the behaviors associated with the region has emerged from the early studies. In addition, in the cerebellum, where one receptor was predicted from binding studies, autoradiography revealed heterogeneity of receptors (Niehoff et al., 1982, J. Pharmacol. Exp. Ther. 221: 670-75).

A physical basis for the differences in drug specificity for the two apparent subtypes of benzodiazepine sites has been demonstrated by q Sieghart Karobath, 1980, Nature 286: 285-87. Using gel electrophoresis in the presence of sodium dodecyl sulfate, the presence of several molecular weight receptors for the benzodiazepines has been reported. The receptors were identified by the covalent incorporation of radioactive flunitrazepam.

a benzodiazepine which can covalently label all receptor types. The major labeled bands have molecular weights of 50,000 to 53,000, 55,000, and 57,000 and the triazolopyridazines inhibit labeling of the slightly higher molecular weight forms (53,000, 55,000, 57,000) (Seighart et al. 1983, Eur. J.

Pharmacol. 88: 291-99).

At that time, the possibility was raised that the multiple forms of the receptor represent "isoreceptors" or multiple allelic forms of the receptor (Tallman Gallager 1985, Ann. Rev. Neurosci. 21-44). Although common for enzymes, genetically distinct forms of receptors have not generally been described. As we begin to study receptors using specific radioactive probes and electrophoretic techniques, it is almost certain that isoreceptors will emerge as important in investigations of the etiology of psychiatric disorders in people.

The GABAa receptor subunits have been cloned from bovine and human cDNA libraries (Schoenfield et al., 1988; Duman et al., 1989). A 20 number of distinct cDNAs were identified as subunits of the GABAa receptor complex by cloning and expression. These are categorized into B, 5, and provide a molecular basis for the GABAa receptor heterogeneity and distinctive regional pharmacology (Shivvers et al., 1980: Levitan et al., 1989). The y subunit appears to enable drugs like benzodiazepines to modify the GABA responses (Pritchett et al., 1989). The presence of low Hill coefficients in the binding of ligands to the GABAa receptor indicates unique profiles of subtype specific pharmacological action.

Drugs that interact at the GABAa receptor can possess a spectrum of pharmacological activities depending on their abilities to modify the actions of GABA. For example, the beta-carbolines were first isolated based upon their ability to inhibit competitively the binding of diazepam to its binding site (Nielsen et al., 1979, Life Sci. 679-86). The receptor binding assay is not totally predictive about the biological activity of such compounds; agonists, partial agonists, inverse agonists, and antagonists can inhibit binding. When the beta-carboline structure was determined, it was possible to synthesize a number of analogs and test these compounds behaviorally. It was immediately realized that the beta-carbolines could antagonize the actions of diazepam behaviorally (Tenen Hirsch, 1980, Nature 288: 609-10).

In addition to this antagonism, beta-carbolines possess intrinsic activity of their own opposite to that of the benzodiazepines; they become known as inverse agonists.

In addition, a number of other specific antagonists of the benzodiazepine receptor were developed based on their ability to inhibit the binding of benzodiazepines. The best studied of these compounds is an imidazodiazepine (Hunkeler et al., 1981, Nature 290: 514-516). This compound is a high affinity competitive inhibitor of benzodiazepine and betacarboline binding and is capable of blocking the pharmacological actions of both these classes of compounds. By itself, it possesses little intrinsic pharmacological activity in animals and humans (Hunkeler et al., 1981, Nature 290: 514-16; Darragh et al., 1983, Eur. J. Clin. Pharmacol. 14: 569-70).

When a radiolabeled form of this compound was studied (Mohler Richards, 1981, Nature 294: 763-65), it was demonstrated that this compound would interact with the same number of sites as the benzodiazepines and beta- 15 carboiines, and that the interactions of these compounds were purely competitive. This compound is the ligand of choice for binding to GABAa receptors because it does not possess receptor subtype specificity and measures each state of the receptor.

The study of the interactions of a wide variety of compounds similar to the above has led to the categorizing of these compounds. Presently, those compounds possessing activity similar to the benzodiazepines are called agonists. Compounds possessing activity opposite to benzodiazepines are called inverse agonists, and the compounds blocking both types of activity have been termed antagonists. This categorization has been developed to 25 emphasize the fact that a wide variety of compounds can produce a spectrum of pharmacological effects, to indicate that compounds can interact at the same receptor to produce opposite effects, and to indicate that betacarbolines and antagonists with intrinsic anxiogenic effects are not synonymous.

A biochemical test for the pharmacological and behavioral properties of compounds that interact with the benzodiazepine receptor continues to emphasize the interaction with the GABAergic system. In contrast to the benzodiazepines, which show an increase in their affinity due to GABA (Tallman et al., 1978, Nature 274: 383-85, Tallman et al., 1980, Science 207: 274- 81), compounds with antagonist properties show little GABA shift change in receptor affinity due to GABA) (Mohler Richards 1981, Nature 294: 763-65), and the inverse agonists actually show a decrease in affinity due to GABA (Braestrup Nielson 1981, Nature 294: 472-474). Thus, the GABA shift predicts generally the expected behavioral properties of the compounds.

(0 Various compounds have been prepared as benzodiazepine agonists and antagonists. "For Example, U.S. Patents Nos. 3.455.943. 4.435,403, 4.596.808, 4.623,649, and 4,719,210, German Patent No. DE 3.246,932, and Liebigs Ann.

Chem. 1986, 1749 teach assorted benzodiazepine agonists and antagonists and related anti-depressant and central nervous system active compounds. U.S.

Patent No. 3.455,943 discloses compounds of the formula: wherein RI is a member of the group consisting of hydrogen and lower alkoxy; R2 is a member of the group consisting of hydrogen and lower alkoxy; R3 is a member of the group consisting of hydrogen and lower alkyl; and X is a divalent radical selected from the group consisting of Y NH lower alkyl "K I lower alkyl lower alkyl and

N

lower alkyl and the non-toxic acid addition salts thereof.

U.S. Patent No. 4,435,403 teaches compounds of the formula:

Y

wherein RC is hydrogen, lower alkyl, alkoxyalkyl of up to 6 C-atoms, cycloalkyl of 3-6 C-atoms, arylalkyl of up to 8 C-atoms, or (CH2)nOR2 wherein

R

2 0 is alkyl of up to 6 C-atoms, cycloalkyl of 3-6 C-atoms or arylalkyl of up to T7 8 C-atoms and n is an integer of 1 to 3; Y is oxygen, two hydrogen atoms or NOR1, wherein RI is hydrogen, lower alkyl. aryl or arylalkyl of up to 6 Catoms. COR2, wherein R 2 is lower alkyl of up to 6 C-atoms, or Y is CHCOOR 3 wherein R 3 is hydrogen or lower alkyl or Y is NNR 4

R

5 wherein R 4 and R can be the same or different and each is hydrogen, lower alkyl, C6-10-aryl, C7-10-arylalkyl or CONR 6

R

7 wherein R 6 and R 7 can be the same or different and each is hydrogen or lower alkyl or R 4 and R 5 together with the connecting N-atom, form a 5- or 6-membered heterocyclic ring which optionally may also contain an 0-atom or up to 3 N-atoms and which optionally may be substituted by a lower alkyl group; Z is hydrogen, or alkoxy or aralkoxy each of up to 10 C-atoms and each optionally substituted by hydroxy, or Z is alkyl of up to 6 C-atoms, C6-10-aryl or C7-10-arylalkyl each of which may optionally be substituted by a COOR 8 or a CONR 9 R 1 0 group, wherein R 8 is alkyl of up to 6 C-atoms, and R 9 and R 1 0 can be the 15 same or different and each is hydrogen or alkyl of up to 6 C-atoms; or Z is

NR

9

R

1 0 wherein R 9 and RIO are as defined above; or Z is NR 1 1

CHR

1 2 R 13wherein R I and R 12 each is hydrogen or together form a N=C double bond, wherein RI 3 is C-1 0-alkyl or NR 1 4 R 15, wherein RI 4 and R 1 5 are the same or different and each is hydrogen. OH or alkyl or alkoxy each of up to 6 Catoms, or wherein R 1 2 and R13 together are oxygen, in which case, R 1 1 is hydrogen; or Z is COOR 2 wherein R 2 is as defined above; or Y and Z, together with the connecting C-atom. may form a 5- or 6-membered heterocyclic ring which contains an 0-atom, adjoining 0- and N-atoms or up to 4 N atoms and which optionally may be substituted by a lower alkyl group, hydroxy or oxo.

