PYRIDYL-SUBSTITUTED THIAZOLIDINE AND 1,3-THIAZINE DERIVATIVES, PROCESSES FOR THEIR PREPARATION, AGRICULTURAL COMPOSITIONS CONTAINING SAID DERIVATIVES AND METHODS FOR REGULATING PLANT GROWTH AND PROTECTING PLANTS FROM FUNGI

Abstract: Novel Pyridyl substituted thiazolidine and 1,3-thiazine derivatives having utility as plant fungicides, and terrestrial and aquatic plant growth regulators, with the formula wherein R is C₃-C₁₀alkyl, C₃-C₈-cycloalkyl, methallyl, phenyl, halophenyl, trifluoromethylphenyl, benzyl, methoxybenzyl, methylbenzyl, halobenzyl, dimethylaminoethyl, methylcyc­ lohexyl, C₃-C₈cycloalkyl(C₁-C₃)alkyl, α-methylbenzyl, 2-thiazolyl, nitrophenyl, phenoxyphenyl, (tetrahydro-2-­ furanyl)-methyl, haloanlyl, trifluoromethylthiophenyl, methylthiophenyl, 2-norbornyl, furfuryl, 2-­ (1-methoxypropyl), methoxyphenyl, fluoro(C₁₋C₂)alkox­ yphenyl, 3-4-(methylenedioxy)phenyl, xlyl, biphenylyl, tolyl, or halotolyl; X is oxygen or sulfur; R¹ is hydrogen, methyl, or -S(C₁-C₆alkyl); R² is hydrogen, C₁-C₆alkyl, or -S(C₁-C₆alkyl); R³ is hydrogen or methyl; R⁴ is hydrogen or C₁-C₆alkyl; and R⁵ is hydrogen or methyl. Methods for their preparation are described, e.g. 4-chloroaniline was reacted with 3-pyridine carboxaldehyde and the reaction mixture was reacted with thiolactic acid to give 3-(4-chlorophenyl)-5 -methyl-2-(3-pyridyl)-­ 4-thiazolidinone.

Description: SUBSTITUTED 1-THIA-3-AZA-4-ONES, THEIR USE AS FUNGICIDES AND PLANT GROWTH REGULATORS, PROCESSES FOR THEIR PREPARATION AND AGRICULTURAL COMPOSITIONS CONTAINING THEM The field of the invention relates to heterocyclic organic compounds identified as l-thia-3aza-4-ones. In the prior art, Surrey, J. Am. Chem. Scc. 69, 2911-2912 (1947), teaches the preparation of 4-thiazolidones by the reaction of thioglycolic acid with Schiff bases. This reference discloses no utii- ities for the compounds prepared as described therein. Also in the prior art, Troutman, et al., J. Am. Chem. Soc. 70, 3436-3439 (1948), describe methods of synthesizing 2-aryl-3-alkyl- or 2-hetero-3-alkyl-4 thiazolidones, alleged to possess anticonvulsant activity. Another prior art reference is Pennington et al., J. Am. Chem. Soc. 75, 109-114 (1953), which teaches the preparation of 2-substituted-4-thiazoliones, alleged to possess in vitro antitubercular activity. Also in the prior art is Surrey et al., J. Am. Chem. Soc. 76, 578-580 (1954), which teaches the preparation of some 2-aryl-4-thiazolidones, alleged to possess significant amoebacidal activity (Endamoeba criceti) when tested in hamsters. Another prior art reference is that of Singh, J. Indian Chem. Soc,, 595-597 (1976), which teaches the synthesis of a number of 5-methyl-3-aryl-2-arylimlno- 4-thiazolidinones, which, together with the acetory- mercuri derivatives thereof are alleged to possess fungicidal activity against Alternaria solani, as the test organism. Yet another prior art reference is Japanese Patent No. 48-17276, which is directed to the manufacture of thiazolidone derivatives bearing a 2-pyridyl moiety in the molecular structure. The compounds are alleged to have central nervous system inhibiting activity. Still another prior art reference is U.S. Patent o. 4,017,628 (April 12, 1977), which is directed to the treatment of mange using a 2-pyridyl substituted thiazolidinone compound. Also in the prior art is Jadhav et al., J. Indian Chem. Soc., 424-426 (1978), which teaches the preparation of some 2-methyl-2-(2-hydroxy-4,5-dim,ethy'- phenyl)-3-aryl-4-thiazolidinones, alleged to possess fungicidal activity against Helmynthosporiurn appatarnae. The present invention relates to novel l-thia-3-aza-4-ones having utility as plant fungicides, terrestrial and aquatic growth regulators, processes for their preparation, methods for the use thereof, and compositions containing the compounds. This invention relates to compounds of the formula EMI2.1 wherein R is C3-C10 alkyl, C3-C8 cycloalkyl, methallyl, phenyl, halophenyl, trifluoromethylphenyl, benzyl, methoxybenzyl, methylbenzyl, halobenzyl, dimethylaminoethyl, methylcyclohexyl, C3-C3 cycloalkyl(Cl-C3)- alkyl, a-methylbenzyl, 2-thiazolyl, nitrophenyl, phenoxyphenyl, (tetrahydro-2-furanyl)methyl, haloanilyl, trifluoromethylthiophenyl, methylthiophenyl, 2norbornyl, furfuryl, 2- (1-methoxypropyl), methoxyphenyl, fluoro (C1-C2)alkoxyphenyl, 3,4-(methylenedioxy)phenyl, xylyl, biphenylyl, tolyl or halotolyl; X is oxygen or sulfur; EMI3.1 R1 is hydrogen, methyl, or -S(C1-C6 alkyl); R2 is hydrogen, C1-C6 alkyl, or -s (C1-C6 alkyl); ; R3 is hydrogen or methyl; R4 is hydrogen or C1-C6 alkyl; and R5 is hydrogen or methyl. A preferred embodiment of formula (I) is compounds of the formula EMI3.2 where in R1 is hydrogen, methyl, or -S(C1-C6 alkyl); is hydrogen, C1-C6 alkyl, or 6 alkyl); and R6 is C3-C10 alkyl, C3-C8 cycloalkyl, methallyl, halophenyl, phenyl, fluoro(C1-C2)alkoxyphenyl, nitrophenyl, tolyl, methoxyphenyl, furfuryl, 3,4-(methyiene- dioxy)phenyl, (tetrahydro-2-furanyl)methyl, trifluoro methylphenyl, methylcyclohexyl, C3-C8 cycloalkyl(C1-C3)- alkyl, biphenylyl, phenoxyphenyl, 2-norbornyl, halobenzyl, 2-thiazolyl, trifluoromethylthiophenyl, halotolyl, or methylthiophenyl. Another preferred embodiment of formula (I) is compounds of the formula EMI4.1 wherein X is oxygen or sulfur; R7 is C-C6 alkyl, C5-C6 cycloalkyl, halobenzyl, xylyl, halophenyl, methylthiophenyl, tolyl, halotoyl, trifluoromethylphenyl, 1-(2-cyclopentyl1-methyl)etehyl, or methoxyphenyl; R8 is hydrogen or methyl; and R9 and R10 are the same or different and are hydrogen or methyl. A process for the preparation of 4-thiazolidinone compounds of the formula EMI5.1 wherein: R, R1 and R2 are defined as for formula (I), which comprises reacting 3-pyridylcarboxaldehyde of the formula EMI5.2 with a substituted amine of the formula R-NH2 wherein R is defined as above, followed by reacting with thioglycolic acid or thiolactic acid. When R1 or R2in formula (VII) is hydrogen, the compound can be mono- or di-alkylated to provide the compounds of formula (VII) wherein R is methyl or -S(C1-C6 alkyl), or i2 is C1-C6 alkyl or -S(C1-C6 alkyl). Also the 4-keto group of formula (VII) can be further reacted with P2S5 to provide the corre- sponding thione. When the R group of the amine is a sterically hindered group, a cyclizing agent such as N,N'-dicyclohexylcarbodiimide or N-ethoxycarbonyl2-ethoxy-1,2-dihydroquinoline should be used to insure ring closure. A process for the preparation of thiazinone compounds of the ormula EMI6.1 wherein: R , R4 and R5 are defined as for formula (I), R17 is C3-C10 alkyl, C5-C6 cycloalkyl, C3-C6 cycloalkyl (C1-C3)alkyl, halophenyl, trifluoromethylphenyl, halobenzyl, haloanilyl, methoxyphenyl, xylyl, tolyl, or methylthiophenyl, which comprises reacting a compound of the formula EMI6.2 wherein R , R4, R5 and R17 are defined as before, with a cyclizing agent. When R or R4 is hydrogen, or when R is methyl and R4 is C1-C6 alkyl and R5 is hydrogen, the compounds of formula (VIII) can be alkylated to provide the compounds of formula (VII) where either R is methyl or R4 is C1-C6 alkyl, or where R is methyl and R4 is C1-C6 alkyl, then R5 is methyl. Also the 4-keto group of formula (VIII) can be further reacted with P2S5 to provide the corresponding thione. This invention relates to a method of pro acting plants from phytopathogenic fungi which comprises contacting the fungi with a fungicidallyeffective and non-herbicidal amount of a compound of the formula EMI7.1 wherein RÚÚ is C3-C10 alkyl, phenyl, halophenyl, methallyl, C3-C8 cycloalkyl, nitrophenyl, methylcyclohexyl, fluoro(C1-C2)alkoxyphenyl, tolyl, xylyl, methoxyphenyl, trifluoromethylphenyl, halotolyl, halobenzyl, 3,4-(methylenedioxy)phenyl, or biphenylyl; R12 is hydrogen or methyl; R13 is hydrogen or C -c R14 is C3-C6 alkyl, C5-C6 cycloalkyl, halobenzyl, trifluoromethyiphenyl, halophenyl, tolyl, or methoxyphenyl; and R15 is hydrogen or methyl. This invention also relates to a method for regulating the growth of submerged and floating aquatic weeds which comprises adding to the water containing said weeds an amount sufficient to provide a growthregulating and non-herbicldal concentration of a compound of the formula EMI8.1 wnerein R16 is C3-C10 alkyl, C3-C8 cycloalkyl, methallyl, phenyl, halophenyl, trifluoromethylphenyl, methoxybenzyl, methylbenzyl, halobenzyl, benzyl, dimethylaminoethyl, C3-C8 cycloalkyl(C1-C3)alkyl, methylcyclohexyl, 2-thiazolyl, a-methylbenzyl, phenoxy- phenyl, (tetrahydro-2-furanyl)methyl, haloanilyl, xylyl, trifluoromethylthiophenyl,methylthiophenyl, methoxyphenyl, fluoro(C1-C2)alkoxyphenyl, 3,4-(methylene dioxy)chenyl, biphenylyl, 2-norbornyl, furfuryl, 2 (l-methoxypropyl), halotolyl, or tolyl; X is oxygen or sulfur; EMI8.2 R1 is hydrogen, methyl, or -S(C1-C6 alkyi); R2 is hydrogen, C1-C6 alkyl, or -S(C1-C6 alkyl); R3 is hydrogen or methyl; R4 is hydrogen or C1-C6 alkyl; and R is hydrogen or methyl. The compounds of formula (VI) are also terrestrial growth regulators. In the above formulae, C3-C10 alkyl represents n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, t-butyl, n-pentyl, isopentyl, sec-pentyl, t-pentyl, n-hexyl, sec-hexyl, isohexyl, t-hexyl, n-heptyl, isoheptyl, sec-heptyl, n-octyl, sec-octyl, isooctyl, n-nonyl, sec-nonyl, isononyl, n-decyl, sec-decyl, and the like. C1-C6 alkyl represents