US2902402A - Thioamine anthelmintic agents - Google Patents

Description

United States Patent 9 THIOAMINE ANTHELIVHNTIC AGENTS Joseph. A. Lambrech, (Charleston, and William H. Hensley, St..Albans,.W..Va., Robert E. Kent, Groton, Conn., and John E. Lynch, Maywood,,N.J., assignors to, Chas. Pfizer & (30., Inc., Brooklyn, N.Y., a corporation of Delaware No Drawing. Application November 27, 1956 Serial No. 624,509

8 Claims. (Cl. 167-53) This invention relates to a new group of therapeutic agents. useful in. the; treatment of helminthic infections and to the therapeutic treatment of such conditions with these agents- More particularly, this invention relates to the use of N,N -thioamines and N,N-polythioamines in. the treatment of helminthiasis.

Helininthic infections are among the most common disease conditions in the world today. They involve infestation of the body of animals with various types of parasitic worms known as. helminths. The public health significance of these organisms and the economic losses brought about by infestation of domestic animals with them has resulted in extensive research for new and more useful anthelmintics.

A. variety of agents have been used for the treatment of this condition. These include various herb preparations such as .arecoline, aspidium, and chenopodium; heavy metal compounds including various antimony and arsenic compounds; phenolic substances including thymol and. hexylresorcinol; and many synthetic materials. Many of these have fallen into disrepute due to their toxicity, low activity, or limited anthelmintic spectrum. Indeed" there are a number of disease producing helminths that are resistant to -all presently known agents and methods. of therapy. Any addition to the anthelmintic armamentarium useful against such organisms would be indeedi welcome. Thus, a definite need exists for an elfective, inexpensive, well-tolerated anthelmintic agent andi particularly one which is elfective against these resistant species.

Recently piperazine, either as the base or the citrate salt, has come into favor as an anthelmintic agent. Its activity, however, is limited primarily to pinworm infestations- (.oxyuriasis) and large round worm infestations (ascariasis). Another piperazine derivative which has been used is piperazine-l-carbodithioic betaine, but it too suffers from the disadvantage of having rather limited anthelmintic activity. Among the untoward side effects ofjpiperazine, is that it occasionally produces diarrhea, urticaria, vomiting, blurred vision, and general muscle weakness. Further, there has been some indication that piperazine is rapidly absorbed from the gastrointestinal tract. This of course, is disadvantageous since heliminthic infestations are frequently seated in the intestinal tract, and it is important to maintain thereapeutic levels of the drug in these organs.

Many derivatives of piperazine have been tested in the continuing search for a substance with broad anthelmintic activity, but these have .proven uniformly inferior to the parent substance. It is rather well accepted in the art that activity in this series is confined to iperazine, its salts, and one or two related substances. Thus, Brown, in the American Journal of Tropical Medicine and Hygiene, volume 3, page 504 (1954), reports the results of testing 32 iperazine derivatives against pinworm. Piperazine proved the most active substance and The piperazine bearing hydroxyl, keto, ester, and various nitrogen containing functions; and more complicated substituents such as aromatic and'heterocyclic rings. i

It has now been found that the class of compounds known as theN,N-'-thio.- and.N,N'-polythioamines possess useful anthehninticactivity against a number of disease producingparasites. These substances have as a common structural feature two amino nitrogen atoms of. primary or secondary amines connected to one another: through one or more sulfur atoms.

N-s.-N This nitrogen sulfur linkage is illustrated in the above formula wherein x is a positive integer. Those thick amines are preferred in which x is- 1 or 2, that is-the N,N'-thioamines and N,N '-dithioamines.. However, the N,N'-polythioamines. containing up to about, 8. sulfur atoms per sulfur unit are operative. The sulfur unit or chain may be straight or branched. By sulfur unit is meant either a sulfide, a disulfide, or a polysulfidelinleage connecting two amino nitrogen atoms i.e.,, S-,. SS-, -SS--S,

-s-s-S- i etc. Thus, the compounds useful in the present. inven: tion are: the N,N'-thioamines, and N,N--polythioamines derived from primary and. secondary amines. Amines from which the active sulfides are derived. belong to a widerange of functional types including. primary and secondary amines having substituents such as aliphatic hydrocarbon groups asin diethylamine, methylbutyle amine, dioctyl amine, butylarnine, allylamine, hendecen ylamine, dodecylamine, cyclohexenylamine, and octadec-- ylamine; substituted aliphatic hydrocarbon groups bears ing OH, CN, -Cl, Br, F, I, ester, ether, 'SOZ, SO3, 404,-, -S, 'NO2, NHz, 61C. as in ethyl (Z-cyanoethyDamine, butyl (cyanomethyl),; amine,,ethylenediamine, hydroxyethylamine, taurinea, ethoxyethylamine, methylmercaptoethylamine, ethyl iii-aminopropionate, chlorobutylamine, and. nitroisobutylamine; aromatic hydrocarbon groups as. in N-methylaniline; l:- naphthylamine, o-tolylamine; substituted aromatic. hye drocarbon groups bearing OH, -CN, I, Cl, Br; F, ester, ether, ,fiSO SO SO'4.-, -S NO -N-H etc. as in. p-chloroaniline, Z-carbethdxy; L-naphthylamine, ethyl p-aminobenzoate, methyl'sulfmN methylaniline, 2ecyano-l-naphthylamine, and. minitnoe aniline; araliphatic hydrocarbon groups as in benzyl amine, naphthylmethylamine, benzhydrylamine; substituted araliphatic groups bearing. OH, CN, Cl; Br, F, ester, ether, I, SO -SO -SO -S, NO NH etc. as in p-chlorobenzhydryl-- amine p-hydroxybenzylamine, I-aminomethyl-Z-naphthol etc.; and. heterocylic groups suchlas quinolinyl, pyridih-yl} thiazolyhlfuryl, tetrahydrofuryl, etc; The amine groups of the N,N-thioamines and. N,N-po1ythioamines= can also be, part of a1 heterocyclic system as in morpholine; piperazine, phenothiazine, thiazoline, imidazoline, etc'.

