AU594676B2 - Oxadiazolyl imidazobenaodiazepine compound, pharmaceutical composition containing said compound, method of preparing said compound and method of treating a central nervous system ailment - Google Patents

Description

COMM

7 0NWEALT H OF AUSTRALIA PATENT ACT 1952 594676 COMPLETE SPECIFICATION (original) FOR OFFICE USE Class Int. Class Applioajton Number: Lodged: 5-7 31 (Ti Complal e ipf&L jic ion Lodged: Accepted: Pub lished: a At .oriri Rla~ed rt: 4a41 Ihis document contains the ncndments made under Section 49 and is correct for printing.

o 0*D o,~m f? APpicfln:

~IL-~O-

A/5 VBRROSAN pop Adress of Applicant: o 6 1.1t1 Actual Invcnkor(s) Addren3 for Service: Symarken 5, DK-2860 Sborj, Denmark.

Frank WATJEN Mogens ENGELSTOFT John Bondo HANSEN Leif H1olth JENSEN LODGED AT SUB.OfICE 1I4 MAY 1986 Melbouxne DAVIES COLLISON, Pato10nL Attorneys, 1 Litle Collins Straot., Melbourne, 3000.

Complato Specification for the invenLion entitled: "OXADIAZOLYL IMIDAZODENZODXAZEPINE COMPOUND, PhARMACEUTICAL COMPOSITION CONTAINING SAID COMPOUND, METHOD OF PREPARING SAID COMPOUND AND METHOD OF TREATING A CENTRAL NERVOUS SYSTEM

AILMENT"

The following statemuent is a full doscription of this invention, including the bast method of performing it known to us S"I

I

w-4-; la o Oxadiazolyl imidazobenzodiazepine compound, pharmaceutical composition containing said compound, method of preparing said compound and method of treating a central nervous system ailment.

This invention relates to novel oxadiazolyl imidazobenzo- 5 diazepine compounds.

The novel compounds are useful in psychopharmaceutical compositions, e.g. for the treatment of central nervous system ailments, such as anticonvulsants and anxiolytics.

It is well known (Squires, R.F. and Braestrup, Nature (London) 266, (1977) 732) that specific sites In the central nervous systems of vertebrates exhibit a high specific affinity for binding 1,4- and 1,5-benzodiazepines. These sites are called benzodiazepine receptors.

European patent application No. 109,921 discloses com- 15 pounds having the general formula I 0 00 0 0 0 0 0 0 0 0 0000 0000 0 0 0 0 00 a o 00 0 00 0 0 00 0 0 000 o o 0 S0 0 0 Q0 0 0 0 00 000 0 i 0 0840P

R

440' 9C '0 30 wherein R' is hydrogen, chlorine, fluorine or nitro in the 7- or 8 -position, R is hydrogen or C 1 3 -alkyl, 3 s an oxadaolyl group havng the formula R is an oxadiazolyl group having the formula

ON

N.0 N Ro r 1 -L 2 wherein SR" is C 1 3 -alkyl, A B is a group having the formula

C-N

I I or C=N 5 O R R" wherein

R

5 is hydrogen or methyl and R" is hydrogen or chlorine.

European patent application No. 109,921 further discloses 0 00 °o'o that certain oxadiazolyl benzodiazepines and oxadiazolyl beta-carbo- 0° lines exhibit stronger binding affinity for the benzodiazepine recep- 15 tors than the alkyl esters of the corresponding acids, 0 European patent application No. 150.040 discloses 1,2,4- Soxadiazolyl benzodiazpine compounds having the formulae II and 111: o oo o 20 N 0 0 0 0 0 0 20 0 0 Oo o 0400 5a

N

R

wherein R is alkyl, cycloalkyl, methoxymethyl,

R

3 is H, CH 3 and R and R 5 each is H or halogen, 3 x *x (111) 0 4 RSN (H

R

R

4 r "D i wherein X is

N

<\o or o

R

or r 0o 0 0o 0 !s o 0 0 0 o nO o o o 0 q 0 o 00 0 f 4 a 'I6 a tf 0 H wherein R is alkyl, cycloalkyl, CF 3 or methoxymethyl, 4 5 R and R each is H, halogen, CF 3 and n is 2 or 3.