methyl, ethyl, npropyl, isopropyl, n-butyl, sec-butyl, isobutyl, t-butyl, n-pentyl, isopentyl, sec-pentyl, t-pentyl, n-hexyl, sec-hexyl, isohexyl, t-hexyl, and the like. The term -S(C1-C6 alkyl) represents alkylthio such as methylthio, ethylthio, n-propylthio, isopropylthio, n-butylthio, isobutylthio, sec-butylthio, tbutylthio, n-amylthio, isoamylthio, sec-amylthio, n-hexylthio, sec-hexylthio, isohexylthio, and the like. C3-C8 Cycloalkyl represents saturated monocyclic cycloalkyl such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl. Halophenyl represents o-chlorophenyl, P- chiorophenyl, p-fluorophenyl, p-bromophenyl, -iodo- phenyl, m-chlorophenyl, o-bromophenyl, o-fluorophenyl, 2,4-difluorophenyl, 2,5-dichlorophenyl, 2,5-dibZomc- phenyl, 2,4-dichlorophenyl, 2-bromo-4-chiorophenyi, 2,4-dibromopher.yl, 3, 4-difluorophenyl, 4-bromo-2 chiorophenyl, 4-bromo-3-fluorophenyl, 3,4-dichloro phenyl, 3,4-dibromophenyl, 4-chloro-3-fluorophenyl, 3,5-difluorophenyl, 3,5-dichlorophenyl, 3,5-dibromophenyl, 2,3,4-trichlorophenyl, 2,4,5-trichlorophenyl, 2,3,4,5-tetrachlorophenyl, and the like Halobenzyl represents o-chlorobenzyl, P chlorobenzyl, p-fluorobenzyl, p-bromobenzyl, piodobenzyl, m-chlorobenzyl, m-bromobenzyl, m-±1uoro- benzyl, 2,4-dichlorobenzyl, 2-bromo-4-chlorobenzyl, 3,4-dibromobenzyl, 2,5-dichlorobenzyl, 3,5-dibromobenzyl, 4-chloro-3-fluorobenzyl, 2,5-difluorobenzyl, and the like. Haloanilyl represents p-chlorcanilyl, o- chloroanilyl, m-chloroanilyl, 2,6-dichloroanilyl, p-bromoanilyl, o-bromoanilyl, and the like. Fluoro(C1-C2)alkoxyphenyl represents trifluoromethoxyphenyl, 1,1,2,2-tetrafluoropethoxyphenyl and pentafluoroethoxyphenyl. C3-C8 Cycloalkyl(C1-C3)alkyl represents cyclopropylmethyl, cyclobutylmethyl, cyclopentylmethyl, cynlchexylmethyl, cyclopropylethyl, cyclobutylethyl, cyclopentylethyl, cyclohexylethyl, cycloheptylethyl, cyclooctylethyl, cycloheptylmethyl, cyclooctylmethyl, cyclopropylpropyl, cyclobutylpropyl, cyclopentylpropyl, cycloheptylpropyl, cyclooctylpropyl, 1-(2-cyclopentyll-methyl)ethyl, 1-cyclohexylpropyl, and the like. Methoxyphenyl represents 4-methoxyphenyl, 3,4-dimethoxyphenyl, 3-methoxyphenyl, and 3,5-dimethoxyphenyl. Halo or halogen is chlorine, bromine, iodine, or fluorine. Xylyl represents 3,4-dimetylphenyl, 2,3dimethylphenyl, 3,5-dimethylphenyl, 2, 4-dimethylphenyl, and 2,5-dimethylphenyl. Tolyl represents o-, m-, and p-tolyl. Compounds of formula (VI) have been found effective for regulating the growth of aquatic weeds when applied to the locus of the weeds at a concen tration in the range of from about 0.25 to about 10 ppm., suitably at a concentration in the range of from about 0.25 to about 2 ppm. The compounds preferred for use in the novel aquatic growth regulating embodiment are of formula (VI) wherein R is cyclopentyl, cyclohexyl, l-methylhexyl, n-hexyl, o-tolyl, 2-chlorophenyl, 2-fluorophenyl, 2,4 difluorophenyl, 4-chlorophenyl, and 2,4-dichlorophenyl; R1 Z is -C-; R2 R1is hydrogen or methyl; and R2 is hydrogen, methyl, n-propyl, cr n-butyl. Another embodiment relates to a method of protecting plants from phytopathogenic fungi which comprises contacting the loci of the fungi, be that some portion of the plant, namely leaves, stems, flowers or roots, or the soil wherein the fungi may be located, with a fungicidally-effective but non- - herbicidal amount of a compound of formula (IV) or (V). Application rates will vary according to whether the method of protecting plants from phytopathogenic fungi is practised in a greenhouse or out of doors in the field, as well as with th severity of the fungal infection. Thus, for use in a greenhouse, the fungicidal compound is applied as a soil drench using a composition having a concentration in the range of from about 1 to about 200 ppm. of active ingredient, preferably from about 5 to about 100 ppm. As is well understood by those of ordinary skill in the art, application rates for use in the field are usually greater than for use in a greenhouse, and range from about 25 to about 1000 ppm. Novel compounds of formula (iV) or (V) have been shown by suitable tests to control a number of fungi, including Erysiphe graminis tritici, the causative organism of powdery mildew of wheat; Erisiphe cichoracearum, the causative organism of cucumber powdery mildew; Erisiphe polygoni, the causative organism of bean powdery mildew; Helminthosporium sativum, the causative organism of h-elmlnthosporium leaf spot; Venturia inaequalis, the causative organism of apple scab; Plasmopara viticola, the causative organism of grape downy mildew; Cercospora beticola, the causative organism of Cercospora leaf spot; Septoria t-itici, the causative organism of Septoria leaf blotch; and Rhizoctonia solani, the causative organism of Rhizoctonia damping-off. The compounds preferred for use in the method of protecting plants from plant pathogenic fungi are of formula (IV) or (V) wherein R is halophenyl, cyclohexyl or tolyl; EMI13.1 R1 is hydrogen or methyl; R2 is hydrogen, methyl, or propyl; R3 is hydrogen or methyl; and R4 is hydrogen or methyl. The novel compounds of formula (I) are prepared by the following described processes, varying somewhat depending upon whether the particular compound is a thiazolidinone or a thiazinone. Those substituted 1thia-3-aza-4-one compounds, identified as substituted 4-thiazolidinone compounds, are prepared according to the following general reaction sequence: EMI13.2 wherein R has the same values as set forth hereinabove. Thus, in carrying out the reaction, a suitably substituted aniline or alkylamine is dissolved in a water-immiscible solvent inert to the conditions of the reaction to be carried out, and to this solution there is added the 3-syridylcarboxaldehyde. Suitable solvents include benzene, toluene, xylene, and the like. The mixture is refluxed for a period of time during which water, which is a by-product of the reactIon, is collected in a suitable water trap, for instance, the Dean-Stark trap. The intermediate formes is a 3-[(substituted phenylirino)methyljpyridine which is usually not isolated. After the calculated amount of water given off by the reaction mixture has been collected, the reaction mixture is cooled to approximately room temperature, an excess of thioglycolic (a-mercaptoacetic acid) or thiolactic acid (2-mercapto- propionic acid) is added, and the reaction mixture again refluxed until no more water is collected in the Dean-Stark trap. This requires approximately t hours. The reaction product mixture is cooled, concentrated t dryness in vacuo, and purified by recrystallization of the residue from a suitable solvent, or by column chromatography. By this general procedure the ,- thiazolidinones are prepared, which compounds have a 5-membered heterocyclic nucleus The process used to repare the tetrahydro thiazin-4-one compounds, the compounds with a 6membered heterocyclic nucieus, is carried out stepwise according to the following general reaction sequence: EMI15.1 R17 has the same values as set forth hereinabove. In Step 1, a mixture of the 3-pyridylcarboxaldehyde, a suitably substituted amine, and an inert water-immiscible solvent, such as toluene, benzene, xylene, or the like, is refluxed under a Dean-Stark trap to collect the water given off by the reaction. The reaction mixture is cooled, filtered, and concen treated in vacuo. The residue is purified by crystallization or column chromatography. The product of this step is identified as a 3-[(substituted phenylimino)methyl]pyridine, and is used in Step 2. The 3- (substituted phenylimino)methyl]pyridine is mixed with B-mercaptopropionic acid and an inert water-immiscible solvent, such as toluene, benzene, or xylene, and allowed to stand at room temperature overnight, or allowed to reflux for a few hours. The product of this reaction is isolated in crude form by concentrating the reaction mixture in vacuo. The crude product, identified as a 3-[a-(sub- stituted anilIno)-- (3-pyridyl)methylthio]propionic acid, is used in Step 3. The 3-[&alpha;-(substituted anilino)-&alpha;-(3-pyridyl)- methylthio]propionic acid is allowed to react with N,N'-dicyclohexylcarbodiimide in an inert solvent, at room temperature for from about 3 to about 15 hours, or until substantially complete reaction occurs. Another cyclizing agent which can be used in place of N,N'- dicyclohexylcarbodilmide (DCC) is N-ethoxycarbonyl-2ethoxy-1,2-dihydroquinoline (EEDQ). Other known peptide cyclizing agents can also be used. Suitable inert solvents include methylene chloride, chloroform, carbon tetrachloride, and ethylene dichloride. The solid which separates is filtered off and discarded. The filtrate is concentrated to dryness in vacuo to leave a residue which is purified by usual procedures, such as recrystallization or column chromatography. The product is identified as the desired 3- (substituted phenyl)tetrahydro-2-(3-pyridyl)-4H-1,3-thiazin-4one. Those compounds of formula I wherein Z is EMI16.1 and RÚ and/or Rê equal hydrogen; wherein Z is EMI16.2 and R3 = R = R5 = hydrogen; or R3 = methyl and R4 = R5 = hydrogen, are conveniently alkylated by methods known to those of ordinary skill in the art. The alkylatlon appears to occur at the position alpha to the carbonyl function of the 4-thiazolidinone or thiazin-4-one ring. Thus, for example, 3-(4-chloro