NZ229750A - Benzoxazole and benzthiazole derivatives and control of parasitic helminths in humans and animals - Google Patents

Description

New Zealand Paient Spedficaiion for Paient Number £29750 229750 NO DRAWINGS "ST Priority DaM(>): ....

Complete Specification Filed: •.

Class: Publication Date: .........^f.^f...^^ P.O. Journal, No: ..A^.Qr.^....; Patents Form No. 5 NEW ZEALAND PATENTS ACT 1953 COMPLETE SPECIFICATION NEW BENZAZOLE DERIVATIVES, PROCESSES FOR THEIR PREPARATION AND PHARMACEUTICAL PREPARATIONS CONTAINING SUCH COMPOUNDS AND THE USE THEREOF ^/We, CIBA-GEIGY AG/ A';Swiss Corporation/ of Klybeckstrasse 141, 4002 Basle, SWITZERLAND hereby declare the invention, for which $/we pray that a patent may be granted to iffe/us, and the method by which it is to be performed, to be particularly described in and by the following statement: (followed by page la) - la- 2 2 9 7 5 0 4-17114/CIN 112 New Benzazole Derivatives, Processes for their Preparation and Pharmaceutical Preparations Containing such Compounds and the Use thereof The invention relates to new benzazole derivatives of the formula I wherein X is oxygen or sulphur, Ri is lower alkyl,.lower alkenyl or cycloalkyl, optionally substituted, R? and R3 independently of one another are each hydrogen, lower alkyl or cycloalkyl radicals or taken together are a substituted or unsubstituted bivalent hydrocarbon residue of aliphatic character in which the carbon atoms of the chain may be interrupted by a heteroatom, Rt» is either a group wherein R5 and R6 independently of one another are each hydrogen, lower alkyl or cycloalkyl radicals, optionally substituted, or taken together R5 and Rg are a substituted or unsubstituted bivalent hydrocarbon residue of aliphatic character in which the carbon atoms of the chain may be interrupted by a heteroatom, or, Ri* is a group where R7 is a lower alkyl group, and their salts and N-oxides and processes for their preparation, pharmaceutical preparations containing them and their uses.

The term 'lower' used to qualify radicals denotes that these contain upto 7 carbon atoms, preferably upto 4 carbon atoms.

I 3 (I) (followed bv Daae ?) 229 75 0 Lower alkyl and allcenyl radicals may be straight-chain or branched-chain radicals substituted by free, esterified or etherified hydroxy groups such as lower alkanoyloxy, lower alkoxy or lower alkenyloxv groups, free or esterified carboxyl groups such as lower alkoxycarbonvl, as for example, methoxy or ethoxv-carbonyl, dialkvlamino, lower alkyl thio and lower alkenyl thio or halogen atoms.

Halogen atoms are in particular fluorine, chlorine or. bromine atoms but can also be iodine atoms.

Lower alkyl groups are, for example, preferably methyl groups and also ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butvl. Lower alkenyl groups are, for example, the allyl group or 2-rnethyl-allvl group. Substituted lower alkyl groups are, for example, the trifluoro-methyl group or a free or esterified carboxymethyl group, for example, the methoxycarbonylmethyl group.

A cycloalkyl group is primarily a monocyclic residue having, for example, 3 to 10 carbon atoms, preferably 5 to 7 carbon atoms, for example, a cyclopentyl, cyclohexyl and cycloheptyl group.

The groups R~ and R3 or R5 and Rg when taken together represent an optionally substituted bivalent hydrocarbon residue of aliphatic character which contains between 4 and 7 carbon atoms in the chain. The sub-stituents on the bivalent hydrocarbon may be one or more lower alkyl groups or an optionally substituted phenyl radical. Thus the substituted bivalent hydrocarbon radical, e.g. as lower allcylene together with the nitrogen atom represents a heterocyclic radical such as pvrrolidino, piperidino, 4-methyl or 4-phenyl piperidino, hexahydroazepino or octa-hydroazocino group. The bivalent hydrocarbon chain may be interrupted by a hetero atom, for example, oxygen, sulphur, substituted or unsubstituted nitrogen representing as oxa-lower alkyleneamino, for example, roorpho-lino, 2,6-dimethylmorpholino, or as thia-lower alkyleneamino, for example, thiamorpholino, or optionally substituted aza-lower alkyleneamino, for example, N-methyl, N-phenyl, N-acetyl, N-methoxycarbonyl, N-ethoxycarbonyl- or N-methanesulphonyl piperazino groups as well as 2 2 9 7 5 0 3 their N-oxides. Substituents on the optionally substituted nitrogen atom which interrupt the bivalent hydrocarbon chain as indicated above may be an optionally substituted lower alkyl group or an arvl group such as phenyl groups, an acyl group such as lower alkanoyl, e.g. acetyl, or aroyl, e.g. benzoyl, or a lower alkoxycarbonvl group such as ethoxv-carbonyl or methoxycarbonvl or an alkanesulphonvl group such as methane-sulphonvl.

The benzene nucleus may be optionally substituted by lower alkyl, aikoxy, carballcoxy groups or halogen atoms.