U.S. Patent No. 4,596,808 discloses compounds of the formula: wherein R A is H, F, CI, Br, 1, N02. CN, CH3, CF3, SCH3, NR 16

R

17 or NHCOR 16, wherein R 1 6 of R 1 7 are the same or different and each is hydrogen or alkyl, alkenyl or alkynyl each of up to 6 C-atoms, arylalkyl or cycloalkyl each of up to 10 C-atoms, or wherein R 1 6 and RI7 together form a saturated or unsaturated 3-7 membered heterocyclic ring.

U.S. Patent No. 4,623,649 teaches compounds of the formula: wherein R 3 is an oxadiazolyl residue of the formula O-

N

9* wherein R 5 stands for lower alkyl of up to 3 carbon atoms or an ester -C02R 6 with R 6 being hydrogen or lower alkyl of up to 3 carbon atoms, R 4 is hydrogen, lower alkyl of up to 3 carbon atoms, or CH20R 9 wherein R 9 is lower alkyl of up to 3 carbon atoms, RA is phenyl or a hydrocarbon residue containing 2-10 carbon atoms which can be cyclic or acyclic, saturated or unsaturated, branched or unhranched, and which can optionally be substituted by oxo, formyl OH. 0-alkyl of up to 3 carbon atoms or phenyl, and wherein in a cyclic hydrocarbon residue, a CH2-group can be replaced by oxygen.

U.S. Patent No. 4,719,210 discloses compounds of the formula: R R 2

RR

N H

RI

wherein R 1 is hydrogen or a protecting group, R 2 is -CH=CR4 or -C=CR 4

R

4 is hydrogen or halogen, R 3 is hydrogen, lower alkyl or lower alkoxyalkyl, R A is, inter alia, hydrogen, OR 7 lower alkyl, which optionally is substituted with aryl, lower alkoxy or NR 5

R

6

R

5 and R 6 can be the same or different and in each case is hydrogen, lower alkyl or together with the 10 nitrogen atom a 5-6 member ring, which can contain another heteroatom.

R 7 is lower alkyl, optionally substituted aryl or arylalkyl, and each compound can contain one or more RA radicals which are not hydrogen.

These compounds differ from the compounds of the present invention. These U.S. Patents teach carbocyclic compounds having pyridine or piperidine rings but lacking the pyrimidine ring present in the compounds of the present invention.

German Patent No. DE 3,246,932 discloses compounds of the formula:

R

1

N

H

wherein R halogen, N02, CO2H, modified CO2H, R 2 0, R2S(O)n; n 0-2; and RI H, alkyl, cycloalkyl, arylalkyl, aryl, CO2H, amino

R

2 0, R2S(0)n. However no examples were exemplified in this patent with R1-aryl.

Liebigs Ann. Chem. 1986, 1749-1764 teaches compounds of the formula:

R

3

RX\

N H

H

where RX is hydrogen, methyl, benzyloxy, or methoxy, and R 3 is carboethoxy.

None of these compounds are indole-3-carboxamides and no such compounds displaying activity at GABA receptors have been described.

A variety of indole-3-carboxamides are described in the literature.

For example, J. Org. Chem., 42: 1883-1885 (1977) discloses the following compounds.

H 0 H C-N

C-N

IIH

N

N

I Ci I Br H

H

0 H 0 C-N

-N

I

I

N I H

H

it J. Heterocylic Chem., 14: 519-520 (1977) discloses a compound of the following formula: 0

H

N-

N:

H

None of these -Indole-3-carboxam ides includes an oxy substiuen-t at the 4-position of the indole ring.

a. a.

a a a a. a SUMMARY OF THE INVENTION This invention provides novel compounds of Formula I which interact with a GABAa binding site, the benzodiazepine receptor.

The invention provides pharmaceutical compositions comprising compounds of Formula I. The invention also provides compounds useful in the diagnosis and treatment of anxiety, sleep and seizure disorders, overdose with benzodiazepine drugs and for enhancement of memory. Accordingly, a broad embodiment of the invention is directed to compounds of general Formula I: 0

W

N

c H

T

I

or the pharmaceutically acceptable non-toxic salts thereof wherein: T is halogen, hydrogen, hydroxyl, amino or straight or 20 branched chain lower alkoxy having 1-6 carbon atoms; X is hydrogen, hydroxyl or straight or branched chain lower alkyl having 1-6 carbon atoms; W is phenyl, 2 or 3-thienyl, 2, 3, or 4-pyridyl or 6quinolinyl, each of which may be mono or disubstituted with halogen ,cyano, hydroxy, straight or branched chain lower alkyl having 1-6 carbon atoms, amino, mono or dialkylamino where each alkyl is independently straight or branched chain lower alkyl having 1-6 carbon atoms, straight or branched chain lower alkoxy having 1-6 carbon atoms, or NRICOR2, COR2.

CONRIR2 or C02R2 where RI and R2 are the same or different and represent hydrogen or straight or branched chain lower alkyl having 1-6 carbon atoms; and represents

R

0 or (CH,)n wherein: Y represents nitrogen or C-R 4 Z represents N-R 7 or a carbon atom substituted with R8 and R9, i.e..

C(Rs)(R9); n is 1, 2, 3, or 4; R3 is hydrogen, phenyl, 2, 3 or 4-pyridyl, straight or branched chain lower alkyl having 1-6 carbon atoms, or phenylalkyl or 2, 3 or 4-pyridylalkyl where each alkyl is straight or branched chain lower alkyl having 1-6 carbon atoms: R4 is halogen or trifluoromethyl; or -CORIO, -CO2R10, -OCOR10, or -RO1, where RO1 is hydrogen, phenyl, 2, 3 or 4-pyridyl, straight or branched chain lower alkyl having 1-6 carbon atoms, or phenylalkyl or 2, 3 or 4-pyridylalkyl where each alkyl is straight or branched chain lower alkyl having 1-6 carbon atoms; or

-CONR

1 IR12 or -(CH2)mNRllR12, where m is 0, 1, or 2: R i I represents hydrogen, straight or branched chain lower alkyl having 1-6 carbon atoms; and R12 is hydrogen, phenyl.