The compounds disclosed in examples 2, 3, 16, 29, 32, 43, 44, 45, 49, 50, 51, 52, 53 and 56 of E? No. 150.040 are 5,6-dihydro-6-oxo-4H-imidazo(1,5-a)(1,4)benzodiazepine compounds (having the above formula II), whereas the compounds disclosed in examples 1, 8, 9, 17, 18, 23 and 30 are !0,11,12,12a-tetrahydro-9-oxo-9H-imidazo-(1,5-a)azeto(2,1-c)(1 ,4)benzodiazepine compounds (having the above formula III) and the compounds disclosed in examples 4, 5, 6, 7, 10, 11, 12, 13, 14, 15, 19, 20, 21, 22, 24, 25, 26, 27, 28, 31, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 46, 48, 54, 55, 57, 58 and 20 59 are 11,12,13, 3a-tetrahydro-9-oxo-9H-imidazo-(1,5-a)pyrrolo(2,1- -c)(1,4)benzodiazepine compounds (also having the formula III).

Finally, the compound disclosed in example 47 of EP 150.040 is an 11,13a-dihydro-9-oxo-9H-imidazo(1,5-a)pyrrolo(2,1-c)(1,4)benzodiazepine compound.

25 The compounds disclosed in examples 11, 15, 26 and 40 of EP 150.040 are compounds of formula III, in which X is 1,2,4-oxadia.

zol-3-yl group and in the compound disclosed in example 40 X is a 5-cyclopropyl-1,2,4-oxadiazol-3-yl group.

EP No. 150.040 also discloses a method of preparing compounds having the formulae II and II, said process comprising reacting a compound having the formula V and VI, respectively:

Y

a

I

N

4 3CH3

R

(V)

O

R

5

(CH

2

R

4 0

(VI)

n~;p 1 4 wherein R 4

R

5 and n have the meanings defined above and Y is a leaving group, with a compound of the formula CN-CH 2

-CO

2 R to form a compound of Formula II or III comprising a -CO2R substituent in the 3-position and converting in several steps this compound to the desired oxadiazole derivative.

According to the invention there is provided a novel group of oxadiazolyl benzodiazepine compounds having the general formula

VII

N-O

(VII)

0 o 0 o 0 0 00 00 0 00 00 0 00 0 0d0 00 o oP

CH

3 wherein X is CI, Br, F, CF 3

CH

3 or CN, as well as pharmaceutically acceptable acid addition salts thereof. The novel compounds are useful in the treatment of central nervous system disorders or ailments, especially as anticonvulsants and anxiolytics.

The melting points of some basic compounds of the invention are as follows: X Melting point *0 0

F

CF

3

CH

3

CN

165.1 169.20C 212 213 GC 188.2 189.00C 200.10C 175.0 175.50C 237 -2390C

I

*e The invention also relates to a method compound of the invention. The compound of the prepared by a) the following reaction sequence: of preparing a invention can be r

CN

N

X CH 3 x

NH

2

OH

(VIII)

j a: 1'

NOH

2 CI C-Cl

N-

3

(VII)

N

CH

3

(IX)

wherein X has the meaning defined above or b) by the following iij reaction 0 0 0 a at a o o a *0 0* a 0* o o a a a 00 0 Y N-O o CH 3 0 3^-v

O

IN)

N

N

X CH 3

(XI)

.1 tI wherein Y is a leaving group and X has the meaning defined above.

20 Examples of suitable leaving groups are halogen, alkylthio, methylthio, aralkylthio, N-nitrosoalkylamino, alkoxy, mercapto,

-OP-(O)(OR)

2 wherein R is lower-alkyl or wherein R and R" each represents lower-alkyl, or phenyl, or together with the adjacent nitrogen atom form a heterocyclic radical such as mor- 25 pholino, pyrrolidino, piperidino, or methylpiperazino.

The reaction b) is preferably carried out under alkaline conditions, in the presence of a base. Preferred bases are alkali metal, potassium or sodium, alkoxides or hydrides. The reaction is preferably effected in the presence of an orga.nic solvent which does not react with the reactants and products of reaction under the prevailing reaction conditions. Suitable solvents are anhydrous solvents and preferably anhydrous aprotic solvents such as dimethylformamide (DMF) or the like. The reaction temperature should be sufficiently high to allow the reaction to proceed at a reasonable rate and without undue delay or decomposition and a range from a -40° to about 30 0 C is ordinarily suitable.

The compounds of the formula X may be prepared as described in US patent specifications Nos. 4.352.817 and 4.316.839.

4 t t~

II

-3: ~i rl i rr~- IP-uu'~--rac 0 00 09 0 00 0 0* 000 00 0 00b 900 0u 0 4 00 0 00 00 0 i 6 The invention also relates to a pharmaceutical composition comprising an effective amount of a compound of the invention or a pharmaceutically acceptable acid addition salt thereof. The pharmaceutical composition of the invention is suitable for the treatment of central nervous system ailments such as convulsions and states of anxiety.