The novel compounds have valuable pharmacological properties. They are useful in the control of parasitic helminths such as nematodes, cescodes and trematodes. They are particularly useful in the control of pathogens in filariasis such as Litomosoides carinii, Brugia inalavi, Brugia pahangi and Dipetalonema viteae and of their developmental stages. In the treatment of filariasis in multimammate rat Qfastomvs natalensis) ana jirds (Meriones unguiculatus), the new compounds have proved to be very potent as macro and microfilaricides on administration orally 1-5 times of dose of 6.25 to 25 mg/kg.

Particularly useful by virtue of their potent antifilarial activity are compounds of the formula I wherein X is sulphur or oxygen, Ri is lower alkyl, and R2 and R3 together represent lower alkylene optionally interrupted by oxygen, sulphur or nitrogen with a total of 4 to 6 carbon atoms wherein nitrogen is optionally substituted by lower alkyl, lower alkanoyl or lower alkoxycarbonvl group and Ri» is a group wherein R5 and R& taken together are lower alkylene optionally interrupted by oxygen or optionally substituted nitrogen with a total of 4 to 6 carbon atoms, R4 e.g. thus constituting a heterocyclic group such as pyrrolidino, piperidino, hexahydroazepino,• morpholino, piperazino, 4-methyl piperazino and its N-oxide, 4-acetylpiperazino, 4-carbethoxv-piperazino groups, or, Ri» is a group — S—CHz H—NH—CO—R7 6 OOH 2 2 9 7 5 0 where R7 is a lower allcyl group.

Of particular interest are compounds of the formula I, wherein X is sulphur, Ri is lower alkyl with 3 and 4 carbon atoms, and R? and R3 together represent lower alkylene with a total of 4 to 6 carbon atoms in the chain optionally interrupted by oxygen or nitrogen wherein nitrogen is optionally substituted by lower alkyl or lower alkoxy carbonyl, and Ru is a group /5 "< Re where R5 and R6 together are lower alkylene with a total of 4 to 6 carbon atoms in the chain optionally interrupted by oxygen or nitrogen wherein nitrogen is optionally substituted by lower alkyl, lower alkanoyl or lower alkoxycarbonyl, Ri, thus constituting e.g. a heterocyclic group such as a piperidino group, piperazino group and 4-methylpiperazino group and its N-oxide thereof or Ri^ is a group -S-CH2—CH-NH—CO-R7 COOH where R7 is a lower alkyl group, e.g. methyl.

The most preferred compounds of formula I are compounds, wherein X is sulphur, Ri is tert-butyl, R2 and R3 together with the nitrogen atom form a heterocyclic group, such as piperidino optionally substituted by lower alkyl group, R^ is a group —N(RsRe) wherein R5 and R6 together with the nitrogen atom form a heterocyclic group, such as piperidino or piperazino with a lower alkyl, alkanoyl or alkoxycarbonyl group as substituent on the nitrogen atom of the piperazine, or Ri» is — S—CH^— CH(COOH)— NH—CO—R7 wherein R7 is a methyl group, and their pharmaceutical^ acceptable salts.

The invention relates especially to compounds of the formula I mentioned in the Examples and their salts. Particularly mentioned are the following compounds: 2-Tert-butyl-6~l(4-methylpiperazin-l-yl)thiocarbonylamino j-5-(4-methyl-piperidin-l-yl)benzothiazole. 2 2 9 7 5 0 2-Tert-butyl-6-[4-methylpiperazin-l-yl)thiocarbonvlami.noj—5—(piperidin-1 yl)benzothiazole. 2-Tert-butyl-5-(piperidin-l-yl)-6-|. ( piper idin-1-yl) thiocarbonvl amino J ben zothiazole. 2-Tert-butyl-6-[(morpholin-4-yl)thiocarbonylamino j-5-(piperidin-1-vl)ben zothiazole. 2-Tert-butyl-6-[(piperidin-1-yl)thiocarbonylamino J-5-(4-methvlpiperazin-l-yl)benzothiazole.

S-(Acetamido-2-carboxyethyl)-M-f 2-tert-butyl-5-(4-methylpiperidin-1-yl)benzothiazol-6-yl]dithiocarbamate.

S-(Acetamido-2-carboxyethyl)-N-f2-tert-butyl-5-(piperidin-l-yl)benzothia zol-6-yl]dithiocarbamate.

According to the present invention there is provided a process for the preparation of novel benzazole derivatives of the formula I, wherein X, Ri , R2, R3 and Ri* have the meanings defined above, which comprises the reaction of an isothiocyanatobenzazole of the formula II wherein X, Ri, Rj and R3 have the meanings defined above, with a nucleo-philic compound of the formula R^—H. The nucleophile Ri,—H can have eithe the formula III (II) (III) 229 7 5 0 wherein R5 and Rg independently of one another are each hydrogen, lower alkyl or cycloalkyl radicals, optionally substituted, or taken together R5 and Rg are a substituted or unsubstituted bivalent hydrocarbon residue of aliphatic character in which the carbon atoms of the chain may be interrupted by a heteroatom, or, Rif —H can have the formula IV HS—CH2—CH—NH-CO-Ry (IV) COOH where R7 is a lower alkyl group.