The, preferred. products of the present invention are thet-hioamines derived from piperazine. Since piperazine is a diainine two. or more piperazine molecules can be linked together toform thioaminesof a polymeric nature! The term. piperazine thioamines as used herein applies to those:chemical compounds composed of two'or morepiperazine molecules connected through their heterocycli'c nitrogen atoms by one or more sulfur-atoms. In the case of poly-N,N-thiobis(piperazine) and poly-N,N-dithio bi's(piperazine) wherein the sulfur linkages .aretlihear;

, integer from Oup to about 5, are repesentative;

In the case of poly-N,N'-polythiobis(piperazine), the sulfur linkages are sometimes linear and sometimes branched. The structure of the polysulfides of this type is not precisely known, but they are thought to be snrnlar to the above with up to about 8 sulfur atoms between piperazine nitrogen atoms. They are obtained e1ther from the mono or disulfides of piperazine referred to above by heating with sulfur or directly from piperazme by heating with sulfur in the presence of various metal oxide catalysts such as lead oxide. For example, poly- N,N'-polythiobis(piperazine) can be obtained by heating poly-N,N-dithiobis(piperazine) at 110 to 130 C. with approximately two atoms of sulfur for each disulfide linkageinvolved. Thus, in an example wherein the compound of Formula. II with n=1 was employed, one mole of this disulfide and four gram atoms of sulfur were allowed to react yielding a polysulfide of the type just described.

The sulfur monohalides and dihalides are employed um der substantially the same reaction conditions to produce poly-N,N'-dithiobis(piperazine) and poly-N,N-thiobis- (piperazine) respectively. The reaction is preferably carried out in an inert solvent such as benzene, toluene, xylene, liquid aliphatic hydrocarbons, and chlorinated liquid aliphatic hydrocarbons, diethyl ether, etc. Solvents such as the alcohols and ketones have been found to be less satisfactory due to interaction of them with the sulfur halide. An excess of the amine, if liquid, can be employed as the solvent. The reaction is carried out at temperatures up to about 100 C. but the range from about to 50 C. is preferred. Below 0 C. the reaction is rather slow while above 50 C. side reactions and decomposition sometimes occur.

Hydrogen chloride is a by-product of the reaction when sulfur mono or dichloride is used and provision must be made for its neutralization. This is most simply accom plished by using an excess of piperazine in the reaction mixture. Thus, if two moles if piperazine for each mole of sulfur mono or dihalide are employed, one mole of piperazine is available to neutralize the hydrogen halide evolved. Therefore, the preferred range for the piperazine to sulfur halide ratio is from about 2 to about 4 moles of piperazine per mole of sulfur halide when this mode of operation is employed. Higher ratios can be employed but there is no purpose achieved by using larger excesses of piperazine. Use of lower ratios of piperazine results in lower yields and in products containing a high sulfur analysis possibly due to polysulfide formation. Other arganic bases in sufficient amount to neutralize hydrogen halide evolved including pyridine, triethylamine, and other tertiary amines can be used. However, this complicates, in many instances, the isolation problem. Inorganic bases such as sodium carbonate, calcium carbonate, and potassium and sodium hydroxides can also be used. At least about a stoichiometric amount of added base is required, two moles of hydrogen halide being evolved per mole of sulfur halide reacted to form a thioamine. When a base other than piperazine of the organic or inorganic type is employed for neutralization, the amount if piperazine charged can be reduced to about an equimolar amount. The ratio range for piperazine to sulfur halide is thus 1 to about 4 depending upon the neutralizing agent employed.

A preferred method of operation involves preparing solutions of the piperazine and the sulfur halide, for instance sulfur dichloride in benzene, cooling them to about 5 C. mixing them with one another with cooling, and then .allowing theresulting solution to warm to about 25 C 4 Piperazine hydrochloride and the product precipitate. The piperazine hydrochloride is neutralized and separated from the poly-N,N'-thiobis(piperazine) by adding dilute (about 3-20%) aqueous sodium hydroxide, collecting the product, and washing it with water. Material prepared in this fashion has a melting point in the range of C. to 215 C. and corresponds in composition to a product having one atom of sulfur for each molecule if piperazine combined. It varies in color from white to pale yellow. Spectral measurements indicate that no uncombined piperazine remains in the product.