phenyl)-5-methyl-2-(3-pyridyl)-4-thiazolidone, dissolved in tetrahydrofuran, is added with stirring to a mixture of a hexane solution of n-butyllithium and tetrahydrofuran, maintained under an atmosphere of dry nitrogen, and cooled to a temperature of about -500C. to about -700C. After stirring the reaction mixture for about one-half hour at about -70oC., methyl iodide is added dropwise, with stirring, and then the reaction mixture is stirred for about 12 hours, and allowed to warm gradually to ambient room temperature. The reaction product mixture is worked up by adding water thereto and extracting with ether. The ether extracts are dried, concentrated in vacuo, and the residue recrystallized from a suitable solvent, in the present case a mixture of petroleum ether (BP 60-70 C.) and ethyl ether, to yield product having a melting point of about 140-141 C., and identified as 3-(4-chlorophenyl)5,5-dimethyl-2-(3-pyridyl)-4-thiazolidinone. The preparation of those compounds of formula {I) wherein the carbonyl oxygen is replaced by sulfur is carried out by allowing the carbonyl oxygen compound to react with phosphorus pentasulfide (P2S) in a suitable solvent, preferably dry pyridine, at a temperature of about 90 C. for a period of about 18 hours, and then isolating the product. Thus, for example, 3- (4-chlorophenyl) tetra- hydro-2-(3-pyridl)-4-1,3-thiazin-4-one is is mixed with dry pyridine and heated to a temperature of abut 90 C., whereby a soluto is obtained To this solution phosphorus pentasulfide is added portionwise, with stirring and heating, and when the addition is complete, the reaction mixture is heated at about 90 C., and stirred overnight, that is, for about 18 hours. The reaction mixture is then cooled and the pyridine solvent evaporated in vacuo, leaving a viscous, oily, residue, which is washed by trituration wit water. The oil is then taken up in a solvent, in this case a mixture of ethanol and dimethylformamide, decolorized with carbon, filtered, and the ethanol removed in vacuo. The dimethylformamide solution is poured slowly into cold water, whereby a solid precipitates. The solid is extracted into ethyl acetate, and the extract washed with cold aqueous sodium chloride solution. The ethyl acetate solution is concentrated in vacuo to yield an oil which is chromatographed over a silica gel column using ethyl acetate as solvent and eluant. The viscous oil product obtained is crystallized from a suitable solvent, in this case a mixture of ethyl acetate and ether, and there is obtained product having a melting poInt of about 115-117"C., identified by elemental analyses as 3-(4-chlorophenyl)tetrahydro 2- (3-pyridyl)-4fl-l,3-thiazine-4-thione. Suitable acid addition salts of the compounds of formula (I) are readily prepared by the usual procedures well-known to those skilled in the art, using acids selected fro the group consisting of hydrochloric, hydrobromic, sulfuric, p-toluenesul- fonic, and the like. It must be noted that compounds of formula (I) occur as stereoisomers when Z is EMI19.1 wherein R1 &num; R2; when Z is EMI19.2 wherein R3 ,' R4 when R5 = H; and when Z is EMI19.3 wherein R5 r H when R3 and R4 are both hydrogen or both methyl. Such stereoisomers are capable of being separated through the application of suitable resolving agents, or chromatography, as is well-recognized by those of ordinary skill in the art. The synthesis of the compounds of formula (I) is more specifically illustrated following the above general procedures, which are not to be regarded as limiting the scope of the invention. Example 1 3-(4-Chlorophenyl)-5-methyl-2-(3-pyridyl)-4-thiazolidinone In a round bottomed 3-neck flask equipped with a condenser, Dean-Stark trap, and a mechanical stirrer, there was placed 25.4 g. (0.27 mole) of 4chloroaniline and 250 ml. of toluene. With stirring, there was added to this solution 21.4 g. (0.27 mole) of 3-pyridinecarboxaldehyde, and the reaction mixture refluxed until the calculated amount of water-(approx- imately 3.6 ml.) had been collected in the Dean-Stark trap. The hot reaction mixture was cooled to room temperature and an excess of thiolactic acid, totaling 30 g., was added and the reaction mixture again heated to reflux until no more water was collected in the Dean-Stark trap. This required about 4 hours of heating The reaction mixture was then cooled and concentrated to dryness in vacuo. The solid residue was recrystallized from a mixture of hot ethyl ether and acetone to yield product having a melting point of about 120-122 C., and identified by infrared and NMR spectra, and elemental analyses as 3-(4-cblorophenyl)- 5-methyl-2-(3-pyridyl)-4-thiazolidinone. Wt. 7 g. Analyses calculated for C15H13ClN20S: Theoretical Found C 59.11 59.23 H 5.30 4.26 N 9.19 9.19 Following the general procedure of Example 1, additional compounds were prepared and identified. The compounds, together with the principal starting materials and weights thereof used in the preparations, are listed in the examples set forth hereinafter. Example 2 3-(2,4-Difluorophenyl)-2-(3-pyridyl)-4thiazolidinone, having a melting point of about 125-127 C., from 13 g. of 2,4-difluoroaniline, 10 g. of 3-pyrldyl- carboxaldehyde, and 13 g. of thioglycolic acid. Wt. 15 g. Analyses calcula or C14H10F2N2OS Theoretical Found C 57.53 57.80 H 3.45 3.68 N 9.58 9.61 Example 3 3-(2-Fluorophenyl)-2-(3-pyridyl)-4-thiazolidinone, having a melting point of about 142-1430C., from 15 g. of 2-fluoroaníline, 15 g. of 3-pyridylcarboxaldehyde, and 13 g. of thioglycolic acid. Wt. 8 g. Analyses calculated for C14H11FN2 OS: Theoretical Found C 61.30 61.50 H 4.04 4.34 N 10.21 10.07 Example 4 3-Nonyl-2-(3-pyridyl)-4-thiazolidone, having a melting point of about 82-830C., from 11.2 g. of N-nonylamine, 15 g. of 3-pyridylcarboxaldehyde, and 13 g. of thioglycolic acid. Wt. 2.3 g. Analyses calculated for C17H26N20S: Theoretical Found C 66.62 66.38 H 8.55 8.22 N 9.14 8.85 Example 5 3-(4-Chlorobenzyl)-2-(3-pyridyl)-4-thiazolidinone, having a melting point of about 134 C., from 15 g. of 4-chlorobenzylamine, 15 g. of 3-pyridyl- carboxaldehyde, and 13 g. of thioglycolic acid. Wt. 20 g. Analyses calculated for C15H13ClNOS: Theoretical Found C 59.11 58.78 H 4.30 4.42 N 9.13 8,89 Example 6 3-Cyclopentyl-2-(3-pyridyl)-4-thiazolidinone having a melting point of about 1l8-1190C., from 12 g. of cyclopentylamine, 15 g. of 3-pyridylcarboxaldehyde, and 13 g. of thioglycolic acid. t. 6.5 g. Analyses calculated for C13H16N2OS: Theoretical Found C 62.S7 63.C1 H 6.49 6.21 N 11.28 11.19 Example 7 3-Phenyl-2-(3-pyridyl)-4-thiazolidinone, having a melting point of about 177-178 C., from 13 g. of aniline, 15 g. of 3-pyridylcarboxaldehyde, and 13 g. of thioglycolic acid. Wt. 9 g. Analyses calculated for C14H12N2OS: Theoretical Found C 65.60 65.44 H 4.72 4,89 N 10.93 10.76 Example 8 3-(2-Methallyl)-2-(3-pyridyl)-4-thia zolidinone, having a melting point of about 840C., from 15 g. of 2-methallylamine, 20 g. of 3-pyridylcarboxaldehyde, and 20 g. of thioglycolic acid. t. 23 g. Analyses calculated for C12H13N2OS: Theoretical Found C 61.54 61.56 H 5.98 5.90 N 11.97 11.70 Example 9 3-(1-Metehylhexyl)-2-(3-pyridyl)-4-thiazolidinone, having melting point of about 670C., from 16 g. of 2-aminoheptane 15 g. of 3-pyridylcarbox- aldehyde, and 13 g. of thioglycolic acid. wt. 3 g. Analyses calculated for C15H22N20S: Theoretical Found C 64.71 64.70 H 7.97 7.76 N 10.06 9.97 Example 10 3-(3-Chlorphenyl)-2-(3-pyridyl)-4-thiazolidinone, having a melting point of about 154-155 C., from 13 g. of 3-chloroanilire 10 g of 3-pyridylcarboxaldehyde, and 10 g. of thioglycolic acid. Wt. 13 g. Analyses calculated for C14H11ClN2OS: Theoretical Found C 57.83 57.63 H 3.81 4.07 N 9.63 9.66 Example 11 2-(3-Pyridyl)-3-(&alpha;,&alpha;,&alpha;-trifluoro-m-tolyl)- 4-thiazolidinone, as an oil, from 16 g. of 3-trifluoromethylaniline, 15 g. of 3-pyridylcarboxaldehyde, and 13 g. of thioglycolic acid. t. 8 g. NMR )CDCl3) (#) 3.9 ( -CH2); 6.3 EMI24.1 7.5 (m, phenyl -CF3); 8.8 EMI24.2 Analyses calculated for C15H11F3N2OS: Theoretical Found C 55.55 55.79 H 3.42 3.56 N 8.64 8.75 Example 12 3-(4-Fluorophenyl)-2-(3-pyridyl)-4-thiazolidinone, having a melting point of about 161 C., from 55.5 g. of 4-fluoroaniline, 53.5 g. of 3-pyridyl- carboxaldehyde, and 46 g. of thioglycolic acid. Wt. 70 g. Analyses calculated for C14H11FN2OS: Theoretical Found C 61.30 61.08 H 4.04 4.15 N 10.21 10.i7 sample 13 3-(Cyclohexylmethyl)-2-(3-pyridyl)-4thiazolidinone, having a melting point of about 70 C., from 11.3 g. of cyclohexanemethanamine, 10 g. of 3-pyridylcarboxaldehyde, and 10 g. of thioglycolic acrid. t. 15 g. Identified by NMR spectrum. Example 14 3-(3,5-Dichlorophenyl)-2-(3-pyridyl)-4thiazolidinone, having a melting point of about 160-1610C., from 16.2 g. of 3,5-dichloroaniline, 11 g. of 3-pyridylcarboxaldehyde, and 10 g. of thioglycolic acid. Wt. 11 g. EMI25.1 Example 15 (2-Fluorobenzyl)-2-(3-pyridyl)-4-thiazolidinone, having a melting point of about 103 C., from 12.5 g. of 2-fluorobenzylamine, 10.7 g. of 3-pyridylcarboxaldehyde, and 10 g. of thioglycolic acid. Wt. 6 g. NMR (CDC13) (6) 3.9 (s, S-CH2-C(O)); 4.5 (q, EMI26.1 Example 16 3- (3, 4-Methylenedioxybenzyl) - 2- (3-pyridyl) 4-thiazolidinone, having a melting point of about 121-122 C., from 15.1 g. of piperonylamine, 11 g. of 3-pyridylcarboxaldehyde, and 14 g. of thioglycolic