2, 3 or 4-pyridyl, straight or branched chain lower alkyl having 1-6 carbon atoms, or phenylalkyl or 2, 3 or 4pyridylalkyl where each alkyl is straight or branched chain lower alkyl having 1-6 carbon atoms; or NR R 12 forms a heterocyclic group which is morpholyl, piperidyl, pyrrolidyl.

or N-alkyl piperazyl; and R6 are the same or different and represent hydrogen, halogen, straight or branched chain lower alkyl having 1-6 carbon atoms, or straight or branched chain lower alkoxy having 1-6 carbon atoms; R7 is hydrogen, phenyl, 2, 3 or 4-pyridyl, straight or branched chain lower alkyl having 1-6 carbon atoms, or phenylalkyl or 2.3, or 4-pyridylalkyl where each alkyl is straight or branched chain lower alkyl having 1-6 carbon "atoms; R8 is 20 hydrogen or straight or branched chain, lower alkyl having 1-6 carbon atoms; and :R9 is

-COR

13 -C02R 1 3 or -R13, where R13 is hydrogen, phenyl, 25 2, 3 or 4-pyridyl. straight or branched chain lower alkyl having 1-6 carbon atoms, or phenylalkyl or 2, 3, or 4pyridylalkyl where each alkyl is straight or branched chain lower alkyl having 1-6 carbon atoms; or

-CONR

14

RI

5 or -(CH2)kNR14R15, where k is 0, 1, or 2; R 14 represents hydrogen, straight or branched chain lower alkyl having 1-6 carbon atoms; and R1 5 is hydrogen, phenyl, 2, 3, or 4-pyridyl, straight or branched chain lower alkyl having 1-6 carbon atoms, or phenylalkyl or 2, 3 or 4pyridylalkyl where each alkyl is straight or branched chain lower alkyl having 1-6 carbon atoms; or NRI4R15 forms a heterocyclic group which is morpholyl, piperidyl, pyrrolidyl.

or N-alkyl piperazyl.

These compounds arc highly selective agonists. antagonists or inverse agonists for GABAa brain receptors or prodrugs of agonists, antagonists or inverse agonists for GABAa brain receptors. In other words.

while the compounds of the invention all interact with GABAa brain receptors, they do display identical physiologic activity. Thus, these compounds are useful in the diagnosis and treatment of anxiety, sleep and seizure disorders, overdose with benzodiazepine drugs and for enhancement of memory. For example, these compounds can easily be used to treat overdoses of benzodiazepine-type drugs as they would competitively bind to the benzodiazepine receptor.

S BRIEF DESCRIPTION OF THE DRAWINGS Figures 1-20 show representative fused pyrr olecarboxaniljIdes of the present invention.

17 DETAILED DESCRIPTION OF THE INVENTION The novel compounds encompassed by the instant invention can be described by general formula I set forth above or the pharmaceutically acceptable non-toxic salts thereof.

In addition, the present invention encompasses compounds of Formula II.

0

S

or the pharmaceutically acceptable non-toxic salts thereof wherein W, R8 and R9 are as defined above.

The present invention also encompasses compounds of Formula Ilia and IIIb: Ilia Illb or the pharmaceutically acceptable non-toxic salts thereof wherein W, R3, and R5 are as defined above.

The present invention also encompasses compounds of Formula IV:

IV

or the pharmaceutically acceptable non-toxic salts thereof wherein W, Y.

R3, and R5 are defined above.

The present invention also encompasses compounds of Formula V: 0

W

N

R N H

N

Rs

H

V

or the pharmaceutically acceptable non-toxic salts thereof wherein W. R4, and R5 are defined above.

The invention further encompasses compounds of Formula VI: Ri16 H R19

VI

or the pharmaceutically acceptable non-toxic salts thereof where Ri6 is hydrogen, benzyl or straight or branched chain lower alkyl having 1-6 carbon atoms; R 17 is hydrogen or straight or branched chain lower alkoxy having 1-6 carbon atoms; R 18 is hydrogen, straight or branched chain lower alkozy having 1-6 carbon atoms, NRICOR2, COR2, C02R2 where RI and R2 are as defined above, cyano, or halogen; and R19 is hydrogen or 42 halogen.

The invention additionally encompasses compounds of formula

VII:

N

H

VII

or the pharmaceutically acceptable non-toxic salts thereof where R17, R18 and R19 are defined above.

The invention further encompasses compounds of Formula VIII;

F

17 *a* a a

S**

oa a *l *o *o* o *o o

VIII

where R17, R18, and R19 are defined above and R20 is hydrogen or straight or branched chain aikyl having 1-6 carbon atoms.

The invention further encompasses compounds of Formula IX;

N

Rl7 HN Nt ^H R 19

H

IX

where R17, R18. and R19 are defined above.

The invention further encompasses compounds of Formula X; x where RI6, R17, RI8, and R19 are defined above.

The invention further encompasses compounds of Formula XI; where R4, R5, R17, Rig, and R 1 9 are defined above.

The invention further encompasses compounds of Formula XII: too.

wherein W represents phenyl, 2 or 3-thienyl, 2, 3, or 4-pyridyl or 6quinolinyl, each of which may be mono or disubstituted with halogen, cyano, hydroxy, straight or branched chain lower alkyl having 1-6 carbon atoms, amino, mono or dialkylamino where each alkyl is independently straight or branched chain lower alkyl having 1-6 carbon atoms. straight or branched chain lower alkoxy having 1-6 carbon atoms, or NRICOR2, COR2, CONRIR2 or CO2R2 where RI and R2 are the same or different and represent hydrogen or straight or branched chain lower alkyl having 1-6 carbon atoms Non-toxic pharmaceutical salts include salts of acids such as hydrochloric, phosphoric, hydrobromic, sulfuric, sulfinic, formic, toluene sulfonic, hydroiodic, acetic and the like. Those skilled in the art will recognize a wide variety of non-toxic pharmaceutically acceptable addition salts.

Representative compounds of the present invention, which are encompassed by Formula I, include, but are not limited to the compounds in Figure I and their pharmaceutically acceptable salts. The present invention 15 also encompasses the acylated prodrugs of the compounds of Formula I.

Those skilled in the art will recognize various synthetic methodologies which may be employed to prepare non-toxic pharmaceutically acceptable addition salts and acylated prodrugs of the compounds encompassed by Formula I.

By lower alkyl in the present invention is meant, straight or branched chain alkyl groups having 1-6 carbon atoms, such as, for example, methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, pentyl, 2pentyl, isopentyl, neopentyl, hexyl, 2-hexyl, 3-hexyl, and 3-methylpentyl.

By lower alkoxy in the present invention is meant straight or branched chain alkoxy groups having 1-6 carbon atoms, such as, for example, methoxy, ethoxy, propoxy, isopropoxy, n-butoxy, sec-butoxy, tertbutoxy, pentoxy, 2-pentyl, isopentoxy, neopentoxy, hexoxy, 2-hexoxy, 3- •hexoxy, and 3-methylpentoxy.

By halogen in the present invention is meant fluorine, bromine, chlorine, and iodine.

By N-alkylpiperazyl in the invention is meant radicals of the formula: N N- R whcre R is a straight or branched chain lower alkyl as defined above.

The pharmaceutical utility of compounds of this invention are indicated by the following assay for GABAa receptor binding activity.

Assays are carried out as described in Thomas and Tallman Bio.