One reason suggested for the variation in melting point observed is that mixtures of piperazine thioamines of various molecular weights are obtained. Accurate determinations of the average molecular weights of these products have not been obtained since their insolubility in the solvents usually used for ebullioscopic and cryoscopic methods for determining molecular weight has prevented use of these techniques. Further, the fact that they are extremely nonvolatile has rendered mass spectrographic analysis of them unsatisfactory. Poly- N,N'-thiobis(piperazine) is stable to dilute aqueous alkali but appears to be degraded in the presence of 0.1 N hydrochloric acid at room temperature. It is slightly soluble in ethanol, isopropanol, dimethylformamide, and dimethyl sulfoxide. This apparent partial solubility may be the result of leaching out lower molecular weight components. It is virtually insoluble in water and in the non-polar organic solvents. Poly-N,N'-dithiobis piperazine has similar properties. Variations sometimes encountered in technical grade sulfur mono or dihalide also may have some effect on the composition of the product.

Some insight into the molecular structure of these substances has been obtained by end group titration with carbon disulfide. Carbon disulfide is known to react with secondary amines to form dithiocarbamates. In the case of piperazine itself, when one mole of carbon disulfide is allowed to react with one mole of piperazine, a dithiocarbamic acid betaine is formed. This substance is an inner salt formed between the acidic thiol group of the dithiocarbamic acid and the remaining free secondary amino group of the piperazine. The reaction with carbon disulfide thus provides a method for determining the number of free NH groups in a thio or dithiopiperazine molecule. If it is assumed that one mole of carbon disulfide reacts with each free NH group, then one mole of a thio or dithiopiperazine will react with two moles of carbon disulfide, one mole for each terminal amino group. Thus, by measuring the increase in weight on reaction with carbon disulfide, the molecular weight of the piperazinyl sulfide can be calculated. If it is assumed that only one terminal amino group reacts with carbon disulfide and inner salt formation occurs between the resulting dithiocarbamic acid and the remaining terminal amino group at the opposite end of the molecule, the molecular weight can be calculated in an analogous fashion. However, a value one-half as large as that as obtained on the former basis is obtained. it is thought that the former is the correct assumption, that is each terminal amino group combines with a molecule of carbon disulfide.

Employing this technique, it has been found that poly- N,N-thiobis(piperazine) melting at about 200 C. reacts with carbon disulfide in the ratio 20 g. to 9 g. CS Assuming 1 molecule of CS per terminal amino group this product then contains an average of three piperazine mollecules and two sulfide linkages, i.e. Formula I, n: I

A similar technique was used in the preparation of the other N,N'-thioamine and N,N-polythioamines useful in the anthelmintic compositions of this invention. Many such compounds are known inthe art. Use of these substances in anthelmintic compositions and in the treatment of helminthiasis is also within the scope of this invention. Representative N,N'-thioamines and N,N-dithioamines known in the prior art have been derived from the fol piperazine,

lowing aminesz diethylamine, diisopropylamine, dioctylamine, beta-isopropylaminopropionitrile, hutylaminoactonitrile, N-butjltetrahydicfurfurylamine, pyrrolidine, piperidine, pipecoline, moipholine, aniline, and butylamine. These sulfides all possess a degree of anthelmintic activity. A number of new compounds of this type also useful in this invention were prepared from the fllowing amines: cisand trans-2,S-dimethylpiperazine, N-(2- hydroxyethyhpiperazine, ethylenediamine, N-dodecyland N-(2-aminoethyl)piperazine. Experimental details for the preparation of these materials appear hereinafter.

In the preparative procedure above, it is not essential that anhydrous piperazine be employed. The main impurity in the 90% piperazine which was used in many of the preparations was water. which contains a higher proportion of water is somewhat less satisfactory. The reaction can be carried out in the presence of a rather high proportion of Water if a water immiscible solvent is used. One convenient method is to allow the piperazine and sulfur halide to react in an inert organic solvent such as benzene or toluene, and to continuously neutralize the hydrogen chlorideformed in the reaction by stirring or mixing the benzene solution with a concentrated (about 3550%) aqueous: solution of sodium hydroxide or other base. This can be done by simply placing the two immiscible solutions in a container and agitating gently during the course of the reaction. For the preliminary anthelmintic evaluation of the valuable thioamine compositions of the present invention, a natural infection of mice with pinworm (Syphacia obi/21am) was used. The test mice were readily infected by associating them with naturally infected mice known as source mice. The experimental mice acquired their infection over a number of days and therefore harbored worms in several stages of development when treated with the test compounds. This technique is described by Kam- Fai Chan in the American Journal of Hygiene, volume 56, pages 22-30 (1952). The test mice were housed for a period of eight days with the source mice during which time they became infested with the pinworm which is similar in its host-parasite relationship to nematodes of human and veterinary importance. On the 8th and 9th days after exposure to the source mice, the amine sulfides under test were administered to the test mice by the oral route. A single dose daily was employed on each of the days. The treated mice were then sacrificed on the 11th day, about 48 hours after their last doses of the drug, and all stages of S. obvelata in the cecum were counted. Differences in worm burden between thetreated groups provided a numerical value called percent reduction in worm burden which served to express the relative antipinworm activities of the compounds. Results of this test with avariety of thioamines are tabulated below. For purposes of comparison, the values obtained for piperazine citrate and piperazine carbodithioic acid betaine, known anthelmintic agents, are given. In addition, the results obtained for certain of the amines from which some of the amino sulfides and disulfides tabulated were prepared are also given. This table illustrates the high activity of poly-N,N-thiobis (piperazine), poly-N,N'- dithiobis(piperazine) and of several samples of poly-N,N'- polythiobis(piperazine); the effectiveness of poly-N,N- thiobis(piperazine) of relatively low dosages; the consistent activity although in somewhat larger dosages of the thioamines as a class; and the increase in activity of the thioamines over that of their parent amines.