The pharmaceutical composition of the invention may comprise a conventional adjuvant, carrier, or diluent and may be used in unit dosage form. The compound of the invention may be administered in solid form e.g as tablets or filled capsules, in liquid form e.g. as solutions, suspensions, emulsions, elixirs, or capsules filled with the same, all for oral use; in the form of suppositories for rectal administration; or in the form of sterile injectable solutions for parenteral (including subcutaneous) use. Such pharmaceutical compo- 15 sitions and unit dosage forms thereof may comprise conventional ingredients in conventional proportions, with or without additional active compounds or principles. The unit dosages forms should contain an effective central nervous system ailment alleviating amount of the active ingredient commensurate with the intended daily dosage range to be employed. Tablets containing about 10 milligrams of active ingredient or, more broadly, from about 10 to 30 milligrams, per tablet, are suitable unit dosage forms.

The compound of this invention can be formulated for oral and parenteral administration to mammals including humans in accordance with conventional methods of galenic pharmacy.

Conventional excipients are pharmaceutically acceptable organic or inorganic carrier substances suitable for parenteral or oral application which do not deleteriously react with the active compound.

Examples of such carriers are water, salt solutions, alcohols, polyethylene glycols, polyhydroxyethoxylated castor oil, gelatin, lactose, amylose, magnesium stearate, talc, silicic acid, fatty acid monoglycerides and diglycerides, pentaerythritol fatty acid esters, hydroxymethylcellulose and polyvinylpyrrolidone.

The pharmaceutical preparations can be sterilized and mixed, if desired, with auxiliary agents, such as lubricants, preservatives, stabilizers, wetting agents, emulsifiers, salt for influencing osmotic pressure, buffers and/or coloring substances and the like, which do not deleteriously react with the active compound.

Ni 1

I

1 1

I

I i i oa p4 00 0 0 aP p aool a o 09 o0 p0 pap.

p pp 0 00

II

Injectable solutions or suspensions, preferably aqueous solutions with the active compound dissolved in polyhydroxylatod castor oil are particularly suitable for parenteral application.

Ampoules are conveniently unit dosages.

Tablets, dragees, or capsules containing talc and/or a carbohydrate carrier or binder or the like, the carrier preferably being lactose arid/or corn starch and/or potato starch are particularly suitable for oral application. A syrup, elixir or the like can be used when a sweetened vehicle can be employed. Generally, the compound of the invention is dispensed in unit dosage form comprising 0.05-100 mg in a pharmaceutically-acceptable carrier per unit dosage.

The invention also relates to a method of treating central nervous system ailments and the method comprises the step of administering an effective amount of the compound of the invention or a pharmaceutically acceptable acid addition salt thereof.

Due to their high degree of affinity for the benzodiazepine receptors, the compounds of the invention are extremely useful in the treatment of central nervous system ailments or disorders, when 20 administered in an amount effective for the alleviation, amelioration, or elimination of such ailments or disorders. The important CNS activity of the compounds of the invention includes both anticonvulsant and anxiolytic activities along with a low toxicity, which together present a most favourable therapeutic index. The compounds of the invention may accordingly be administered to a mammal such as a human being in need of the same for the treatment, alleviation, amelioration, or elimination of an indication associated with the central nervous system and the benzodiazepine receptors and needing such psychopharmaceutical treatment, e.g. a human being suffering from convulsions or being in the state of anxiety. The compound of the invention is preferably administered in the form of a pharmaceutical composition as described above and preferably in a daily dosage of 1-200 mg, preferably 10-100 mg and more preferably 30-70 mg depending upon the exact mode of administration, the form of administration, the indication toward which the administration is directed, the subject involved and the body weight of the subject involved, and the preference and experience of the physician or veterinarian in charge. Broader ranges for dosages of the compound according to this invention are 0.1-300 mg/day, when administered to patients,

I*

IN

i n r 9 0 0 0 0 0 0 0 099 000 9 99 9 099 9 0 0 a a or o o o f n S0 49 a tia 00 09 0 0 0o 6 rua O 8 e.g. humans, as a drug.

The invention will now be described in further detail with reference to the following non-limiting examples.

EXAMPLE 1.

a. 5,6-dihydro-5-methyl-6-oxo-7-chloro-4H-imidazo(1,5-a)(1,4)benzodiazepine-3-carboxamide oxime.

A mixture of 1.2 g 3-cyano-5,6-dihydro-5-methyl-6-oxo-7- -chloro-4H-imidazo (1,5-a)(1,4)benzodiazepine (prepared as described in US patent specification No. 4,316,839), 0.45 g of hydroxylamine hydrochloride, 20 ml of 99% ethanol, 2 ml water, and 1.2 g potassium carbonate was refluxed for hours. The reaction mixture was 15 filtered and the filtrate was concentrated. The residue was treated with 50 ml of water and the crystalline solid was filtered off and washed with water.