Chem. 156: 9838-9842 J. Neurosci. 3: 433-440, 1983). Rat cortical tissue is dissected and homogenized in 25 volumes of 0.05 M Tris HCI buffer (pH 7.4 at 4 0 The tissue homogenate is centrifuged in the cold (40) at 20.000 x g for 20'. The supernatant is decanted and the pellet is rehomogenized in the same volume of buffer and again centrifuged at 20,000 x g. The supernatant is decanted and the pellet is frozen at -20 0 C overnight. The pellet is then thawed and rehomogenized in 25 volume (original wt/vol) of buffer and the procedure is carried out twice. The pellet is finally resuspended in volumes (w/vol of 0.05 M Tris HCI buffer (pH 7.4 at 40 0

C).

Incubations contain 100 ml of tissue homogenate, 100 ml of radioligand 0.5 nM 3 H-RO15-1788 3 H-Flumazenil] specific activity Ci/mmol), drug or blocker and buffer to a total volume of 500 ml.

Incubations are carried for 30 min at 4 0 C then are rapidly filtered through GFB filters to separate free and bound ligand. Filters are washed twice with fresh 0.05 M Tris HCI buffer (pH 7.4 at 4 0 C) and counted in a liquid scintillation counter. 1.0 mM diazepam is added to some tubes to determine nonspecific binding. Data are collected in triplicate determinations, averaged and inhibition of total specific binding is calculated. Total Specific Binding Total Nonspecific. In some cases, the amounts of unlabeled drugs is varied and total displacement curves of binding are 20 carried out. Data are converted to a form for the calculation of. IC50 and Hill Coefficient Data for the compounds of this invention are listed in Table I.

°oo..o TABLE I Compound Number 1 .004 2 .430 6 .001 8 .025 12 .028 15 14 .133 17 .470 1.

1 Compound numbers relate to compounds shown in the figures.

The compounds of general formula I may be administered orally, topically, parenterally, by inhalation or spray or rectally in dosage unit formulations containing conventional non-toxic pharmaceutically acceptable carriers, adjuvants and vehicles. The term parenteral as used herein includes subcutaneous injections, intravenous, intramuscular, intrasternal injection or infusion techniques. In addition, there is provided a pharmaceutical formulation comprising a compound of general formula I and a pharmaceutically acceptable carrier. One or more compounds of general formula I may be present in association with one or more non-toxic pharmaceutically acceptable carriers and/or diluents and/or adjuvants and if desired other active ingredients. The pharmaceutical compositions containing compounds of general formula I may be in a form suitable for oral use, for example, as tablets, troches, lozenges, aqueous or oily suspensions, dispersible powders or granules, emulsion, hard or soft capsules, or syrups or elixirs.

Compositions intended for oral use may be prepared according to any method known to the art for the manufacture of pharmaceutical compositions and such compositions may contain one or more agents selected from the group consisting of sweetening agents, flavoring agents.

coloring agents and preserving agents in order to provide pharmaceutically elegant and palatable preparations. Tablets contain the active ingredient in admixture with non-toxic pharmaceutically acceptable excipients which are suitable for the manufacture of tablets. These excipients may be for example, inert diluents, such as calcium carbonate, sodium carbonate, lactose, calcium phosphate or sodium phosphate; granulating and disintegrating agents, for example, corn starch, or alginic acid; binding agents, for example starch, gelatin or acacia, and lubricating agents, for example magnesium stearate, stearic acid or talc. The tablets may be uncoated or they may be coated by known techniques to delay disintegration and absorption in the gastrointestinal tract and thereby provide a sustained action over a longer period. For example, a time delay material such as glyceryl monosterate or glyceryl distearate may be employed.

Formulations for oral use may also be presented as hard gelatin capsules wherein the active ingredient is mixed with an inert solid diluent, for example, calcium carbonate, calcium phosphate or kaolin, or as soft gelatin capsules wherein the active ingredient is mixed with water or an oil medium, for example peanut oil, liquid paraffin or olive oil.

Aqueous suspensions contain the active materials in admixture with excipients suitable for the manufacture of aqueous suspensions. Such excipients are suspending agents. for example sodium carboxymethylcellulose, methylcellulose, hydropropylmethylcellulose.

sodium alginate, polyvinyipyrrolidone, gum tragacanth and gum acacia; dispersing or wetting agents may be a naturally-occurring phosphatide, for example, lecithin, or condensation products of an alkylene oxide with fatty 25 acids, for example polyoxyethylene stearate, or condensation products of ethylene oxide with long chain aliphatic alcohols, for example heptadecaethyleneoxycetanol, or condensation products of ethylene oxide with partial esters derived from fatty acids and a hexitol such as polyoxyethylene sorbitol monooleate, or condensation products of ethylene oxide with partial esters derived from fatty acids and hexitol anhydrides, for example polyethylene sorbitan monooleate. The aqueous suspensions may also contain one or more preservatives, for example ethyl, or n-propyl phydroxybenzoate, one or more coloring agents, one or more flavoring agents, and one or more sweetening agents, such as sucrose or saccharin.

Oily suspensions may be formulated by suspending the active ingredients in a vegetable oil, for example arachis oil, olive oil, sesame oil or coconut oil. or in a mineral oil such as liquid paraffin. The oily suspensions may contain a thickening agent, for example beeswax, hard paraffin or cetyl alcohol. Sweetening agents such as those set forth above, and flavoring agents may be added to provide palatable oral preparations. These compositions may be preserved by the addition of an anti-oxidant such as ascorbic acid.

Dispersible powders and granules suitable for preparation of an aqueous suspension by the addition of water provide the active ingredient in admixture with a dispersing or wetting agent. suspending agent and one or more preservatives. Suitable dispersing or wetting agents and suspending agents are exemplified by those already mentioned above. Additional excipients, for example sweetening, flavoring and coloring agents, may also be present.

Pharmaceutical compositions of the invention may also be in the form of oil-in-water emulsions. The oily phase may be a vegetable oil, for example olive oil or arachis oil, or a mineral oil, for example liquid paraffin or mixtures of these. Suitable emulsifying agents may be naturallyoccurring gums, for example gum acacia or gum tragacanth, naturally- 15 occurring phosphatides, for example soy bean, lecithin, and esters or partial esters derived from fatty acids and hexitol, anhydrides, for example sorbitan monoleate, and condensation products of the said partial esters with ethylene oxide. for example poiyoxyethylene sorbitan monoleate. The *o oemulsions may also contain sweetening and flavoring agents.

Syrups and elixirs may be formulated with sweetening agents, for example glycerol. propylene glycol, sorbitor or sucrose. Such formulations may also contain a demulcent, a preservative and flavoring and coloring agents. The pharmaceutical compositions may be in the form of a sterile injectable aqueous or oleaginous suspension. This suspension may be formulated according to the known art using those suitable dispersing or wetting agents and suspending agents which have been mentioned above.

The sterile injectable preparation may also be sterile injectable solution or *suspension in a non-toxic parentally acceptable diluent or solvent, for example as a solution in 1,3-butanediol. Among the acceptable vehicles and solvents that may be employed are water, Ringer's solution and isotonic sodium chloride solution. In addition, sterile, fixed oils are conventionally employed as a solvent or suspending medium. For this purpose any bland fixed oil may be employed including synthetic mono-or diglycerides. In addition, fatty acids such as oleic acid find use in the preparation of injectables.

The compounds of general formula I may also be administered in the form of suppositories for rectal administration of the drug. These compositions can be prepared by mixing the drug with a suitable nonirritating excipient which is solid at ordinary temperatures but liquid at the rectal temperature and will therefore melt in the rectum to release the drug.

Such materials are cocoa butter and polyethylene glycols.