Poly-N,N-thiobis(piperazine) was further evaluated in swine against round worm (Ascaris lzlmbricoides), and against whipworms (T irchuris suis). infected with the above organisms were selected as test animals. The presence of infection by the above helminths was verified by fecal examination on three con secutive days prior to closing with the test compounds. In each instance, ova were found in the feces. Treated Piperazine hexahydrate Swine naturally swine were held 72 hours after dosing during which time periodic fecal examinations were made. At the end of the holding period, the animals were sacrificed and the intestine examined for the presence of ascarid's and whipworms. Control "experiments were carried out for comparison in which infested swine were medicated with sodium fluoride, pip'erazinyl dihydrochloride monohydrate and .piperazin'e carbodithioic betaine individually. Autopsy examination revealed that sodium fluoride, piperazine dihydrochloride monohydrate, and piperazine carbodithioic acid betaine were ineffective against whipworm 'at doses of 580 trig/kg, 200 mg./kg., and 250 mg./kg. respectively. On the other hand, polyN,N-thiobis(pipe'razine) proved to be active against whipwonn in a single dose of 250 rug/kg. In ftu'ther single dose experiments with swine infested with asca'rids, poly-N,N-thiobis(piperazin'e) proved to be active in doses of 75 mg./kg. The commercial anthelmintic agents above are also active against ascarids, but at higher levels. The increased activity of poly-N,N'-thiobis(piperazine) was particularly striking in multiple dose experiments. In these experiments, the drugs were administered in two or three consecutive daily doses. Poly-N,N' thiobis(piperazine) proved to be active in swine at 25 mgJkg. against'both whipworrns and ascarids when administered on three consecutive days. Piperazine carbodithioic acid betaine was completely inactive against these helminths when admin istered according to this regimen. It was found to be active in multiple doses of mg./kg. The activity of poly-N,N-thiobis(piperazine) at this low level is indeed a great advantage (from both physiologic and economic points of view, and in fact its use on a prophylactic basis is suggested. This material was also found to be active against nodular worms in pigs in doses of mg/kg. polyN,N'-dithiobis(piperazine) and poly-N,N'-polythiobis(piperazine) were found to be similarly active.

No toxic manifestations were observed with poly-N,N- thiobis (piperazine) in the above experiments. In fact, in acute toxicity tests with mice, the LD by the intraperitoneal route was found to be 2,000 mg./ kg. This is indeed a remarkably lov toxicity when it is considered that piperazine has an intrape'ritoneal toxicity (LD of 360 mg./kg. and piperazine carbodithioic betaine 30 mg/kg. Of course, these substances are not customarily administered by this route for therapeutic purposes, but the fact that this pipera'zine thioamine has such a low toxicity "even when administered by this route reflects its safety as a therapeutic agent. The oral toxicity (LD of poly N,N-thiobis(piperazine) is also 2000 rug/kg. Low toxicities were observed for the other piperaiine thicam nes.

Thus, the piperazine thioamines of this invention were found to have a very low toxicity, to be active against ascarids and nodular worms; and significantly to be effective against whipworms Where previous. 'anthelr'nintic agents have failed. There is indeed no satisfactory agent for the treatment of whip worm in swine presently a'v'ail able although sodium fluoride has been recommended. Notwithstanding its superior activity to this material, piperazinyl sulfide has the highly important advantage over sodium fluoride of being non-toxic and safe to use.

Use of the thioamines for the treatment of helminthiasis in animals according to the present invention involves intestinal contact of the infecting helminth with the drug. Dosage is preferably by the oral route since the major site of infection is ordinarily the intestinal tract. It is of course possible to administer these drugs rectally, but of course, this method is not as convenient as oral medication. One of the attributes of these new drugsis that they are highly effective orally. The daily dose required varies with the particular thioamine employed and the animal which is being treated.

For the treatment of domestic animals, with poly-N,N- thiobis(piperazine) or poly-N,N-dithiobis(piperazine), a single dose of 75 to 250 mg/kg. is generally sulficient'to clear the animal of the infecting parasite. Doses as low as 10-25 mg./kg. can be used if repeated on three or more consecutive days. Administration of the amino sulfides to animals can best be effected by mixing the drug with the feed. Thus, the required dose for the animal is calculated on the basis of the above formula and the drug is then blended with all or a portion of the animals daily rotation. The thioamines are generally supplied as the substantially pure substance for this purpose. However, they can be diluted with inert carriers such as starch, lactose, etc. This is preferred with small animals where the total dosage is low since blending of only a few milligrams of drug with a relatively large amount of feed is inconvenient. For this purpose a dry solid composition containing the calculated dosage of amino sulfide is blended with a convenient amount of carrier, generally from about 1 to 10 parts by weight based on the weight of th-ioamine.