M.p. 227.6-228.4cC.

20 b. 3-(5-cyclopropyl-1 ,2,4-oxadiazol-3-yl)-5,6-dihydro-5-methyl-6oxo-7-chloro-4H-imidazo (1,5-a)(1,4)benzodiazepine.

A mixture of 580 mg 5,6-dihydro-5-methyl-6-oxo-7-chloro- -4H-imidazo (1,5-a)(1,4)benzodiazepine-3-carboxamide oxime prepared as described above and 0.3 ml of cyclopropyl carboxylic acid chloride was stirred in 15 ml THF for two hours at 20 0 C and evaporated.

After evaporation 20 ml of acetic acid was added and the mixture was refluxed for 2-1 hours and then evaporated. The reaction mixture was allowed to stand overnight at room temperature, whereafter the mixture was cooled, filtered, and the filtrate evaporated to give a residue as oily crystals.

The residue was treated with ether to give the title compound as pale crystals which were collected by filtration.

M.p. 165-169 0

C.

EXAMPLE 2.

a. Formvlaminomethvl-carboxamide oxime.

0.55 mol freshly liberated hydroxylamine dissolved in 370

I

r i .I ml methanol was added to 53.6 g (0.638 mol) N-formylamino-acetonitrile prepared as described in Synthesis, Vol 10, pg 681-82. An ice bath was used to keep the temperature below 200C during the addition. The solution was allowed to stand at room temperature overnight, whereafter it was evaporated to give the title compound as pa!e crystals.

Decomp. 104-1100C.

b. 3-Formylaminomethyl-5-cyclopropyl-1,2,4-oxadiazole.

A mixture of 35 ml ethyl cyclopropylcarboxylate, 30 g formylamino-methyl-carboxamide oxime, 1 g sodium and 30 g crushed mol sieves (4A) was refluxed in 300 ml abs. EtOH for 8 hours during which period a further 1 g sodium was added. The reaction mixture 15 was filtered and the filtrate was evaporated. The dark oily residue was suspended in 300 ml CHCI 3 filtered and the filtrate was evaporated to give the title compound as an oil.

H-NMR (60 MHz, CDCL 3 6 (ppm): 1.2 (4 H, 2.8 (1 H, 4.5 (2 H, d, J=6 HZ), 7.8 (1 H, broad-NH), 8.2 (1 H, s).

o C., 0' C1 o ooc 404 00 0 04 0P 4 00 0 0 400 4 c. 5-Cyclopropyl-3-isocyanomethyl-1,2,4-oxadiazole.

i~ t a A stirred solution of 5-cyclopropyl-3-formylamino-methyl- 1,2,4-oxadiazole (60 mmol) and triethylamine (176 mmol) in CH 2

CI

2 (100 ml) was charged dropwise with POCI 3 (60 mmol) at 0°C, whereafter a solution of Na 2

CO

3 (60 mmol) in H 2 0 (50 ml) was added. The mixture was heated to room temperature, whereafter the organic phase w. separated, dried and evaporated in vacuo. The residue was treated with ether, decanted and the solution was evaporated to give the tit!e compound as an oil.

The oil was processed without any further purification.

IR, cm" 1 2160.

'.4 4 in I nii n r I I dione.

2.3 g of 3,4j- 0 o-4-methyl--6-bromo-2H-1,4-benzodiazepine-2,5(1 ne and 1.26 g of cupro cyanide was dissolved in imTthvl formamid Tha mivture thius formorL..was hoated t 11 0 0.

fr 30 min'utes and then coolcd to 50°C 2w'h.rcsftcr 2. g 5 cyanide in 6 ml water was added. The resulting mixture then stirred for 10 minutes, whereafter 30 ml wate as added. The mixture was extracted twice with 25 J yl acetate. The organic phase was dried with calciu oride. After filtration the organic solution was evapo in vacuo to give 0.78 g of the title compound.

A. 3-(5-cyclopropyl-1,2,4-oxadiazol-3-yl)-5,6-dihydro-5-methyl-6oxo-7-chloro-4H-imidazo( ,5-a)(1,4)benzodiazepine.

3,4-dihydro-4-methyl-6-chloro-2H-1,4-benzodiazepine-2,5 (1H) dione (9.17 mmol) was dissolved in dry DMF (20 ml) and charged with sodium hydride (10 mmol). The resulting solution was :oo cooled under N 2 to -20 0 C, whereafter chlorodiethylphosphate (11 o, o mmol) was added.