Compounds of general formula I may be administered parenterally in a sterile medium. The drug, depending on the vehicle and concentration used, can either be suspended or dissolved in the vehicle. Advantageously.

adjuvants such as local anaesthetics, preservatives and buffering agents can be dissolved in the vehicle.

Dosage levels of the order of from about 0.1 mg to about 140 mg per kilogram of body weight per day are useful in the treatment of the aboveindicated conditions (about 0.5 mg to about 7 g per patient per day). The amount of active ingredient that may be combined with the carrier materials to produce a single dosage form will vary depending upon the host treated and the particular mode of administration. Dosage unit forms will generally contain between from about I mg to about 500 mg of an active ingredient.

*I

*It will be understood, however, that the specific dose level for any S* particular patient will depend upon a variety of factors including the S.activity of the specific compound employed, the age, body weight, general •health, sex, diet, time of administration, route of administration, and rate of 20 excretion, drug combination and the severity of the particular disease undergoing therapy.

An illustration of the preparation of compounds of the present invention is given in Schemes I and II.

**o Sc hemine 0 z

(OH

(CH2)n

O

1) KOH, MeOH 2) BrCH 2 COCO,Et 3) NaGH 1) AcCi, EtOH 2) NH 4 OAc, DMIF 3) 5N NaOH WNH2, EDCI, aq. dioxane where: W, Z, and ii are as defined above.

Scheme II R3

O

0 1) HC(NMe,) 3

DMF

2) H,NNHCONH_, R s NO 2

NHCONH

2 e Reduction 1) C1 3

CCOCI

2) NaOMe, MeOH 3) NaOH

R

6

N

Re

H

EDCI

for R 3

=CH

2 Ph: H2,Pd/C, EtOH

S.

W, R3, Y, R5. and R6 are as defined above.

Those having skill in the art will recognize that the starting materials may be varied and additional steps employed to produce compounds encompassed by the present invention, as demonstrated by the following examples. In some cases protection of certain reactive functionalities may be necessary to achieve some of the above transformations. In general the need for such protecting groups will be apparent to those skilled in the art of organic synthesis as well as the conditions necessary to attach and remove such groups.

The invention is illustrated further by the following examples which are not to be construed as limiting the invention in scope or spirit to the specific procedures described in them.

Example 1 0 0 OH 0 4-Oxo-4,5,6,7-tetrahydrobenzofuran-3-carboxylic acid was prepared according to a modified literature procedure 1 To a stirring solution of potassium hydroxide 28.06 g, 0.5 mol) in methanol (100 mL) under Nitrogen at 00 C was added dropwise a solution of cyclohexanedione (56.07 g, 0.5 mol) in methanol (100 mL). The mixture was stirred at 0 C for 0.5 h, then a solution of ethyl bromopyruvate (66 mL, 0.525 mol) in methanol (100 mL) was added dropwise. After allowing the mixture to stir at ambient temperature for 17 h, a 50% aqueous sodium hydroxide solution (60 mL) was added dropwise and stirring continued an additional 7 h. After dilution with 15 water, the solution was acididfied and the methanol removed in vacuo. Ice water was added and the precipitate filtered and dried in vacuo to afford 4- Oxo-4,5,6,7-tetrahydrobenzofuran-3-carboxylic acid.

20 Example 2 0 -OH

N

H

To a stirring suspension of 4-Oxo-4,5,6,7-tetrahydrobenzofuran- 3 carboxylic acid (28.2 g, 157 mmol) in ethanol (500 mL) under Nitrogen at ambient temperature was added acetyl chloride(56 mL, 783 mmol) dropwise.

After stirring I h, the solution was then heated at reflux for 1 h. The solution was cooled and concentrated in vacuo. The residue was taken up into dichloromethane, washed with aqueous sodium bicarbonate, washed quickly with IN sodium hyroxide, dried over magnesium sulfate, filtered, and concentrated in vacuo to afford Ethyl 4-oxo-4,5.6.

7 36 tetrahydrobenzofuran-3-carboxylate as an oil. A mixture of this ester (24.46 g, 117 mmol) and ammonium acetate (15.85 g, 206 mmol) in dimethylformamide (225 mL) was heated at 100° C under Nitrogen for 1.25 h.

The mixture was cooled, poured into ice water, and extracted two times with dichloromethane. The combined organic extracts were washed with water, dried over magnesium sulfate, filtered, concentrated in vacuo, and the residue triturated with ether to give Ethyl 4 -oxo- 4 ,5,6,7-tetrahydroindole-3carboxylate. A mixture of this ester (11.31 g, 55 mmol) in 5N sodium hydroxide (200 mL) and ethanol (20 mL) was heated at reflux for Ih. After cooling in an ice bath, the mixture was acididified with concentrated hydrochloric acid, the precipitate filtered, rinsed with ice water, and dried in vacuo to afford 4 -Oxo- 4 ,5, 6 ,7-tetrahydro-lH-indole-3-carboxylic acid.

Example 3 o N 0 -N Compound 1 20 A mixture of 4 -Oxo-4,5,6,7tetrahydroHindole-3-carboxylic acid (179 mg, I mmol), p -anisidine (616 mg, 5 mmol). and 1-(3dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride [EDCI] (959 mg, mmol) in 50% aqueous 1,4-dioxane (10 mL) was stirred at ambient temperature for 17 h. After concentrating in vacuo, the residue was taken up in 10% methanol in ethyl acetate, washed with 1.3M hydrochloric acid then with aqueous sodium bicarbonate, dried over magnesium sulfate, filtered, and concentrated in vacuo. Recrystallization from ethyl acetate afforded

N-(

4 Methoxyphenyl)-4-oxo-4,5,6,7-tetrahydro-lH-indole-3-carboxyH-indole-3carboxamide (Compound yl)-3-ethylcarbodiimide mp 219-220 0

C.

3O Example 4

CH

3 0

H

A solution of 2-methyl-3-nitroanisole (9.96 g, 60 mmol) and tris(dimethylamino)methane (15.5 mL, 89 mmol) in dimethylformamide mL) was heated at 1150C under Nitrogen for 3 h. After cooling to ambient temperature a solution of semicarbazide hydrochloride (6.98 g, 63 mmol) and concentrated hydrochloric acid (5.3 mL) in water (75 mL) was added dropwise with vigorous stirring. The mixture was cooled further in an ice bath and the precipitate filtered, rinsed with ice water followed by, in sequence, cold 50% aqueous ethanol, cold ethanol, and ether, then dried to give semicarbazone. The semicarbazone was suspended with 10% Palladium on Carbon (3 g) in ethanol (120 mL) in a Parr shaker and placed under a Hydrogen atmosphere (50 psi) for 16 h. The mixture was filtered through Ceiite and concentrated in vacuo. The residue was triturated with ice water.

filtered and dried to give 4-methoxy-lH-indole.

o• Example

N

H

A solution of 2-nitro-6-benzyloxytoluene (13.0 g, 53 mmol) and tris(dimethylamino)methane (13.9 mL. 80 mmol) in dimethylformamide mL) was heated at 115°C under Nitrogen for 3 h. Upon cooling to ambient temperature, a solution cf semicarbazide hydochloride (6.26 g, 56 mmol) and o* concentrated hydrochloric acid (4.8 mL) in water (70 .mL) was added dropwise with vigorous stirring. Ethanol (25 mL) was added and the heterogeneous mixture stirred for 2 h. After cooling in an ice bath, the precipitate was filtered, rinsed with, in sequence, ice water, cold aqueous ethanol, cold ethanol, then ether and dried to give semicarbazone.