Since the thioamines with few exceptions and in particular those derived from piperazine, are substantially insoluble in water formulation into aqueous suspensions can be readily accomplished. These suspensions possess good biological stability, perhaps due to the insolubility of the active ingredient, and can be stored on the shelf for prolonged periods without decomposition or loss of activity. Other vehicles such as glycerol and propylene glycol can, of course, be used. However, when aqueous vehicles are employed it is important to adjust the pH to neutral or slightly alkaline values to ensure the stability of the product.

ANTHELMINTIC ACTIVITY OF REPRESENTA- TIVE THIOAMINES MEASURED AGAINST SYPHACIA OBVELATA IN MICE Per Cent Reduction in Worm Burden at Various Dosages (dosage levels in mgJkg.) Compound 1. Piperazine 40 60 95 99 2. Piperazlne Carbodithioic Betaine. 79 85 91 100 3. Poly-N N-thiobis(piperazine) (1) 51 86 95 99 4. Poly- ,N dithiobis(piperazine) (II) 41 83 9O 5. Poly N, N polythiobis (piperaziue) 50% S (XXI) 80 6. Poly-N,N-polythiobis(piperazine) 41% S (XXII) 53 77 92 7. N,N-Thiobis(diethylamine) (VI) 52 67 8. N,N-Dithiobis(diethylamine) (XIII) 53 9. N, N-Thiobis(di-2-ethylhexyl) amine (V) 54 60 10. N351; hiobis(2-etl1ylhexylamine) 46 11. Poly N,N thiobis(ethy1enedia mine) (X) 54 59 12. N ,N-Dithiobis (oetadecylarnme) (XXVIII) 46 13. Ois-2,5-Dimethylpiperazine 0 0 0 0 0 14. Poly N,N thiobis(eis 2,5 dimethylpiperazine) (III) 36 15. N,N-Thiobis(morpholine) 50 16. N,N-Dithiobis(morpholine) (XII). 48 17. N,N-Thiobis(piperidine) (VII) 56 18. 1-(2-Arninoethyl)piperazine 0 0 19. Poly N,N dithiobisfl (2 aminoethybpiperazine) (XV) 21 39 20. 1-(2-Hydroxyethyl)piperazine 0 0 0 0 0 21. N,N Dithiolois (l 2 hydroxyethyl)piperazine (IX) 14 20 22. N,N-Thiobis(1dodecy1piperazine) (XI) 34 23. N,N-Thiolois(N-nnethlyanalme) XIX 32 75 26. N,N-Thiobis(phenothiazine) XXIV 40 27. N,N-Dithiobis (phenothiazine) (XXV) 36 28. N,N- Thiobis (4 amino-5-ethyl 2 methylpyridine) (XXVII) 52 1 The numerals in parentheses following the compound names refer to the experimental examples at the end of the specification. Where no numeral appears, the compound is known in the art.

2 At dosage levels of 15.6, 7.8, and 3.9 rug/kg. reduction values of 57% 45%, and 28% were obtained. With piperazine, no activity was noted at these levels.

The following examples are provided to illustrate specific methods for the synthesis of the thioamines, their compounding into pharmaceutical preparations, and their administration to animals. They are, however, not to be construed as limiting the scope of the invention in any way.

Example I POLY-N,N-THIOBIS PIPERAZINE) Sulfur dichloride, 10.5 g. (0.1 mole) was dissolved in 15 ml. of benzene with cooling. A similar solution was then prepared containing 38 g. of anhydrous piperazine in 300 ml. of benzene. These two solutions were mixed with cooling at 5 C. and the temperature allowed to rise slowly to 25 C. During this time, a precipitate formed which was comprised of piperazine hydrochloride and poly-N,l-l-thiobis(piperazine). A solution of 8 g. of sodium hydroxide in 50 ml. of Water was added to neutralize the piperazine hydrochloride. The desired prod uct which remained was then collected, washed thoroughly with water, and air-dried. It was a pale yellow solid having a melting point of 214 C.

Analysis.Calcd. for C H N S: C, 41.37; H, 6.8; N, 24.13; S, 27.6. Found: C, 39.84; H, 7.64; N, 23.36; S, 28.68.

The average molecular weight of the above material was determined by agitating a 20 g. sample of it with g. of carbon disulfide for a period of 24 hrs. at room temperature to obtain complete reaction of the poly-N, N'-thiobis(piperazine) with the carbon disulfide. The excess carbon disulfide was then removed by distillation in vacuo at room temperature and the solid residue weighed: M.P. 142 C. dec. The increase in Weight corresponded to the combination of the sample with 9 g. of carbon disulfide. Thus, 20 g. of poly-N,N-thiobis- (piperazine) is equivalent to 9 g. of carbon disulfide or 0.118 mole. Thus 20 g. corresponds to 0.059 mole and the average molecular weight 339. This corresponds to a linear product made up of 3 molecules of piperazine and two atoms of sulfur connected to one another through nitrogen sulfur bonds, M.W. 318. The following structure is therefore proposed for the carbon disulfide adduct.

Analysis.Calcd. for C H N S N, 17.87. Found: N, 17.33.

Example II POLYN,N -DITHIOBI S (PIPERAZINE) Sulfur monochloride, 27 g. (0.2 mole), was dissolved in 100 ml. of benzene and added with stirring to a solution of 72 g. (0.8 mole) of 90.4% piperazine in 500 ml. of benzene at 10-15 C. A precipitate formed at once. A solution of 18 g. of sodium hydroxide in 500 ml. of Water was added, the precipitate collected, washed with water, and air-dried. The product obtained in this fashion was a white solid, M1. 156 C.