acid. Wt. 4 g. Analyses calculated for C16H14N2O3S: Theoretical Found C 61.13 60.95 H 4.49 4.45 N 8.90 8.83 Example 17 3-(3,4-Dichlorophenyl)-2-(3-pyridyl)-4 niazolidinone, having a melting point of about 160-1620C., from 16.2 g. of 3,4-dichloroaniline, 11 g. of 3-pyridylcarboxaldehyde, and 14 g. of thioglycolic acid. Wt. 14 g. Analyses calculated for C14H 10C12N2OS: Theoretical Found C 51.71 51.54 H 3.10 2.96 N 8.61 8.54 Example 18 3- (2,4-Dichlorophenyl)-2- (3-pyridyl)-4- thiazolidinone, having a melting point of about 170-171 C., from 16.2 g. of 2,4-dichloroaniline, 12 g. of 3pyridylcarboxaldehyde, and 12 g. of thioglycolic acid. Wt. 4 g. Analyses calculated for C14H10Cl2N2OS: Theoretical Found C 51.71 51.52 H 3.00 2.90 N 8.61 8.62 Example 19 3-(4-Chlorophenyl)-2-(3-pyridyl)-4-thiazolidinone, having a melting point of about 149-1510C., from 9 g. of 4-chloroaniline, 7.5 g. of 3-pyridylcarboxaldehyde, and 15 g. of thioglycolic acid. Wt. 9 g. Analyses calculated for C14HllClN2OS: Theoretical Found C 57.83 58.73 H 3.81 4.47 N 9.63 9.48 Example 20 2-(3-Pyridyl)-3-[3-(1,1,2,2-tetrafluoroethoxy)phenyl]-4-thiazolidinone, as an oil, from 21 g. of 3-tetrafluoroethoxyaniline, 11 g. of 3-pyridyl- carboxaldehyde, and 14 g. of thioglycolic acid. Wt. 4 g. EMI28.1 Analyses calculated for C16H12F421202S: Theoretical Found C 51.61 51.84 H 3.25 3.19 N 7.52 7.32 Example 21 3-Cyclohexyl-2-(3-pyridyl)-4-thiazolidinone, having a melting point of about liO-111 C., from 10 g. of cyclohexylamine, 15 g. of 3-pyridylcarboxaldehyde, and 13 g. of thioglycolic acid. Wt. 4.6 g. Analyses calculated for C14H,8N2CS: Theoretical Found C 64.09 63.90 H 6.92 6.72 N 10.68 10.44 Example 22 3-Cyclopropyl-2-(3-pyridyl)-4-thiazolidinone, having a melting point of about 112-1130C., from 8 g. of cyclopropylamine, 15 g. of 3-pyridylcarboxaldehyde, and 13 g. of thioglycolic acid. Wt. 16 g. Analyses calculated for C11H12N2OS: Theoretical Found C 60.00 60.11 H 5.45 5.32 N 12.73 12.55 Example 23 3- (3-Chlorophenyl) - 5-methyl- 2- (3-pyridyl) - 4-thiazolidinone, having a melting point of about 1330C., from 18 g. of 3-chloroaniline, 15 g. of 3pyridylcarboxaldehyde, and 13 g. of thiolactic acid. Wt. 9.5 g. Analyses calculated for C15H13ClN2OS: Theoretical Found C 59.11 58.98 H 4.30 4.26 N 9.19 9.10 Example 24 3- (2-Chlorophenyl)-2- (3-pyridyl)-4-thia- zolidinone, having a melting point of about 1340C., from 18 g. of 2-chloroaniline, 15 g. of 3-pyridylcarboxaldehyde, and 13 g. of thioglycolic acid. Wt. 4.6 g. Analyses calculated for C14H11ClN2OS: Theoretical Found C 57.83 57.49 H 3.81 3.74 N 9.63 9.32 Example 25 2-(3-Pyridyl)-3-(4-tolyl)-4-thiazolidinone, having a melting point of about i870C., from 15 g. of 2-toluidine, 15 g. of 3-pyridylcarboxaldehyde, and 13 g. of thioglycolic acid. Wt. 16 g. Analyses calculated for C15Hl4N2OS: Theoretical Found C 66.64 66.79 H 5.22 5.13 N 10.36 10.58 Example 26 3-(4-Methoxyphenyl)-2-(3-pyridyl)-4-thiazolidinone, having a melting point of about 144-1450C., from 17 g. of 4-methoxyaniline, 15 g. of 3-pyridylcarboxaldehyde, and 13 g. of thioglycolic acid. Wt. 5 g. Analyses calculated for C15Hl4N202S: Theoretical Found C 62.92 63.20 H 4.93 5.05 N 9.78 9.99 Example 27 2-(3-Pyridyl)-3-(&alpha;,&alpha;,&alpha;-trifluoro-p-tolyl)- 4-thiazolidinone, having a melting point of about 1480C., from 16 g. of 4-aminobenzotrifluoride, 15 g. of 3-pyridylcarboxaldehyde, and 13 g. of thioglycolic acid. Wt. 8 g. Analyses calculated for C15H11F3N ? OS: Theoretical Found C 55.55 55.15 H 3.42 3.41 N 8.64 8.85 Example 28 3-Hexyl-2-(3-pyridyl)-4-thiazolidinone, having a melting point of about 780C., from 12 g. of n-hexylamine, 11 g. of 3-pyridylcarboxladehyde, and 10 g. of thioglycolic acid. Wt. 21 g. Analyses calculated for C14H20N2OS: Theoretical Found C 63.60 63.52 H 7.63 7.47 N 10.60 10.59 Example 29 3-Cyclohexyl-5-methyl-2-(3-pyridyl)-4-thiazolidinone, having a melting point of about 1060C., from 10 g. of cyclohexylamine, 10.7 g. of 3-pyridylcarboxaldehyde, and 10.6 g. of thiolactic acid. Wt. 13 g. Analyses calculated for C15H20N2OS: Theoretical Found C 65.18 65.40 H 7.29 7.00 N 10.14 10.00 Example 30 5-Methyl-3-(4-tolyl)-2-(3-pyridyl)-4thiazolidinone, having a melting point of about 170 C., from 10.7 g. of p-toluidine, 10.7 g. of 3-pyridyl carboxaldehyde, and 10.6 c. of thiolactic acid. Wt. 18 g. Analyses calculated for Ci6H16N2OS: Theoretical Found C 68.06 68.32 H 5.00 5.29 N 9.92 9.86 Example 31 3-(4-Chlorbenzyl)-5-methyl-2-(3-pyridyl)4-thiazolidinone, as an oil, from 14 g. of 4-chlorobenzylamine, 10.7 g. of 3-pyridylcarboxaldehyde, and 10.6 g. of thiolactic acid. Wt. 7.9 g. Analyses calculated for C16H15ClN2OS: Theoretical Found C 60.28 60.42 H 4.71 4.61 N 8.79 8.59 Example 32 3- (2-Chlorophenyl)-5-methyl-2- (3-pyridyl) 4-thiazolidinone, having a melting point of about 104-105 C., from 12.7 g. of 2-chloroaniline, 10.7 g. of 3-pyridylcarboxaldehyde, and 10.6 g. of thiolactic acid. Wt. 600 mg. Analyses calculated for C15H13ClN2OS: Theoretical Found C 59.11 59.32 H 4.30 4.5a N 9.19 8.95 Example 33 5-Methyl- 3- (1-methylhexyl)-2- (3-pyridyl) 4-thiazolidinone, as an oil, from 11.5 g. of 2aminoheptane, 10.7 g. of 3-pyridylcarboxaldehyde, and 10.6 g. of thiolactic acid. Wt. 14 g. NMR (CDCl3) (#) EMI33.1 Analyses calculated for C16Hz4N2OS: Theoretical Found C 65.71 65.49 H 8.27 8.18 N 9.58 9.32 Example 34 3-Hexyl-5-methyl-2-(3-pyridyl)-4-thiazoli dlnone, having a melting point of about 67-680C., from 10.1 g. of n-hexylamine, 10.7 g. of 3-pyridylcarboxalde- hyde, and 10.6 g. of thiolactic acid. Wt. 5.7 g. Analyses calculated for C15H22N2OS: Theoretical Found C 64.71 64.61 H 7.97 7.77 N 10.05 10.05 Example 35 3- (2-Fluorophenyl)-5-methyl-2- (3-pyridyl) 4-thiazolidinone, having a melting point of about 105 C., from 11 g. of 2-fluoroaniline, 10.7 g. of 3-pyridylcarboxaldehyde, and 10.6 g. of thiolactic acid. Wt. 16 g. Analyses calculated for C15Hl3FN2OS: Theoretical Found C ó2.48 62.26 H 4.54 4.52 N 9.72 9.6 Example 36 3- (4-Fluorophenyl)-5-methyl-2- (3-pyridyl)- 4-thiazolidinone, having a melting point of about 1480C., from 22.2 g. of 4-fluoroaniline, 21.4 g. of 3-pyridylcarboxaldehyde, and 24 g. of thiolactic acid. Wt. 36 g. Analyses calculated for C15H13FN2OS: Theoretical Found C 62.48 62.56 H 4.54 4.31 N 9.72 9.41 Example 37 3-(3-Nitrophenyl)-2-(3-pyridyl)-4-thiazolidinone, having a melting point of about 114-115 C., from 13.8 g. of 3-nitroaniline, 11 g. of 3-pyridylcarboxaldehyde, and 9 g. of thioglycolic acid. Wt. 1.5 g. Analyses calculated for C14HllN303S: Theoretical Found C 55.81 55.74 H 3.65 3.69 N 13.95 13.77 Example 38 3-(4-Phenoxyphenyl)-2-(3-pyridyl)-4-thiazolidinone, having a melting point of about 168-170 C., from 26 g. of 4-phenoxyaniline, 15 g. of 3-pyridylcarboxaldehyde, and 13 g. of thioglycolic acid. Wt. 26 g. Analyses calculated for C20H16N202S: Theoretical Found C 68.94 68.80 H 4.63 4.60 - N 8.04 7.91 Example 39 3-[1-(2-Cyclophentyl-1-methyl)]ethyl-5methyl-2-(3-pyridyl)-4-thiazolidinone, having a melting point of about 102 C., from 26 g. of &alpha;-methylcyclopentane- ethylamine, 22 g. 3-pyridylcarboxaldehyde, and 25 g. tniolactic acid. Wt. 2 g. NMR (CDCl3) (#) EMI36.1 Example 40 5-Methyl-3-(&alpha;-methylbenzyl)-2-(3-pyridyl)- 4-thiazolidinone, having a melting point of about 890C., from 12 g. of a-methylbenzylamine, 10.7 g. of 3-pyridylcarboxaldehyde, and 10.7 g. of thiolactic acid. Wt. 1.8 g Analyses calculated for C17H 18N 2OS: Theoretical Found C 68.43 68.17 H 6.08 5.87 N 9.39 9.31 Example 41 3-Isopropyl-5-methyl-2-(3-pyridyl)-4thiazolidinone, having a melting point of about 110-1110C., from 11.8 g. of isopropylamine, 20.0 g. of 3-pyridylcarboxaldehyde, and 22.0 g. of thiolactic acid. Wt. 21 g. Analyses calculated for C12H16N2 OS: Theoretical Found C 60.99 60.76 H 6.82 6.54 N 11.85 12.07 example 42 3-(3,5-Xylyl)-5-methyl-2-(3-pyridyl)-4thiazolidinone, having a melting point of about 140-1420C., from 25 g. of 3,5-dimethylaniline, 22 g. of 3-pyridylcarboxaldehyde, and 12 g. of thiolactic acid. Wt. 12. NMR (CDC13) t6) 1.7 (q, -CH3); 2.2 (s, -CH3); 4.1 (q, EMI37.1 Analyses calculated for C16H18N2OS: Theoretical Found C 68.43 68.17 H 6.08 5.83 N 9.39 9.31 Example 43 2- (3-Pyridyl )-3- (2-thiazolyl) -4-thiazoli- dinone, having a melting point of about 164-165 C., from 14.0 g. of 2-aminothiazole, 15.0 . of 3-pyridyl- carboxaldehyde, and 13.0 g. of thioglycolic acid. Wt. 2.0 g. Analyses calculated for C11H9N3OS2: Theoretical Found C 50.17 50.37 H 3.44 3.51 N 15.96 15.88 Example 44 3-(3,4-Xylyl)-5-methyl-2-(3-pyridyl)-4thiazolidinone, having a melting point of about 189oC., from 12.1 g. of 3,4-dimethylaniline, 10.7 g. of 3pyridylcarboxaldehyde, and 12 g. of thiolactic acid. Wt. 16 g. EMI38.1 Analyses calculated for C17H18N2OS: Theoretical Found C 68.43 68.64 H 6.08 6.22 N 9.39 9.29 Example 45 3-[2-(1-Methoxypropyl)]-2-(3-pyridyl)-5methyl-4-thiazolidinone, having a melting point of about 111-112 C., from 8.9 g. of 2-amino-1-methoxypropane, 10.7 g. 3-pyridylcarboxaldehyde, and 15 g. of thiolactic acid. Wt. 6.9 g. NMR (CDC13) (o) 1.3 (q, -CH3); 3.3 (s, -OCH3); 3.8 (m, EMI39.1 Example 46 (deleted) Example 47 3-Isopropyl-2-(3-pyridyl)-4-thiazolidinone, having a melting point of about 119-1200C., from 7 g. of isopropylamine, 15 g. of 3-pyridylcarboxaldehyde, and 13 g. of thioglycolic acid. wt. 12 g. Analyses