Starting compounds of the formula II can be prepared by methods described in European Patent Application No. 85810418.5 published under No. 0175650 from the corresponding 6-amino benzazoles. The preferred procedures for this conversion are the reaction of the amines with ammonium thiocvanate to yield the thioureas and pvrolysis of the latter to yield the isothiocyanates or the direct conversion of the amines by treatment with thiophosgene to yield the isothiocyanates.

The reaction of the isothiocyanates II with the nucleophile Rij— H can be carried out in solvents such as chloroform, methylene dichloride, ethanol or dimethyl formamide.

The process described can be carried out in the conventional manner at ambient temperature, with cooling or warming, under normal pressure or elevated pressure and, if necessary, in the presence or absence of a diluent, catalyst or condensing agent. If necessary, the reaction can also be carried out in the atmosphere of an inert gas, for example, nitrogen.

In resulting compounds substituents can be introduced, modified or detached within the scope of the definition of the end products.

Compounds of the formula I wherein R^ = R5 22 9 7 5 0 can also be obtained by the reaction of 6-aminobenzazoles of the formula V A /\ i ! ✓ (v) ' H,/ V V with a thiocarbamoyl halide of formula VI Hal-CS-IT (VI) in which Hal is chlorine or bromine in the presence of an acid binding agent.

Another method of obtaining compounds of the formula I wherein R» - *6 is to react a thiocarbamic acid derivative of formula VII, r=-\A./\ , ^ 1 II >-Ri (VII) • • 0-C-NH/ ^ % / fl wherein X, Ri, R2, and R3 have the meanings as defined above under formula I, with an amine of the formula III R\ ^H (III) Re Compounds of formula VII are obtained by reacting a 6-aminobenzazole of formula V with a halothiocarboxylic acid-O-phenyl ester or 0, O-diphenyl thiocarbonate.

The invention also relates to these embodiments of a process in which a process is discontinued at any stage or in which a compound obtainable as an intermediate at any stage is used as a starting material and the missing process steps are carried out, or a starting material is formed 229750 under the reaction conditions, or if desired, is used in the form of a salt. The invention also includes novel intermediates resulting therefrom.

Depending on the process conditions and the starting materials the end products are obtained in the free form or in the form of their salts, especially acid addition salts which are also included in the invention. The acid addition salts of the novel compounds can be converted to the free compound in a manner known per se, for example with basic agents such as alkali or ion exchangers. On the other hand the resulting free bases can form salts with organic or inorganic acids. Acids used to prepare acid addition salts are in particular those which are suitable for forming therapeutically usable salts.

The following may be mentioned as examples of suitable acids: hydrohalic acids, sulfuric acids, phosphoric acids, nitric acid, perchloric acid, aliphatic, alicyclic, aromatic or heterocyclic carboxvlic or sulfonic acids, such as formic acid, acetic acid, propionic acid, succinic acid, glycolic acid, lactic acid, malic acid, tartaric acid, citric acid, ascorbic acid, maleic acid, hydroxymaleic acid or pyruvic acid; phenyl-acetic acid, benzoic acid, p-aminobenzoic acid, anthranilic acid, p-hydroxybenzoic acid, salicylic acid or p-aminosalicvclic acid, embonic acid, methane-sulfonic acid, ethanesulfonic acid, hydroxvethanesulfonic acid, or ethylenesulfonic acid; halogenobenzenesulfonic acid, toluene-sulfonic acid, naphthalenesulfonic acid or sulfanilic acid; and methionine, tryptophane, lysine or arginine.

Evaluation in the animal test systems mentioned above show the excellent potential of the novel compounds as micro and macrofilaricides, for example, for lymphatic filariasis and onchocerciasis for which an effective dosage range of 6.25 to 50 mg/kg daily by oral administration over a period of one to 5 days is to be used. The compounds may be used for the treatment of lymphatic and tissue-dwelling filarial infections in man. The compounds may also be used for the treatment of intestinal helminthic infections like ancylostomiasis, ascariasis, oxyuriasis and trichuriasis and also schistosomiasis in animals and in human beings at dose range of 10 to 500 mg/kg. 229750 The pharmaceutical preparations according to the invention, which contain compounds of the formula I or pharmaceutical^ acceptable salts thereof, are those for enteral, such as oral or rectal, and parenteral, administration to warm-blooded animals, that contain the pharmacologically active substance alone or together with a pharmacologically acceptable carrier. The dosage of the active substance depends on the species of warm-blooded animal, the age and the individual condition, and on the method of administration.

The new pharmaceutical preparations contain, for example, from approximately 10 % to approximately 80 % preferably from approximately 20 % to approximately 60 % of the active substance. Pharmaceutical preparations according to the invention for enteral or parenteral administration are, for example, those in dosage unit forms, such as dragess, tablets, capsules, suppositories, or also ampoules. These are produced in a manner known per se, for example by means of conventional mixing, granulating, coating, dissolving or lyophilising processes. Thus, pharmaceutical preparations for oral administration can be obtained by combining the active substance with solid carriers, optionally granulating a resulting mixture, and processing the mixture or granulate to form tablets or dragee cores, if desired or necessary after the addition of suitable adjuncts.