Analysis.Calcd. for C H N S N, 18.9. Found: N, 18.25.

Example Ill POLY-N,N-TI-IIOBIS (CIS-2,S-DIMETHYL-PIPERAZINE) Sulfur dichloride, 0.1 mole, was dissolved in 15 ml. of benzene and mixed with a solution of 46 g. (0.4 mole), of cis-2,5-dirnethylpiperazine in 300 ml. of benzene at 5 C. A precipitate formed at once. It was treated with a solution of 8 g. of sodium hydroxide in ml. of water. A clear biphasic solution resulted. The layers were separated, the aqueous layer extracted with several portions of ether, and the combined organic layers concentrated by vacuum distillation. The residue was a tan solid having a melting point of 57 C.

assa-402 Xhdlysisr-Caflcd for CfImNQSl N, 19.4. "Found: N, 18.47. Example I'V POLY=Ng-N THIBIstraws-2;5-DI-ME'1HYL- PIPERAZINE) i The reaction wascarried out as in Example III. However, 3..S0l1d. precipitate remained after -neutralization of the reactionmixture with aqueous sodium hydroxide.

This was collected, washed with water, and air-dried. The poly N,N-thiobis(:trans 2,5-dimethylpiperazine) :so obtained was a cream colored solid, 204 C.

Analysis.-Calcd. for G l-1 N 82 N, 19.4. Found: N, 19.09.

This substance was tested in the fashion described above and found to be active against pinworm in mice.

. Example V ,N-THIOBIS- DIQETHYLHEXYL AMINE Solutions of 51.5 g. of sulfur dichloride in .150 ml. of ether and 82 g. of di(2-ethylhexyl)amine in 750 ml. of ether were mixed with stirring and cooling. The precipitate which formed was neutralized by the addition of .aqueoussodi um hydroxide and thelayers separated. The aqueous layer-was'ext-racted several times with ether, theorga-nic layers combined, and concentrated .invacuo alfording the productas a dark brown viscousliquid having a specific gravity of 0.880 at .20" C. and refractive index 71 1.4700.

Example VI NfN' -THIOBIS (DIETHYLAMINE) Ether solutions containing 2 molesoffdiethylamine 'in 750 ml. and 0.5.mole sulfur dichloride in 150 ml. were prepared, cooled in ice, and mixed atO-lO C. The amine hydrochloride by-product which precipitated was removed by washing with water. The ether layer was separated, dried, and concentrated yielding the product as a yellow liquid which was distilled in vacuo; B.P 80 C113 mm., sp. gr. 0.9024 at 27 C., and n 1.4613.

Example VII N,N-THIOBIS (PIPERIDINE) This product was prepared by reacting 0.5 mole sulfur dichloride dissolved in ether with 1.0 mole of dodecylamine dissolved in ether at 0 to 10 C. After stirring 2 hrs., the mixture was neutralized by the additionof aqueous sodium hydroxide and the product recovered from the ether layer by distillation ofthe solvent. The product remained as a solid residue. It was washed thoroughly with a mixture of hexane and ether affording a wax-like pale yellow solid, M.P. 130 C.

Analysis.-Calcd. for C H N S: N, 7.0; S, 8.0. Found: N, 6.94; S, 8.07.

This compound was tested as described above and found tobe active against pinworm in mice.

Example IX N,N'-DITHIOBIS(14(2-HYDROXYETHYL)PIPERAZINE) A benzene solution containing '24 g. (0.18) of sulfur monochloride was added to a mixture of 47 g. (0.36 mole) of 1-(2-hydroxyethyl)piperazine in 300 m1. of benzene at C. After stirring for a period to permit the reaction to be completed the solvent was distilled 10 under reduced pressure. The residue was neutralized by treatment with 500 mL of metha'nolic. potassium hydroxide containing 24 g. ofpotassium hydroxide and the potassium chloride filtered. 'Thefme'thano'l was distilled in *vacuo leaving a dark viscous liquid.

. collected by" filtration, and "the ethylenediamine *monosulflde separated by leaching the ethyl'enediamin'e lrydrochloride from it with water. The flight brownsolid was air-dried, M.P. 98 C.

' Example XI. N,N'-THIOBIS(l-DODECYLPIPERAZINE) Sulfur chloride, 10 .g. (0.1 mole), was added with stirring and cooling at '0'to 10 C. to an etheral solution of 50 g. of l-dodecylpiperazine. The reaction was allowedto come to completion by mixing for a brief period, and the solventrernoved byevaporation under reduced pressure. The aminehydrochloride by-product was then removed by washing with a solution of 8g. of sodium hydroxide in m1. of water, and the precipitated product was isolated by filtration and washed with water. The air-dried material was a white wax+like soli'd, M.P. 46-48 :C. t

Analysis.Ca'1cd. for C H N S: N, 10.4; S, 5.96. Found: N, l0.07;lS, 6.52.

Example XII .N,N-DITHIOBIS (MORPHOLINE) A solution of 341g. (0.25 mole) of sulfur monochlor lde was slowly added with stirring and cooling at 0-10 C. to a solution of 87 g. of morpholine in 300 ml. of ether. After -jthe-rea'ction was complete, the solvent was distilled andthe solidresidue washed with water to remove the morpholine hydrochloride. The water insoluble N,N-dithiobis(morpholine) was collected, washed with water, and dried at room temperature. It was a pale ,yellow solid, M.P. 112 C.