calculated for C11H14N2 OS: Theoretical Found C 59.43 59.19 H 6.35 6.25 N 12.60 12.32 Example 48 3-(Cyclohexylmethyl)-5-methyl-2-(3-pyridyl)4-thiazolidinone, having a melting point of about 73-740C., from 10.7 g. of 3-pyridylcarboxaldehyde, 11.3 g. of cyclohexanemethanamine, and 10.8 g. of thiolactic acid. Wt. 11 g. Analyses calculated for C16H22N2 OS: Theoretical Found C 66.17 65.91 H 7.64 7.47 N 9.65 9.69 Example 49 3-Cyclooctyl-5-methyl-2-(3-pyridyl)-4thiazolidinone, having a melting point of about 58-61 C., from 12.7 g. of cyclooctylamine, 10.7 g. of 3-pyridyl- carboxaldehyde, and 10.6 g. of thiolactic acid. wt. 11.2 g. Analyses calculated for C17H24N2OS: Theoretical Found C 67.07 66.89 H 7 95 7.72 N 9.20 9.33 Example 50 5-Methyl-3-phenyl-2-(3-pyridyl)-4-thiazolidinone, having a melting point of about 159-161 C. from 18.6 g. of aniline, 21.4 g. of 3-pyridylcarboxalde- hyde, and 21.2 g. of thiolactic acid. Wt. 15 g. Analyses calculated for C15Xl4N2OS: Theoretical Found C 66.64 66.59 H 5.22 5.07 N 10.36 10.59 Example 51 5-Methyl- 3- (2-tolyl)-2- (3-pyridyl)-4- thiazolidinone, as an oil, from 21.4 g. of 2-toluidine, 21.4 g. of 3-pyridylcarboxaldehyde, and 25 g. of thiolactic acid. Wt. 6 g. NMR (CDC13) (6) 1.6 (q, -CH3); 2.1 (s, -CH3); 2.3 (s, EMI41.1 Analyses calculated for C16H16N2O5: Theoretical Found C 67.58 67.54 H 5.67 5.57 N 9.89 10.02 Example 52 5-Methyl-3- (4-methylthiophenyl)-2- (3- pyridyl)-4-thiazolidinone, having a melting point of about 147-1480C., from 17.5 g. of 4-methylthioaniline hydrochloride, 10.7 g. of 3-pyridylcarboxaldehyde, and 12 g. of thiolactic acid. Wt. 23 g. Analyses calculated for C16H16N2OS2: Theoretical Found - C 60.73 60.63 H 5.10 4.90 N 8.85 9.00 Example 53 5-Methyl-3-[2-(1-methoxypropyl)]-2-(3pyridyl)-4-thiazolidinone, having a melting point of about 111-112 C., from 8.9 g. cf 2-amino-1-methoxy propane, 10.7 g. of 3-pyrldylcarboxaldehyde, and 15 g. of thiolactic acid. Wt. 2.1 g. Identified by MIR spectrum. Example 54 3-(4-Nitrophenyl)-2-(3-pyridyl)-4-thiazolidinone, having a melting point of about 142-143 C., from 13.8 g. of 4-nitroanlline, 11 g. of 3-pyridylcarboxaldehyde, and 9 g. of thioglycolic acid. Wt. 4.0 g. Analyses calculated for C14H11N3I3S: Theoretical Found C 55.81 55.6S H 3.68 3.61 N 13.95 13.62 Example 55 2-(3-Pyridyl)-3-(2-norbornyl)-4-thiazolidinone, having a melting point of about 1430C., from 14 g. of norbornylamine, 15 g. of 3-pyridylcarboxaldehyde, and 13 g. of thioglycolic acid. Wt. 7.5 g. Analyses calculated for C14H18N2 SO: Theoretical Found C 65.66 65..,9 H 6.61 6.40 N 10.21 10.05 Example 56 3- (2,4-Difluorophenyl)-5-methyl-2- (3- pyridyl)-4-thiazolidinone, having a melting point of about 1020C., from 6 g. of 2,4-difluoroaniline, 6 g. of 3-pyridylcarboxaldehyde, and 8 g. of thiolactic acid. wt. 3.2 g. Analyses calculated for C15H12F 2N2 OS: Theoretical Found C 58.81 58.69 H 3.95 3.94 N 9.14 8.84 Example 57 3-(4-Iodophenyl)-5-methyl-2-(3-pyridyl)-4thiazolidinone, having a melting point of about 149-1500C., from 21.9 g. of 4-iodoaniline, 11 g. of 3-pyridylcarboxaldehyde, and 12 g. of thiolactic acid. Wt. 12 g. Analyses calculated zor C1jHl3IN2OS: Theoretical Found C 45.47 45.24 H 3.31 3.09 N 7.07 6.97 Example 58 5-Methyl-3- (4-methylbenzyl)-2- (3-pyridyl)- 4-thiazolidinone, having a melting point of about 96 C., from 12 g. of 4-methylbenzylamine, 10.7 g. of 3-pyridylcarboxaldehyde, and 10.7 g. of thiolactic acid. Wt. 4.9 g. Analyses calculated for C17H18N2OS: Theoretical Found C 68.43 68.33 H 6.08 5.7 N 9.39 9.21 Example 59 5-Mewthyl-3-(4-methylcyclohexyl)-2-(3 pyridyl)-4-thiazolldinone, having a melting point of about 108-1090C., from 11.5 g. 4-methylcyclcexyiamine, 10.5 g. of 3-pyridylcarboxaldehyde, and 11 g. thiolactic acid. Wt. 500 mg. Analyses calculated for C16H22N20S: Theoretical Found C 66.17 66.45 H 7.64 7.82 9.65 9.78 Example 60 3-(2,4-Dichlorobenzyl)-2-(3-pyridyl)-5methyl-4-thiazolidinone, having a melting point of about 125-126 C., from 17.6 g. of 2,4-dichlorobenzylamine, 10.7 g. of 3-pyridylcarboxaldehyde, and 12 g. of thiolactic acid. Wt. 15 g. Analyses calculated for C16H14Cl2N2OS: Theoretical Found C 54.40 54.38 H 3.99 3.71 N 7.93 8.08 Example 61 3- (2-Methoxybenzyl) - 5-methyl- 2- (3-pyridyl) 4-thiazolidinone, as an oil, from 13.7 g. of 2methoxybenzylamine, 10.5 g. of 3-pyridylcarboxaldehyde, and 10.7 g. of thiolactic acid. Wt. 2 g. NMR (CDC13) (6) 1.7 (q, -CH3); 3.7 (s, -OCH3); 4.1 (s, EMI45.1 Analyses calculated for C17H18N202S: Theoretical Found C 64.94 64.71 H 5.77 5.53 N 8.91 8.97 Example 62 3-(2-Furfuryl)-5-methyl-2-(3-pyridyl)-4thiazolidinone, having a melting point of about 740C., from 19.4 g. of furfurylamine, 22 g. of 3-pyridylcarboxaldehyde, and 25 g. of thiolactic acid. Wt. 6 g. Analyses calculated for C14H14N202S: Theoretical Found C 61.29 60.91 H 5.14 5.30 N 10.21 10.43 Example 63 5-Methyl-2-(3-pyridyl)-3-[(tetrahydro-2furanyl)methyl]-4-thiazolidinone, having a melting point of about 86-870C., from 10.6 g. of 3-pyridylcarboxaldehyde, 10.1 g. of tetrahydro-2-furanmethane- amine, and 10.7 g. of thiolactic acid. Wt. 5.5 g. Analyses calculated for C14H18N20 2 Theoretical Found C 60.41 60.15 H 6.52 6.36 N 10.06 10.20 Example 64 3-[2-(Dimethylamino)ethyl]-5-methyl-2 (3-pyridyl)-4-thiazolidinone, as a solid, from 10.7 g of 3-pyridylcarboxaldehyde, 8.8 g. of 2-dimethylaminc- ethylamine, and 12 g. of thioglycolic acid. wt. 12 g. NMR (CDCl3) (a) 1.6 (d, -CH3); 2.1 (s, -N(CH3)2); 2.6 (m, EMI46.1 Analyses calculated for C13H19N30S: Theoretical Found C 58.87 58.57 H 7.17 6.99 N 15.85 15.53 Example 64A 3-[(2,6-Dichlorophenyl)amino]-5-methyl-2 (3-pyridyl)-4-thiazolidinone, having a melting point of about 198-2O00C., from 11 g. of 3-pyridylcarboxaldehyde, 21.3 g. of 2,6-dichlorophenylhydrazine hydrochloride, and 7 g. of thiolactic acid. Wt. 2 g. Analyses calculated for C15H13Cl2N3OS: Theoretical Found C 50.86 50.86 H 3.70 3.62 N 11.84 12.03 Example 64B 3-[(3-chloro-4-methylphenyl)amino]-5methyl-2-(3-pyridyl)-4-thiazolidinone, having a melting point of about 150-1600C., from 6.43 g. of 3-pyridylcarboxaldehyde, 8.5 g. of 3-chloro-4-methylaniline, and 6.7 g. of thiolactic acid. Wt. 10.5 g. Analyses calculated for C16 H15C1N2 OS: Theoretical Found C 60.28 60.10 H 4.74 4.93 N 8.79 8.76 Example 64C 3-(2,4-Dimethylphenyl)-5-methyl-2-(3pyridyl)-4-thiazolidinone, having a melting point of about 121-123 C., from 25 g. of 2,4-dimethylaniline, 22 g. of 3-pyridylcarboxaldehyde, and 24 g. of thiolactic acid. Wt. 14 g. EMI48.1 Example 64D 3-(2-Trifluoromethylphenyl)-5-methyl-2 (3-pyridyl)-4-thiazolidine, having a melting point c about 870C., from 24 g. of 2-trifluoromethylaniline, 16 g. of 3-pyridylcarboxaldehyde, and 18 g. of thiolactic acid. t. 4.0 g. Analyses calculated for C16H13N2F3SO: Theoretical Found C 53.93 53.64 H 4.24 4.22 N 7.86 8.02 EMI48.2 Example 64E 3- (4-Bromo-3-methylphenyl) -5-methyl-2- (3-pyridyl)-4-thiazolidinone, having a melting point of about 127-1290C., from 11.2 g. of 4-bromo-3methylaniline, 6.4 g. of 3-pyridylcarboxaldehyde, and 6.7 g. of thiolactic acid. Wt. 12.2 g. Analyses calculated for C15Hl4BrN20S: Theoretical Found C 51.44 51.64 H 4.03 4.22 N 8.00 7.82 Example 65 3- (4-Chlorophenyl)-5, 5-dmethyl-2- (3-pyridyl) -4- thiazolidinone To 150 ml. of anhydrous tetrahydrofuran cooled to -700C., under an atmosphere of dry nitrogen, there was added 25 ml. of a hexane solution of n butyllithium all in one portion. The mixture was again cooled to -700C., and a solution of 15 g. of 3 (4-chlorophenyl)-5-methyl-2- (3-pyridyl)-4-thiazolidinone (prepared as in Example 1, supra) in 100 ml. of anhydrous tetrahydrofuran was added dropwise with stirring. Approximately 0.5 hour after the addition was complete 14 g. of methyl iodide was added to the mixture dropwise with continued stirring and then the reaction mixture was stirred overnight and allowed to gradually warm to room temperature. The reaction was worked up by adding water and extracting with ether. The ether layer was drye over anhydrous magnesium sulfate, the drying agent filtered off and the filtrate concentrated in vacuo t leave a residual oil. The oil was crystallized using a mixture of petroleum ether boiling point 60-70 C.) and ethyl ether. A product was obtained having melting point of about 140-141 C., which product was identified as 3-(4-chlorophenyl)-5,5-dimethyl-2-(3-pyridyl)-4thiazolidinone. Wt. 4.8 g. NMR (CDC13/DMSO) (6) EMI50.1 Analyses calculated for C16H 15C1N20S: Theoretical Found C 60.28 60.07 H 4.74 4.67 N 8.79 -8.52 Following the same general procedure of Example 65, the following additional compounds were prepared and identified. The compounds, together with the principal starting materials and weights thereof used in the preparations, are listed in the examples set forth hereinafter. Example 66 5-Butyl-3-(4-chlorophenyl)-5-methyl-2-(3pyridyl)-4-thiazolidinone, having a melting point of about 76-770C., from 15 g. of 3-(4-chlorophenyl)-5methyl-2-(3-pyridyl)-4-thiazolidinone, 25 ml. of a hexane solution of n-butyllithium, and 9 g. of n-butyl iodide. Wt. 2 g. Analyses calculated for C19H21C1N2 OS: Theoretical Found C 63.23 63.03 H 5.87 5.66 N 7.76 8.03 Example 67 3-(4-Chlorophenyl)-5-methyi-5-propyl-2 (3-pyridyl)-4-thiazolidinone, having a melting point of about 81-830C., from 15.2 g. of 3-(4-chlorophenyl)-5- methyl-2- (3-pyridyl) -4-thiazolidinone (prepared as in Example 1, supra), 8.5 g. of n-propyl iodide, and 23 ml. of a hexane solution of n-butyllithium. Wt. 1.6 g. Analyses calculated for C18HlgClN2OS: L - Theoretical Found C 62.33 62.55 H 5.52 5.28 N 8.08 8.13 Example 68 3-(4-Chlorophenyl)-5-hexyl-5-methyl-2 (3-pyridyl)-4-thiazolidinone, having a melting point of about 82-830C., from 15.2 g. of 3-(4-chlorophenyi)- 5-methyl-2-(3-pyridyl)-4-thiazolidinone (prepared as Example 1, supra), 10.5 . of n-hexI iodide, and 23ml. of a hexane solution of n-butyllithium. Wt. 1.5 g. Analyses calculated for C21H25ClN2OS: Theoretical Found C 64.85 64 59 H 5.48 6.23 N 7.20 7.19 Example 69 5-Butyl-3-(4-chlorophenyl)-2-(3-pyridyl)-4thiazolidinone, having a melting point of about 93-94 C. from 13 g. of 3-(4-chlorophenyl)-2-(3-pyridyl)-4- thiazolidinone (prepared as in Example 19, supra), 9.2 g. of n-butyl iodide, and 25 ml. of a hexane solution of n-butyllithium. t. 700 mg. Analyses calculated for C18H19 ClN2 OS: Theoretical Found C 62.33 62.11 H 5.52 5.28 N 8.08 8.08 Example 70 3- (4-Chiorophenyl) tetrahydro-2- (3-pyridyl)-4H-l, 3- thiazin-4-one This compound was prepared stepwise as follows. Step 1. A mixture of 53.5 g. of 3-pyridylcarboxaldehyde, 63.5 g. of 4-chloroaniline, and 600 ml. of toluene was refluxed for about 4 hours, using a Dean Stark trap to collect the water given off by the reaction. A total of about 9 ml. of water was collected. The reaction product mixture was cooled, filtered, and the filtrate concentrated to dryness in vacuo. The residue was recrystallized from hot ethyl ether to yield 87 g. of product having a melting point of about 720C., and identified as 3-[(4-chlorophenyl imino ) methyl pyridine Step 2. A mixture was prepared of 15 g. of 3-[(4 chlorophenylimino)methyl]pyridine (prepared above), 15 g. of h-mercaptopropionic acid, and 200 ml. of toluene, and allowed to stand overnight at ambient room temperature. The reaction mixture was concentrated in vacuo to yield a yellow oIl, identified as chloroanilino)-a- (3-pyridyl)methy1thiopropionic acid. A portion of the yellow oil was used in the nest step. Step 3. A mixture of 6 g. of the addition product from step 2, supra, 6 g. of N,N'-dicyclohexylcarbodi imide, and 100 ml. of methylene chloride was prepared at room temperature. On standing for a period of time, hite solids precipitated. The solids were filtered off, and identified as N,N'-dicyclohexylurea. The filtrate was concentrated to dryness in vacuo, and the residue thus obtained was again taken up in methylene chloride, and filtered to remove additional WrN7'- dicyclohexylurea. The filtrate was concentrated to dryness in vacuo. The residue remaining was washed with 20 ml. of cold acetone and the white solids filtered off and air dried. The solids had a melting point of about 149-150 C. and shown to be 3-(4chlorophenyl)tetrahydro-2-(3-pyridyl)-4H-1,3-thiazin4-one. NMR (CDC13/DMSO) (d) EMI54.1 Following the stepwise general procedure of the above Example 70, additional compounds were prepared and identified. In some examples, better yields were obtained in Step 2 by refluxing the reactants and this is so indicated at the end of those examples. The compounds, together with the principal starting materials and weights or volumes thereof used in the preparations, are listed in the examples set forth hereinafter. Example 71 3-(4-Tolyl)tetrahyaro-2-(3-pyridyl)-4H-1,3- thiazin-4-one, having a melting point of about 178-1800C., from 3.21 g. of 3-pyridylcarboxaldehyde, 3.21 g. of - toluidine, 3.18 g. of 5-mercaptopropionic acid, and 6.18 g. of N,N'-dicyclohexylcarbodiimide. Refluxed overnight. Wt. 1.6 g. Analyses calculated for C16Hl6N2OS: Theoretical Found C 67.58 67.36 H 5.67 5.72 N 9.85 9.56 S 11.28 11.08 Example 72 3-Cyclohexyltetrahydro-2-(3-pyridyl)-4H1,3-thiazin-4-one, having a melting point of about 162-1640C., from 3.21 g. of 3-pyridylcarboxaldehyde, 2.97 g. of cyclohexylamine, 3.18 g. of B-mercapto- propionic acid, and 6.18 g. of N,N'-dicyclohexylcarbodiimide. Refluxed 4 hours. Wt. 3.58 g. Analyses calculated for C15H20N2OS: Theoretical Found C 65.18 64.95 H 7.27 6.99 N 10.14 9.92 S .60 11.39 Example 73 3-Hexyltetrahydro-2-(3-pyridyl)-4H-1,3thiazin-4-one, having a melting point of about 84-86 C., from 3.21 g. of 3-pyridylcarboxaldehyde, 3.03 g. of hexylamine, 3.18 g. of ss-mercaptopropionic acid, and 6.18 g. of N,N'-dicyclohexylcarbodiimide. Refluxed overnight. wt. 2.36 g. Analyses calculated for C15H22N2OS: Theoretical Found C 64.71 64.92 H 7.97 8.03 N 10.06 9.77 S 11.52 11.57 Example 74 3-Cyclopentyltetrahydro-2-(3-pyridyl)-4H1,3-triazin-4-one, having a melting point of about 147-1490C., from 3.21 g. of 3-pyridylcarboxaldehyde, 2.55 g. of cyclopentylamine, 3.18 g. of 3-mercapto- propionic acid, and 6.18 g. of N,N'-dlcyclohexylcar- bodiimide. Refluxed overnight. Wt. 1.38 g. Example 75 3-(3,4-Dichlorophenyl)tetrahydro-2-(3 pyridyl)-4H-1,3-thiazin-4-one, having a melting point of about 157-l590C., from 3.21 g. of 3-pyridylcarboxaldehyde, 4.86 g. of 3,4-dichloroaniline, 3.18 g. of D-mercaptopropionic acid, and 6.18 g. of N,N'-dicyclo- hexylcarbodiimide. Refluxed overnight. t. 6.5 g. Example 76 3- (2-Chlorophenyl) tetrahydro-2- (3-pyridyl)4H-1,3-thiazin-4-one, having a melting point of about lll-1130C., from 9.63 g. of 3-pyridylcarboxaldehyde, 11.49 g. of 2-chloroaniline, 9.55 g. of R-mercapto- propionic acid, and 18.57 g. of N,N'-dicyclohexyl- carbodiimide. Refluxed overnight. Wt. 6.0 g. Analyses calculated for C15H13C iN2 OS: Theoretical Found C 59.11 59.31 H 4.30 4.22 N 9.19 9.34 S 10.52 10.73 Example 77 3-(4-Chlorobenzyl)tetrahydro-2-(3-pyridyl)4H-1,3-thiazin-4-one, having a melting point of about 88-900C., from 6.42 g. of 3-pyridylcarboxaldehyde, 8.50 g. 4-chlorobenzylamine, 6.4 g. of h-mercapto- propionic acid, and 12.37 g. of N,N'-dicyclohexylcarbodiimide. Refluxed 6 hours. wt. 3.1 g. Analyses calculated for C16H15ClN2OS: Theoretical Found C 60.28 60.50 H 4.78 4.89 N 8.79 8.66 S 10.06 9.79 Example 78 3-(4-Fluorophenyl)tetrahydro-2-(3-pyridyl)4H-1,3.thiazin-4-one, having a melting point of about 162-1640C., from 6.43 g. of 3-pyridylcarboxaldehyde, 6,67 g. of 4-fluoroaniline, 6.37 g. of ss-mercaptopropionic acid, and 12.4 g. of N,N'-dicyclohexylcar- bodiimide. Refluxed overnight. Wt. 6.6 g. Analyses calculated for C15H13FN2OS: Theoretical Found C 62.48 62.29 H 4.54 4.66 N 9.72 9.91 S 11.12 10.91 Example 79 Tetrahydro-2-(3-pyridyl)-3-[4-(trifluoromethyl)phenyl]-4H-1,3-thiazin-4-one, having a melting point of about 131-133 C., from 6.e3 g. of 3-pyridyl- carboxaldehyde, 9.66 g. of 4-trifluoromethylaniline, 6.37 g. of ss-mercaptopropionic acid, and 12.4 g. of N,N'-dicyclohexylcarbodiimide. Refluxed overnight. Wt. 10.6 g. Analyses calculated for C16H13F3N2OS: Theoretical Found C 56.80 56.62 H 3.87 3.76 N 8.28 8.31 S 9.48 9.40 Example 80 3-(2-Cyclopentyl-1-methylethyl)tetrahydro2-(3-pyridyl)-4H-1,3-thiazin-4-one, having a melting point of about 100-1120C., from 6.43 g. of 3-pyridylcarboxaldehyde, 7.63 g. of 2-cyclopentyl-1-methylethylamine, 6.37 g. of -mercaptopropionic acid, and 12.4 g. of N,N'-dicyclohexylcarbodiimide. Refluxed overnight. Wt. 2.55 g. Analyses calculated for C17H24N2OS: Theoretical Found C 67.07 66.77 H 7.95 8.05 N 9.20 9.26 S 10.53 10.55 Example 81 3- (3, 4-Xylyl) tetrahydro-2- (3-pyridyl) - 4H-1,3-thiazin-4-one, having a melting point of about 185-188 C., from 6.43 g. of 3-pyridylcarboxaldehyde, 7.27 g. of 3,4-dimethylaniline, 6.37 g. of ss-mercapto- propionic acid, and 12.4 g. of N,N'-dicyclohexylcar bodiimide. Refluxed overnight. Wt. 8.75 g. Analyses calculated for C17H18N2OS: Theoretical Found C 68.43 68.66 H 6.08 6.26 N 9.39 9.62 S 10.75 10.56 Example 82 3-(4-Methylthiophenyl)tetrahydro-2-(3pyridyl)-4H-1,3-thiazin-4-one, having a melting point of about 164-1660C., from 6.43 g. of 3-pyridylcar boxaldehyde, 4-methylthioanil-ne (obtained from 10.54 ? of 4-methylthioaniline hydrochloride), 6.37 g. of ss-mercaptopropionic acid, and 8.25 g. of N,N'-dicyclohexylcarbondiimide. Refluxed overnight. Wt. 5.72g. Analyses calculated for C16H16N2OS2: Theoretical Found C 60.,6 60.68 H 5.06 5.18 N 8.86 8.64 S 20.25 20.34 Example 83 3-(2-Fluorophenyl)tetrahydro-2-(3-pyridyl)4-H-1,3-thiazin-4-one, having a melting point of about 147-1490C., from 6.43 g. of 3-pyridylcarboxaldehyde, 6.67 g. of 2-fluoroaniline, 6.37 g. of 5-mercapto- propionic acid, and 12.4 g. of N,N'-dicyclohexylcar- bodiimide. Refluxed overnight. Wt. 6.93 g. NMR (CDCl3, DMSO, (5) 3.0 (s, -CH2CH2-); 6.2 (s, EMI61.1 8.8 (m, EMI61.2 Example 84 3- (2-Methoxyphenyl)-2- (3-pyridyl)-4-thiazclidinone This compound was prepared stepwise. Step 1. A mixture of 17 g. of o-anisidine, 15 g. of 3-pyridylcarboxaldehyde, and 13 g. of thioglycolic acid in toluene was refluxed for several hours. The reaction product mixture was cooled and the material which had precipitated was collected on 2 filter. The product weighed 20 g., had a melting point of about 118-1200C., and was identified by NMR and IR spectra as [[(o-methoxyanilino) (3-pyridyl)methyl]thio]acetic acid. Step 2. A mixture of 5 g. of [[(0-methoxyanilino) (3- pyridyl)methyl]thio]acetic acid, 3.4 g. of N,N'- dicyclohexylcarbodiimide, and 300 ml. of toluene was refluxed for several hours. The toluene was then removed in vacuo. The residue thereby obtained was chromatographed over a silica