A slurry of semicarbazone (17.64 g, 54 mmol), Raney Nickel (18 g of a aqueous slurry) in 1:1 tetrahydrofuran:methanol (145 mL) was heated to 0 C. Hydrazine monohydrate was added in four equal portions (2.7 mL each) at 0.5 h intervals. The mixture was cooled, then filtered through a small pad of silica gel using ether. The filtrate was dried over magnesium sulfate, filtered, concentrated in vacuo, and the residue purified by flash chromatography to afford 4-benzyloxy-lH-indole as a low melting solid.

-21 Example 6 0

CH

3 0

OH

H

To a solution of 4-methoxy-lH-indole (7.15 g, 49 mmol) and pyridine (19.7 mL, 243 mmol) in dichloromethane (50 mL) at 0°C under Nitrogen was added dropwise a solution of trichloroacetyl chloride (27.1 mL, 243 mmol) in dichloromethane (50 mL). After stirring at 0OC for an additional 1.5 h. the 10 mixture was concentrated in vacuo. The residue was taken up in the minimal volume of methanol necessary and placed in a freezer overnight.

The precipitate was filtered, rinsed well with methanol, and dried to yield 4methoxy-3-trichloroacetyl-lH-indole. To a stirring solution of sodium methoxide (3.5 mL of a 25 weight solution in methanol) in methanol (200 mL) at ambient temperature was added 4 -niethoxy-3-trichloroacetyl-lHindole (9.07 g, 31.0 mmol) in portions over 0.75 h. After stirring an additional 0.75 h, the mixture was cooled in an ice bath, diluted with ice water, acidified with concentrated hydrochloric acid, and the methanol removed in vacuo. The resulting heterogeneous mixture was cooled in an ice bath, the precipitate filtered, rinsed with water, and dried to afford methyl 4-methoxy-1H-indole-3-carboxylic ester. A slurry of this ester (5.6 g 27 mmol) in 50% aqueous sodium hydroxide (50 mL) and methanol (50 mL) go• was stirred at ambient temperature for 19 h. The mixture was cooled in an ice bath, acidified with concentrated hydrochloric acid, the precipitate filtered, rinsed with ice water, and dried to afford 4-methoxy-1H-indole-3carboxylic acid.

2~(7/ Example 7 OMe HO N F

H

N

H

(Compound 2)

N-(

2 -Fluoro-4-methoxyphenyl)-4.benzyloxy- 1 H-indole-3 *carboxamide (1.34 g. 3.4 mmol), prepared using the method above, was *slurried with 10% Palladium on Carbon (134 mg) in ethanol (35 mL) in a Parr bottle and placed under a Hydrogen atmosphere (50 psi) for 5 h.

Methanol (5 ml) was added and the mixture returned to the Hydrogen atmosphere for an additional 18 h. The solution was filtered through Celite, concentrated in i'acuo, and the residue purified by flash chromatography to *.afford N-2fur--ehxpey)4hyrx-Hidl--abxmd (Compound 2) as a beige solid; mp 259-26]'C Example 8 The following compounds were prepared essentially according to the procedures described in Examples 1-6:

N-(

4 -Ethoxyphenyl)-4-oxo..4,5,6,7-tetrahydro IH-indole-3carboxamide (Compound mp 217-2180C

N-(

4 -Ethoxyphenyl)-4methoxyIHindole-3carboxanmide (Compound mp 259-261'C

N-(

3 -Ethoxyphenyl)-4-methoxyIH-indole-3carboxamide (Compound N-(2-Fluoro-4-mcthoxypheny I)-4-oxo-4,5,6,7-tetrahydro- IHindole-3-carboxamide (Compound 6).

N-(2-Fluoro-4-ethoxyphcnyI)-4-oxo-4,5,6,7-tetrahydro- 1 Hindole-3-carboxamide (Compound 7).

N-(4-Methoxyphenyl)-4-methoxy- I1H-indole-3-carboxamide (Compound 8).

0 N-(2-Fluoro-4-ethoxyphenyl)-4-methoxy-1H-indole-3carboxamide (Compound 9).

*9 C C CC C.

C

C

a

C

CC..

C C C. (h carboxamide 0i) carboxamide (j 20 carboxamide (k) c arbo xam ide N-(4-Cyanophenyl)-4-oxo-4,5 .6,7-tetrahyd ro- 1 H -indole -3 (Compound 10); mp 287-288'C.

N-(3-Methoxypheny I)-4-oxo -4,5,6 .7-tetrahydro- 1 H -indole-3 (Compound 11); mp 220-223'C N-(4-Acetamidophenyl)-4-o xo-4,5 .6,7-tetrahydro- 1 H- indole-3 (Compound 12); mp 339-341'C.

N-(4-Chlorophenyl)-4-oxo-4,5 .6,7 -tetrahyd ro- 1 H- indol e-3 (Compound 13).

C.

C C

CC..

C

CCC...

C

(I)

carboxamide (in) carboxamide N-(2-Fluoro-4-methoxyphenyl)-4-benzyloxy- 1H-indole-3 (Compound 14).

N-(4-acetylphenyl)-4-oxo-4 .5 6,7-tetrahydro- IH-indole-3 (Compound n) N-(2-Fluoro-5-methoxyphenyl)-4-oxo-4,5,6,7-tetrahydro- 1Hindole-3-carboxamide (Compound 16).

N-(6-quinolinyl)-4-oxo-4,5,6,7-tetrahydro-1H-indole-3carboxamide (Compound 17); mp 319-321'C.

N-(4-Carbomethoxyphenyl)-4-oxo-4.5.6,7-tetrahydro- 1 Hindolc-3-carboxamide (Compound 18); mp 261-2620C

N-(

4 -Carboxyp hen),I) -4-oxo4,.6,7-tetrahydro1 H-indoIc-3..

carboxamide (Compound 19).

r) (Compound 2

(S)

carboxamide Mt c arbo xam ide u) carboxamide 09 S p *5 p p. p p *5 p p *5 pp

S

p. p p

(V)

carboxamide

(W)

carboxamide N-(4-Ethoxyphenyl )-4-hyd roxy- IH-indoic-3-carboxaniide N-(3-ethoxypheny I)-4-oxo-4,5,6 .7-tetrahydro- 1H-indole-3- (Compound 21).

N-(

2 -fluoro-4-methoxyphenyl)-4-benzyloxy I H-indole-3 (Compound 22).

N-(4-isopropoxyphenyl)-4-oxo-4,5 .6,7-tetrahydro- IH- indolc-3 (Compound 23).

N-(4-fluorophenyl )-4-oxo -4,5 .6,7-tetrahydro- 1H-indole -3- (Compound 24).

N-(4-pyridy I)-4-ox 0-4.5,6.7-tetrahydro- IH-indole-3- (Compound N-(4-hydroxyphenyl)-4-oxo-4,5 .6,7-tetrahydro- 1H-indole-3 (Compound 26).

N-(4-aminopheny I)-4-oxo-4.5 .6 7-tetrahydro- 1H -indole-3 (Compound 27).

N-(3 -pyridyl)-4-oxo-4,5 .6,7-tetrahydro- 1H-indole-3- (Compound 28).

(X)

carboxamide (y) carboxamide Wz carboxamide (aa) N-( 4 -(methoxymethyl)phenyl)-4-oxo-4,5,6,7-tetrahydro-1Hindole-3-carboxamide (Compound 29).