Example XIII N,N"DITHIVOBIS(DIETHYLAMINE) A solution of 102 g. (0.75 mole) of sulfur monochloride in 225 m1. of ether was slowly added with stirring and cooling at 0-10 C. to a solution of 219 g. (3 moles) of diethylamine in 900 ml. of ether. The reaction mixture was then washed with water to separate the diethylamine hydrochloride, the layers separated, and the ether layer dried anddistilled. The product remained as a yellow liquid residue, 'B.P. 90 C./0.9 mm.; specific gravity at 25 C. 0.992; and refractive index N 1511.

Example XI-V N,N-DITHIOBI S (l-DODECYLPIPERAZINE) This material was prepared from sulfur monochloride and l-dodecylpiperazine. Sulfur monochloride, 19 g. dissolved in 75 ml. of ether, and .l-dodecylpiperazine, 71 g. dissolved in ml. of ether were mixed at 0-10 C. The solvent was removed by distillation under reduced pressure and the residue washed with aqueous sodium hydroxide, 11 g. dissolved in 250 ml. of water. The product was collected by filtration, washed with water, and air-dried. It was a White wax-like solid, M.P. 44 C.

.AnalySis-Calcdifbr C H N S N, 9.8. Found: N, 9.22.

This compound was tested as described above and found to be effective against pinworm in the mouse.

11 Example XV Sulfur monochloride, 34 g., dissolved in 100ml. of

benzene was added with stirring to a solution of 65 g.

of 1-(2-aminoethyl)piperazine dissolved in 400 ml. of benzene. The temperature was maintained at 510 C. with external cooling during the addition. Following the completion of the addition the mixture was agitated while the temperature was allowed to rise to room temperature. The mixture was then heated at 50 C. for 30 minutes, cooled to 25 C., and the precipitated solid collected. The filtrate was concentrated in vacuo at 30 C. The residue obtained from this process was combined with the solid previously collected by filtration and washed with aqueous caustic, 20 g. of sodium hydroxide in 750 ml. of water. The solid product remaining after this step was collected, washed with water, air-dried, and then washed by agitation with ethanol at 55 C. for 3 hrs. The slurry was cooled to -30 C., and the solid product collected, and air-dried. The product obtained was a brown solid, M.P. 154 C.

Example XVI One and one half grams of poly-N,N'-thiobis(piperazine) was blended with an equal weight of lactose and sealed in a glass vial. This composition was then suitable for mixing with the daily ration of a 30 pound dog for the treatment of various helminth infestations.

Example XVII A pig weighing 58 pounds was diagnosedas being infested with ascarids by examination of its feces by the flotation method. Seven and one half grams of poly- N,N'-thiobis(piperazine) were then mixed with the animals daily ration. The dose was entirely consumed. After about 72 hrs., no further ova could be detected in the feces. The animal was sacrificed and found to be free of the helminth on post mortem examination.

Example XVIII The following materials were thoroughly blended and then compressed into tablets containing 75 mg. of the piperazinyl monosulfide per tablet. The total tablet Weight was 330 mg.

Gram Poly-N,N'-thiobis(piperazine) 7.5 Lactose 25.2 Magnesium stearate 0.3

Example XIX N,NTHIOBIS (N-METHYLANILINE) Example XX N,N-DITHIOBIS (3-AMINOQUINOLINE) Sulfur monochloride, 22.5 g. (0.17 mole), and 3- arninoquinoline, 48 g. (0.33 mole), were allowed to react in 350 ml. of diethyl ether in a fashion similar to Example XIX. The product was received as a brown 12 Analysis.Calcd. for C H N S S, 19.85. Found: S, 19.59.

Example XXI POLY-N,N -POLYTHIOBIS PIPERAZIN E) A solution of 26 g. (0.25 mole) of sulfur dichloride in 75 ml. of hexane was added to a solution of 86 g. (1.0 mole) of anhydrous piperazine in 250 ml. of water. The mixture was neutralized with aqueous sodium hydroxide, and the product collected by filtration, washed with water, and air-dried. It was a white solid, M.P. 94 C. having a sulfur content of 49.78%.

Example XXII POLY-N,N-'POLYTHIOBIS (PIPERAZINE) The process of Example XXI was repeated using double the quantity of sulfur dichloride dissolved in a corresponding volume of hexane. The product was recovered in a similar fashion as a white solid, M.P. 98 C. analyzing 40.72% sulfur.

Example XXIII N ,N' -THIOBIS (LNAPHTHYLAMINE) This preparation was carried out by gradually adding with stirring and cooling a solution of 52 g. (0.5 mole) of sulfur dichloride in 150 ml. of diethyl ether to a solution of 143 g. (1.0 mole) of l-napththylamine in 850 ml. of diethyl ether. The amine hydrochloride was decomposed by the addition of aqueous sodium hydroxide and the precipitated naphthylamine collected, washed with water, and then with 500 ml. of methanol. The filtrate was diluted with an equal volume of water and the product which precipitated collected, washed with water, and airdried. It was a purple solid, M.P. 150 C.