gel/toluene column and eluted with a mixture of acetone/toluene. The desired fraction was concentrated and the residue recrystallized from a mixture of ether and pentane to yield product having a melting point of about 104-1050C., and identified as 3- (2-methoxyphenyl)-2- (3-pyridyl)4-thiazolidinone. Wt. 1.5 g. Analyses calculated for C15H,4N O2S: Theoretical Found C 61.29 61.47 H 5.14 4.86 N 10.21 9.97 Example 85 3- (4-Chlorophenyl) tetrahydro-5-methyl-2- (3-pyridyl) - 4H-1,3-thiazin-4-one 3- (4-Chlorophenyl) tetrahydro-2- (3-pyridyl)- 4H-1,3-thiazin-4-one, 3.05 g. (0.01 mole), prepared as described in Example 70, supra, was added with mechanical stirring to 40 ml. of anhydrous tetrahydrofuran maintained under a nitrogen atmosphere and then cooled to about -750C. To the cold solution there was added, over a period of about 15-20 minutes, 4.28 ml. of a hexane solution of n-butyllithium (2.4 molar in hexane), while maintaining the reaction temperature below -70 C. After the addition was complete, the reaction mixture was stirred for about 30 minutes at a temperature of about -75 C., followed by the dropwise addition of 5 ml. of methyl iodide over period of about 10-15 minutes. The reaction product mixture was stirred overnight while being cooled in a dry iceacetone bath, warming gradually to about 0 C., by morning. A peach-colored sol,d precipitated during the night. The reaction product mixture was warmed to roor. temperature and methylene chloride added, forming a rec solution. The solution was concentrated in vacuo. The residue thus obtained was redissolved in methylene chloride and the solution was washed twice with cold salt water and dried over anhydrous sodium sulfate. The drying agent was filtered off and the filtrate concentrated in vacuo to leave a residue. The residue was taken up in ethyl acetate and passed through a layer of silica gel (400 ml.). The ethyl acetate solution so treated was concentrated in vacuo, and the oil which remained was dissolved in methylene chloride, treated with decolorizing carbon, filtered, and the filtrate concentrated to dryness in vacuo. The residue thus obtained was dissolved in ethyl ether, and, upon cooling, a solid crystallized, and was filtered off. The solid had a melting point of about 128-130 C., and weighed 1.1 g. The solid was identified by elemental analyses as 3- (4-chlorophenyl) tetrahydro-5-methyl-2- ±3-pyridyl) -4H-l, 3-thiazin-4-one. Analyses calculated for C16H15C1N2 OS: Theoretical Found C 60.28 60.46 H 4.74 4.65 N 8.79 8.77 S 10.06 9.94. Following the general procedure of Example 85r the following additional compound was prepared and icentiried. Example 86 3- (4-Chlorophentl)tetrahydro-5,5-dimethyl- 2- (3-pyridyl)-4H-1,3-thiazin-4-one, having a melting point of about 126-1280C., and weighing 2.60 g., from 4 g. of 3- (4-chlorophenyl)tetrahydro-5-methyl-2- (3-pyridyl)-4H-1,3-thiazin-4-one (from Example 85), 8 ml. of methyl iodide, and 5.4 ml. of a 2.4M hexane solution of n-butyllithium. Analyses calculated for C17H17ClN2OS: Theoretical Found C 61.34 61.15 H 5.15 4.95 N 8.42 8.47 S 9.63 9.53 Example 87 5-Methyl-2- (3-pyridyl)-3- (3-trifluoromethylthiophenyi)- 4-thiazolidinone This compound was prepared step wise. Step 1. A mixture of 15 g. of trifluoromethylthio3-nitrobenzene in 100 ml. of absolute methanol was hydrogenated in the presence of Raney nickel catalyst, using a Parr hydrogenation apparatus. then hydrogen uptake had ceased, the reaction was stopped, the catalyst filtered off, and the filtrate concentrated to yield product weighing 12 g. and identified as trifluoromethylthio-3-aminobenzene. Ste mixture of 11 a. of tritluoromethylthio- 3-aminobenzene, 7.7 g. of 3-pyridylcarboxaldehyde and 200 ml. of toluene was reflexed for about 2 hours using a Dean-Stark trap to collect the water produced by the reaction. A total of 1.2 ml. of water was isolated. The reaction product mixture was cooled and concentrated in vacuo. The residual oil was dissolved in toluene and chromatographed on a silica column. The material was eluted using toluene-5% acetone eluant, the several fractions from the column being checked for their content by thIn layer chromatography. The appropriate fractions were then combined and concentrated to leave a residual oil. The isolated material, 2 yellow oil weighing 15 g., was identified by NMR spectrum as 3-(3-trifluoromethylthio)-N-(3-pyridylmethylene)benzenamine. The material was used without further puriricatnon in the next step of the reaction. Stet 3. A mixture of 14 g. of 3-(3-trifluoromethyl- thio)-N-(3-pyridylmethylene)benzenamine, 8 g. of thiolactic acid, and 200 ml. of toluene was refluxed for about 6 hours, using a Dean-Stark trap to collect the water produced by the reaction. The reaction product mixture was then concentrated in vacuo and the residue thereby obtained was dissolved in toluene and chromatographed on a silica column The product was eluted from Th- he column using 5% acetone-toluene, and the fractions concentrated to leave a yellow oil weighing 6 g. It was identified as 5-methyl-2-(3-pyridyl)-3-(3-tri- fluoromethylthiophenyl)-4-triazolidinone. Example 88 3- (4-Chlorophenyl )-2- (3-pyridyl) -4-thiazolidinone hydrochloride A solution of 1.5 g. of 3-(4-chlorophenyl) 2-(3-pyridyl)-4-thiazoiidinone (Example 19, supra) in ethyl ether was prepared, cooled, and saturated with anhydrous hydrogen chloride. The solid material which precipitated was filtered off and identified as 3 (4-chlorophenyl)-2- (3-pyridyl)-4-thiazolidinone hydrochloride. Example 89A 3- (4-Chlorophenyl) -5- (methylthio)-2- (3-pyridyl) -4thiazolidinone and Example 89B 3- (4-Chlorophenyl)-5,5-bis knethylthio)-2-(3-pyridyl)- 4- thiazolidinone A mixture of 10.1 g. of diisopropylamine and 500 ml. of tetrahydrofuran was cooled to a temperature of about OOC. under a nitrogen atmosphere. There was added to the mixture 45 ml. of a hexane solution of n-butyllithium dropwise, with stirring, and the stirring was continued for about 30minutes after addition was complete. The mixture was then cooled to about -700C., and a solution of 14.5 g. of 3-(4-chlorophenyl)-2 (3-pyridyl)-4-thiazolidinone (Example 19, supra) in 100 ml. of tetrahydrofuran was added dropwise. Thirty minutes after this addition was completed, 9.4 g. of methyldisulfide was added. The reaction mixture was stirred overnight and allowed to gradually war to ambient room temperature. The reaction mixture was worked up by adding water dropwise, at about room temperature. The organic phase was ten extracted with methylene chloride. The methylene chloride layer was washed with dilute aqueous hydrochloric acid. The methylene chloride layer was separated and dried over anhydrous sodium sulfate. The drying agent was filtered off and the filtrate concentrated in vacuo to leave a residual oil. The oil was dissolved in toluene and chromatographed over silica gel. Eiution was accomplished with toluene: 10% acetone, and a separation was effected so that there was obtained, after con centrating the fractions, a product having a melting point of about 104-106 C., and weighing 1 g., identified as 3- (4-chlorophenyl)-5- (methylthio)-2- (3- pyridyl) -4-thiazolidinone. Analyses calculated for C15H13C1N20S 2: Theoretical Found C 53.48 53.40 H 3.89 3.91 N 8.32 8.20 A second product having a melting point of about 133-1350C., and weighing 400 mg. was isolated in the same manner and identified as 3-(4-chlorophenyl)- 5,5-bis(methylthio)-2-(3-pyridyl)-4-thiazolidinone. Analyses calculated for C16Hl5ClN20S3: Theoretical Found C 50.18 50.09 H 3.95 3.91 N 7.32 7.08 Example 5G 3-(4-Chlorphenyl)tetrahydro-2-(3-pyridyl)-4H-1,3 thiazine-4-thione A suspension was prepared of 10 g. (0.033 moles) of 3- (4-chiorophenyl) tetrahydro-2- (3-pyridyl)4H-1,3-thiazin-4-one (prepared in Example 70, supra) in 30 ml. of dry pyridine, and with mechanical stirring the mixture was heated to about 900C., forming a solution. To the solution thus formed, and with continued stirring, there was added 1.78 g. (0.008 moles) of phosphorous pentasulfide portionwise over a period of about 10-15 minutes. The solution turned orange in color. After the addition was completed, the reaction mixture was stirred overnight at a temperature of about 900C. The then red-colored solution was cooled and the pyridine solvent evaporated in vacuo. The viscous oily residue was washed by triturating it with water. The oil was then taken up in a mixture of dimethylformamide and ethanol, decolorized with carbon, filtered, and the ethanol evaporated in vacuo. The dimethylformamide solution was poured slowly into cold water, whereby a crude orange solid precipitated. The solid was extracted from the aqueous mixture with ethyl acetate. The extract was washed with cold aqueous sodium chloride solution and the ethyl acetate solution concentrated in vacuo to yield a dark red oil. The oil was taken up in a minimum volume of ethyl acetate and chromatographed over a silica gel column. There was obtained a red viscous oil which was crystallized from. a mixture of ethyl acetate and ether to yield a yellow solid, having a melting point of about 115-1170C., and weighing 3.91 g. The product was identified by elemental analyses as 3-(4-chlorophenyl)tetrahydro-2-(3-pyridyl) 4H-1,3-thiazine-4-thior.e. Analyses calculated for C15Hl3ClIi252: Theoretical Found C 