(ab) N-(3-fluoro-4-methoxyphenyl)-4-oxo-4,5,6.7-tetrahydroIHindole-3-carboxamide (Compound (ac) (compound 31 (d cmon 2 (ad) (compound 32) (ad) (compound 33) (ac) (compound 34)

H

0.

-0 0

OSOO

6 @0 @6 S

OSSO

OS

@0 S 6@ 6 0@ 00 @0 0

S

*6 0 0S

SS

5000 0@ 0@ 0 0@ *0 0 @605 0

*SS@

*5 S. 0

S

000000

S

H

H

(af) N-( 2 -fluoro-4-isopropoxypheny)4oxo456,7etrahydroIHindole-3-carboxamide (Compound (ag) N-(4-fluorophenyl)-4-oxo-5 .5-dimethyl-4,5,6,7-tetrah ydro- IH- 10 indole-3-carboxamide (Compound 36).

(ah) N-(2-fluoro-4-methoxyphenyl)4oxo5,5-dimethylI4,5,6,7tetrahydro-1H-indole-3-carboxamide (Compound 37).

15 (ai) N-( 4 -ethoxypheny)-4-oxo55dimethy45,6,7tetrahydro. 1Hindole-3-carboxamide (Compound 38).

(aj) N-(4-(methoxymethyi)phenyl)-4oxo5,5-dimethyI-4,5,6,7.

tetrahydro- 1H-indole-3-carboxamide (Compound 39).

(ak) N-( 4 -methoxyphenyl)-4-oxo-5.S-dimethyl-4,5,6,7-tetrahydro- 1H-indole-3-carboxamide (Compound (al) N-( 2 -methoxy-5-pyridyl)-4-oxo45,67tetrahydro.I H-indole-3carboxamide (Compound 41).

(am N-( 3 4 -dihydroxypheny)-4-oxo-4,5,6,7tetrahydro IH-Indole 3-carboxamide (Compound 42).

(a n) N -ph enylI- 4 -oxo-4.5,6,7-Ltrahydro- IH-indole-3-c arbox am ide (Compound 43).

(ao) N-( 2 -pyridyl)-4-oxo-4,56,7-tetrahydrolIH-indole-3carboxamide (Compound 44).

(ap) N-( 2 -fluoro- 4 -hydroxyphenyI)-4oxo4,5,6,7-tetrahydro 1Hindole-3-carboxamide (Compound (aq) 1N-(2-fluoro-4-methoxyphenyI)-4-oxo-6,6dimethyI-4,5,6,7 tetrahydro-1H-indole-3-carboxamidc (Compound 46).

(ar) N-(2-fluoro-4-ethoxyphenyl)-4-oxo-6,6dimethyl-4,5,6,7 tetrahydro-1H-indole-3-carboxamide (Compound 47).

0* N 4 -e th o xy ph en y) -4 -ox o 6- dm eth y456,7-tect r ah y dro -IH indole-3 -carboxamide (Compound 48).

0 0* 0 (at) N-( 2 -amio-3-pyridyl)-4-oxo-467tetrahydroIH-indole-3 carboxamide (Compound 49).

o o..

00.1* (au) N meth yIp hcn y1) -4-o x o -4,5,6,7 -te trah y dro -IH in d oIe -3 carboxamide (Compound 0.0 25 (av) N-(-eh~hnI--x-.,,~erhdoHnoe carboxamide (Compound 51).

(aw) N-( 2 -amino-4-methylphenyl)-4-oxo4,5,6.7tetrahydro iRindole-3-carboxamide (Compound 52).

(ax) N-( 4 -methylaminophenyl)-4-oxo-4,5,6,7tetrahydroIH-indole- 3-carboxamide (Compound 53).

(ay) N-phenyl-4-oxo-6.6-dimethyl-4,5,6,7-tetrahydrolIH-indole-3carboxamide (Compound 54).

(az) N-( 3 -hydroxy-4-methoxyphenyl)-4-oxo4,.6,7-tetrahydrolIH indole-3-carboxamide (Compound 39 (ba) N-( 2 -f Iuorop hen yI) 4oxo467tetrahydro I H-In do Ie-3 carboxamide (Compound 56).

(bb) N-( 3 -fluoropheny)-4oxo66dimethy1.4567tetrahydroIHindole-3-carboxamide (Compound 57).

(bc) N-( 4 2 -hydroxyethoxy)phnyl4oxo-4,5,6,7-tetrahydro..IHindole-3-carboxamidc (Compound 58).

(bd) N-( 2 -thienyl).4-oxo-4,5,67tetrahydro-IH-indole-3 carboxamide (Compound 59).

(be) N-( 4 2 -methoxyethoxy)phnyl)4oxo4,5,67tetrahydro-

IH-

indole-3-carboxamide (Compound (bf) N-( 2 4 -hydroxyphenyl)ethyl4oxo456,7tetrahydroIHindole-3-carboxamide (Compound 61).

0*00 .0

N-(

2 4 -ethoxyphenyl)thyl4oxo4,5,67-tetrahydroIHindole-3-carboxamide (Compound 62).

(bh) (compound 63) (bi) (compound 64) QEt

NN

H

H,

H

H

(compound 65) (k cmon 6 (bk) (compound 66)

CI

-N

N

/N

-N

(bi) (compound 67) (bin) (compound 68)

-N

(bn) (compound 69) QEt (bo) N-( 4 -fI u oro -2 -h y drox yp he n y1) -4 -o xo 4,56,7 te tra hy dro -IH indole-3-carboxarnide (Compound 41 The invention and the manner and process of making and using it.

are now described in such full. clear, concise and exact terms as to enable any person skilled in the art to which it pertains, to make and use the same.

It is to be understood that the foregoing describes preferred embodiments of the present invention and that modifications may be made therein without departing from the spirit or scope of the present invention as set forth in the claims. To particularly point out and distinctly claim the subject matter regarded as invention, the following claims conclude this specification.

It will be understood that the term "comprises" or its grammatical variants as used herein is equivalent to the term "includes" and is not to be taken as excluding the presence of other elements or features.

7

I:

Claims (21)

1. A compound of the formula:- or non-toxic salts thereof wherein W represents phenyl, 2 or 3-thienyl, 2, 3 or 4- pyridyl or 6- quinolinyl, each of which may be mono or disubstituted with halogen, cyano, hydroxy, straight or branched chain lower alkyl having 1-6 carbon atoms, amino, mono or dialkylamino where each alkyl is independently straight or branched chain lower alkyl having 1-6 carbon atoms, straight or branched or branched chain lower alkoxy having 1-6 carbon atoms, or NR 1 COR 2 COR 2 CONR 1 R 2 or C00 2 R 2 where R, and R 2 are the same or different and represent hydrogen or straight or branched chain lower alkyl having 1-6 carbon atoms.

2. A compound according to claim 1 of the formula:- H-N 0 S/ OEt or non-toxic salts thereof. CD/9909701 4.7

3. A compound of the formula:- H N 0 0 or non-toxic salts thereof.

4. A compound of the formula:- H or non-toxic salts thereof. A compound of the formula:- H or non-toxic salts thereof.

6. The compound: N- (2-flu oro-4- meth oxyph enyl) -4-oxo-6,6-d imet hyl.4,5,6,7- CD/99097014.7 44 tetrahydro-1 H-indole-3-carboxamide or non-toxic salts thereof.