Eaxmple XXIV N,N-THIOBIS (PHENOTHIAZINE) A solution of 26 g. (0.25 mole) of sulfur dichloride in 75 ml. of diethyl ether was gradually mixed While stirring and cooling with a solution of 100 g. (0.5 mole) of phenothiazine in 425 ml. of diethyl ether. The reaction mixture neutralized with aqueous sodium hydroxide and the precipitated amine collected. The ether filtrate was evaporated to dryness yielding the product which was washed with water, air-dried. It was a pea-green solid, M.P. 134 C.

Example XXV N,N'-DITHIOBIS (PHENOTHIAZINE) This product was obtained as an olive-green solid, M.P. 96 C. by the substitution of 34 g. (0.25 mole) of sulfur monochloride for the sulfur dichloride in the procedure of Example XXIV.

Example XXVI N,N-THIO BIS (2-ETHYLHEXYLAMINE) A suspension of 32 g. (1 gram atom) of sulfur and 129 g. (1 mole) Z-ethylhexylamine was heated until the evolution of hydrogen sulfide ceased. The excess 2-ethylhexylamine, 30 g., was then distilled. The product which remained was a liquid, 1 0.925.

Analysis.--Calcd. for C H N S: S, 11.1. Found: S, 12.2.

Example XXVII POLY-N,N -THIOBIS (4-AMINO-5-ETHYL2- METHYLPYRIDINE) A solution of 4 g. (0.039 mole) of sulfur dichloride in 15 ml. of diethyl ether was added gradually with stirring and cooling to a solution of 12 g. (0.078 mole) of 4 amino-5-ethyl-2-methylpyridine monohydrate in 100 ml. of diethyl ether. The precipitated amine hydrochloride was neutralized with aqueous sodium hydroxide and the product collected by filtration, washed with water, airdried. It was a white solid, M.P. 59 C.

Example XX VIII N,N'-DITHIOBIS (OCTADECYLAMINE) A solution 67.5 g. (0.5 mole) sulfur monochloride in 250 m1. of diethyl ether was gradually added with stirring and cooling to a solution of 279 g. (1 mole) of octadecylamine in 150 ml. of diethyl ether. Methanol, 1.1 l. was added to aid in stirring. The amine hydrochloride was neutralized with methanolic potassium hydroxide. The mixture was then evaporated to dryness on a steam bath and air-dried yielding a waxy-brown solid M.P. 72 C.

Example XXIX Benzylamine, 18.5 g. (0.1 mole) dissolved in 50 ml. of ether was treated with 5.2 g. (0.05 mole) of sulfur dichloride in 25 ml. of ether. The mixture was then treated at room temperature with dilute aqueous sodium hydroxide to decompose hydrochloride'salts and dissolve the benzylamine. The product was recovered and tested against Syphacia obvelata in mice as described above and found to be active.

What is claimed is:

1. A process for treating helminthic infestations of domestic animals comprising intestinal contact of said heliminths with a compound selected from the group consisting of N,N-thioamines and N,N'-polythioamines of the formula:

wherein x is a positive integer up to eight and N- is selected from the group consisting of alkylamino, dialkylamino, arninoalkylamino, hydroxyalkylamiuo, anilino, N- alkylanilino, napththylamino, quinolinylamino, pyridylamino, alkylpyridylamino, benzylamino, piperazino, alkyl piperazino, aminoalkylpiperazino, hydroxyalkylpiperazino, morpholino, and phenothiazino.

2. The process of claim 1 wherein N- is piperazino.

3. The process of claim 1 wherein x is two and N- is piperazino.

4. The process of claim 1 wherein said domestic animals receive a daily dose of at least about mg./kg. of body weight of said compound.

5. The process of claim 1 wherein said domestic animal receives, in dosage unit form, a composition con- 14 taining a significant amount of a pharmaceutical carrier and at least about 35 mg. of said compound.

6. The process of claim 5 wherein the minimum daily dosage received by said domestic animal is at least about 10 mg./ kg. of body weight.

7. An anthelmintic composition for domestic animals comprising as the principal anthelmintically active ingredient a compound selected from the group consisting of N,N'-thioamines and N,N'-polythioamines of the formula:

wherein x is a positive integer up to eight and N-- is selected from the group consisting of alkylamino, dialkylamino, aminoalkylamino, hydroxyalkylamino, anilino, N-alkylanilino, naphthylamino, quinolinylamino, pyridylamino, alkylpyridylamino, benzylamino, piperazino, alkyl piperazino, aminoalkylpiperazino, hydroxyalkylpiperazi-no, morpholino, and phenothiazino, the amount of said ingredient providing for the average daily food intake of the animal, a daily dose of at least about 10 mg./kg. of body weight.

References Cited in the file of this patent UNITED STATES PATENTS 2,766,236 Harman Oct. 9, 1956 OTHER REFERENCES White: Brit. Med. J. No. 4839, October 3, 1953, p. 755.

Claims (1)

1. A PROCESS FOR TREATING HELMINTHIC INFESTATIONS OF DOMESTIC ANIMALS COMPRISING INTESTINAL CONTACT OF SAID HELIMINTHS WITH A COMPOUND SELECTED FROM THE GROUP CONSISTING OF N,N''-THIOAMINES AND N,N''-POLYTHIOAMINES OF THE FORMULA: