NOVEL PIPERAZINYLALKYLTHIOPYRIMIDINE DERIVATIVES, PHARMACEUTICAL COMPOSITIONS CONTAINING THE SAME AND A PROCESS FOR THE PREPARATION OF THE NOVEL COMPOUNDS

Abstract: The invention refers to novel piperazinylalkylthiopyrimidine derivatives of formula (I) being suitable for the treatment of diseases due to pathological alterations of the central nervous system, pharmaceutical compositions containing the above derivatives, and a process for the preparation of the novel compounds.

Description: Novel piperazinylaIkylthiopyrimidine derivatives, pharmaceutical compositions containing the same and a process for the preparation of the novel compounds The invention refers to novel piperazinyl- alkylthiopyrimid.ine derivatives, pharmaceutical compositions containing the above derivatives, a method for the treatment of diseases of especially the central nervous system, and a process for the preparation of the novel compounds. Specifically . - the invention refers to compounds of the formula wherein R " and R represent, independently, a hydrogen . , a C, _ . alkyl group, an amino group, a (C, - alkanoyl) amino group, or a phenyl group optionally bearing 1 to 3 substituents selected from the group consisting of, independently, a halo, a C, _. alkoxy group, a di(C,_. alkyl)amino group or a benzyloxy group, 2 R stands for a hydrogen, a cyano group, a furylmethyl group, a (C--_ 7 cycloalkyl )methyl group, a (C,_ 4 alkoxy)carbonyl group, a hydroxy(C-. , alkyl) group or a benzyl group optionally bearing 1 to 3 substituents selected from the group consisting of, independently, a halo, a C,_ 4 alkyl group, a C, 4 alkoxy group, a trifluoro methyl group, a hydroxy group, a benzyloxy group or a di(C- . alkyDamino group, 4 R means hydrogen, or R 3 forms with R4 an oxygen atom, R is hydrogen, or 4 5 R forms with R a valence bond, R represents a halo, a cyano group, a nitro group, a C^ 4 alkyl group, a C,_ 4 alkoxy group or a trifiuoromethyl group, m has a value of 0 or 1, n has a value of 1 or 2, p is an integer between 2 to 11, and k has a value of 0, 1, 2 or 3, and pharmaceutically acceptable acid addition salts thereof. PC17HU96/00061 - 3- The novel piperazinylalkylthiopyrimidine derivatives can be employed, in the first place, for the treatment of diseases due to pathological alterations of the central nervous system. Pyrimidine derivatives connected with a piperazine ring and used for the treatment of urination disorders are described by Japanese Patent Application No. J 3 090 027. Uracil compounds of similar type are known, from DE-P No. 1 942 405. One of the known uracil compounds is urapidil, a blood pressure lowering drug. However, in case of the above compounds, the two heterorings are connected through an alkylamino group. Pyrimidine derivatives bonded to .a piperazine ring through an alkoxy group and having sedative and hypotensive activity are described by BE-P Nr. 756 127. It was found that the novel compounds of the formula I, wherein the heterorings containing nitrogen atoms are connected through an alkylthio group, have excellent biological activity influencing the serotonerg system. In the description, a C, _ . alkyl group is a methyl, ethyl, n-propyl, isopropyl, sec. -butyl, tert. -butyl, n-butyl or isobutyl group. Preferably, C, . alkyl is methyl. A C, . alkanoyl group is a formyl, acetyl, n-propanoyl, n-butanoyl etc. group, preferably an acetyl group. In general, a halo is a fluoro, chloro or bromo, preferably chloro or bromo. A C, . alkoxy group is generally a methoxy, ethoxy, n-propoxy or n-butoxy group, preferably a methoxy group. The pharmaceutically acceptable acid addition salts of the compounds of the formula I are acid addition salts of the compounds formed with pharmaceutically acceptable inorganic or organic acids. Preferred acid addition salts are hydrogen haloids such as hydrochlorides or hydrobro ides, carbonates, hydrogen carbonates, sulfates, phosphates, acetates, fumarates, maleates, citrates and ascorbates. A preferred sub-group of the compounds of the invention consists of the compounds of the formula I, wherein R and R represent, independently, a hydrogen, a methyl group, an amino group, an acetylamino group or a phenyl group optionally bearing 1 to 3 substituents selected from the group consisting of, independently, a chloro group, a methoxy group, a dimethylamino group or a benzyloxy group, 2 R stands for a hydrogen, a cyano group, a furylmethyl group, a cyclohexylmethyl group, an ethoxycarbonyl group, a hydroxyethyl group or a benzyl group optionally bearing 1 to 3 substituents selected from the group consisting of, independently, a chloro, a fluoro, a C, -, alkyl group, a methoxy group, a trifiuoromethyl group, a hydroxy group, a benzyloxy group or a dimethylamino group, 4 R means a hydrogen, or 3 4 R forms with R an oxygen atom, R is a hydrogen, or R 4 forms with R5 a valence bond, R represents a chloro, a fluoro, a cyano group, a nitro group, a methyl group, a methoxy group or a trifluoro methyl group, m has a value of 0 or 1, n has a value of 1 or 2, p has a value of 2 or 11, and k has a value of 0, 1, 2 or 3, and pharmaceutically acceptable acid addition salts thereof. A specifically preferred sub-group of the compounds of the invention consists of the compounds of the formula I, wherein 1 and R represent an amino group, stands for a hydrogen or a benzyl group optionally bearing 1 to 3 substituents selected from the group consisting of, independently, a fluoro, a chloro, a methoxy group and a dimethylamino group, R 4 forms with R5 a valence bond, R means a fluoro, a chloro, a nitro group, a cyano group, a methyl group, a methoxy group or a trifiuoromethyl group, k has a value of 1, has a value of 1, n has a value of 1 , and p has a -value of 2, and pharmaceutically acceptable acid addition salts thereof. The piperazinylalkylthiopyrimidine derivatives of the invention are prepared by reacting a 2-mercaptopyrimidine of the formula 4 5 wherein R , R 2 , R 3 , R and R are as defined above, or an alkali metal salt thereof with a haloalkylpiperazine derivative of the formula wherein R , m, n, p and k are as stated above, Hlg stands for chloro or bromo, or an acid addition salt thereof, and, if desired, transforming an obtained compound of the formula I into a pharmaceutically acceptable acid addition salt or liberating the base from the acid addition salt. The process of the invention is performed in a solvent or solvent mixture that is indifferent from the point of view of the reactants. For example aliphatic alcohols such as methanol, ethanol, isopropanol; dialkylamides preferably dimethylformamide; dialkyl sulfoxides preferably dimethyl sulfoxide; or the mixtures thereof can be used. It is especially preferred to react the reactants in methanol, dimethylformamide or a mixture of methanol and dimethyl¬ formamide. The reaction of the 2-mercaptopyrimidine of the formula II with haloalkylpiperazine derivative of the formula III can be performed in the presence of an acid binding agent. Preferred acid binding agents are alkali metal carbonates such as sodium carbonate, alkali metal hydrocarbonates such as sodium or potassium hydrocarbonate, alkali metal hydroxides such as sodium or potassium hydroxide, alkali earth metal hydroxides such as calcium hydroxide or tertiary amines such as pyridine, triethylamine or other trialkylamines. Preferably, potassium carbonate or sodium carbonate is employed as the acid binding agent. Optionally, a catalyst is used to accelerate the reaction. In general, alkali metal halides or alkali earth metal halides such as potassium iodide, potassium fluoride, sodium bromide or calcium chloride are employed as the catalyst. The reaction is preferably performed in the presence of potassium iodide catalyst. Depending on the reactivity of the starting compounds, the reaction proceeds at a temperature between room temperature and the boiling point of the reaction mixture It is preferred to react the reactants at 60 to 80 °C. The reaction time is 1 to 10 hours depending on the reactivity of the reactants and the reaction temperature used. The starting compounds of the formulae II and III can be employed in an equimolar amount, or the haloalkylpiperazine derivative of the formula III is used up to 10 per cent excess, at the most. The acid binding agent is used in an equimolar quantity referring to the amount of the haloalkylpiperazine derivative of the formula III. The catalyst is employed in 0.1 to 0.2 molar, preferably in 0.1 molar quantity for each mole of the starting compounds. The reaction mixture is worked up in a manner known per se. Preferably, the product is separated as follows: the inorganic salts precipitated are filtered, the filtrate is distilled off in vacuo, and the residue is dissolved in water or an organic solvent to crystallize the product; or the product separated is filtered together with the inorganic salts, then the inorganic salts are removed by dissolution in water. A further alternative is to pour the reaction mixture into water in order to dissolve the inorganic salts, and filtering the product precipitated. If desired, the reaction product is purified by known purification methods such as recrystallization or chromatography. The compounds of the formula I can be also separated in the form of pharmaceutically acceptable acid addition salts mentioned above, " or a compound of the formula I obtained as a base can be converted to acid .addition salt in a subsequent step by reaction with the suitable acid in an indifferent solvent. From the acid addition salt, the base can be repeatedly liberated and optionally converted to another acid addition salt. A large part of the starting compounds of the formula II is known from the literature or is commercially available. These known compounds can be prepared by the modified Traube 's synthesis / . Traube, Ann., 331, 64 (1904)/ or by the method of Jose et al . /Heterocycles, 19 (2), 305-311 (1982)/. However, the compounds of the formula II, wherein R 1 is an amino group, R2 represents a nitrile group, R stands for a 4-bromophenyl, 2- or 4-chlorophenyl , 2- or 4-methoxy.phenyl, 4-dimethylaminophenyl, 4-benzyloxy-3-methoxyphenyl or 3, 4 , 5-trimethoxyphenyl group, R 4 and R5 mean hydrogen, as well as the compounds of the formula II, wherein R and R stand for 2 an amino group, R is a 2-furylmethyl, cyclohexylmethyl, benzyl or mono-, di- or 4 trisubstituted benzyl group, R forms together 5 with R a valence bond, are novel, that are not described in the literature. They can be prepared by the synthesis methods of the known compounds (e.g. European Patent Application No. 465 323). A part of the haloalkylpiperazine derivatives of the formula III is also known from the literature. They can be prepared by means of the method described by e.g. CB. Pollard et al . /j. Org. Chem., 24 , 764-767 (1959)/ or Sidney D. Ross et al. /J. Am. Chem. Soc, 8_5 (24), 3999-4003 (1963)/. The starting compounds of the formula III, wherein R represents a 2-nitro, 3-chloro, 3-nitrile, 3-trifluoromethyl , 4-methoxy or 4-methyl group, m has a value of 1, n has a value of 1 or 2, p has a value of 2, and Hlg is chloro or bromo, or R stands for a 2, 6-dinitro-4-trifluoromethyl or 2-nitro-4-trifluoromethyl group, m has a value of 0, n has a value of 1 or 2, p has a value of 2, and Hlg is a chloro or bromo, are novel compounds that can be prepared by the methods given in connection with the known compounds. Compounds of the formula I have valuable biological activity. Our studies revealed that the compounds of the invention bind strongly to different serotonin receptor subtypes, and inhibit serotonin-evoked smooth muscle contractions of the rat gastric fundus and the rabbit aorta. The chemical name of serotonin is 3- (2-aminoethyl )-lH-indol-5-ol. 5-HT-, and 5-HT-, receptor binding studies 5-HT- and 5-HT ?f , receptor binding was measured according to the methods described by Leysen et al. /Mol. Pharmacol., l' 301 (1981)/ and Pazos et al. /Eur. J. Pharmacol., 106, 539 (1985)/, respectively. 