The reaction mixture was kept under N 2 with stirring at o2 -20 0 C and charged with a -30 0 C cold solution of 5-cyclopropyl-3-iso- S°o 20 cyanomethyl-1,2,4-oxadiazole (11 mmol) and K-t-butylate (11 mmol) in dry DMF (15 mmol).

The resulting reation mixture was allowed to heat to room o, temperature, whereafter it was evaporated to dryness in vacuo. The oily residue containing the crude product was purified on SiO 2 with 25 ethyl acetate as eluent. This gave the title compound as white crystals.

M.p. 165-168.50C.

EXAMPLE 3 3-(5-cyclopropyl-1,2,4-oxadiazol-3-yl)-5,6-dihydro-5-methyl-6-oxo- 7-bromo-4H-imidazo(1,5-a)(1,4)benzodiazepine.

g of 3,4-dihydro-4-methyl-6-bromo-2H-'l,4-benzodiazepine-2,5(1H)-dione (8.5 mmol) was dissolved in dry DMF (30 ml) and charged with 480 mg sodium hydride. The resulting solution was cooled under an atmosphere of N 2 to -20 0 C, whereafter chlorodiethyl phosphate (1.6 ml) was added.

AL4 The reaction mixture was kept under N 2 with stirring at

*I-

S1 -200C and was charged with a -30°C cold solution of 2 cyclopropyl-3-isocyanomethyl-1,2,4-oxadiozol (1.64 g) and 3 K-t-butylate (1.23 g) in dry DMF (15 ml).

4 The resulting reaction mixture was allowed to heat to room temperature and was stirred for 30 minutes. A crude 6 product was formed by precipitation by addition of 150 ml 7 water. The crude product was partitioned between 50 ml 8 ethyl acetate/diethylether and 100 ml 4M hydrochloric 9 acid. The organic phase was discharged and the product was precipitated by neutralizing the aqueous phase with 2M 11 sodium hydroxide. The precipitated product was crystalized 12 from ethyl acetate. This gave the title compound as white 13 crystals.

14 M.p. 212-13 0

C.

S 16 EXAMPLE 4.

17 18 a. 3,4-Dihydro-4-methyl-6-cyano-2H-1,4-benzodiazepine-2,5- 19 (1H)-dione 21 2.3 g of 3,4-dihydro-4-methyl-6-bromo-2H-1,4-benzo- 22 diazepine-2,5(1H)-dione and 1.26 g of cupro cyanide was 23 dissolved in 5 ml dimethyl formamide. The mixture thus 24 formed was heated to 110 0 C for 30 minutes and then cooled to 25 50 0 C whereafter 2.4 g sodium cyanide in 6 ml water was a 26 added. The resulting mixture was then stirred for 27 minutes, whereafter 30 ml water was added. The mixture was 28 extracted twice with 25 ml ethyl acetate. The organic phase 29 was dried with calcium chloride. After filtration the organic solution was evaporated in vacuo to give 0.78 g of 31 the title compound.

32 M.p. 261-69 0

C.

33 34 b. 3-(5-cyclopropyl-1,2,4-oxadiazol-3-yl)-5,6-dihydro-5methyl-6-oxo-7-methyl-4H-imidazol(l,5-a)(1,4)benzodiazepine S36 890802 dt.057erro. 10 890802,c sdat.057,ferro.1,10 i 3-isocryanomethiyl-i ,2,4-oxadlazoI (1,.64 gj) and K-t-butylato g) In dry DMF (15 mi).

The resultingj reaction mixture was allowed to eat to room temperature and was stirred for $0 minutes, A cr de product was formed by precipitation by addition or 15o water. The crude product was partitioned between 50 ml e, I acetate/' diethylether and 100 ml QM hydrochloric~ acd. he organic phase was discharged and the product was proc t ed by neutralizing the aqueous phase with 2Mv sodbIm hydro,701 The precipitated product was crystallzed from ethyl ocet, T1his gave the title compound as white crystala, M.p. 2.12-13 C.

EXMLE4 3 'Cyclopropyl -1 ,2,4-oxadilazol -3-yi G-d ihyd ro-6-mothyl -6-oxo 3,4-dlydro-4-methyl-6-mothiyl-2H-1 14-benzodlazepine-215 (11-1) dr (4,0 mmol} was dissolIved in dry OMF (20 ml) tund chargod with sodium hydride (S mmol). The resulting solution was cooled under+ N 2 to -20 0 C, whereafter chiorodiathyl phosphate (11 mmol) was added.