Suitable carriers are especially fillers, such as sugars, for example lactose, saccharose, mannitol or sorbitol, cellulose preparations and/or calcium phosphates, for example tricalcium phosphate or calcium hydrogen phosphate, also binders, such as starch pastes using, for example, corn, wheat, rice or potato starch, gelatin, tragacanth, methylcellulose and/or polyvinylpyrrolidone, and/or if desired, disintegrators, such as the above-mentioned starches, and also carboxymethylstarch, cross-linked polyvinylpyrrolidone, agar, alginic acid or a salt thereof, such as sodium alignate. Adjuncts are especially flow-regulating agents and lubricants, for example, silica, talc, stearic acid or salts thereof, such as magnesium or calcium stearate, and/or polyethylene glycol. Dragee cores are provided with suitable, optionally gastric juice-resistant coating, there being used, inter alia, concentrated sugar solutions, 229750 which optionally contain gum arabic, talc, polyvinylpyrrolidone, polyethylene glycol and/or titanium dioxide, lacquer solutions in suitable organic solvents or solvent mixtures or, to produce gastric juice-resistant coating, solutions of suitable cellulose preparations, such as acetylcellulose phthalate or hydroxypropvlmethylcellulose phthalate. Colouring matter or pigments may be added to the tablets or dragee coating, for example for identification purposes or for indicating different doses of active substance.

Other pharmaceutical preparations for oral administration are dry-filled capsules made of gelatin, and soft sealed capsules consisting of gelatin and a plasticiser, such as glycerin or sorbitol. The dry-filled capsules may contain the active substance in the form of a granulate, for example, in admixture with fillers, such as lactose, binders, such as starches, and/or glidants, such as talc or mangesium stearate, and optionally, stabilisiers. In soft capsules th eactive substance is preferably dissolved or suspended in suitable liquids, such as fatty oils, paraffin oil or liquid polyethylene glycols, it likeweise being possible for stabilisers to be added.

These come into consideration as rectally administerable pharmaceutical preparations, for example, suppositories consisting of a combination of the active substance with a suppository base. Suitable suppository bases are, for example, natural or synthetic triglycerides, paraffin hydrocarbons, polyethylene glycols or higher alkanols. It is also possible to use gelatin rectal capsules that contain combination of the active substance with base substances, for example, liquid triglycerides, polyethylene glycols or paraffin hydrocarbons.

Especially suitable forms for parenteral administration are aqueous solutions of an active substance in water-soluble form, for example, a water-soluble salt, or suspensions of the active substance, such as corresponding oily injection suspensions, suitable lipophilic solvents or vehicles, such as fatty oils, for example sesame oil, or synthetic fatty acid esters, for example ethyl oleate or triglycerides, being used, or 22 9 7 5 0 aqueous injection suspensions that contain viscosity-increasing substances, for example, sodium carboxvmethylcellulose, sorbitol and/or dextran and optionally also stabilisers.

Tinctures and solutions usually have an aqueous ethanolic base, to which there are added, inter alia, polyalcohols, for example, glycerin, glycol and/or polyethylene glycol, as moisture-retaining agents for reducing evaporation, and fat-restoring substances, such as fatty acid esters with low polyethylene glycols, that is to say lipophilic substances soluble in aqueous mixture as a replacement for the fatty substances removed from the skin by the alcohol, if necessary, other adjuncts and additives.

The present invention relates also to the use of the compounds of the formula I and the salts of such compounds with salt-forming properties, preferably for combating parasitising helminths, especially those of the families mentioned above.

The following Examples illustrate the above-described invention but are in no way intended to limit the scope thereof. In the following Examples temperatures are in degrees centigrade.

Example 1: To a stirred solution of 90 g of 2-tert-butyl-6-isothio-cyanato-5-(4-methylpiperidin-l-yl)benzothiazole in 900 ml of methylene chloride is added dropwise 26 g of N-methylpiperazine. The solution is stirred for 1 hour, washed with water, dried over anhydrous sodium sulphate and evaporated to give 110 g of 2-tert-butyl-6-l. (4-methyl-piperazin-l-yl)thiocarbonylamino J-5-(4-methylpiperidin-1-yl)benzo-thiazole, melting at 192 - 195UC.

The starting material for the above synthesis is prepared as follows: A solution of 32,4 g of 2-tert-butyl-5-chloro-6-nitrobenzothiazole, (described in European patent application 85810418.5 published under No. 017 5650) in 300 ml of diroethylsulphoxide, is stirred and heated at 140° for 6 hours with 12.8 g of 4-methylpiperidine and 35.8 g of anhydrous potassium carbonate, cooled and poured into water. The solid obtained is dissolved in chloroform and filtered through a silical gel 22 9 7 5 0 column. The filtate is evaporated to give 2-tert-butyl-5-(4-methyl-piperidin-l-yl)-6-nitrobenzothiazole melting at 116 - 120".

A solution of 15.2 g of 2-tert-butyl-5-(4-methyl-piperidin-l-yl)-6-nitro-benzothiazole in 600 ml of methanol is hydrogenated in presence of 6.5 g of Raney Nickel at room temperature. After removing the catalyst the solution is concentrated and the solid filtered to give 6-amino-2-tert-butyl-5-(4-methylpiperidin-l-yl)benzothiazole melting at 146 - 148°.

To a cooled mixture of 2.1 g of 6-amino-2-tert-butyl-5-(4-methylpiperi-din-l-yl)benzothiazole and 2.8 g of potassium bicarbonate in 20 ml of chloroform is added dropwise 1.6 g of thiophosgene in 5 ml of chloroform under stirring. The stirring is continued for 2 hours maintaining the temperature at 0 - 2°. The solid is filtered and the filtrate is evaporated. The solid thus obtained is dissolved in chloroform and filtered through a silica gel column. The filtrate is evaporated to give 2-tert-butyl-6-isothiocyanato-5-(4-methyl-piperidin-l-yl)benzothiazole, melting at 54 - 58".

Example 2: Using the procedure described in Example 1 by reaction of 2-tert-butyl-6-isothiocyanato-5-(4-methvl-piperazin-l-yl)benzothiazole with 4-methylpiperazine is obtained 2-tert-butyl-6-(. (4-methylpiperazin-1-yl)thiocarbonylamino J-5-(4-methyl-piperazin-l-yl)benzothiazole, melting at 190 - 193°.

The starting material for the above synthesis is prepared as follows: A solution of 171 g of N-tert-butylthiocarbonyl-2,5-dichloro-4-nitro-aniline (described in European patent application No. 85810418.5 published under No. 0175650) and 605 ml of N-methylpiperazine in 1700 ml of dimethylsulphoxide is heated at 140° for 8 hours, cooled and poured into water. The solid is filtered, washed with water and cold isopropanol to yield 2-tert-butyl-5-(4-methylpiperazin-l-yl)-6-nitrobenzothiazole, melting at 132 - 135". 229 7 5 0 A solution of 86 g of the above nitro compound in 150 ml of ethanol is hydrogenated in presence of 30 g of Raney nickel at 45^. The solution is filtered to give 6-amino-2-tert-butyl-5-(4-methylpiperazin-l-yl)benzo-thiazole, melting at 130UC.

To a stirred mixture of 75 g of 6-Amino-2-tert-butyl-5-(4-methvlpipera-zin-l-yl)benzothiazole and 29 g of sodium bicarbonate in 1100 ml of chloroform at 0° is added 41 g of thiophosgene and the mixture stirred at 10° for 4 hours. After filtering off the solid, the solution is evaporated to get a yellow solid which is dissolved in water and the pH of the solution is brought to 7 by the addition of dilute sodium hydroxide. The solid separated is extracted with hexane and filtered through 150 g of neutral alumina to give 2-tert-butvl-6-isothiocyanato-5-(4-methyl-piper-azin-l-yl)benzothiazole, melting at 124 - 126°.

Example 3: Reaction of 2-tert-butyl-6-isothiocyanato-5-(4-methvl-pipera-zin-l-yl)benzothiazole described in Example 2 with piperidine under conditions described in Example 1 gives 2-tert-butyl-6~l(piperidin-1-yl)thiocarbonylamino j-5-(4-methvl-piperazin-l-yl)benzothiazole, melting at 202 - 206°.

Example 4: The following compounds can be prepared by the process described in Example 1 by reaction of 2-tert-butvl-6-isothiocvanato-5-(piperidin-l-yl)benzothiazole (described in European Patent application No. 85810418.5) with the appropriate amine: 2-tert-butyl-5-(piperidin-1-yl)-6-[(piperidin-l-yl)thiocarbonylamino Jben-zothiazole, melting at 183 - 186°; 2-tert-butyl-6-[(4-methylpiperazin-l-yl)thiocarbonylamino]-5-(piperidin- 1-yl)benzothiazole, melting at 191 - 193°; 2-tert-butyl-6-[(4-carbethoxypiperazin-l-yl)thiocarbonylamino]-5-(piperi-din-l-yl)benzothiazole, melting at 191 - 194°; 2-tert-butyl-6-[(morpholin-4-yl)thiocarbonylamino]-5-(piperidin-l-yl)ben-zothiazole, melting at 187 - 191°; 229 7 5 0 2-tert-butyl-6-[(hexamethyleneimin-l-yl)thiocarbonylaraino J-5-(piperidin-1-yl)benzothiazole, melting at 185 - 188°; N-[2-tert-butyl-5-(piperidin-1-yl)benzothiazo1-6-y1J-N'-(2-dimethylamino-ethyl)thiourea, melting at 61 - 65°; N-[2-tert-butyl-5-(piperidin-l-yl)benzothiazol-6-ylJ-N'-(2-diethylamino-ethyl)thiourea, melting at 102 - 104°; N-[2-tert-butyl-5-(piperidin-l-yl)benzothiazol-6-ylJ-N' - [ S^piperidin- 1-yDpropylJthiourea, melting at 113 - 115°; N-[2-tert-butyl-5-(piperidin-l-yl)benzothiazol-6-ylJ-N'-[3-(4—methy1-piperazin-l-yl)propvl]thiourea, melting at 133 - 135°; N-[2-tert-butyl-5-(piperidin-l-yl)benzothiazol-6-ylJ-N'-[3-(N,N-dimethvl-amino)propylJthiourea, melting at 155 - 157°; N-[2-tert-butyl-5-(piperidin-l-yl)benzothiazo1-6-y1J-N'-(2-hydroxy-ethyl)thiourea, melting at 177 - 178°; 2-tert-butyl-6-[(4-methylpiperidin-l-yl)thiocarbonylamino J-5-(piperidin-l-yl)benzothiazole, melting at 214 - 217°; L-N-[2-tert-buty1-5-(piperidin-l-yl)benzothiazo1-6-y1]araino-thiocarbony1- proline, melting at 183 - 187°; £ L-N -[2-tert-butyl-5-(piperidin-l-yl)benzothiazol-6-yl )J aminothiocar-bonylarginine, melting at 175 - 178°; Example 5: A solution of 3.45 g of 2-tert-butyl-6-isothiocyanato-5-( 4-methylpiperidin-l-yl)benzothiazole, described in Example 1, and 8.6 g of anhydrous piperazine in 30 ml of chloroform is stirred for 3 hours, washed with water, dried over anhydrous sodium sulphate and evaporated to 229 7 5 0 get a sticky residue which is triturated with isopropanol and filtered to obtain 3 g of 2-tert-butyl-5-(4-methyl-piperidin-l-yl)-6-l(piperazin-1-yl)thiocarbonylaminoJbenzothiazole, melting at 278 - 281°.

Example 6: A solution of 2.0 g of 2-tert-butyl-6-isothiocvanato-5-(4-methylpiperidin-l-yl)benzothiazole and 0.78 g of 1-acetyl-piperazine in 30 ml of chloroform is stirred for 30 minutes and the product triturated with petroleum ether to obtain 6-[(4-acetyl-piperazin-l-yl)thiocarbo-nylamino]-2-tert-butyl-5-(4-methylpi peridin-l-yl)benzothiazole, melting at 187 - 190°.

Example 7: To a freshly prepared solution of sodium ethoxide (1.4 g of sodium in 100 ml of absolute ethanol) is added 5.2 g of 1-methyl-l-oxido-piperazine dihydrochloride. The mixture is stirred at 50° for 15 to 20 minutes and then at room temperature for 1 hour. The precipitated sodium chloride is filtered off and the filtrate is treated with a suspension of 8.6 g of 2-tert-butyl-6-isothiocvanato-5-(4-methylpiperi-din-l-yl)benzothiazole, described in Example 1, in 25 ml of ethanol under stirring. The mixture is refluxed for 1 hour, cooled, concentrated under reduced pressure and the solid filtered to yield 3 g of 2-tert-butyl-5-(4-raethyl-piperidin-l-yl)-6-(4-methyl-4-oxopiperazin-l-yl) thiocarbo-nylaminobenzothiazole, melting at 115 - 117°.

Example 8: A mixture of 69 g of 2-tert-butyl-6-isothiocyanato-5-(4-methylpiperidin-l-yl)benzothiazole and 39.2 g of N-acetyl-L-cvsteine in 250 ml of dimethyl formamide is stirred under nitrogen atmosphere at room temperature for 72 hours, poured into water, the solid filtered and washed with water. The wet cake is dissolved in 500 ml of methylene chloride, dried over anhydrous sodium sulphate and treated with 1.5 1 of hexane. The solid is filtered to give 85 g of S-(acetamido-2-carboxy-ethyl)-N-(2-tert-butyl-5-(4-methy1-piperidin-1-yl) benzothiazol-6-yl]dithiocarbamate, melting at 140 - 143°.

Example 9: Using the procedure described in Example 8, S-(acetamido-2-carboxyethyl)-N-[2-tert-butyl-5-(piperidin-l-yl)-6-benzothiazol-6-ylJ di— thiocarbamate, melting at 138 - 140° can be prepared.

Claims (37)

229 7 5 0 - 16 - Example 10: To a solution of 0.6 g of 6-amino-2-tert-butyl-5-(4-methvl-piperidin-l-yl)benzothiazole and 0.36 g of l-chloro-thiocarbonyl-4-methvlpiperazine in 30 ml of dioxane is added 0.3 g of 1,8-diazabicyclo (5,4,0) undec-7-ene (DBU) and the mixture heated at 100° for 6 hours. The reaction mixture is evaporated to dryness, the residue triturated with water and the solid filtered. Chromatography of the solid over silica gel and elution with methylene dichloride-methanol (98:2) gives 2-tert-butyl-6-[(4-methylpiperazin-l-yl)thiocarbonylamino]-5-(4-methylpiperi-din-l-yl)benzothiazole, identical with the compound described in Example 1. Example 11: A solution of 0.5 g of 2-tert-butyl-5-(4-methyl-piperidin-l-yl)-6-phenoxythiocarbonylaminobenzothiazole and 0.11 g of 4-methyl-piperazine in 20 ml of dioxane is refluxed for 16 hours. Evaporation of the solvent and chromatography of the residue over silica gel and elution with methylene dichloride-methanol (98:2) gives 2-tert-butyl-6-[(4-methvlpiperazin-1-yl)thiocarbonylamino]-5-(4-methylpiperidin-1-yl)ben-zothiazole, identical with the compound described in Example 1. The starting material for the above synthesis is prepared as follows: A mixture of 1.5 g of 6-amino-2-tert-butyl-5-(4-methvlpiperidin-l-yl)benzothiazole and 1.15 g of 0,0-diphenylthiocarbonate in 8 ml of pyridine is refluxed for 3.5 hours. The solvent is evaporated and the residue purified by chromatography over silica gel. Elution with methylene dichloride gives 2-tert-butyl-5-(4-methylpiperidin-l-yl)-6-phenoxy-thiocarbonylarainobenzothiazole melting at 201 - 205°. 229750 17 WHAT >fWE CLAIM fS: What ia claimed ia!

1. Benzazole derivatives of the formula I 3 R*-p - x (i) wherein X is oxygen or sulphur, Ri is lower alkyl, lower alkenyl or cycloalkyl, optionally substituted, R2 and R3 independently of one another are each hydrogen, lower alkyl or cycloalkyl radicals or taken together are a substituted or unsubstituted bivalent hydrocarbon residue of aliphatic character in which the carbon atoms of the chain may be interrupted by a heteroatom, Ri) is either a group wherein R5 and Rg independently of one another are each hydrogen, lower alkyl or cycloalkyl radicals, optionally substituted, or taken together R5 and R$ are a substituted or unsubstituted bivalent hydrocarbon residue of aliphatic character in which the carbon atoms of the chain may be interrupted by a heteroatom, or, Ri» is a group where R7 is a lower alkyl group, and their salts, and N-oxides.

2. A compound of formula I according to claim 1, wherein X is oxygen or sulphur, Ri is lower alkyl, and R2 and R3 together represent lower alkylene optionally interrupted by oxygen, sulphur or nitrogen with a total of 4 to 6 chain atoms wherein nitrogen is optionally substituted by lower alkyl, lower alkanoyl or lower alkoxycarbonyl group, and R4 is a group -S-CH2-CH-NH-CO-R7 COOH t 6 229750 - 18 - wherein R5 and taken together are lower alkylene with a total of 4 to 6 carbon atoms in the chain optionally interrupted by oxygen or optionally substituted nitrogen, or Ru is a group —S—CH 2 CH—N*H—CO-Ry COOH where R7 is a lower alkyl group, and their salts and N-oxides.

3.A compound of formula I according to claim 1, wherein X is sulphur, Ri is lower alkyl with 3 or 4 carbon atoms, R2 and R3 together represent lower alkylene with a total of 4 to 6 carbon atoms in the chain optionally interrupted by oxygen or nitrogen wherein nitrogen is optionally substituted by lower alkyl or lower alkoxycarbonyl, and Ru is a group -/ wherein R5 and R5 together are lower alkylene with a total of 4 to 6 carbon atoms in the chain optionally interrupted by oxygen or nitrogen where nitrogen is optionally substituted by lower alkyl, lower alkanoyl or lower alkoxycarbonyl group, or Ri* is a group —S—CHj—CH—Nff-CO—R7 COOH where R7 is a lower alkyl group, and their salts and N-oxides.

4. A compound of formula I according to claim 1, where X is sulphur, Ri is tert-butyl, R2 and R3 together with the nitrogen form a heterocyclic radical, is a group 5 \ *. X*. where R5 and R6 together with the nitrogen fortr. a het3erocyclicxg"r.aitp? ' or a R4 is a grot?) -S-CH2-CH-VH-CO-R7 COOH where R7 is a methyl group, and their pharmaceutically acceptable salts and N-oxides. - 19 - 229750

5. A compound according to claim 4, wherein and together with the nitrogen form a piperidyl optionally substituted by lower alkyl groups.

6. A compound to according to claim 4 or claim 5, wherein and Rg together with the nitrogen form a piperidino or piperazino with a lower alkyl, alkanoyl or alkoxycarbonyl group on the nitrogen of the piperazine.

7? 2-Tert-butyl-6-l(4-methylpiperazin-l-yl)thiocarbonylaminoJ-5-(4-methylpiperidin-l-yDbenzothiazole and pharmaceutically acceptable salts thereof.

• 8. 2-Tert-buty1-6-1(4-methvlpiperazin-l-yl)thiocarbonylaminoJ-5-(4- methylpiperazin-l-yl)benzothiazole and pharmaceutically acceptable salts thereof.

9'. 2-Tert-butyl-6-[ (piperidin-l-yl)thiocarbonylamino J-5-( 4-methylpiper-azin-l-yl)benzothiazole and pharmaceutically acceptable salts thereof.

10. 2-Tert-butyl-5-(piperidin-l-yl)-6-[ ( piperidin-l-yl.) thiocarbonylamino jbenzothiazole and pharmaceutically acceptable salts thereof.

11. 2-Tert-butyl-6-[(4-methylpiperazin-l-yl.)thiocarbonylamino]-5-(piperi-din-l-yl)benzothiazole and pharmaceutically acceptable salts thereof.

12. 2-Tert-butyl-6-[(4-carbethoxyoiperazin-l-yl)thiocarbonvlamino]- _ •o" ^ T £ 5-(piperidin-l-yl)benzothiazole and pharmaceutically acceptable sa^lts thereof. ' j5 'may, 99;'v

13. 2-Tert-buty 1-6-[ (mo rpholin-4-yl) thiocarbonvlamino j-5-(piperiaSL?t-l-yl)benzothiazole and pharmaceutically acceptable salts thereof.

14. 2-Tert-buty 1-6-f (hexaraethyleneimin-l-yl)thiocarbonylaraino J-5-( pipe=:--;2S2£^i^^g ridin-l-yl)benzothiazole and pharmaceutically acceptable salts thereof.

15. fJ-[2-Tert-buty1-5-(piperidin-l-yl)benzothiazo1-6-y1]-N'-(2-dimethy1-aminoethyl)thiourea and pharmaceutically acceptable salts thereof.

16. N-[2-Tert-buty1—5—(piperidin-1-yl.) benzothiazo1-6-y1]-N'-(2-diethyl-aminoethyl)thiourea and pharmaceutically acceptable salts thereof. - 20 - 229750

17. N-[2-Tert-butyl-5-(piperidin-1-yl)benzothiazo1-6-y1]—N'—[3—(piperi-din-l-yl)propyljthiourea and pharmaceutically acceptable salts thereof.

IS- N-[2-Tert-butyl-5-(piperidin-1-yl)benzothiazo1-6-y1]—N1 —[3—(4-methvl-piperazin-l-yl)propyl]thiourea and pharmaceutically acceptable salts thereof.

19. N-[2-Tert-butyl-5-(piperidin-l-yl)benzothiazo1-6-y1j —N1 — [3-(N,N-di-methylamino)propyl]thiourea and pharmaceutically acceptable salts thereof.

20. N-[2-Tert-butyl-5-(piperidin-l-yl)benzothiazo1-6-yl]-S*-(2-hydroxy-ethvl)thiourea and pharmaceutically acceptable salts thereof.

21- 2-Tert-butyl-6-[ ( 4-me thy lpiperidin-1-yl) thiocarbonylamino J-5-(, piper i-din-l-yl)'oenzothiazole and pharmaceutically acceptable salts thereof.

22. L-N-[2-Tert-buty1-5-(piperidin-l-yl)benzothiazol-o-yl]aminothio- carbonylproline and pharmaceutically acceptable salts thereof. £

23. L-N -[2-Tert-butyl-5-(piperidin-l-yl)benzothiazol-6-yl]aminothio-carbonylarginine and pharmaceutically acceptable salts thereof.

24. 2-Tert-butyl-5-(4-methvl-piperidin-l-yl)-6-[(piperazin-l-y1)thi carbonylarainojbenzothiazole and pharmaceutically acceptable sal^ thereof.

2 5. 6-[(4-Acetylpiperazin-l-yl)thiocarbonylamino]-2-tert-butyl-methylpiperazin-l-yl)benzothiazole and pharmaceutically acceptaalFc%^ thereof. ^

2 6. 2-Tert-butyl-5-(4-methyl-piperidin-l-yl)-6-[(4-methy1-4-oxopipera-zin-l-yl)thiocarbonylamino]benzothiazole and pharmaceutically acceptable salts thereof. - 21 - 229750

2 7. S-(Acetamido-2-carboxvethyl)-N-[ 2-tert-'outyl-5-( 4-met'nvl-piperidin- salts thereof.

28. S-(Acetamido-2-carboxyethvl)-M-[2-tert-butvl-5-(piperidin-l-yl)-6-benzothiazol-6-yl]dithiocarbamate and pharmaceutically acceptable salts thereof.

29. A pharmaceutical preparation containing a compound of the formula I of claim 1.

30. A compound of the formula I of claim 1 for application in a process for the therapeutic treatment of the human or animal body.

31. A compound of the formula I of claim 1 for use as an antifilarial or anthelmintic agent for human and veterinary use.

32. Use of a compound of the formula I of claim 1 for producing pharmaceutical preparations.

33- A process for producing compounds of formula I as defined in claim 1, which comprises a) treating compounds of formula II with a compound of formula R^—H wherein X, Ri , Rj > R3 and R* have the meanings defined under formula I, l-vl)benzothiazol-6-ylJdithiocarbamate and pharmaceutical!]/ acceptable (II) b.) treating compounds of formula V (V) ;9 7 229750 - 22 - with a thiocarbamoyl halide of formula VI Hal-CS-N^ (VI) wherein R$ and Rg have the meanings defined under formula I, c) treating compounds of the formula VII R2"\ A A, I jj y—Ri (viD \J"0Tra/ v ^ with an amine of formula III /NH (III) Rs

34. The process as claimed in claim 33, substantially as described in the examples 1 to 9.

35. The process as claimed in claim 33, substantially as described in example 10.

3-6. The process as claimed in claim 33, substantially as described in example 11.

37. A compound when obtained by any one of the processes of claim 33. CIBA-GEIGY AG lr Attorneys^ IN, SON & CAREY^ .V-' k T H A/ >- ^ ' o\ ^ i if 3 1 MAY 1991 £ / i