7. The compound: N-(2-fluoro-4-ethoxyphenyl)-4-oxo-6,6-dimethyl-4,5,6,7. tetrahydro-1 H-indole-3-carboxamide or non-toxic salts thereof.

8. The compound: N-(4-ethoxyphenyl)-4-oxo-6,6-dimethyl-4,5,6,7-tetrahydro- 1 H-indole-3-carboxamide or non-toxic salts thereof.

9. The compound: N-phenyl-4-oxo-6 ,6-dimethyl-4,5,6,7-tetrahydro- 1 H-indole- 3-carboxamide or non-toxic salts thereof. The compound: N-(3-fluorophenyl)-4-oxo-6,6-dimethyl-4,5,6,7-tetrahydro- 1 H-indole-3-carboxamide or non-toxic salts thereof.

11. A compound of the formula:- CI I\ N N or non-toxic salts thereof.

12. A compound of the formula:- CD/99097014.7 or non-toxic salts thereof.

13. A compound according to any one of claims 1 to 12, substantially as hereinbefore described, with reference to the Examples.

14. A method for treating anxiety, sleep disorders, seizure disorders, overdoses of benzodiazepine-type drugs, or for enhancing alertness, the method comprising administering to a mammal an effective amount of at least one compound of the formula:- w O N N N I H or a pharmaceutically acceptable non-toxic salt thereof jwherein W represents phenyl, 2 or 3-thienyl, 2, 3 or 4- pyridyl or 6-quinolinyl, each of which may be mono or disubstituted with halogen, cyano, hydroxy, straight or branched chain lower alkyl having 1-6 carbon atoms, amino, mono or dialkylamino where each alkyl is independently straight or branched chain lower alkyl having 1-6 carbon atoms, straight or branched chain lower alkoxy having 1-6 carbon atoms, or NRICOR 2 COR 2 CONRiR 2 or C0 2 R 2 where RI and R 2 are the same or different and represent hydrogen or straight or branched chain lower alkyl having 1-6 carbon atoms. The method according to claim 1 wherein the compound is of the, formula:- 0 H-N N/ OEt S or a pharmaceutically acceptable non-toxic salt thereof. o 16. A method for treating anxiety, sleep disorders, seizure disorders, overdoses of benzodiazepine-type drugs, or for enhancing alertness, the method comprising ooooIo/ 47 administering to a mammal an effective amount of at least one compound selected from the following:- or a pharmaceutically acceptable non-toxic salt thereof; or a pharmaceutically acceptable non-toxic salt thereof; and H *o* *ooo *ooo oo :^oo 48 or a pharmaceutically acceptable non-toxic salt thereof.

17. A method for treating anxiety, sleep disorders, seizure disorders, overdoses of benzodiazepine-type drugs, or for enhancing alertness, the method comprising administering to a mammal an effective amount of a compound selected from the group consisting of N-(2-fluoro-4- methoxyphenyl)-4-oxo-6,6-dimethyl-4,5,6,7-tetrahydro-lH- indole-3-carboxamide, N-(2-fluoro-4-ethoxyphenyl)-4-oxo- 6,6-dimethyl-4,5,6,7-tetrahydro-lH-indole-3-carboxamide, N- (4-ethoxyphenyl)-4-oxo-6,6-dimethyl-4,5,6,7-tetrahydro-lH- indole-3-carboxamide, N-phenyl-4-oxo-6,6-dimethyl-4,5,6,7- tetrahydro-lH-indole-3-carboxamide and N-(3-fluorophenyl)- 4-oxo-6,6-dimethyl-4,5,6,7-tetrahydro-lH-indole-3- carboxamide or a pharmaceutically acceptable non-toxic salt thereof. o

18. A method for treating anxiety, sleep disorders, seizure disorders, overdoses of benzodiazepine-type drugs, or for enhancing alertness, the method comprising administering to a mammal an effective amount of at least one compound selected from the following:- N H or a pharmaceutically acceptable non-toxic salt thereof; and 6* S S S S. S. S S 0 S S. S S S.O.S. 0 500 0. S or a pharmaceutically acceptable non-toxic salt thereof.

19. A pharmaceutical composition comprising at least one compound of the formula:- w N N N H or a pharmaceutically acceptable non-toxic salt thereof wherein W represents phenyl, 2 or 3-thienyl, 2, 3 or 4- pyridyl or 6-quinolinyl, each of which may be mono or disubstituted with halogen, cyano, hydroxy, straight or *00 branched chain lower alkyl having 1-6 carbon atoms, amino, mono or dialkylamino where each alkyl is -independently o.0 straight or branched chain lower alkyl having 1-6 carbon atoms, straight or branched chain lower alkoxy having 1-6 carbon atoms, or NR 1 COR 2 COR 2 CONR 1 R 2 or C0 2 R 2 where R 1 and R 2 are the same or different and represent hydrogen or straight or branched chain lower alkyl having 1-6 carbon atoms and a pharmaceutically acceptable carrier. 51 The pharmaceutical composition according to claim 19 wherein the compound is of the formula:- H-N 0 OEt or a pharmaceutically acceptable non-toxic salt thereof and a pharmaceutically acceptable carrier.

21. A pharmaceutical composition comprising at least one compound of the formula:- .4. .4 .4 4 4 oooo 444444 4 44 *oo or a pharmaceutically acceptable non-toxic salt thereof and a pharmaceutically acceptable carrier. 52

22. A pharmaceutical composition comprising at least one compound of the formula:- or a pharmaceutically acceptable non-toxic salt thereof and a pharmaceutically acceptable carrier.

23. A pharmaceutical composition comprising at least one compound of the formula:- *o o or a pharmaceutically acceptable non-toxic salt thereof and a pharmaceutically acceptable carrier.

24. A pharmaceutical composition comprising at least one compound selected from the group consisting of N-(2-fluoro- OF 53 4-methoxyphenyl) -4-oxo-6,6-dimethyl-4, 5,6, 7-tetrahydro-lH- indole-3-carboxamide, N- (2-fluoro-4-ethoxyphenyl) -4-oxo- 6,6-dimethyl-4,5,6,7-tetra-hydro-lH-indole-3-carboxamide, N- (4-ethoxyphenyl) -4-oxo-6, 6-dimethyl-4, 5,6, 7-tetra--hydro- lH-indole-3-carboxamide, N-phenyl-4-oxo-6, 6-dimethyl- 4,5,6,7-tetrahydro-lH-indole-3-carboxamide and N- (3- fluorophenyl) -4-oxo-6,6-dimethyl-4,5, 6,7-tetrahydro-iK- indole-3-carboxamide or a pharmaceutically acceptable non- toxic salt thereof and a pharmaceutically acceptable carrier. A pharmaceutical composition comprising at least one compound of the formula:- ci N 0 N N H or a pharmaceutically acceptable non-toxic salt thereof and a pharmaceutically acceptable carrier.

26. A pharmaceutical composition comprising at least one compound of the formula:- N 0 0 N H or a pharmaceutically acceptable non-toxic salt thereof and a pharmaceutically acceptable carrier.

27. A method for treating anxiety, sleep disorders, seizure disorders, overdoses of benzodiazepine-type drugs, or for enhancing alertness, comprising administration of a therapeutically effective amount of a compound according to any one of claims 1 to 13 ,'or a pharmaceutical composition according to any one of claims 19 to 26, substantially as described herein. Neurogen Corporation By its Registered Patent Attorneys Freehills Carter Smith Beadle 4 December 2000