1* 25The reaction mixture was kept under N 2 with stirrine at -2 and charged with a -30'oC cold solution or B-cyciopropyl-3-isooyanomothyl-1#2#4-oxadlizole (S mrnol) and K-t-butylate (S mmol) In dry OMPI (16 rimol).

The resulting reaction mixture was allowed to heat to room temperaturo, whereafter It was evaporated to dryness in vauo An y oily residue containing tha crudea produat was cryntaized from ethanot giving 0.45 (j or the title compound.

mip 17517S5.6C The following compound& were synthesized In an analogous "Inn"r'e 7'Nluoro-3' (5'cyclopropyi -,2,4-oxadlazol-3-y -5,6-dihiydro-.s)mtyG-oxo4Hldazo( 4 )be-nzodiazopire from 3,4- -dhda4iitllGfut- 4-ezdaole2 SC I H)-dlont.

/0v 1 p 1 1 I'll C1 '12 H-NMR (60 mliz, DMSO-D 6 e 8.2 1, 7.2-8,O (m,31-1 aromatic), 5.1-4.2 (degenerate coupling, 211), 3.1 (s,3H, NME), 2.3 (m,1H)1 1.5 (m,41-1).

7-Cyano-3-(5-cyclopropyl-1 2, 4-oxadazol -3-yl -methyI-6-oxo-4H -imidazo(1 ,4)benzodiazepine from 3,4-dihydro-4-methyl-6-cyano-2H-1,4-benzodlzeplne-2, 5(1 H)-dione, Mp. 237-9 0

C.

IR: 0,3% KBr dish showed the characteristic CnN band at 2230 cm" 1 NMR (60 mlz, CDCI 3

+DMS-D

6 6 8.2 7.2-8.0 (m,3H,aromatlc), 5.2-4.3 (2m, degenerate couplino, 211), 3.1 (s,3H, N-ME), 2,3 1.1-1.5 (m,4H).

7-Triflwo,-romthyf-3-(5-cyclopropyl-12, 4-oxodiazol-3-y)- -5,6-dihydro-5-methyl-6-oxo-4H-lmldazo(1 ,4)benzodizepine from 3, 4-dlhydro-4-methyl-6-tri f luoromothy-211I-1 ,4-benzodiazepinodione.

M.P. 20U.10C.

11-NMR (60 mHz, DMSO-D +CDCL 3 5 (m,31- aromatic), 5.3-4.4(m, degenerate couplilo, 211), 3.1 (s,3HN-ME), 2.3 (m)1H) 1,1-1.5 t(41-1).: IiXAMPLE Representative Pharmaceuticaul Cornmpositions, a) Tablets.

A typical tablet for use In treating states of anxiety and capable of being prepared by conventional tableting techniques contains Compound of the Invention 1.0 mg Lactose 67.4 mg Ph.Eur.

Avicel 0 (microcellulose) 31.4 mg Amboriite, 0(IRP 88) (ton exchangO resin) 1.0 mg Magnesium stearato 0.25 mg Ph. Eur.

The same tablet may be used ror treating convuisons, ii i pCr~Clti--

V

9 "O C 9 C) 9 Cc 9" 9@ t 9 99 a ii 99 91 13 b) Suppositories.

Any usual suppository base may be employed for incorporation thereinto by usual procedure of the active ingredient, such as a polyethyleneglycol which is solid at room temperature and which melts at or about body temperature.

c. Sterile solutions for parenteral (including subcutaneous) administration.

The active ingredient together with conventional Ingredients such as sodium chloride, sodium dihydrogen phosphate, disodium edetete (ethylenediaminetetraacetic acid disodum salt), benzyl alcohol, sodium hydroxide to adjust pH, and double-distilled water 15 are treated in conventional manner e.g. by filtration, aseptic filling into ampoules, and autoclaving for sterility.

The compounds of the invention have been found to exhibit a surprising favourable and highly advantagenous degree of activity in a standard classical test for determining the in vivo affinity for the benzodiazepine receptor's, as well as in a standard test considered predictive for pharmaceutical activity against convulsions and states of anxiety mediated through the benzodiazepine receptors.

The following test was performed on some compounds of the invention as well as representative examples of prior art compounds.

In vivo inhibition of 3H-flunitrazepam binding to mouse forebrain membranes by test substances administered intraperitoneally.