5-HT 2 receptor binding was measured in rat brain frontal cortex membrane preparation using tritiated ketanserine /3-/2-( 4-fluorobenzoyl) - -1-piperidinyl/ethyl-2, 4-(lH,3H)-quinazoline- dione/ (60-90 Ci/m ole) as ligand. 5-HT-, r receptor binding was measured in pig brain choroid plexus membrane preparation using tritiated mesulergine /N'-/ (8) -1, 6-dimethyl- ergoline-8-yl/-N,N-dimethylsulfamide (70-85 Ci/mmole) as the ligand. Non-specific binding to 5-HT- and 5-HT- receptors were determined in the presence of 10 micro M cyproheptadine /4-( 5H-dibenzo/a,d/cycloheptene-5-ylidene)-1- -methylpiperidine/ and 1 micro M mianserine /l , 2, 3, 4 , 10, 14b-hexahydro-2-methyldibenzo- /c,f/pyrazino/l,2-a/azepine/, respectively. The final incubation volumes were 250 and 1000 microlitres. Samples were incubated for 15 and 30 minutes at 37 C. Incubation was stopped by adding 9 ml of ice-cold 50 mM tris(hydroxymethyl )-aminomethane hydrochloride (pH = 7.7) to the reaction mixture. The samples were rapidly filtered through Whatman GF/B glass fiber filters using reduced pressure. Before use, the filters were soaked in a 0.05 % poly¬ ethyleneimine solution for 2 to 3 hours. Radioactivity of the filters was determined by a scintillation spectrometer. The results obtained are shown in Table I. Table I Effect of the compounds examined on 5-HT- and 5-HT-._, receptors Compound Inhibition of recept<DΓ binding (Example of the radioactive 1: Lgand No. ) 5-HT 2c 5"HT 2A (K. in nm/1) 3 >100 58 5 67 16 12 47 >100 13 12 20 14 >100 78 19 >100 48 20 >100 203 21 39 >100 22 >100 56 23 >100 20 24 22 18 25 >100 20 26 ' 45 48 28 50 >100 31 21 >100 34 >100 71 35 69 >100 36 18 >100 39 27 not tested 40 >100 21 44 >100 93 45 25 27 47 33 >100 53 >100 15 56 57 38 Table I (continued) Compound Inhibition of receptor binding (Example of the radioactive ligand (K. in nm/1) 57 42 >100 65 42 34 66 >100 61 67 8 . 6 4 . 6 68 >100 21 69 26 38 72 20 24 101 24 16 From Table I it can be seen that the compounds of the formula I have considerable affinity for 5-HT--. Λ and 5-HT 2c receptors. Inhibition of serotonin-induced contractions of rat stomach fundus smooth muscle The experiments were performed on male Wistar rats weighing 350 to 400 g. The animals were fasted for 24 hours before the experiments, however, they were allowed to drink tap water ad libitum. The method used was a modified version of Vane et al. /J. Pharmac. Chemother., 12, 344 (1957)/. The rats were killed by decapitation and their stomach was removed, and 3 mm wide and 20 to 30 mm long strips were cut in parallel with the greatest curvature of the stomach. The strips were incubated for 60 minutes in a 6 ml Lucite chamber filled with Tyrode solution (NaCl 136.9 M, KCI 2.7 mM, CaCl-, 1.8 mM, MgCl 2 1.0 mM, NaHC0 3 11.9 M, glucose 5.6 mM, NaH 2 P0 4 0.4 mM) warmed to 37 °C and bubbled with a gas consisting of 95 % of oxygen and 5 % of carbon dioxide. The strips were stre ' tched with 0.5 g during the 60 minutes equilibration time and were washed every 20 minutes. The tension was measured isometrically by a strain gauge (Hugo Sachs) and was recorded on a Graphtech Mark VII 3101 polygraph. Experimental protocol : Three control contractions were evoked by 5-HT added to the bath in 10~ 7 M concentration (Cl , C2, C3). If peak tension did not differ more than by 10 % between C2 and C3 , a threshold concentration of the compound to be tested was added to the bath and the strip was _7 contracted by 5-HT (10 M) in its presence (Tl). The effects of the test compounds were determined in 5 increasing concentrations (T2, T3, T4, T5, and T6 ) . After determining the effect of two concentrations of the test compounds, the control 5-HT response was checked after each test measurement. Results and evaluation: IC-- was calculated by nonlinear curve fitting of the inhibitory effect of increasing concentrations of the test compound. The compounds of the invention inhibit the 5-HT-evoked contractions of the isolated rat stomach fundus smooth muscle strips. The results obtained are shown in Table II. Table II Inhibition of 5-HT-evoked contractions of isolated rat stomach fundus Compound Inhibition, ( Example No. ) IC 5o < micro M /D 20 0.56 22 0.32 48 0.42 57 0.89 64 0.68 Determination of 5-HT-.. receptor antagonistic effect on isolated rabbit aorta New-Zealand, male, white rabbits weighing 2.0 to 2.5 kg were killed by a blow on the head. The thoracic aorta segment after the aortic arch was removed and placed into a Krebs' solution (NaCl 118 mM, KCl 4.6 M, NaHC0 3 25 mM, glucose 10.5 mM, Mg 3 (S0 4 ) 2 1 mM, KH 2 P0 4 1 mM, CaCl 2 2.6 mM) . The aorta was carefully cleaned from fat and connective tissue, and was cut into 3 mm wide and 30 mm long helical strips. Four strips were obtained from each rabbit. The strips were equilibrated at 37 C for 60 minutes in an organ chamber filled with Krebs' solution. The strips were also oxygenated by bubbling carbogen gas ( 5 % of carbon dioxide and 95 % of oxygen) through the solution. The strips were stretched by 1 g tension. The contractions were measured by a Hugo Sachs K-30 type strain gauge, and were registered on a Multicorder type polygraph. During the last 40 minutes of the equilibration, the MAO enzym inhibitor tranylcypramine (10 M) /chemical name: (-)-trans-2-phenylcyclopropylamine/ was also added to the bath. Any alpha-adrenergic effects of the —8 test compounds were eliminated by 10 M of phenoxybenzamine /N- ( 2-chloroethyl )-N- -( l-methyl-2-phenoxyethyl)benzylamine/ /Clancy et al., J. Pharm. Exp. Ther., 233, 761 (1985). Testing of the serotonergic antagonistic effect was started at the 90th minute of incubation. The stability and reproducibility of the contractile response of the aortic strips to serotonin was tested by two consecutive application and wash-out —fi procedures of 10 M concentration of 5-HT, 40 minutes apart. Measurements were continued only in the case if peak tensions in the above test did not differ by more than 10 %. 30 minutes after the second testing, a preset concentration of the test compound was added to the bath, and, after a 10 minutes incubation time, the response to 10 ~ M of 5-HT was determined in the presence of the compound to be tested. Two different concentrations of a given compound were tested on each aortic strip by the above method. Reproducibility of the control 5-HT-evoked response was checked between testing the two concentrations of the compound. The second concentration was tested only if the 5-HT-evoked tension did not differ by more than .10 % from the original control response. IC t - n was calculated by nonlinear curve fitting of the inhibitory effect of increasing concentrations of the test compound. The results obtained are shown in Table III. Table III Inhibition of 5-HT-evoked contractions on isolated rabbit aortic strips Compound Inhibition, ( Example No. ) IC 5o (m:Lcro M /l ) 3 0.96 5 0.25 13 0.12 14 6.0 20 1.5 22 0.42 23 0.67 24 0.24 25 0.28 26 0.26 27 0.9 31 0.73 39 0.3 44 0.65 45 0.43 53 0.47 54 0.57 56 0.9 57 0.89 65 0.17 67 0.039 68 0.78 69 0.096 72 0.084 Based on the results presented in Table III, it can be stated that the compounds of the invention effectively inhibit the serotonin-evoked contractions of the isolated rabbit aortic preparation. Based on the results of the above studies, the novel compounds of the formula I can be applied for the treatment of various disorders due to pathological alterations of the central nervous system. The compounds of the formula I demonstrated inhibitory activity primarily at 5-HT- and 5-HT ?r serotonergic receptor subtypes. Based on literature data, these receptors play a fundamental role in the pathomechanis of anxiety disorders, schizophrenia and migraine. The 5-HT- receptor agonist m-chlorophenylpiperazine /Conn et al., Proc. Natl. Acad. Sci. USA, 83, 4086 (1986)/ induces anxiety both in rats /Kennett et al., Eur. J. Pharmacol., 164, 455 (1989)/ and human beings /Kahn and Weltzer, Biol. Psychiat., 30, 1139 (1991)/. Based on studies performed in rats, the anxiogenic effect of m-chlorophenylpiperazine can be attributed to the activation of 5-HT_ ( formerly 5-HT lf -) receptors /Kennett et al., Eur. J. Pharmacol., 164, 455 (1989)/. Compounds with antagonistic effect at the 5-HT_ ,„ receptors have been shown to be anxiolytic in animal experiments /Kennett, Psychopharmacol., 107, 379 (1992)/. The 5-HT2-A,/,2_C,, recep^tor antag^onistic compound ritanserin /chemical name: 6-/ " 2-/4- -bis(4-fluorophenyl )methylene/-1-piperidinyl- ethyl _7-7-methyl-5H-thiazolo/3 , 2-a/pirimidine- -5-one/ has been proved to be effective for the treatment of different forms of human anxiety /Ceulemans et al. , Phar acopsychiat. , 18, 303 985)/. Usefulness of 5-HT 2 receptor antagonists for neuroleptic indication is proved by the fact that a basic role is attributed to the 5-HT- antagonistic effect in the therapeutic efficacy of clozapine /chemical name: 8-chloro-ll-( 4-methyl- 1-piperazinyl ) -5H-dibenzo/b,e//l , 4/- diazepine/, a widely used neuroleptic compound /Meltzer, J. Clin. Psychiatry, ^5_ Suppl. B, 47 (1994)/. Usefulness of the compounds of the invention for prophylactic treatment of migraine is supported by both the 5-HT-, ,_ receptor antagonistic properties of the compounds /Sleight et al . in Serotonin Receptor Subtypes: Basic and Clinical Aspects, ed. Peroutka, S.J., pp. 211, Wiley-Liss Inc., (1991)/ and their activity exhibited in rat stomach fundus test. Besides central nervous system disorders, the compounds of the invention can be useful for the treatment of ischemic heart disease. Results of the rabbit aorta test make it probable that the compounds can have 5-HT- antagonistic effect also on the heart vessels and the myocardium. It is known that 5-HT-, receptor antagonists play a role in the development of heart disease. 5-HT-, receptor antagonistic compounds also improve contractility and accelerate regeneration of the myocardium after an ischemic insult /Grover et al., J. Cardiovasc. Pharmacol., 2 , 664 (1993)/. A role of serotonergic receptors is assumed in the regulation of food consumption and body temperature as well as development of depression, addiction to drugs and alcohol, some other gastroenterologic and circulatory disorders, and in the pathomechanism of pain /Sleight et al. in Serotonin Receptor Subtypes: Basic and Clinical Aspects, ed. Peroutka, S.J., pp. 211, Wiley-Liss Inc., (1991); Kennett, Drugs, 125 (1993)/. Due to the above test results, the novel compounds of the formula I or pharmaceutically acceptable acid addition salts thereof can be used as active ingredients of pharmaceutical compositions. The pharmaceutical compositions of the invention contain a therapeutically active amount of the compound of the formula I or a pharmaceutically acceptable acid addition salt thereof and one or more conventional carrier( s ) . The pharmaceutical compositions of the invention are suitable for peroral, parenteral or rectal administration or for local treatment, and can be solid or liquid. The solid pharmaceutical compositions suitable for peroral administration may be powders, capsules, tablets, film-coated tablets, microcapsules etc., and can comprise binding agents such as gelatine, sorbitol, poly(vinylpyrrolidone) etc.; filling agents such as lactose, glucose, starch, calcium phosphate etc.; auxiliary substances for tabletting such as magnesium stearate, talc, poly(ethyleneglycol ) , silica etc.; wetting agents such as sodium laurylsulfate etc. as the carrier. The liquid pharmaceutical compositions suitable for peroral administration may be solutions, suspensions or emulsions and can comprise e.g. suspending agents such as gelatine, carboxymethylcellulose etc.; emulsifiers such as sorbitane monooleate etc.; solvents such as water, oils, glycerol, propyleneglycol , ethanol etc.; preservatives such as methyl p-hydroxybenzoate etc. as the carrier. Pharmaceutical compositions suitable for parenteral administration consist of steril solutions of the active ingredient, in general. Dosage forms listed above as well as other dosage forms are known per se, see e.g. Remington's Pharmaceutical Sciences, 18th Edition, Mack Publishing Co., Easton, USA (1990). The pharmaceutical compositions of the invention contain, in general, 0.1 to 95.0 per cent by mass of a compound of the formula I or a pharmaceutically acceptable acid addition salt thereof. A typical dose for adult patients amounts to 0.1 to 20 mg of the compound of the formula I or a pharmaceutically acceptable acid addition salt thereof, daily. The above dose can be administered in one or more portions. The actual dosage depends on many factors and is determined by the doctor. The pharmaceutical compositions of the invention are prepared by admixing a compound of the formula I or a pharmaceutically acceptable acid addition salt thereof to one or more carrier(s), and converting the mixture obtained to a pharmaceutical composition in a manner known per se. Useful methods are known from the literature, e.g. Remington's Pharmaceutical Sciences. Suitably, the pharmaceutical compositions of the invention contain a compound of the formula I, wherein R and R represent, independently, a hydrogen, a methyl group, an amino group, an acetylamino group or a phenyl group optionally bearing 1 to 3 substituents selected from the group consisting of, independently, a chloro . . a methoxy group . , a dimethylamino group or a benzyloxy group, 2 R stands for a hydrogen, a cyano group, a furylmethyl group, a cyclohexylmethyl group, an ethoxycarbonyl group, a hydroxyethyl group or a benzyl group optionally bearing 1 to 3 substituents selected from the group consisting of, independently, a chloro, a fluoro, a C, -. alkyl group,, a methoxy group, a trifiuoro¬ methyl group, a hydroxy group, a benzyloxy group or a dimethylamino group. R means a hydrogen, or 3 4 R forms with R an oxygen atom, R is a hydrogen, or 4 5 R forms with R a valence bond, R represents a chloro, a fluoro, a cyano group, a nitro group, a methyl group, a methoxy group or a trifluoro methyl group, m has a value of 0 or 1, n has a value of 1 or 2, p has a value of 2 or 11, and k has a value of O. 1 r 2 or 3, and pharmaceutically acceptable acid addition salts thereof as the active ingredient. Preferably, the pharmaceutical compositions of the invention contain a compound of the formula I. wherein R and R represent an amino group, 2 R stands for a hydrogen or a benzyl group optionally bearing 1 to 3 substituents selected from the group consisting of, independently, a fluoro, a chloro, a methoxy group and a dimethylamino group. 4 5 R forms with R a valence bond, R means a fluoro, a chloro.. a nitro group, a cyano group, a methyl group- a methoxy group or a trifiuoromethyl group, k has a value of 1, m has a value of 1, n has a value of 1, and p has a value of 2, and pharmaceutically acceptable acid addition salts thereof as the active ingredient. Furthermore, the invention refers to a method for the treatment of diseases especially due to pathological alterations of the central nervous system. The method of the invention comprises administering an effective non-toxic dose of a compound of the formula I or a pharmaceutically acceptable acid addition salt thereof to a patient suffering from said diseases. The invention also refers to the use of a compound of the formula I or a pharma¬ ceutically acceptable acid addition salt thereof for the preparation of a pharma¬ ceutical composition. The invention is further elucidated by means of the following Examples. General method for preparing compounds of the formula I 0.05 moles of a mercaptopyrimidine of the formula II or an alkali metal salt thereof, 6.9 g (0.05 moles) of potassium carbonate and 0.83 g (0.005 moles) of potassium iodide are stirred in 300 ml of solvent at room temperature for 15 minutes, and, to the mixture obtained, 0.05 moles of haloalkylpiperazine of the formula III or an acid addition salt thereof are added. If the solvent consists of methanol or ethanol, the reaction mixture is boiled under reflux, while if the solvent is dimethyl¬ formamide, the reaction mixture is heated at 65 to 70 °C for the time given in the Examples. After the lapse of the reaction time, the mixture is worked up by one of the following methods. Method "A": The inorganic salts separated are filtered, then the filtrate is evaporated under reduced pressure. Method "B": The reaction product separated is filtered together with the inorganic salt, then latter is removed by washing with water. Method "C": The reaction mixture is poured onto 300 ml of water to dissolve the inorganic salts, then the product separated is filtered. The reaction product obtained by any of the above methods is purified as indicated in the Examples. Using the above general method, the following compounds of the formula I were prepared: Example 1 2- j T 2-/4-( 2-Chlorobenzyl )-1-piperazinyl/- ethylthio J7pyrimidine Solvent employed in the reaction: methanol. Reaction time: 3 hours. The reaction mixture is worked up by flash chromatography using a mixture of chloroform and methanol in a ratio of 99:1 as the eluent. Yield: 4 g (23 %) . Melting point: oil. Analysis for C 17 H 21 C1N 4 S (348.90) calculated: C 58.53 %, H 6.07 %, Cl 10.16%, N 16.06 %, S 9.18%; found: C 58.13 %, H 6.25 %, Cl 9.97%, N 15.73 %, S 8.98%. Example 2 2-/2-( 4-Benzyl-l-piperazinyl )ethylthio/-4,6- -diaminopyrimidine Solvent employed in the reaction: methanol. Reaction time: 3 hours. The reaction mixture is worked up by method "B". Yield: 11.2 g (65 %) . Purification: recrystallization from aqueous ethanol . Melting point: 167-169 °C. Analysis for 17 H 42 NgS (344.485) calculated: C 59.27 %, H 7.02 %, N 24.40%, S 9.31 %; found: C 58.78 %, H 6.85 %, N 24.20%, S 9.31 %. Example 3 2-/72-/4-(4-Fluorobenzyl)-1-piperazinyl/- ethylthio J7-4, 6-diaminopyrimidine Solvent employed in the reaction: methanol. Reaction time: 3 hours. The reaction mixture is worked up by method "A". Yield: 8.2 g (45 %) . Purification: recrystallization from aqueous ethanol . Melting point: 179-182 °C. Analysis for C 17 H 23 FN 6 S (362.475) calculated: C 56.25 %, H 6.32 %, N 23.19%, S 8.93 %; found: C 56.33 %, H 6.40 %, N 23.19%, S 8.84 %. • Example 4 2- 72-/4-( 4-Chlorobenzyl )1-piperazinyl/- ethylthio 7- , 6-diaminopyrimidine Solvent employed in the reaction: methanol. Reaction time: 3 hours. The reaction mixture is worked up by method "A". Yield: 17.5 g (92 %) . Purification: recrystallization from aqueous methanol . Melting point: 192-194 °C. Analysis for C^H^ClNgS (378.930) calculated: C 53.89 %, H 6.12 %, Cl 9.36%, N 22.18 %, S 8.46%; found: C 53.45 %, H 6.25 %, Cl 9.26%, N 22.35 %, S 8.59%. Example 5 2- 72-/4-( 2-Chlorobenzyl ) -1-piperazinyl/- ethylthio 7-4 , 6-diaminopyrimidine Solvent employed in the reaction: methanol. Reaction time: 3 hours. The reaction mixture is worked up by method "A". Yield: 9.5 g (50 %) . Purification: recrystallization from aqueous ethanol. Melting point: 150-153 °C. Analysis for C 1? H 23 C1N 6 S (378.930) calculated: C 53.89 %, H 6.12 %, Cl 9.36%, N 22.18 %, S 8.46%; found: C 53.45 %, H 6.25 %, Cl 9.50%, N 22.18 %, S 8.41%. Example 6 2- 72-/4-( 4-Nitrobenzyl)-1-piperazinyl/- ethylthio _7-4 , 6-diaminopyrimidine Solvent employed in the reaction: methanol. Reaction time: 3 hours. The reaction mixture is worked up by method "B". Yield: 17.5 g (90 %) . Purification: recrystallization from methanol Melting point: 218-219 °C. Analysis for C 17 H 23 N 7 0 2 S (389.483) calculated: C 52.43 %, H 5.95 %, N 25.17%, S 8.23 %; found: C 52.10 %, H 6.17 %, N 24.54%, S 8.04 %. Example 7 2- 2-/4-( 2-Nitrobenzyl) -1-piperazinyl/- ethylthio .7-4 , 6-diaminopyrimidine Solvent employed in the reaction: methanol. Reaction time: 3 hours. The reaction mixture is worked up by method "A". Yield: 8.6 g (44 %) . Purification: recrystallization from aqueous ethanol. Melting point: 165-169 °C. Analysis for c i7 H 23 N 7°2 S ( 389.483) calculated: C 52.43 %, H 5.95 %, N 25.17%, S 8.23 %; found: C 52.19 %, H 5.94 %, N 24.33%, S 8.07 %. Example 8 2-__~ 3-/4- ( 4-Nitrobenzyl) -1-piperazinyl/- propylthio 77-4 , 6-diaminopyrimidine Solvent employed in the reaction: methanol. Reaction time: 3 hours. The reaction mixture is worked up by method "A". Yield: 6.5 g (32 %) . Purification: recrystallization from aqueous dimethylformamide. Melting point: 186-188 °C. Analysis for C 18 H 25 N 7 0 2 S (403.510) calculated: C 53.38 %, H 6.25 %, N 24.30%, S 7.95 %; found: C 54.01 %, H 6.26 %, N 23.62%, S 7.72 %. Example 9 2- 72-/4- ( 2, 4-Dinitrophenyl ) -1-piperazinyl/- ethylthio -7-4 , 6-diaminopyrimidine Solvent employed in the reaction: methanol. Reaction time: 3 hours. The reaction mixture is worked up by method "C". Yield: 17.2 g (82 %) . Purification: treatment with water, acetone, then chloroform. Melting point: 235-237 °C. Analysis for C 16 H 20 N 8°4 S ( 420.453 ) calculated: C 45.71 %, H 4.79 %, N 26.65%, S 7.63 ' %; found: C 45.75 %.. H 4.59 %, N 27.71%, S 7.29 %. Example 10 2-£ " 2-/4-(4-Trifluoromethyl-2, 6-dinitro- phenyl )-l-pipera∑inyl/ethylthio.7-4,6- -diaminopyrimidine Solvent employed in the reaction: methanol. Reaction time: 3 hours. The reaction mixture is worked up by method "C". Yield: 20.3 g (83 %) . Purification: recrystallization from ethanol. Melting point: 195-196 °C. Analysis for C 17 H 19 F 3 N 8 0 4 S (488.451) calculated: C 41.80 %, H 3.93 %, F 11.67%, N 22.94 %, S 6.56%; found: C 41.08 %, II 4.10 %, F 11.37%, N 22.53 %. S 6.76%. Example 11 2- 72-/4-(4-nitrobenzyl)-1-piperazinyl/- ethyIthio _7-4,6-diamino-5-(2-furylmethyl)- pyrimidine Solvent employed in the reaction: methanol. Reaction time: 3 hours. The reaction mixture is worked up by method "B". Yield: 14 g (50 %) . Purification: chromatography on a column filled with Kieselgel 60 and elution with acetone, then recrystallization from ethanol Melting point: 157-159 °C. Analysis for C 22 H 27 N 7 0 3 S (469.6) calculated: C 56.27 %, H 5.80 %, N 20.88%, S 6.83 %; found: C 54.26 %, H 5.81 %.. N 20.18%. S 6.69 %. Example 12 2- 72-/4-( 3-Methoxybenzyl) -1-piperazinyl/- ethylthio _7-4.6-diamino-5-benzylpyrimidine Solvent employed in the reaction: methanol. Reaction time: 3 hours. The reaction mixture is worked up by method "A" . Yield: 12.6 g (54 %) . Purification: recrystallization from aqueous ethanol. Melting point: 143-145 °C. Analysis for C_2 c 5H3-.2_N 1 6,OS (464.637) calculated: C 64.49 %, H 7.14 %, N 18.05%, S 6.89 %; found: C 64.67 %, H 6.98 %, N 17.84%, S 6.95 %. Example 13 2-7 2-/4- ( 2-Chlorobenzyl) -1-piperazinyl/- ethylthio J -4 , 6-diamino-5-benzylpyrimidine Solvent employed in the reaction: methanol. Reaction time: 3 hours. The reaction mixture is worked up by method "B". Yield: 14.5 g (62 %) . Purification: recrystallization from aqueous ethanol. Melting point: 177-180 °C. Analysis for C 24 H 2g ClN 6 S (469.056) calculated: C 61.46 %, II 6.23 %, Cl 7.55%, N 17.92 %, S 6.83%; found: C 60.85 %, H 6.20 %, Cl 7.54%, N 17.46 %, S 6.56%. Example 14 2-/7 " 2-/4-( 4-Nitrobenzyl)-1-piperazinyl/- ethylthio 77-4, 6-diamino-5-benzylpyrimidine Solvent employed in the reaction: methanol. Reaction time: 3 hours. The reaction mixture is worked up by method "B". Yield: 17.5 g (73 %) . Melting point: 188-191 °C. Analysis for C 24 H 2g N ? 0 2 S (479.608) calculated: C 60.10 %, H 6.10 %, N 20.44%, S 6.68 %; found: C 59.25 %, H 6.10 %, N 19.92%, S 6.43 %. Example 15 2- /T 2- / 4 - ( 3-Trif luoromethylbenzyl ) -l - -piperazinyl /ethylthio 77 -4 , 6-diamino- -5 -benzyl pyrimidine Solvent employed in the reaction: methanol. Reaction time: 3 hours. The reaction mixture is worked up by method "A". Yield: 20.6 g (82 %) . Purification: recrystallization from aqueous ethanol . Melting point: 179-180 °C. Analysis for C 2 5 H 29 F 3 N 6 S ( 502.609 ) calculated: C 59.62 %, H 6.00 %, N 16.69%, S 6.37 %; found: C 59.72 %, H 5.57 %, N 17.01%, S 6.23 %. Example 16 2- 72-/4-(2, 6-Dinitro-4-trifluoromethyl¬ phenyl )-1-piperazinyl/ethylthio 77-4 , 6-diamino- 5-benzylpyrimidine Solvent employed in the reaction: methanol. Reaction " time: 3 hours. The reaction mixture is worked up by method "A". Yield: 13 g (45 %) . Purification: chromatography on a column filled with Kieselgel 60 and elution with ethyl acetate. Melting point: 159-163 °C. Analysis for C 2 4 H 25 F 3 N 8°4 S ( 578.577 ) calculated: C 49.82 %, H 4.36 %, N 19.37%, S 5.54 %, F 9.85%; found: C 49.36 %, H 4.33 %, N 18.54%, S 5.76 %, F 9.85%. Example 17 2- C 2-/4-( 4-Nitrobenzyl) -1-piperazinyl/- ethylthio -4, 6-diamino-5-(cyclohexylmethyl ) - pyrimidine Solvent employed in the reaction: methanol. Reaction time: 3 hours. The reaction mixture is worked up by method "A". Yield: 9.7 g (40 %) . Purification: chromatography on a column filled with Kieselgel 60 and elution with acetone, then recrystallization from ethanol. Melting point: 160-162 °C. Analysis for C 24 H 35 N 7°2 S ( 485.656) calculated: C 59.36 %, H 7.26 %, N 20.19%, S 6.60 %; found: . C 59.65 %, H 7.20 %, N 19.90%, S 6.57 %. Example 18 2- 72-/4-( 2, 6-Dinitro-4-trifluoromethyl¬ phenyl ) -1-piperazinyl/ethylthio 77-4 , 6-diamino- 5-(cyclohexylmethyl)pyrimidine Solvent employed in the reaction: methanol. Reaction time: 3 hours. The reaction mixture is worked up by method "C". Yield: 11.1 g (38 %) . Purification: chromatography on a column filled with Kieselgel 60 and elution with ethyl acetate. Melting point: 176-178 °C. Analysis for C 24 H 3i F 3 N 8°4 S ( 584.625 ) calculated: C 49.31 %, H 5.34 %, N 19.17%, S 5.48 %, F 9.75%; found: C 48.80 %, H 5.28 %, N 18.80%, S 5.60 %, F 10.19%. Example 19 2- C 2-/4-( 4-Nitrobenzyl ) -1-piperazinyl/- ethylthio 77- , 6-diamino-5- ( 2-hydroxybenzyl ) - pyrimidine Solvent employed in the reaction: methanol. Reaction time: 3 hours. The reaction mixture is worked up by method "A". Yield: 9.9 g (40 %) . Purification: flash chromatography using a mixture of chloroform and methanol in a ratio of 8:2 as the eluent. Melting point: 195-199 °C. Analysis for C 24 H 2g 7 0.-S (495.608) calculated: C 58.16 %, H 5.90 %, N 19.78%, S 6.47 %; found: C 60.26 %, H 6.08 %, N 19.97%, S 6.55 %. Example 20 2- 72-/4-( 4-Nitrobenzyl )-1-piperazinyl I - ethylthio 77- , 6-diamino-5-( 4-fluorobenzyl )- pyrimidine Solvent employed in the reaction: methanol. Reaction time: 3 hours. The reaction mixture is worked up by method "B". Yield: 5.5 g (47 %) . Purification: recrystallization from aqueous ethanol. Melting point: 201-203 °C. Analysis for C 24 H 2 gFN 7 0 2 S (497.599) calculated: C 57.93 %, H 5.67 %, N 19.70%, S 6.44 %; found: C 57.53 %, H 5.66 %, N 19.55%, S 6.60 %. Example 21 2- 72-/4- (3-Trifluoromethylbenzyl)-1- piperazinyl/ethylthio 77 _ 4,6-diamino-5- -( -fluorobenzyl )pyrimidine Solvent employed in the reaction: methanol. Reaction time: 3 hours. The reaction mixture is worked up by method "A". Yield: 20.6 g (79 %) . Purification: recrystallization from aqueous ethanol. Melting point: 162-164 °C. Analysis for C 25 H 28 F 4 N 6 S (520 - 6o ° ) calculated: C 57.68 %, H 5.42 %, N 16.14%, S 6.16 %; found: C 57.08 %, H 5.34 %, N 16.36%, S 6.11 %. Example 22 2-/2-( 4-Benzyl-l-piperazinyl)ethylthio/-4 , 6- -diamino-5-( 4-methoxybenzyl)pyrimidine Solvent employed in the reaction: methanol. Reaction time: 3 hours. The reaction mixture is worked up by method "B". Yield: 21.8 g (94 %) . Melting point: 152-154 °C. Analysis for C 5 H 32 N 6 0S (464.637) calculated: C 64.63 %, H 6.94 %, N 18.09%, S 6.90 %; found: C 63.11 %, H 6.86 %, N 17.77%, S 6.76 %. Example 23 2- [ 2-/4-( 4-Methylbenzyl )-1-piperazinyl/- ethylthio -4 , 6-diamino-5-(4-methoxybenzyl ) - pyrimidine Solvent employed in the reaction: methanol. Reaction time: 3 hours. The reaction mixture is worked up by method "A". Yield: 16.3 g (68 %) . Purification: recrystallization from aqueous ethanol . Melting point: 183-185 °C. Analysis for C^H^NgOS (478.664) calculated: C 65.24 %, H 7.16 %, N 17.56%, S 6.70 %; found: C 64.52 %, H 6.95 %, N 17.70%, S 6.49 %. Example 24 2- 2-/4-( 2-Methylbenzyl ) -1-piperazinyl/- ethylthio 77-4 , 6-diamino-5-(4-methoxybenzyl ) - pyrimidine Solvent employed in the reaction: methanol. Reaction time: 3 hours. The reaction mixture is worked up by method "A". Yield: 18.4 g (77 %) . Purification: recrystallization from aqueous ethanol. Melting point: 166-168 °C. Analy 1 sis for C2_6 £ H3,4„N6,0S (478.664) calculated: C 65.24 %, H 7.16 %, N 17.56%, S 6.70 %; found: C 64.63 %, H 7.30 %, N 17.47%, S 6.90 %. Example 25 2- 72-/4-( 2-Fluorobenzyl )-1-piperazinyl/- ethylthio 77-4 , 6-diamino-5-( 4-methoxybenzyl )- pyrimidine Solvent employed in the reaction: methanol Reaction time: 3 hours. The reaction mixture is worked up by method "A". Yield: 20.5 g (85 %) . Purification: recrystallization from aqueous ethanol . 29 PC17HU96/00061 - 43- Melting point: 162-164 °C. Analysis for C^H^FNgOS (482.628) calculated: C 62.22 %, H 6.47 %, N 17.41%, S 6.64 %; found: C 62.17 %, H 6.68 %, N 17.42%, S 6.64 %. Example 26 2- 72-/4-( 3-Cyanobenzyl)-1-piperazinyl/- ethy1thio J - , 6-diamino-5-( 4-methoxybenzyl) - pyrimidine Solvent employed in the reaction: methanol. Reaction time: 3 hours. The reaction mixture is worked up by method "A". Yield: 21.3 g (87 %) . Purification: flash chromatography using a mixture of chloroform and methanol in a ratio of 9:1 as the eluent. Melting point: 142-144 °C. Analysis for C 26 H 31 N 7 OS (489.647) calculated: C 63.78 %, H 6.38 %, N 20.02%, S 6.55 %; found: C 63.32 %, H 6.31 %, N 20.34%, S 6.43 %. Example 27 2-/72-/4-( 2-Cyanobenzyl ) -1-piperazinyl/- ethylthio 7-4,6-diamino-5-( -methoxybenzyl ) - pyrimidine Solvent employed in the reaction: methanol. Reaction time: 3 hours. The reaction mixture is worked up by method "A". Yield: 21.3 g (87 %) . Purification: recrystallization from aqueous ethanol. Melting point: 150-153 °C. Analysis for C 2 gH 31 N 7 OS (489.647) calculated: C 64.36 %, H 6.43 %, N 20.08%, S 6.57 %; found: C 63.78 %, H 6.38 %, N 20.02%, S 6.55 %. Example 28 2-/~ 2-/4- ( 3-Methoxybenzyl ) -1-piperazinyl/- ethylthio 77-4,6-diamino-5-( 4-methoxybenzyl ) - pyrimidine Solvent employed in the reaction: methanol. Reaction time: 3 hours. The reaction mixture is worked up by method "A". Yield: 18.8 g (76 %) . Purification: recrystallization from aqueous ethanol . Melting point: 150-152 °C. Analysis for C 2 6 H 34 N 6°2 S ( 494.664 ) calculated: C 63.13 %, H 6.93 %, N 16.99%, S 6.48 %; found: C 62.86 %, H 6.98 %, N 17.15%, S 6 . 68 % . Example 29 2- 2-/4- ( 4-Methoxybenzyl )-l-piperazinyl/- ethylthio J -4, 6-diamino-5-(4-methoxybenzyl)- pyrimidine Solvent employed in the reaction: methanol. Reaction time: 3 hours. The reaction mixture is worked up by method "A". Yield: 17.8 g (72 %) . Purification: recrystallization from aqueous ethanol . Melting point: 156-158 °C. Analysis .for C 2 6 H 34 N 6°2 S ( 494.664 ) calculated: C 63.13 %, H 6.93 %, N 16.99%, S 6.48 %; found: C 63.50 %, H 7.23 %, N 16.31%, S 6.66 %. Example 30 2-/~ 2-/4-( 4-Methoxybenzyl)-1-piperazinyl/- ethylthio77-4 , 6-diamino-5-( 2-methoxybenzyl) - pyrimidine Solvent employed in the reaction: methanol. Reaction time: 3 hours. The reaction mixture is worked up by method "A". Yield: 20.0 g (81 %) . Purification: flash chromatography using a mixture of chloroform and methanol in a ratio of 9:1 as the eluent. Melting point: 149-152 °C. Analysis for C 26 H 3 4 N 6 ° S (494.664) calculated: C 63.13 %, H 6.93 %, N 16.99%, S 6.48 %; found: C 60.83 %, H 6.74 %, N 16.55%, S 6.16 %. Example 31 2-C 2-/4- ( 3-Methoxybenzyl ) -1-piperazinyl/- ethy1thio 7-4 , 6-diamino-5-(2-methoxybenzyl) - pyrimidine Solvent employed in the reaction: methanol. Reaction time: 3 hours. The reaction mixture is worked up by method "A". Yield: 22 g (89 %) . Purification: flash chromatography using a mixture of chloroform and methanol in a ratio of 9:1 as the eluent. Melting point: 118-120 °C. Analysis for C,^H- .N.-O-S (494.664) 26 34 6 2 calculated: C 63.13 %, H 6.93 %, N 16.99%, S 6.48 %; found: C 61.89 %, H 6.84 %, N 17.17%, S 6.26 %. Example 32 2- £ 2-/4-( 4-Chlorobenzyl )-1-piperazinyl/- ethylthio 77-4, 6-diamino-5-(4-methoxybenzyl )- pyrimidine Solvent employed in the reaction: methanol. Reaction time: 3 hours. The reaction mixture is worked up by method "A". Yield: 11.5 g (46 %) . Purification: recrystallization from aqueous ethanol . Melting point: 185-187 °C. Analysis for C.-H-.ClN.OS (499.082) calculated: C 60.17 %, H 6.26 %, Cl 7.10%, N 16.84 %, S 6.42%; found: C 58.32 %, H 6.19 %, Cl 6.95%, N 17.10 %, S 6.42%. Example 33 2-/72-/4-( 4-Nitrobenzyl)-1-piperazinyl/- ethylthio77-4, 6-diamino-5-( 4-methoxy¬ benzyl )pyrimidine Solvent employed in the reaction: methanol. Reaction time: 3 hours. The reaction mixture is worked up by method "A". Yield: 25.2 g (99 %) . Purification: recrystallization from aqueous acetone. Melting point: 191-193 °C. Analysis for C 2 0 ,DHJ,l, N-/0J-.S (509.635) calculated: C 58.92 %, H 6.13 %, N 19.24%, S 6.29 %; found: C 58.20 %, H 6.08 %, N 18.65%, S 6.14 %. Example 34 2-/_ 2-/4- ( 4-Nitrobenzyl ) -1-piperazinyl/- ethylthio 77-4,6-diamino-5-( 2-methoxy¬ benzyl )pyrimidine Solvent employed in the reaction: methanol. Reaction time: 3 hours. The reaction mixture is worked up by method "A". Yield: 12.2 g (48 %) . Purification: flash chromatography using a mixture of acetonitrile and methanol in a ratio of 8:2 as the eluent. Melting point: 99-104 °C. Analysis for C 25 H 31 N 7 0 3 S (509.635) calculated: C 58.91 %, H 6.13 %, N 19.24%, S 6.29 %; found: C 57.51 %, H 6.25 %, N 19.49%, S 6.22 %. Example 35 2-/72-/4- ( 3-Trifluoromethylbenzyl ) -1- piperazinyl/-ethyl-thio_7-4,6-diamino-5- ( 4-methoxybenzyl )pyrimidine Solvent employed in the reaction: methanol. Reaction time: 3 hours. The reaction mixture is worked up by method "A". Yield: 17.8 g (67 %) . Purification: recrystallization from aqueous ethanol . Melting point: 164-165 C. Analysis for C 2 gH 31 F 3 NgOS (532.636) calculated: C 58.63 %, H 5.87 %, N 15.78%, S 6.02 %; found: C 58.16 %, H 5.76 %, N 15.28%, S 5.93 %. Example 36 2-ZT 2-/4-( 3-Trifluoromethylbenzyl ) -1- piperazinyl/ethylthio 77-4 , 6-diamino-5- -( 2-methoxybenzyl )pyrimidine Solvent employed in the reaction: methanol. Reaction time: 3 hours. The reaction mixture is worked up by method "A". Yield: 14.7 g (55 %) . Purification: recrystallization from aqueous ethanol . Melting point: 140-144 °C. Analysis for C 2 gH 31 F 3 g0S (532.636) calculated: C 58.63 %, H 5.87 %, N 15.78%, S 6.02 %; f ound : C ' 56 . 51 % , H 5 . 88 % , N 15 . 47 % , S 5 . 81 % . Example 37 2- 72-/4-( 2, 6-Dinitro-4-trifluoromethyl¬ phenyl ) -1-piperazinyl/ethylthio -7-4 , 6-diamino- 5-( 4-methoxybenzyl )pyrimidine Solvent employed in the reaction: methanol. Reaction time: 3 hours. The reaction mixture is worked up by method "B". Yield: 13.4 g (44 %) . Purification: recrystallization from aqueous ethanol . Melting point: 178-180 °C. Analysis for C 25 H 27 F 3 N Q 0 5 S (608.604) calculated: C 49.34 %, H 4.47 %, N 18.41%, S 5.27 %; found: C 48.69 %, H 4.29 %, N 18.35%, S 5.48 %. Example 38 2-/2-( 4-Benzy1-1-piperazinyl)ethylthio/-4 , 6- diamino-5-( 4-chlorobenzyl)pyrimidine Solvent employed in the reaction: methanol. Reaction time: 3 hours. The reaction mixture is worked up by method "B". Yield: 14.1 g (60 %) . Melting point: 182-184 °C. Analysis for C 24 H 2g ClNgS (469.056) calculated: C 61.46 %, H 6.23 %, Cl 7.56%, N 17.92 %, S 6.84%; found: C 59.31 %, H 6.25 %, Cl 7.40%, N 17.58 %, S 6.63%. Example 39 2-ZT -/4- ( 2-Methylbenzyl )-l-piperazinyl/- ethyIthio 77-4 , 6-diamino-5-(2-chloro¬ benzyl)pyrimidine Solvent employed in the reaction: methanol. Reaction time: 3 hours. The reaction mixture is worked up by method "A". Yield: 22.5 g (93 %) . Purification: recrystallization from aqueous ethanol . Melting point: 146-148 °C. Analysis for C^H^ClNgS (483.083) calculated: C 62.16 %, H 6.46 %, Cl 7.34%, N 17.40 %, S 6.64%; found: C 62.06 %, H 6.47 %, Cl 7.35%, N 17.30 %, S 6.75%. Example 40 2-7 " 2-/4-( 4-Methylbenzyl ) -1-piperazinyl/- ethy1thio -7- , 6-diamino-5-(2-chlorobenzyl ) - pyrimidine Solvent employed in the reaction: methanol. Reaction time: 3 hours. The reaction mixture is worked up by method "A". Yield: 19.3 g (80 %) . Purification: flash chromatography using a mixture of chloroform and methanol in a ratio of 95:5 as the eluent or recrystallization from aqueous ethanol. Melting point: 166-168 °C. Analysis for C^H^ClNgS (483.083) calculated: C 62.16 %, H 6.46 %, Cl 7.34%, N 17.40 %, S 6.64%; found: C 62.55 %, H 6.56 %, Cl 7.67%, N 16.86 %, S 6.46%. Example 41 2-/2-( 4-Benzy1-1-piperazinyl )ethylthio/-4- ( 2-chlorophenyl )-5-cyano-6-aminopyrimidine Solvent employed in the reaction: dimethylformamide. Reaction time: 30 hours. The reaction mixture is worked up by method "B". Yield: 5.9 g (25 %). Purification: recrystallization from ethanol Melting point: 177-178 °C. Analysis for C 24 H 25 ClNgS (465.017) calculated: C 61.99 %, H 5.42 %, Cl 7.62%, N 18.07 %, S 6.89%; found: C 61.45 %, H 5.50 %, Cl 7.54%, N 17.90 %, S 6.69%. Example 42 2-/72-/4- ( 2-Cyanobenzyl )-1-piperazinyl/- ethylthio .7-4,6-diamino-5-( 2-chlorobenzyl ) - pyrimidine Solvent employed in the reaction: methanol. Reaction time: 3 hours. The reaction mixture is worked up by method "A". Yield: 22.2 g (90 %) . Purification: recrystallization from aqueous ethanol. Melting point: 170-173 °C. Analysis for C 25 H 28 C1 7 S (494.066) calculated: C 60.78 %, H 5.71 %, Cl 7.18%, N 19.84 %, S 6.49%; found: C 61.11 %, H 5.86 %, Cl 7.04%, N 19.09 %, S 6.56%. Example 43 2- t 2-/4-( 4-Methoxybenzyl) -1-piperazinyl/- ethylthio 77-4 , 6-diamino-5-(chlorobenzyl ) - pyrimidine Solvent employed in the reaction: methanol. Reaction time: 3 hours. The reaction mixture is worked up by method "A". Yield: 22.2 g (89 %) . Purification: recrystallization from aqueous ethanol. Melting point: 181-184 °C. Analysis for C 25 H 31 ClNgOS (499.082) calculated: C 60.17 %, H 6.26 %, Cl 7.10%, N 16.84 %, S 6.42%; found: C 58.89 %, H 6.07 %, Cl 6.80%, N 16.15 %, S 6.49%. Example 44 2-/72-/4-( 3-Methoxybenzyl ) -1-piperazinyl/- ethylthio 77-4, 6-diamino-5- ( 2-chlorobenzyl ) - pyrimidine Solvent employed in the reaction: methanol. Reaction time: 3 hours. The reaction mixture is worked up by method "A". Yield: 22.2 g (89 %) . Purification: recrystallization from aqueous ethanol . Melting point: 151-153 °C. Analysis for C 25 H 31 C1N 6 0S (499.082) calculated: C 60.17 %, H 6.26 %, Cl 7.10%, N 16.84 %, S 6.42%; found: C 60.57 %, H 6.16 %, Cl 7.02%, N 16.64 %, S 6.46%. Example 45 2-/72- I4-(2-Chlorobenzyl)-1-piperazinyl/- ethylthio77-4, 6-diamino-5- (2-chlorobenzyl )- pyrimidine Solvent employed in the reaction: methanol. Reaction time: 3 hours. The reaction mixture is worked up by method "B". Yield: 10.8 g (43 %) . Purification: recrystallization from aqueous ethanol. Melting point: 178-183 °C. Analysis for C 24 H 2 gCl 2 N 6 S (503.501) calculated: C 57.25 %, H 5.61 %, Cl 14.08%, N 16.69 %, S 6.37%; found: C 57.45 %, H 5.36 %, Cl 13.59%, N 16.80 %, S 6.14%. Example 46 2- T 2-/4-( 4-Chlorobenzyl) -1-piperazinyl/- ethy1thio - , 6-diamino-5-(2-chlorobenzyl )- pyrimidine Solvent employed in the reaction: methanol. Reaction time: 3 hours. The reaction mixture is worked up by method "A". Yield: 10.82 g (43 %) . Purification: recrystallization from aqueous ethanol. Melting point: 173-175 °C. Analysis for C 24 H 28 Cl 2 NgS (503.501) calculated: C 57.25 %, H 5.61 %, Cl 14.08%, N 16.69 %, S 6.37%; found: C 56.48 %, H 5.53 %, Cl 13.59%, N 16.38 %, S 6.11%. Example 47 2-/72-/4-( 2-Chlorobenzyl )-1-piperazinyl/- ethy1thio77-4 , 6-diamino-5-( 4-chlorobenzyl ) - pyrimidine Solvent employed in the reaction: methanol. Reaction .time: 24 hours. The reaction mixture is worked up by method "B". Yield: 15.1 g ( 60 % ) . Purification: recrystallization from aqueous ethanol . Melting point: 190-191 °C. Analysis for C 24 H 28 Cl 2 NgS (503.501) calculated: C 57.25 %, H 5.61 %, Cl 14.08%, N 16.69 %, S 6.37%; found: C 56.42 %, H 5.67 %, Cl 14.14%, N 16.25 %, S 6.27%. Example 48 2-/72-/4-( 4-Nitrobenzyl ) -1-piperazinyl/- ethylthio 77-4 , 6-diamino-5- ( 4-chlorobenzyl ) - pyrimidine Solvent employed in the reaction: methanol. Reaction time: 3 hours. The reaction mixture is worked up by method "B". Yield: 25.4 g (99 %) . Purification: recrystallization from aqueous acetone. Melting point: 133-135 °C. Analysis for C 24 H 28 C1N 7 0 2 S (514.053) calculated: C 56.08 %, H 5.49 %, Cl 6.90%, N 19.07 %, S 6.24%; found: C 56.55 %, H 5.58 %, Cl 6.76%, N 18.77 %, S 6.15%. Example 49 2-/72-/4- ( 4-Nitrobenzyl )-1-piperazinyl/- ethylthio J - 4 , 6-diamino-5- ( 2-chlorobenzyl ) - pyrimidine Solvent employed in the reaction: methanol. Reaction time: 3 hours. The reaction mixture is worked up by method "B". Yield: 12.1 g (47 %). Purification: recrystallization from aqueous ethanol . Melting point: 201-203 °C. Analysis for C 24 H 28 C1N 7 0 2 S (514.053) calculated: C 56.08 %, H 5.49 %, Cl 6.90%, N 19.07 %, S 6.24%; found: C 56.05 %, H 5.57 %, Cl 6.69%, N 18 . 96 % , S 6 . 17 % . Example 50 2-/72-/4-( 3-Trifluoromethylbenzyl) -1- piperazinyl/ethylthio .7-4 , 6-diamino-5- -( 2-chlorobenzyl )pyrimidine Solvent employed in the reaction: methanol. Reaction time: 3 hours. The reaction mixture is worked up by method "A". Yield: 15.3 g (57 %) . Purification: recrystallization from aqueous ethanol . Melting point: 121-123 °C. Analysis for C 2.D-H ηQ oClFJ-No,S (537.054) calculated: C 55.81 %, H 5.43 %, Cl 6.59%, N 15.62 %, S 5.96%; found: C 53.98 %, H 5.65 %, Cl 6.47%, N 15.31 %, S 5.79%. Example 51 2-/2- ( 4-Benzy1-1-piperazinyl )ethylthio/-4 , 6- diamino-5- ( 4-isopropylbenzyl )pyrimidine Solvent employed in the reaction: methanol. Reaction time: 7 hours. The reaction mixture is worked up by method "B". Yield: 14.5 g (61 %) . Purification: recrystallization from aqueous ethanol. Melting point: 154-155 °C. Analysis for C 2 -,H 3 g 6 S (476.692) calculated: C 68.03 %, H 7.61 %, N 17.63%, S 6.73 %; found: ' C 66.63 %, H 7.57 %, N 17.14%, S 6.96 %. Example 52 2- 2- 14 - ( 4-Nitrobenzyl)-1-piperazinyl/- ethy1thio J - , 6-diamino-5-( 4-isopropylbenzyl ) pyrimidine Solvent employed in the reaction: methanol. Reaction time: 3 hours. The reaction mixture is worked up by method "B" . Yield: 20.8 g (80 %) . Purification: flash chromatography using a mixture of chloroform and acetone in a ratio of 2:8 as the eluent. Melting point: 175-176 °C. Analysis for C^H^N^S (521.690) calculated: C 62.16 %, H 6.76 %, N iβ.79%, S 6.15 %; found: C 62.38 %, H 6.87 %, N 18.40%, S 6.06 %. Example 53 2-l_ 2-/4-( 2-Fluorobenzyl )-1-piperazinyl/- ethy1thio > 7-4,6-diamino-5-( 4-dimethylamino- benzyl )pyrimidine Solvent employed in the reaction: methanol. Reaction time: 3 hours. The reaction mixture is worked up by method "A". Yield: 15.12 g (61 %) . Purification: recrystallization from aqueous ethanol. Melting point: 182-184 °c. Analysis for C 26 H 34 FN--S (495.670) calculated: C 63.00 %, H 6.91 %, N 19.78%, S 6.47 %; found: C 62.86 %, H 7.23 %, N 19.73%, S 6.52 %. Example 54 2- 72-/4- ( 2-Cyanobenzyl )-1-piperazinyl/- ethylthio 77-4, 6-diamino-5-( 4-dimethylamino- benzyl )pyrimidine Solvent employed in the reaction: methanol. Reaction time: 3 hours. The reaction mixture is worked up by method "B". Yield: 23.1 g (92 %) . Purification: recrystallization from aqueous ethanol . Melting point: 170-173 °C. Analysis for C^H^NgS (502.690) calculated: C 64.51 %, H 6.82 %, N 22.29%, S 6.38 %; found: C 64.25 %, H 6.95 %, N 21.78%, S 6.12 %. Example 55 2-/~ 2-/4- (4-Methoxybenzyl)-1-piperazinyl/- ethy1thio -7- , 6-diamino-5-( 4-dimethylamino- benzyl)pyrimidine Solvent employed in the reaction: methanol. Reaction time: 3 hours. The reaction mixture is worked up by method "A". Yield: 21.8 g (86 %) . Purification: recrystallization from aqueous ethanol . Melting point: 192-195 °C. Analysis for C 27 H 37 N 7 OS (507.706) calculated: C 63.88 %, H 7.35 %, N 19.31%, S 6.31 %; found: C 63.93 %, H 7.13 %, N 19.12%, S 6.51 %. Example 56 2- 72- 1 - ( 3-Chlorobenzyl) -1-piperazinyl/- ethylthio 77- , 6-diamino-5-( 4-dimethylamino- benzyl )pyrimidine Solvent employed in the reaction: methanol. Reaction time: 3 hours. The reaction mixture is worked up by method "A". Yield: 16.60 g (65 %) . Purification: recrystallization from aqueous ethanol. Melting point: 179-182 °C. Analysis for C 2 gH 34 ClN 7 S (512.125) calculated: C 60.98 %, H 6.69 %, Cl 6.92%, N 19.15 %, S 6.26%; found: C 60.81 %, H 6.56 %, Cl 6.85%, N 19.00 %, S 6.38%. Example 57 2- 72-/4- ( 4-Nitrobenzyl )-1-piperazinyl/- ethylthio _7- , 6-diamino-5- ( 4-dimethylamino- benzyl )pyrimidine Solvent employed in the reaction: methanol. Reaction time: 3 hours. The reaction mixture is worked up by method "B". Yield: 11 g (42 %) . Purification: recrystallization from aqueous dimethylformamide. Melting point: 219-220 °C. Analysis for C 26 H 34 N 8°2 S ( 522.677 ) calculated: C 59.75 %, H 6.56 %, N 21.44%, S 6.13 %; found: C 58.03 %, H 6.32 %, N 21.08%, S 5.94 %. Example 58 2-/ " 2-/4-( 3-Trifluoromethylbenzyl)-1- piperazinyl/ethylthio - 4, 6-diamino-5- ( 4- -dimethylaminobenzyl)pyrimidine Solvent employed in the reaction: methanol. Reaction time: 3 hours. The reaction mixture is worked up by method "B". Yield: 11.50 g (42 %) . Purification: recrystallization from aqueous ethanol. Melting point: 1.85-189 °C. Analysis for C 27 H 34 F 3 7 S (545.678) calculated: C 59.32 %, H 6.45 %, N 17.94%, S 5.86 %; found: C 58.44 %, H 6.35 %, N 18.01%, S 5.79 %. Example 59 2-/72-/4-(4-Chlorobenzyl)-1-piperazinyl/- ethy1thio J - , 6-diamino-5-(2-chloro-6-fluoro¬ benzyl)pyrimidine Solvent employed in the reaction: methanol. Reaction time: 3 hours. The reaction mixture is worked up by method "B". Yield: 11.7 g (45 %) . Purification: recrystallization from aqueous ethanol . Melting point: 202-206 °C. Analysis for C 24 H 27 Cl 2 FN 6 S (521.491) calculated: C 55.28 %, H 5.22 %, Cl 13.60%, N 16.12 %, S 6.15%; found: C 54.78 %, H 5.20 %, Cl 13.40%, N 16.22 %, S 6.30%. Example 60 2- 72-/4-( 4-Nitrobenzyl ) -1-piperazinyl/- ethyIthio -7-4, 6-diamino-5- ( 2-chloro-6-fluoro¬ benzyl )pyrimidine Solvent employed in the reaction: methanol. Reaction time: 3 hours. The reaction mixture is worked up by method "B". Yield: 17.8 g (48 %) . Purification: recrystallization from acetone. Melting point: 202-204 °C. Analysis for C 24 H 27 C1FN 7 0 2 S (532.044) calculated: C 54.18 %, H 5.12 %, Cl 6.66%, N 18.43 %, S 6.03%; found: C 53.97 %, H 5.04 %, Cl 6.61%, N 17.73 %, S 6.05%. Example 61 2-72-/4-(2, 6-Dinitro-4-trifluoromethyl¬ phenyl ) -1-piperazinyl/ethylthio _7-4 , 6-diamino- -5-( 2-chloro-6-fluorobenzyl)pyrimidine Solvent employed in the reaction: methanol. Reaction time: 3 hours. The reaction mixture is worked up by method "B". Yield: 15.8 g ( 50 %) . Purification: recrystallization from aqueous ethanol . Melting point: 185-192 °C. Analysis " for C 24 H 23 ClF 4 Ng0 4 S (631.013) calculated: C 45.68 %, H 3.67 %, Cl 5.62%, N 17.76 %, S 5.08%; found: C 45.56 %, H 3.62 %, Cl 5.49%, N 17.14 %, S 5.25%. Example 62 2- " 2-/4- ( 4-Nitrobenzyl ) -1-piperazinyl/- ethy1thio 77-4 , 6-diamino-5- ( 4-trifluoromethyl¬ benzyl )pyrimidine Solvent employed in the reaction: methanol. Reaction time: 3 hours. The reaction mixture is worked up by method "B". Yield: 12.6 g (46 %) . Purification: recrystallization from aqueous dimethylformamide. Melting point: 164-166 °C. Analysis for C 2 5 H 28 F 3 N 7°2 S ( 547.607 ) calculated: C 54.83 %, H 5.15 %, N 17.90%, S 5.86 %; found: C 54.00 %, H 5.18 %, N 17.50%, S 6 . 06 % . Example 63 2- 72-/4-( 3-Trifluoromethylbenzyl)-1- piperazinyl/ethylthio 3 -4, 6-diamino-5-( 4- trifluoromethylbenzyl )pyrimidine Solvent employed in the reaction: methanol. Reaction time: 3 hours. The reaction mixture is worked up by method "A". Yield: 14 g (49 %) . Purification: flash chromatography using a mixture of chloroform and methanol in a ratio of 9:1 as the eluent. Melting point: 127-129 °C. Analysis for C 26 H 2 8 F 6 N 6 S ( 570.608 ) calculated: C 54.73 %, H 4.95 %, N 14.73%, S 5.62 %; found: C 54.79 %, H 4.80 %, N 14.46%, S 5.74 %. Example 64 2-/T 2-/4-( 4-Nitrobenzyl ) -1-piperazinyl/- ethy1thio .7-4 , 6-diamino-5-( 4-bromo- benzyl )pyrimidine Solvent employed in the reaction: methanol. Reaction time: 3 hours. The reaction mixture is worked up by method "B". Yield: 12.9 g (46 %) . Purification: recrystallization from aqueous acetone. Melting point: 169-173 °C. Analysis for C 24 H 28 BrN--0 2 S (558.509) calculated: C 51.61 %, H 5.05 %, Br 14.31%, N 17.56 %, S 5.74%; found: C 51.45 %, H 5.04 %, Br 13.94%, N 17.44 %, S 5.50%. Example 65 2- C 2-/4-( 3-Methoxybenzyl)-1-piperazinyl/- ethy1thio 77-4 , 6-diamino-5-(3,4, 5-trimethoxy- benzyl )pyrimidine Solvent employed in the reaction: methanol. Reaction time: 3 hours. The reaction mixture is worked up by method "A". Yield: 17.2 g (62 %) . Purification: recrystallization from aqueous ethanol. Melting point: 137-138 °C. Analysis for C 28 H 38 Ng0 4 S (554.717) calculated: C 60.63 %, H 6.91 %, N 15.15%, S 5.78 %; found: C 58.32 %, H 7.05 %, N 14.95%, S 5.62 %. Example 66 2-7 " 2-/4-( 4-Methoxybenzyl )-1-piperazinyl/- ethy1thio 77-4 , 6-diamino-5-( 3,4, 5-trimethoxy- benzyl )pyrimidine Solvent employed in the reaction: methanol. Reaction time: 3 hours. The reaction mixture is worked up by method "A". Yield: 23.6 g (85 %) . Purification: flash chromatography using a mixture of chloroform and methanol in a ratio of 9:1 as the eluent. Melting point: 152-154 °C. Analysis for 28 H 38 Ng0 4 S (554.717) calculated: C 60.63 %, H 6.90 %, N 15.15%, S 5.78 %; found: C 61.99 %, H 6.89 %, N 14.45%, S 5.52 %. Example 67 2-_7 " 2-/4-( 2-Chlorobenzyl )-1-piperazinyl/- ethylthio -4 , 6-diamino-5-(3,4, 5-trimethoxy- benzyl )pyrimidine Solvent employed in the reaction: methanol. Reaction time: 3 hours. The reaction mixture is worked up by method "A". Yield: 22.4 g (80 %) . Purification: recrystallization from aqueous ethanol. Melting point: 170-172 °C. Analysis for C 27 H 35 ClNg0 3 S (559.135) calculated: C 58.00 %, H 6.31 %, Cl 6.34%, N 15.03 %, S 5.73; found: C 57.30 %, H 6.30 %, Cl 6.27%, N 14.80 %, S 5.74%. Example 68 2-/72-/4-( 4-Nitrobenzyl)-l-piperazinyl/- ethy1thio J - , 6-diamino-5- (3,4, 5-trimethoxy- benzyl)pyrimidine Solvent employed in the reaction: methanol. Reaction time: 3 hours. The reaction mixture is worked up by method "A". Yield: 11.7 g (41 %) . Purification: recrystallization from aqueous ethanol . Melting point: 130-132 °C. Analysis for C 27 H 35 N 7 0 5 S (569.688) calculated: C 56.93 %, H 6.19 %, N 17.21%, S 5.63 %; found: C 56.67 %, H 6.22 %, N 17.38%, S 5.54 %. Example 69 2- ~ 2-/4-( 3-Trifluoromethylbenzyl )-l- -piperazinyl/ethylthio J7-4 , 6-diamino-5- -(3,4, 5-trimethoxybenzyl)pyrimidine Solvent employed in the reaction: methanol. Reaction time: 3 hours. The reaction mixture is worked up by method "A". Yield: 13 g (44 %) . Purification: recrystallization from aqueous ethanol. Melting point: 159-162 °C. Analysis for C 28 H 35 F 3 N 6 0 3 S (592.689) calculated: C 56.74 %, H 5.95 %, N 14.18%, S 5.41 %; found: C 56.90 %, H 6.04 %, N 14.06%, S 5.62 %. Example 70 2- 2-/4- ( 4-Nitrobenzyl )-1-piperazinyl/- ethy1thio_7-4,6-diamino-5-( 4-benzyloxy-3- -methoxybenzyl )pyrimidine Solvent employed in the reaction: methanol. Reaction time: 3 hours. The reaction mixture is worked up by method "B". Yield: 14.5 g (47 %) . Purification: recrystallization from aqueous ethanol. Melting point: 171-173 °C. Analysis for C 32 H 37 N 7 0 4 S (615.760) calculated: C 62.42 %, H 6.06 %, N 15.92%, S 5.21 %; found: C 61.23 %, H 5.83 %, N 15.85%, S 5 . 22 % . Example 71 2-7 " 2-/4-( 2-Nitro-4-trifluoromethylphenyl)- -1-piperazinyl/ethylthio J - , 6-diamino-5- -( 4-methoxybenzyl)pyrimidine Solvent employed in the reaction: methanol. Reaction time: 2.5 hours. The reaction mixture is worked up by method "B". Yield: 23.1 g (82 %) . Melting point: 181-182 °C. Analysis for C 5 H 8 F 3 N 7°3 S (563.607) calculated: C 53.28 %, H 5.01 %, N 17.40%, S 5.69 %; found: C 52.65 %, H 4.89 %, N 17.05%, S 5.91 %. Example 72 2- C 2-/4-(2-Chlorobenzyl)-1-piperazinyl/- ethy1thio 3 - , 6-diamino-5-(4-methoxy¬ benzyl )pyrimidine Solvent employed in the reaction: methanol. Reaction time: 4 hours. The reaction mixture is worked up by method "B". Yield: 16.0 g (64 %) . Purification: recrystallization from aqueous ethanol . Melting point: 173 °C. Analysis for C ^ H^ClNgOS (499.075) calculated: C 60.17 %, H 6.26 %, Cl 7.10%, N 16.84 %, S 6.42%; found: C 59.95 %, H 6.22 %, Cl 6.99%, N 16.55 %, S 6.50%. Example 73 2-/J " 2-/4-( 2-Chlorobenzyl ) -1-piperazinyl/- ethylthio 77- , 6-diamino-5-( -benzyloxy-3- -methoxybenzyl )pyrimidine Solvent employed in the reaction: methanol. Reaction time: 82 hours. The reaction mixture is worked up by method "B". Yield: 25.7 g (85 %) . Purification: recrystallization from benzene, Melting point: 158-160 °C. Analysis for C 32 H 37 ClNg0 2 S (605.201) calculated: C 63.51 %, H 6.16 %, Cl 5.86%, N 13.89 %, S 5.30%; found: C 63.16 %, H 6.12 %, Cl 5.84%, N 13.84 %, S 5.33%. Example 74 2-/72-/4-( 2-Chlorobenzyl )-1-piperazinyl/- ethylthio _7-4,6-diamino-5-{ 4-isopropyl¬ benzyl)pyrimidine Solvent employed in the reaction: methanol. Reaction time: 3 hours. The reaction mixture is worked up by method "B". Yield: 16.1 g (63 %) . Purification: recrystallization from ethanol. Melting point: 138-140 °C. Analysis for C^H^Cl gS (511.130) calculated: C 63.45 %, H 6.90 %, Cl 6.94%, N 16.44 %, S 6.27%; found: C 63.32 %, H 7.00 %, Cl 6.76%, N 16.34 %, S 6.30%. Example 75 2-/2- (4-Benzyl-l-piperazinyl)ethylthio/- , 6- diamino-5-( 4-benzyloxy-3-methoxybenzyl)- pyrimidine Solvent employed in the reaction: ethanol. Reaction time: 7.5 hours. The reaction mixture is worked up by method "C". Yield: 26.6 g (93 %) . Purification: recrystallization from methanol Melting point: 166-167 °C. Analysis for C^H^N^S (570.759) calculated: C 67.34 %, H 6.71 %, N 14.72%, S 5.62 %; found: C 66.52 %, H 6.68 %, N 14.36%, S 5.55 %. Example 76 2- f 2-/4-(2, 6-Dinitro-4-trifluoromethyl¬ phenyl ) -1-piperazinyl/ethylthio 77- -methy1- -5-( 2-hydroxyethyl )uracil Solvent employed in the reaction: methanol. Reaction time: 1.5 hours. The reaction mixture is worked up by method "B". Yield: 13.8 g (52 %) . Purification: stirring in ethyl acetate. Melting point: 196-197 °C. Analysis for C 20 H 3 F 3 N 6°6 S ( 532.502 ) calculated: C 45.11 %, H 4.35 %, N 15.78%, S 6.02 %; found: C 46.30 %, H 4.35 %, N 15.55%, S 6.29 %. Example 77 2-/72-/4- ( 2-Nitro-4-trifluoromethylphenyl ) - -1-piperazinyl/-ethylthio 7 -4-methyl-5- - ( 2-hydroxyethyl )uracil Solvent employed in the reaction: ethanol. Reaction time: 1 hour. The reaction mixture is worked up by method "A". Yield: 17.6 g (72 %) . Purification: stirring in hexane. Melting point: 133-135 °C. Analysis for C 20 H 2 4 F 3 N 5 0 4 S (487.506 ) calculated: C 49.28 %, II 4.96 %, N 14.37%, S 6.58 %; found: C 48.05 %, H 4.75 %, N 14.38%, S 6.56 %. Example 78 2-/72-/4-(2, 6-Dinitro-4-trifluoromethyl¬ phenyl ) -l-piperazinyl/ethylthiς7-4-methyl- uracil Solvent employed in the reaction: methanol. Reaction time: 3 hours. The reaction mixture is worked up by method "B". Yield: 11 g (45 %) . Purification: recrystallization from ethanol Melting point: 226-228 °C. Analysis for c i 8 H 19 F 3 N 6 0 5 S (488.45) calculated: C 44.26 %, H 3.92 %, F 11.67%, N 17.21 %, S 6.56%; found: C 44.04 %, H 4.07 %, F 12.07%, N 16.76 %, S 6.5 " 6%. Example 79 2-/72-/4-(2, 6-Dinitro-4-trifluoromethyl¬ phenyl )-l-piperazinyl/ethylthio 77-4-amino- uracil Solvent employed in the reaction: methanol. Reaction time: 3 hours. The reaction mixture is worked up by method "B". Yield: 17.6 g (72 %) . Purification: flash chromatography using a mexture of chloroform and methanol in a ratio of 9:1 as the eluent, then recrystallization from aqueous ethanol. Melting point: 257-259 °C. Analysis for C 17 H 18 F 3 N 7 OS (489.44) calculated: C 41.72 %, H 3.71 %, F 11.65%, N 20.03 %, S 6.55%; found: C 42.10 %, H 3.64 %, F 11.66%, N 20.23 %, S 6.66%. Example 80 2-/72-/4-( 2-Nitro-4-trifluoromethylphenyl ) - -1-piperazinyl/ethylthio .7-4- ( 4-methoxy¬ phenyl )-5-cyano-6-amino-3, 4-dihydropyrimidine Solvent employed in the reaction: methanol. Reaction time: 1 hour. The reaction mixture is worked up by method "B". Yield: 20.6 g (73.4 %) . Melting point: 225-226 °C. Analysis for C 25 H 2 gF 3 N 7 0 3 S (561.591) calculated: C 53.47 %, H 4.67 %, N 17.46%, S 5.71 %; found: C 53.54 %, H 4.69 %, N 17.18%, S 5.89 %. Example 81 2-/72-/4-( 2-Nitro-4-trifluoromethylphenyl) - -1-piperazinyl/e hylthio .7-4- ( 2-methoxy¬ phenyl ) -5-cyano-6-amino-3 , 4-dihydropyrimidine Solvent employed in the reaction: methanol. Reaction time: 1 hour. The reaction mixture is worked up by method "B". Yield: 24.8 g (88 %) . Melting point: 213-215 °C. Analysis for C 2_ C DH-_-D-FJ-.N-/-0J-S (561.591) calculated: C 53.47 %, H 4.67 %, N 17.46%, S 5.71 %; found: C 53.67 %, H 4.74 %, N 17.27%, S 5.95 %. Example 82 2-72-/4-( 2-Nitro-4-trifluoromethylphenyl) - -1-pj perazinyl/ethylthio .7-4-( -chlorophenyl ) - -5-cyano-6-amino-3 , 4-dihydropyrimidine Solvent employed in the reaction: ethanol. Reaction time: 1 hour. The reaction mixture is worked up by method "B". Yield; 24.9 g (87.9 %) . Melting point: 217-219 °C. Analysis for C2_4.H2_3ClF3N_702_S (556.007) calculated: C 50.93 %, H 4.10 %, Cl 6.26%, N 17.32 %, S 5.66%; found: C 50.09 %, H 4.02 %, Cl 6.32%, N 16.51 %, S 5.65%. Example 83 2- 72-/4- ( 2-Nitro- -trifluoromethylphenyl ) - -1-piperazinyl/ethylthio J -4 - ( 2-chlorophenyl -5-cyano-6-amino-3, 4-dihydropyrimidine Solvent employed in the reaction: ethanol. Reaction time: 45 minutes. The reaction mixture is worked up by method "B". Yield: 25.7 g (90.8 %) . Melting point: 235-236 °C. Analysis for C-, 4 H 23 C1F 3 7 0 2 S (556.007) calculated: C 50.93 %, H 4.10 %, Cl 6.26%, N 17.32 %, S 5.66%; found: C 50.55 %, H 4.11 %, Cl 6.19%, N 17.20 %, S 5.72%. Example 84 2- 72-/4-( 2-Nitro-4-trifluoromethylphenyl ) - -1-piperazinyl/ethylthio 77-4-( 4-dimethyl- aminophenyl )-5-cyano-6-amino-3,4-dihydro- pyrimidine Solvent employed in the reaction: methanol. Reaction time: 1.5 hours. The reaction mixture is worked up by method "B". Yield: 25.8 g (89.8 %) . Purification: recrystallization from aqueous acetone. Melting point: 221-223 °C. Analysis for C 26^29 F 3 N 8°2 S ( 574.634 ) calculated: C 54.35 %, H 5.09 %, N 19.50%, S 5.58 %; found: C 54.48 %, H 5.11 %, N 19.32%, S 5.72 %. Example 85 2- 72-/4- ( 2-Nitro-4-trifluoromethylphenyl )_ -1-piperazinyl/ethylthio 77-4-phenyl-5-cyano- -6-amino-3 , 4-dihydropyrimidine Solvent employed in the reaction: ethanol. Reaction time: 0.5 hours. The reaction mixture is worked up by method "B". Yield: 24 g (90.3 %) . Melting point: 240-242 °C. Analysis for C 24 H 24 F 3 N_,0 2 S (531.565) calculated: C 54.23 %, H 4.55 %, N 18.44%, S 6.03 %; found: C 53.63 %, H 4.49 %, N 18.08%, S 6.21 %. Example 86 2- 72-/4-(2, 6-Dinitro-4-trifluoromethyl¬ phenyl) -1-piperazinyl/ethylthio 77—4—( 4— -methoxyphenyl ) -5-cyano-6-aminopyrimidine Sol vent employed in the reaction: methanol. Reaction time: 20 minutes. The reaction mixture is worked up by method "C". Yield: 15.7 g (51.7 %) . Purification: recrystallization from a mixture of ethanol and acetone. Melting point: 245-247 °C. Analysis for C 2 5 H 2 3 F 3 N 8 °5 S (604.573) calculated: C 49.67 %, H 3.83 %, N 18.53%, S 5.30 %; found: C 49.16 %, H 4.05 %, N 18.30%, S 5.38 %. Example 87 2-/ 2-/4- ( 2-Nitro-4-trifluoromethylphenyl ) - -1-piperazinyl/ethylthio _7-4-( 4-bromophenyl- -5-cyano-6-amino-3,4-dihydropyrimidine Solvent employed in the reaction: ethanol. Reaction time: 1 hour. The reaction mixture is worked up by method "B". Yield: 26.4 g (86.4 %) . Melting point: 220-222 °C. Analysis for C 24 H_ 1 BrF : -N 7 0 2 S (610.467) calculated: C 47.22 %, H 3.80 %, Br 13.09%, N 16.06 %, S 5.25%; found: C 46.50 %, H 3.73 %, Br 13.26%, N 15.99 %, S 5.20%. Example 88 2- 72-/4-( 2-Nitro-4-trifluoromethylphenyl) - -1-piperazinyl/ethylthio 77-4- (4-benzyloxy- -3-methoxyphenyl-5-cyano-6-amino-3, 4- -dihydropyrimidine Solvent employed in the reaction: ethanol. Reaction time: 1 hour. The reaction mixture is worked up by method "B". Yield: 27.7 g (83.0 %) . Purification: recrystallization from ethyl acetate. Melting point: 162-164 °C. Analysis for C 32 H 32 F 3 7 0 4 S (667.717) calculated: C 57.56 %, H 4.83 %, N 14.68%, S .80 % ; found: C 57.10 %, H 4.76 %, N 14.46%, S 4.99 %. Example 89 2- 72-/4-( 2-Nitro-4-trifluoromethylphenyl) - -1-piperazinyl/ethylthio -7-4-(3.4,5- -trimethoxyphenyl) -5-cyano-6-amino-3, 4- -dihydropyrimidine Solvent employed in the reaction: ethanol. Reaction time: 1 hour. The reaction mixture is worked up by method "B". Yield: 26.2 g (84.4 %) . Melting point: 204-206 °C. Analysis for C 27 H 3 F 3 N ? 0-.S (621.644) calculated: C 52.17 %, H 4.86 %, N 15.77%, S 5.16 %; found: C 52.16 %, H 4.72 %, N 15.98%, S 5.32 %. Example 90 2-/7 " 2-/4- ( 2, 6-Dihitro-4-trifluoromethyl¬ phenyl )piperazinyl/ethylthio .7-4- ( 2-methoxy¬ phenyl) -5-cyano-6-aminopyrimidine Solvent employed in the reaction: methanol. Reaction time: 3 hours. The reaction mixture is worked up by method "B" . Yield: 10.7 g (35.4 %) . Purification: recrystallization from aqueous ethanol . Melting point: 194-195 °C. Analysis for C 25 H 23 F-.N 8 0-.S (604.573) calculated: C 49.67 %, H 3.83 %, N 18.53%, S 5.30 %; found: C 48.27 %, H 3.85 %, N 18.29%, S 5.26 %.' Example 91 2-7 * 2-/4- ( 2-Nitro- -trifluoromethylphenyl ) - -1-piperazinyl/ethylthio 7-4-methyl-5-ethoxy- carbonyl-6-phenyl-3, 4-dihydropyrimidine Solvent employed in the reaction: methanol. Reaction time: 1.5 hours. The reaction mixture is worked up by method "A". Yield: 12.2 g (42.1 %) . Purification: recrystallization from a mixture of methanol and hexane. Melting point: 110-112 °C. Analysis for C 2 -,H 30 F 3 N 5 0 4 S (577.632) calculated: C 56.14 %, H 5.23 %, N 12.12%, S 5.55 %; found: C 54.41 %, H 4.91 %, N 12.24%, S 5.63 %. Example 92 2- 72-/4-( 2, 6-Dinitro-4-trifluoromethyl¬ phenyl ) -1-piperazinyl/ethylthio _7-4-(4-chloro- phenyl ) -5-cyano-6-aminopyrimidine Solvent employed in the reaction: ethanol. Reaction time: 1 hour. The reaction mixture is worked up by method "B". Yield: 15.2 g (50.9 %) . Purification: recrystallization from ethyl acetate. Melting point: 247-249 C. Analysis for C 23 H 20 ClF 3 Ng0 4 S (596.977) calculated: C 46.28 %, H 3.38 %, Cl 5.94%, N 18.77 %, S 5.37%; found: C 46.94 %, II 3.27 %, Cl 5.84%, N 18.37 %, S 5.23%. Example 93 2-/2-( 4-Benzyl-1-piperazinyl)ethylthio/-4- -( 4-methoxyphenyl ) -5-cyano-6-aminopyrimidine Solvent employed in the reaction: methanol. Reaction time: 3 hours. The reaction mixture is worked up by method "A". Yield: 13.1 g (55.5 %) . Melting point: 156-158 °C. Analysis for C^H^NgOS (462.617) calculated: C 64.91 %, H 6.54 %, N 18.17%, S 6.93 %; found: C 64.87 %, H 6.59 %, N 17.86%, S 6.98 %. Example 94 2-/72-/4- ( 2, 6-Dinitro-4-trifluoromethyl- phenyl )-l-piperazinyl/ethy1thio 7-4- (4- benzyloxy-3-methoxyphenyl ) -5-cyano- -6-aminopyrimidine Solvent employed in the reaction: ethanol. Reaction time: 1 hour. The reaction mixture is worked up by method "B". Yield: 25.0 g (70.2 %) . Purification: recrystallization from ethyl acetate. Melting point: 201-203 °C. Analysis for C 32 H 2 9 F 3 N 8 ° 6 S (710.698) calculated: C 54.08 %, H 4.11 %, N 15.77%, S 4.51 %; found: C 53.49 %, H 3.99 %, N 15.70%, S 4.38 %. Example 95 2-/2- (4-Benzyl-1-piperazinyl)ethylthio/-4- -( 2-chlorophenyl )-5-cyano-6-amino-3, 4- -dihydropyri idine Solvent employed in the reaction: methanol. Reaction time: 14 hours. The reaction mixture is worked up by method "C". Yield: 15.9 g (67.9 %) . Melting point: 183-184 °C. Analy 1 sis for C2,4 / ,H2---7 7 C1N6,S (467.033) calculated: C 61.72 %, H 5.83 %, Cl 7.59%, N 17.99 %, S 6.86%; found: C 62.20 %, H 5.76 %, Cl 7.85%, N 18.13 %, S 7.04%. Example 96 2-/2-(4-B " enzyl-l-piperazinyl)ethylthio/-4- -phenyl-5-cyano-6-amino-3, 4-dihydropyrimidine Solvent employed in the reaction: methanol. Reaction time: 2.5 hours. The reaction mixture is worked up by method "B". Yield: 11.9 g (55.1 %) . Purification: recrystallization from ethanol Melting point: 175-176 °C. Analysis for C. -..H 2-o-NO.S (432.591) calculated: C 66.64 %, H 6.52 %, N 19.43%, S 7.41 %; found: C 66.54 %, H 6.50 %, N 19.28%, S 7.29 %. Example 97 2- 72-/4-( 2-Nitrobenzyl ) -1-piperazinyl/- ethylthio 77-4-pheny1-5-cyano-6-amino-3, 4- -dihydropyrimidine Solvent employed in the reaction: dimethylforma ide. Reaction time: 3 hours. The reaction mixture is worked up by method "C". Yield: 13.8 g (57.6 %) . Melting point: 198-199 °C. Analy 1 sis for (477.589) calculated: C 60.36 %, H 5.70 %, N 20.53%, S 6.71 %; found: C 59.61 %, H 5.53 %, N 20.52%, S 6.63 %.. Example 98 2-/72- ( 4- ( 2-Nitro- -trifluoromethylphenyl ) - -1-piperazinyl/ethyl hio 77-4-phenyl-5-cy no- -6-aminopyrimidine Solvent employed in the reaction: dimethylformamide. Reaction time: 10 hours. The reaction mixture is worked up by method "B". Yield: 20.3 g (76.8 %) . Purification: recrystallization from ethanol, then from benzene. Melting point: 189-190 °C. Analysis for C 2 H 2 F 3 N 7° 2 S (529.549) calculated: C 54.44 %, H 4.19 %, N 18.52%, S 6.05 %; found: C 55.59 %, H 4.33 %, N 18.02%, S 5.92 %. Example 99 2-7~2-/4-( 2-Nitro-4-trifluoromethylphenyl ) - -1-piperazinyl/ethylthio 3 - - ( 2-methoxy¬ phenyl ) -5-cyano-6-aminopyrimidine Solvent employed in the reaction: dimethylformamide. Reaction time: 35 hours. The reaction mixture is worked up by method "B". Yield: 20.6 g (73.6 %) . Purification: recrystallization from benzene, then the crystals are suspended in kerosene. Melting point: 145-147 °C. Analysis for 25 11 2 4 F 3 N 7°3 S ( 559.575 ) calculated: C 53.66 %, H 4.32 %, N 17.52%, S 5.73 %; found: C 54.04 %, H 4.36 %, N 17.13%, S 5.94 %. Example 100 2- 72-/4- ( 3-Trifluoromethylbenzyl) -1- -piperazinyl/ethylthio_7-4-( 2-chlorophenyl ) - -5-cyano-6-aminopyrimidine Solvent employed in the reaction: dimethylformamide. Reaction time: 5 hours. The reaction mixture is worked up by method "A". Yield: 16.7 g (63.5 %) . Purification: recrystallization from ethanol Melting point: 166-167 °C. Analysis for C 25 H 24 ClF 3 NgS (533.02) calculated: C 56.34 % f H 4.54 %, Cl 6.65%, N 15.77 %, S 6.01%; found: C 55.78 %, H 4.42 %, Cl 6.68%, N 15.81 %, S 6.20%. Example 101 2- 72-/4-( 2-Chlorobenzyl )-1-piperazinyl/- ethylthio 77- , 6-diamino-5-( 4-dimethylamino- benzyl )pyrimidine Solvent employed in the reaction: methanol. Reaction time: 40 hours. The reaction mixture is worked up by method "A". Yield: 5.85 g (22.9 %) . Purification: recrystallization from aqueous acetone. Melting point: 156.4-156.6 °C. Analysis for C 26 H 34 C1 ? S (512.13) calculated: C 60.98 %, H 6.69 %, Cl 6.92%, N 19.15 %, S 6.26%; found: C 60.80 %, H 6.67 %, Cl 6.83%, N 18.85 %, S 6.11%. Example 102 2- 2-/4-( 2-Chlorobenzyl ) -1-piperazinyl/- ethylthio ^- , 6-diamino-5-( 4-dimethylamino- benzyl)pyrimidine Solvent employed in the reaction: methanol. Reaction time: 40 hours. The reaction mixture is worked up by method "A". Yield: 5.30 g (26.5 %) . Purification: recrystallization from aqueous acetone. Melting point: 90-93 °C. Analysis for C 26 H 34 C1 --S (512.13) calculated: C 62.97 %, H 8.05 %, N 20.98%, S 8.00 %; found: C 62.36 %, H 7.92 %, N 20.34%, S 7.86 %. Exa ple 103 2-/11- ( 4-Benzyl-l-piperazinyl )undecylthio/- -4 , 6-diaminopyrimidine x MeOH Solvent employed in the reaction: methanol. Reaction time: 12 hours. The reaction mixture is worked up by method "A". Yield: 18.50 g (78.0 %) . Purification: recrystallization from aqueous ethanol. Melting point: 109-111 °C. Analy 1 sis for C2_-7,H4 ilc 6N6 : 0S (502.77) calculated: C 64.50 %, H 9.22 %, N 16.72%, S 6.38 %; found: C 62.57 %, H 8.90 %, N 16.43%, S 6.36 %. Example 104 2- 711-/4- ( 4-Nitrobenzyl ) -1-homopiperazinyl/- 1-undecylthio -7-4 , 6-diamino-pyrimidine Solvent employed in the reaction: methanol. Reaction time: 12 hours. The reaction mixture is worked up by method "A". Yield: 18.2 g (68.0 %) . Purification: recrystallization from a mixture of chloroform and methanol. Melting point: 185-187 °C. Analysis for C 27 H 43 N 7 0 2 S (529.753) calculated: C 61.22 %, II 8.18 %, N 8.51 %, S 6.05 %; found: C 61.05 %, H 8.10 %, N 8.60 %, S 6.09 %. Preparation of the acid addition salts The pharmaceutically acceptable acid addition salts of the compounds of the formula I are prepared according to the following general method: 0.05 moles of the compound of the formula I are dissolved in 1000 ml of ethanol, and, to the solution obtained, 250 ml of ethanol containing 25 per cent of hydrochlorid acid are added. The reaction mixture is stirred at reflux temperature for 2 hours, then the solvent is removed under reduced pressure. The solid residue is purified by suspending it in 100 ml of anhydrous ethanol, stirring the suspension for 20 minutes, then removing the solvent under reduced pressure. The purification procedures are repeated three times, and the product is dried in a drying oven until a constant weight is attained. Example 105 2- 72-/4- ( 2-Methylbenzyl)-1-piperazinyl/- ethylthio -4, 6-diamino-5-(2-chloro- benzyl)pyrimidine trihydrochloride Yield: 27 g (91 %) . Melting point: 179-186 °C. Analysis for C 25 H 34 Cl 4 NgS (592.466) calculated: C 50.68 %, H 5.78 %, Cl 23.94%, N 14.18 %- S 5.4.1 %; found: C 49.75 %, H 5.75 %, Cl 23.46%, N 14.02 % r S 5.45 %. Example 106 2- C 2 - 14 - ( 3-Methoxybenzyl )-1-piperazinyl/- ethylthio .7-4 f 6-diamino-5-(3,-4.5-trimethoxy benzyl )pyrimidine trihydrochloride Yield: 30 g (89 %) . Melting point: 171-179 °C. Analysis for C 2Q H 41 Cl 3 Ng0 4 S (664.100) calculated: C 50.64 %. II 6.22 %, Cl 16.02%, N 12.65 %, S 4.83 %; found: C 50.07 %, H 6.52 %, Cl 15.79%, N 12.20 %. S 4.64 %. Example 107 2 -C 2 - 1 - ( 2-Cyanobenzyl ) -1-pi erazinyl/- ethylthio .77-4.6-diamino-5-( 4-methoxy- benzyl)pyrimidine trihydrochloride Yield: 28 <j (92 %) . Melting point: 199-210 °C. Analysis for C 26 II 34 Cl 3 7 OS (599.030) calculated: C 52.13 % . H 5.72 %, Cl 17.76%, N 16.37 %, S 5.35 %; found: C 51.76 %, H 5.65 %, Cl 17.57%, N 16.06 %, S 5.45 %. Example 108 2 - £ 2 - 14 - ( 3-Methoxybenzyl) -1-piperazinyl/- ethylthio " - , 6-diamino-5-benzylpyrimidine trihydrochloride Yield: 25 g (87 %) . Melting point: 163-174 °C. Analysis for c 2 5 }1 35 Cl 3 N 6 OS ( 574.020 ) calculated: C 52.31 %, H 6.15 %,. Cl 18.53%, N 14.64 %. S 5.59 %; found: C 51.29 % . H 6.17 %, Cl 19.08%, N 14.26 %, S 5.80 %. Example 109 2-/72-/4- ( 3-Trifluoromethylbenzyl ) -1- -piperazinyl/ethylthio _7-4,.6-diamino-5- -(3,4, 5-trimethoxybenzyl )pyrimidine trihydrochloride Yield: 30 g (85 %) . Melting point: 162-165 °C. Analysis for C 28 H 38 Cl 3 F 3 Ng0 3 S (702.072) calculated: C 47.90 %, H 5.46 %. Cl 15.15%, N 11.97 %. S 4.57 %; found: C 45.84 %, H 5.60 %, Cl 14.51%, N 11.40 %, S 4.63 %. Example 110 2 - 1 2-/4- (3-Methoxybenzyl )-l-piperaziny1/- ethylthio /-4,C-diamino-5-( -methoxy¬ benzyl)pyrimidine trihydrochloride Yield: 26 g (86 %) . Melting point: 172-182 °C. Analysis for C 26 H 37 C1-.N 6 0 2 S (604.047) calculated: C 51.70 %, H 6.17 %. Cl 17.61%, N 13.91 %. S 5.31 %; found: C 50.01 %, H 6.27 %, Cl 16.94%. N 13.29 %, S 5.24 %.

Claims: Claims 1. A piperazinylalkylthiopyrimidine derivative of the formula wherein R and R represent.- independently, a hydrogen, a C, . alkyl group, an αmino group, a (C, . alkanoyl )- amino group, or a phenyl group optionally bearing 1 to 3 substituents selected from the group consisting of. independently, a halo., a C, , alkoxy group, a di(C, 4 alkyl)amino group or a benzyloxy group, 2 R stands for a hydrogen, a cyano group, a furylmethyl group, a ( Cm η cycloalkyl Jmethyl group, a (C, . alkoxy)carbonyl group, a hydroxy- (C,_ 4 alkyl) group or a benzyl group optionally bearing 1 to 3 substituents selected from the group consisting of, independently, a halo, a C, . alkyl group, a C,_. alkoxy group, a trifiuoromethyl group, a hydroxy group, a benzyloxy group or a di-(C,_ 4 alkyl)amino group, R means a hydrogen, or R 3 forms with R4 an oxygen atom, R is a hydrogen, or R 4 forms with R5 a valence bond.. R represents a halo, a cyano group, a nitro group, a C, . alkyl group, a C. . alkoxy group or a tri iuoromethyl group, m has a value of 0 or 1, n has a value of 1 or 2, p is an integer between 2 to 11, and k has a value of 0, 1, 2 or 3, and a pharmaceutically acceptable acid addition salt thereof. 2. A compound of the formula I as claimed in Claim 1. wherein R 1 and R3 represent, independently, a hydrogen, a methyl group, an amino group, an acetylamino group or a phenyl group optionally bearing 1 to 3 substituents selected from the group consisting of independently, a chloro, a methoxy group, a dimethylamino group or a benzyloxy group, 2 R stands for a hydrogen, a cyano group, a furylmethyl group, a cyclohexyl¬ methyl group, an ethoxycarbonyl group, a hydroxyethyl group or a benzyl group optionally bearing 1 to 3 substituents selected from the group consisting of, independently, a chloro, a C, , alkyl group, a fluoro. a methoxy group, a trifiuoromethyl group, a hydroxy group, a benzyloxy group or a dimethylamino group, R means a hydrogen, or R 3 forms with R4 an oxygen atom, R is a hydrogen, or 4 5 R forms with R a valence bond. c R represents a chloro, a fluoro. a cyano group, a nitro group, a methyl group, a methoxy group or a trifiuoromethyl group, m has a value of 0 or 1, n has a value of 1 or 2, p has a value of 2 or 11, and k has a value of 0, 1, 2 or 3, and a pharmaceutically acceptable acid addition salt thereof. 3. A compound of the formula I as claimed in Claim 1 or 2, wherein R and R represent an amino group, 2 R stands for a hydrogen or a benzyl group optionally bearing 1 to 3 substituents selected from the group consisting of, independently, a fluoro, a chloro, a methoxy group and a dimethylamino group, R 4 forms with R5 a valence bond, R means a fluoro, a chloro, a nitro group, a cyano group, a methyl group, a methoxy group or a trifiuoro¬ methyl group, k has a value of 1, m has a value of 1, n has a value of 1, and p has a value of 2, and a pharmaceutically acceptable acid addition salt thereof. 4. 2 - [ 2-/4-(4-Nitrobenzyl)-l- -piperazinyl/ethylthio 77- , 6-diamino- -5-benzylpyrimidine and a pharmaceutically acceptable acid addition salt thereof. 5. A process for preparing a piperazinyl¬ alkylthiopyrimidine derivative of the formula wherein R and R represent, independently, a hydrogen, a C, . alkyl group, an amino group, a (C, . alkanoyl)- a ino group, or a phenyl group optionally bearing 1 to 3 substituents selected from the group consisting of, independently, a halo, a C, . alkoxy group, a di(C, . alkyl)amino group or a benzyloxy group, 2 R stands for a hydrogen, a cyano group, a furylmethyl group, a (Cj-_ 7 cycloalkyl )methyl group, a (C, . alkoxy)carbonyl group, a hydroxy- (C- . alkyl) group or a benzyl group optionally bearing 1 to 3 substituents selected from the group consisting of, independently. a halo, a C, . alkyl group, a C, 4 alkoxy group, a trifiuoromethyl group, a hydroxy group, a benzyloxy group or a di-(C- . alkyl )amino group, 4 R means a hydrogen, or R 3 forms with R4 an oxygen atom. R is a hydrogen, or R 4 forms with R5 a valence bond, R represents a halo, a cyano group, a nitro group, a C, . alkyl group, a C, . alkoxy group or a trifiuoromethyl group, m has a value of 0 or 1, n has a value of 1 or 2. p is an integer between 2 to 11, and k has a value of 0, 1, 2 or 3, and a pharmaceutically acceptable acid addition salt thereof, in which a 2-mercaptopyrimidine of the formula wherein R " R' R " R and R are as defined above, or an alkali metal salt thereof is reacted with a haloalkylpiperazine derivative of the formula wherein R , m. n. p and k are as stated above, Hlg stands for chloro or bromo, or an acid addition salt thereof, and, if desired, an obtained compound of the formula I is transformed into a pharmaceutically acceptable acid addition salt or the base of the formula I is liberated from the acid addition salt. 6. A pharmaceutical composition comprising a piperazinylalkylthiopyrimidine derivative of the formula wherein R and R represent, independently, a hydrogen, C, . alkyl group, an amino group, a (C,_ 4 alkanoyl )- amino group, or a phenyl group optionally bearing 1 to 3 substituents selected from the group consisting of., independently, a halo, a C-,_ 4 alkoxy group, a di(C,_ 4 alkyl)amino group or a benzyloxy group, 2 R stands for a hydrogen, a cyano group, α furylmethyl group, a (C-._ 7 cycloalkyl )methyl group, a ( C-, _ Δ alkoxy)carbonyl group, a hydroxy- (C-_, alkyl) group or a benzyl group optionally bearing 1 to 3 substituents selected from the group consisting of. independently, a halo, a C,_ 4 alkyl group, a C, 4 alkoxy group, a tri iuoromethyl group, a hydroxy group, a benzyloxy group or a di-(C,_ 4 alkyl)amino group, R means a hydrogen, or R 3 forms with R Δ an oxygen atom, R is a hydrogen, or 4 5 R forms with R a valence bond, R represents a halo, a cyano group, a nitro group, a C, 4 alkyl group, a C, . alkoxy group or a trifiuoromethyl group, has a value of 0 or 1, n has a value of 1 or 2, p is an integer between 2 to 11, and k has a value of 0, 1, 2 or 3 , or a pharmaceutically acceptable acid addition salt thereof as the active ingredient and one or more usual carrier(s). 7. A pharmaceutical composition as claimed in Claim 6 in which the piperazinyl¬ alkylthiopyrimidine derivative is α compound of the formula I , wherein R and R represent, independently, a hydrogen, a methyl group, an amino group, an acetylamino group or a phenyl group optionally bearing 1 to 3 substituents selected from the group consisting of, independently, a chloro, a methoxy group, a dimethylamino group or α benzyloxy group, 2 R stands for a hydrogen, a cyano group, a furylmethyl group, a cyclohexyl¬ methyl group, an ethoxycarbonyl group, c hydroxyethyl group or a benzyl group optionally bearing 1 to 3 substituents selected from the group consisting of, independently, a chloro, a C, 3 alkyl group, a fluoro, a methoxy group, a trifiuoromethyl group, a hydroxy group, a benzyloxy group or a dimethylamino group. 4 R means a hydrogen, or R 3 forms with R4 an oxygen atom. R is a hydrogen, or R 4 forms with R5 a valence bond, R represents a chloro, a fluoro, a cyano group, a nitro group, a methyl group, a methoxy group or a trifiuoromethyl group, m has a value of 0 or 1 , n has a value of 1 or 2, p has a value of 2 or 11. and k has a -value of 0, 1, 2 or 3, or a pharmaceutically acceptable acid addition addition salt thereof. 8. A pharmaceutical composition as claimed in Claim 6 or 7 in which the piperazinylalkylthiopyrimidine derivative is a compound of the formula I, wherein R and R represent an amino group, 2 R stands for a hydrogen or a benzyl group optionally bearing 1 to 3 substituents selected from the group consisting of, independently. a fluoro, a chloro, a methoxy group and a dimethylamino group. R 4 forms with R5 a valence bond, R means a fluoro, a chloro, a nitro group, a cyano group, a methyl group, a methoxy group or a trifiuoro¬ methyl group, k has a value of 1, m has a value of 1, n has a value of 1 , and p has a value of 2, or a pharmaceutically acceptable acid addition salt thereof. 9. A pharmaceutical composition as claimed in any of Claims 6 to 8 in which the piperazinylalkylthiopyrimidine derivative of the formula I is 2-/7 " 2-/4- (4-nitrobenzyl ) - -1-piperazinyl/ethylthio .7-4 ,- 6-diamino-5- -benzylpyrimidine or a pharmaceutically acceptable acid addition salt thereof. 10. A method for the treatment of diseases especially due to pathological alterations of the central nervous system which comprises administering an effective non-toxic dose of a piperazinylalkylthio¬ pyrimidine derivative of the formula wherein R and R represent, independently, a hydrogen, a C, . alkyl group, an amino group, a (C-,_ 4 alkanoyl )- amino group, or a phenyl group optionally bearing 1 to 3 substituents selected from the group consisting of, independently, a halo, a C,_ 4 alkoxy group, a di(C,_ 4 alkyl)amino group or a benzyloxy group, 2 R stands for a hydrogen, a cyano group, a furylmethyl group, a ( Cr- 7 cycloalkyl )methyl group, a (C, . alkoxy)carbonyl group, a hydroxy- (C, 4 alkyl) group or a benzyl group optionally bearing 1 to 3 substituents selected from the group consisting of, independently, a halo, a C, 4 alkyl group, a C, . alkoxy group, a trifiuoromethyl group, a hydroxy group, a benzyloxy group or a di-(C, . alkyl )amino group, 4 R means a hydrogen, or R 3 forms with R4 an oxygen atom, 5 R is a hydrogen, or R 4 forms with R5 a valence bond, R represents a halo, a cyano group, a nitro group, a C, . alkyl group, a C, . alkoxy group or a trifiuoromethyl group, m has a value of 0 or 1, n has a value of 1 or 2, p is an integer between 2 to 11, and k has a value of 0, 1, 2 or 3, or a pharmaceutically acceptable acid addition salt thereof to a patient suffering from said diseases. 11. The use of a piperazinylalkylthio¬ pyrimidine derivative of the formula wherein R and R represent, independently,, a hydrogen, a C, . alkyl group, an amino group, a (C, . alkanoyl)- amino group, or a phenyl group optionally bearing 1 to 3 substituents selected from the group consisting of, independently, a halo, a C, . alkoxy group, a di(C, 4 alkyl)amino group or a benzyloxy group, 2 R stands for a hydrogen, a cyano group, a furyl ethyl group, a (C, 7 cycloalkyl )methyl group . , a (C,_. alkoxy)carbonyl group, a hydroxy- (C, . alkyl) group or a benzyl group optionally bearing 1 to 3 substituents selected from the group consisting of. independently, a halo, a C, . alkyl group, a C,_. alkoxy group, a trifiuoromethyl group, a hydroxy group, a benzyloxy group or a di-(C, 4 alkyl )amino group, R means a hydrogen, or R 3 forms with R4 an oxygen atom, R is a hydrogen, or R 4 forms with R5 a valence bond, R represents a halo, a cyano group, a nitro group, a C, . alkyl group, a C, . alkoxy group or a trifiuoromethyl - 108 - group, has a value of 0 or 1 , n has a value of 1 or 2, p is an integer between 2 to 11. and k has a value of 0. 1, 2 or 3. or a pharmaceutically acceptable acid addition salt thereof, optionally in admixture with one or more carrier(s) commonly used in pharmaceutical compositions, for preparing medicaments having an activity in the treatment of diseases especially due to pathological alterations of the central nervous system.

Inventors: BILKEI GORZO ANDRAS, BLASKO GABOR, BOZSING DANIEL, EGYED ANDRAS, GACSALYI ISTVAN, GYERTYAN ISTVAN, JAKOCZI IVAN, MIKLOSNE KOVACS ANIKO, NEMETH GABOR, RATZNE SIMONEK ILDIKO, SCHMIDT EVA, SIMIG GYULA, SZENASI GABOR, TIHANYI KAROLY, BILKEI GORZO, ANDRAS, BLASKO, GABOR, BOZSING, DANIEL, EGYED, ANDRAS, GACSALYI, ISTVAN, GYERTYAN, ISTVAN, JAKOCZI, IVAN, MIKLOSNE KOVACS, ANIKO, NEMETH, GABOR, RATZNE SIMONEK, ILDIKO, SCHMIDT, EVA, SIMIG, GYULA, SZENASI, GABOR, TIHANYI, KAROLY
Applicants: BILKEI GORZO ANDRAS, BLASKO GABOR, BOZSING DANIEL, EGYED ANDRAS, EGYT GYOGYSZERVEGYESZETI GYAR, GACSALYI ISTVAN, GYERTYAN ISTVAN, JAKOCZI IVAN, MIKLOSNE KOVACS ANIKO, NEMETH GABOR, RATZNE SIMONEK ILDIKO, SCHMIDT EVA, SIMIG GYULA, SZENASI GABOR, TIHANYI KAROLY, BILKEI GORZO, ANDRAS, BLASKO, GABOR, BOZSING, DANIEL, EGIS GYOGYSZERGYAR RT., EGYED, ANDRAS, GACSALYI, ISTVAN, GYERTYAN, ISTVAN, JAKOCZI, IVAN, MIKLOSNE KOVACS, ANIKO, NEMETH, GABOR, RATZNE SIMONEK, ILDIKO, SCHMIDT, EVA, SIMIG, GYULA, SZENASI, GABOR, TIHANYI, KAROLY
Application year: 1996
Main classification: C07D239
IPC codes: A61K31, A61P25, C07D239, C07D403