-4 Principle. Twenty minutes after administration of a dose of 3 H-flunltrazepam 3 H-FNM) (200 pCl/kg the amount of specific 3H-FNM binding to brain benzodlazepine receptors has reached Its maximum value. This specific binding of 3 H-FNM can be partly or completely prevented by simultaneous or prior administration of pharmacologically active benzodlazepines and by some benzodiazepinelike agents (Chang and Snyder, Eur.J.Pharmacol. 48, 212-218 (1978)), Test procedure. Suspensions of test substances (2 mg/ml) r .dt 0 0 0 o0 o0 o 0 00 a0 0 0 40 00 0 a 00 4 are prepared in 5% "Duphasol (castor oil-ethylene oxide derivative for emulsifying and solubilizing oil and other water-insoluble substances) by sonification for 10 min. using a Branson B15 microtip ultrasonifier (setting Groups of three mice (female, NMR, 18-22 gram) are injected intraperitorially with the test substance at 100 mg/kg. Fifteen minutes after administration of the test substance the mice are challenged intravenously with 4 pCi in the form of 3

H-FNM

(70-90 Ci/mole) in 200 pI physiological saline. Twenty minutes after 3 H-FNM administration the mice are sacrificed by decapitation, the forebrain rapidly excised (within 30 sec) and homogenized in 12 ml of icecold 25 mM KH 2

PO

4 pH 7.1, using an Ultra-Turrax homogenizer fitted with an N 10 shaft. Two aliquots of 1 ml are immediately filtered through Whatman GF/C glassfibre filters and washed with 2 x 5 ml of the above mentioned buffer. The amounts of radioactivity 15 on the filters are determined by conventional scintillation counting.

One group of untreated mice serves as controls. One to three mice are injected with 25 mg/kg clonazepam i.p. 30 minutes before 3

H-FNM

to determine the amount of non-specific H-FNM binding, which should be between 8-15% 3 H of the total binding.

When doses of 100 mg/kg inhibit more than 50% of specific 3 H-flunitrazepam binding test substances are adminstered in doses, which are factors of 3.16 times lower than the dose inhibiting more than 50% binding.

The ED50 for a test substance is defined as the dose which inhibits 50% of specific 3 H-FNM binding. Specific binding is the degree of binding In controls minus the degree of b,,dlng in clonazepam-treated mice.

Results. The ED 5 0 value is determined from dose response curves. If only one dose of a test substance is administered the 30 ED 5 0 value is calculated as follows (provided that the inhibition of specific binding is within the range of 25-75%): r i 1 1000

EDS

0 administered dose 1000

C

0 1 Cx pg/kg where C O is specific binding in controls and C x is specific binding in mice treated with the test substance,

I

s- -L i :Ij Pentazol clonic conv. mice o o 0 0 0 00 0 0 00 0 00 o o Soo o 0 o o000 0 co 0 o oo 00 0 4 0 09 0 096 Principle. Pentylenetetrazol induces clonic and tonic convulsions in mice at doses of 60-120 mg/kg s.c. The mechanism is unknown but seems to be due to some effects through the GABA receptor/benzodiazepine receptor/chloride ionophore complex. Antagonism of convulsions induced by maximum doses of pentylenetetrazol is considered predictive for drugs effective against petit mal epilepsia and anxiety.

Method. '150 mg/kg pentylenetetrazol dissolved in 0.9% NaCI solution is given by the subcutaneous route in volumes of 15 ml/kg to male or female NMRI mice weighing 20-25 g 30 min after intraperitoneal injection of a test compound. The number of mice exhibiting clonic seizures within the next 30 min is noted. At least 3 doses of 15 each test compound are used with 4 or 8 mice per dose, and with doses both above and below the ED 50 value.

Results. The ED 5 0 value is calculated as the dose in pg/kg at which seizures are inhibited in 50% of the animals using a computer program based on the method of Litchfield and Wilcoxon (1949).

Ill. Pentazol tonic Conv. micf i.p.

Principle. Pentylenetetrazol Induces clonic and tonic convulsions in mice at doses of 60-120 mg/kg s.c. The mechanism is unknown but seems to be due to some effects through the GABA receptor/benzodiazepine receptor/chloride ionophore complex. Antagonism of convulsions induced by maximum doses of pentylenetetrazol is considered predictive for drugs effective against petit mal epilepsia and anxiety.

Method. 150 mg/kg pentylenetetrazol dissolved in 0.9% NaCI solution is given by the subcutaneous route in volumes of 15 mg/kg to male or female NMRI mice weighing 20-25 g 30 min after an intraperitoneal injection of a test compound. The number of mice exhibiting tonic seizures within the next 30 min is noted. At least 3 doses of each test compound are used with 4 or 8 mice per dose, and with doses both above and below the ED 5 0 value.

Results. The ED 5 0 value is calculated as the dose in pg/kg where seizures are inhibited in 50% of the animals using a computer program based on the method of Litchfield and Wilcoxon (1949).

a -If-~

V;I

16 The results obtained by testing the compound of the Sinvention and the most relevant prior art compounds will appear from j the following table.

o o o 0 0 6 00 00 0 000- 0000 OO 0 0 0 00 0 0 0 0000 09 0 0 00 0 r azr 1 -i i:"

I

f 1 I

_.I

17

TABLE.

rN x'

N

SA 0

R

in vivo binding

ED

5 0 pg/kg Activity against pentazol induced convulsions

ED

50 pg/kg clonic tonic 0 00 a 0 0 o00 00 0 00 o Q0 0.00 0000 0 06 S 0 00 0 0 000 *i

A

1

CI

15 A2101H Br A3 20

F

A4H

CF

3 25 B JXH CH 3

H-O

CH 3 :H-a :CH3 ca

CH

CH

3

H

CI

D H

CI

O~jf CH 3 4k 0_-N CH3

NN

1.800 200 60 960 27.000 1.300 41 90 13.000 1.000 E -CH 2

CH

2

CH

2 C I F CH CH CH

CI

a CH 3 M-0

OH

0-n 1.600 2.200 8.000 2.000

SA-A

4 Compounds according to the invention B Compound disclosed in EP 109,921, example 3 C Compound disclosed in EP 109,921, page 3, line D Compound disclosed in EP 150,040, example 29 E Compound disclosed in EP 150,040, example F Compound disclosed in EP 150,040, example 31 G Compound disclosed in EP 109,921, example 1 As will appear from the above table the pharmacological properties of compound A 1 are clearly superior to the corresponding prior art compound Thus compared to said prior art compound the affinity for binding to the benzodiazepine receptor is about 2 times higher and the activity against pentazol induced clonic and tonic convulsions is 2.25 and 10 times, respectively, higher.

o 15 It also appears from the table that the above mentioned 0 00 oo properties of compound Al are 35, 325 and 330 times, respectively, "o higher than those of a prior art compound having the same X ooo0 substituent.

0oo In general it appears that the compounds of the invention o"0o° 20 (compounds A 1

-A

4 exhibit surprisingly improved pharmalogical properties compared with the closely related prior art compounds (compounds B-G).

0 00 o 0 o o r-4-

Claims (9)

1. 7-Substitupd 3-(5-cyclopropyl-1,2,4-oxadiazol-3-yl)-5,6- having the formula VII N- O N 0 N X 0 CH 3 (Vii) wherein X is CI, Br, F, CF 3 CH 3 or CN, and pharmaceuticall.y 15 acceptable acid addition salts thereof. S2. Compound according to claim 1 wherein X is Br. 9 0. Compound according to claim 1 wherein X is CF

4. A method of preparing a compound having the formula N N-0 25 N x 0 (VII) O CH 3 (VI) 30 a) reacting a compound having the formula VIIIl rCCN N (viii) X 3 wherein X has the meaning defined above, with NH 2 OH to form a compound having the formula IX "m- NOH Nfl C N H wherein X has the meaning defined above and reacting the compound thus obtained with COCI to form the compound having the formula VII, or ooOo 15 b) reacting a compound having the formula X 0 0 o O o00 O0to 0000 00 oo 0 C00 H oo 20 (X) x 3 D 00 0 0 0 o' wherein X has the meaning defined above and Y is a leaving group, with a compound having the formula N-O CN-CH N to form a compound having the formula VII. A method as claimed in claim 4 wherein b) is carried out under alkaline conditions.

6. A method as claimed in claim 4 wherein b) is carried out in the presence of an organic solvent.

7. A method as claimed in claim 4 wherein the leaving group is -OP(0)(O-ethyl) 2

8. A method as claimed in claim 4 wherein b) is carried out at a temperature of between -40° and 300C. 1 21

9. A pharmaceutical composition comprising an effective amount of a compound as claimed in claim 1 and a pharmaceutically acceptable carrier or diluent. A method of treating a person suffering from af central nervous system ailment comprising administering to said person an effective amount of-a compound as claimed in claim 1.

11. A method of treating a person suffering from a central nervous system ailment comprising administering to said person an effective dosage of a pharmaceutical composition as claimed in claim 9.

12. A compound according to claim 1, or a method of preparation or use thereof, substantially as hereinbefore described with reference to the Examples.

13. The steps, fcaturoc, cR po~stienQ "nd -'oIunds rfezrrecL 15 to or indicated in the specification and/or cl is application, o o individually or colleci any and all combinations of any two o o 01 SDated this 14th day of MAY, 1986 S 25 A/S FERROSAN r 0 By Its Patent Attorneys DAVIES JOLLISON S S: IL C.)t