56.15 56.10 H 4.08 4.22 N 8.73 8.58 S 19.99 19.94 Aquatic growth regulation is practiced by adding the active substituted l-thia-3-aza-4-one compounds of formula (VI) to the water containing the submerged or floating aquatic weeds. The compounds may be applied to the water as dusts when admixed with a powdered solid carrier such as bentonite, Fuller's earth, diatomaceous earth, or various mineral silicates, e.., mica, talc, pyrophyllite, and clays. The compounds may also be mixed with surface-active dispersing agents to form concentrates to facilitate dispersion in water and to improve the wetting properties when used as sprays. If desired the compounds maybe mixed with a powdered solid carrier, together with a surfaceactive dispersing agent, so that a wettable powder may be obtained which may be applied directly, or which may be shaken with water to make an aqueous dispersion for application in that form. The compounds may be dissolved in an oil, such as a hydrocarbon or chlorinated hydrocarbon oil, and the oil solution of the compound aispersed in water with the aid of a surface-active dispersing agent to give a sprayable aqueous dispersion. Such surface-active dispersing agents may be anionic, nonionic, or cationic surface-active agents. Such surface-active agents are well known, and reference is made to Hoffman et al., U.S. Patent No. 2,614,916, columns 2-4, for detailed examples of the same. The compounds of formula (VI) may also be applied by the aerosol method. Solutions for the aerosol treatment may be prepared by dissolving the compound directly in the aerosol carrier, which is a liquid under pressure, but which is a gas at ordinary temperature (e.g. 200C.) and atmospheric pressure; or, the aerosol solution may be prepared by first dissolving the compound in a less volatile solvent, and then admixing such solution with the highly volatile liquid aerosol carrier. To the water containing the submerged and floating weeds a growth-regulating and non-herbicidal amount of one of the compounds of formula (VI) is added, such that a concentration of from about 0.25 to about 10 ppm. of the active compound is attained. The optimum concentration of active compound for any specific aquatic weed control problem varies with the temperature, the species to be controlled, and the shape of the body of water to be treated. At higher water temperatures, less compound is generally required for a given degree of control than is needed at lower temperatures. In considering the treatment of moving streams for the purpose of controlling flora fixed therein, special account must be taken of the fact that the compounds will pass over the area to be treated and that the concentration during the contact period is dependent upon the water flow rate, the rate of chemical addition, and the period of addition. The novel aquatic growth regulating method and compositions for use therein are illustrated by the hollowing experiments. Trial 1 The following method was used in the laboratory to evaluate the aquatic growth regulating properties of the compounds disclosed herein, when used at a concentration of 10 ppm., against a representative submerged aquatic weed. The compounds of formula (VI) used for this test were formulated in the following manner. Twenty mg. of compound was weighed into a 12 ml. disposable vial. To the vial containing the compound were added 1 ml. of acetone and 9 ml. of aqueous 0.1 percent polyoxyethylene sorbitan monooleate (Tween 80). To obtain the test concentration of 10 ppm., 4.00 ml. of this stock solution was added to 785 ml. of water in a plastic container. The plastic containers used were flowerpot-shaped, having a bottom diameter of 9 cm., a top diameter of oil.5 cm., and a height of 13.5 em Terminal pieces of Florida elodea, Hydrilla verticillata (L.F.), (hereinafter identified as hydrilla) 10 cm. long, without branching, were prepared for testing. Three such cuttings were placed in each plastic container holding 785 ml. of water, to which water the formulated test compound had been added, along with 3 ml. of Hoagland's nutrient solution. Three 10 cm. cuttings of hydrilla were placed in each of several control containers of water. To the water in each control container there was also added the amount of solvent used to formulate the test compound for each container. After a period of two to three weeks, measurments were made to determine the total length of each plant. An average total growth was obtained by dividing the total combined lengths by the number of replicates. By subtracting 10 cm. from the average total length, the average increase in growth was obtained. This difference was divided by the average increase in length of the plants in the solvent controls (SC) and the quotient multiplied by 100 to give a percent inhibition. Total combined length of Replicates = Average Length Number of Replicates Avg. Length - 10 cm. = Avg. Increased Growth (1-Avg. Increased Growth)X 100= % Inhibition ( Avg. Increased Growth SC) Each compound employed in this-experiment is identified by the number of the previous preparative example. The results of the tests, run at a concentration of 10 ppm. of compound, and observed at the end of three weeks, are set forth in Table 1, which follows. In the table, the number in column 1 identifies the test compound; column 2 lists the percent growth inhibition of hydrilla observed. Table 1 Substituted l-Thia-3-aza-4-one Derivatives Approximate % Growth Compound Inhibition 1 91 2 78 3 82 4 93 5 97 6 76 7 61 8 71 9 99 10 73 11 82 12 75 13 64 14 66 15 74 16 57 17 72 18 84 19 89 20 58 21 88 23 93 24 91 25 85 26 69 Table 1, Cont'd. Substituted 1-Thia-3-aza-4-one-Derivatives Approximate % Growth Compound Inhibition 27 88 28 100 29 90 30 93 31 97 32 81 33 95 34 93 35 55 36 77 38 49 39 96 40 91 41 86 42 77 43 80 44 79 45 61 47 53 48 95 49 94 50 81 51 86 52 78 53 60 55 64 56 87 Table 1, Cont'd. Substituted l-Thia-3-aza-4-one Derivatives Approximate % Growth Compound Inhibition 57 93 58 95 59 97 60 96 61 87 62 91 63 71 64A 70 64B 77 64E 84 65 96 66 99 67 98 68 95 69 95 70 97 71 95 72 86 73 88 74 74 75 96 76 94 77 91 78 79 86 80 97 81 91 82 92 83 94 Table 1, Cont'd. Substituted l-TAia-3-aza-4-one Derivatives Approximate f Growth Compound Inhibition 84 69 85 93 87 94 89A 89 89B 62 90 94 Trial 2 The general procedure of Trial 1, again employing Hydrilla verticillata (L.F.), was repeated using a number of the same formula (VI) compounds. This time test concentrations of 1, 0.5 and 0.25 ppm. were employed. The test compounds were formulated in the following manner: Twenty mg. of compound was weighed into a 12 ml. disposable vial. To the vial containing the compound were added 1 ml. of acetone and 9 ml. aqueous 0.1 percent polyoxyethylene sorbitan monooleate. This solution was designated as stock solution A. The 1 ppm. test concentration was obtained as follows: Four ml. of stock solution A was diluted with 36 ml. of aqueous 0.1 percent polyoxyethylene sorbitan monooleate to give stock solution B. Four ml. o; stock solution B, when added to 785 ml. water in the plastic test containers, gave a concentration of test compound of 1 ppm. The plastic test containers were identical to those employed to Trial 1. The 0.5 ppm. concentration of test compound was obtained as follows: Stock solution B, 20 ml., was diluted with 20 ml. aqueous 0.1 percent polyoxyethylene sorbitan monooleate, and this solution was designated stock solution C. Four ml. of stock solution C was added to 785 ml. of water in the plastic test containers to give a concentration of 0.5 ppm. The 0.25 ppm concentration of test compound was obtained as follows: Stock solution C, 20 ml., was diluted with 20 ml. aqueous 0.1 percent polyoxyethylene sorbitan monooleate to give stock solution D. This stock solution D, 4 ml., added to 785 ml. of water in the plastic test containers gave a concentration of test compound of 0.25 ppm. Three weeks after the date of application of the test compounds, measurements were made on the total growth of each plant, as described in Trial 1, and the percent inhibition observed was calculated using the formulas set forth in Trial 1, above. The results are recorded in Table 2, which follows. The test compounds are each identified by the prior preparative examples. Table 2 Substituted l-Thia-3-aza-4-one Derivatives Approximate t Growth Inhibition at Indicated Test Concentrations Compound 1 ppm. 0.5 ppm. 0.25 ppm. 1 63 74 73 2 64 67 65 3 72 55 56 5 83 75 54 6 50 29 37 9 71 40 34 18 71 69 73 19 72 57 32 21 67 62 61 23 63 48 45 24 61 58 62 29 67 45 50 31 66 60 52 33 52 12 32 35 73 68 64 36 63 63 62 64A 33 21 8 64B 59 16 17 64E 46 36 33 67 61 51 57 68 64 39 65 50 63 55 40 Another embodiment of this invention is practiced by applying to the loci of plant pathogenic fungi, fungicidally-effective amounts of one or more of the compounds of generic formulae IV or V. The compounds are applied in effective amounts, varying somewhat with the severity of the fungus infection and with other factors such as the environment in which the treatment is conducted. The compositions desirably contain, in addition to the substituted l-thia-3-aza-4-one antifungal, one or more of a plurality of additaments including water, polyhydroxy compounds, petroleum distillates, and other dispersion media, surfaceactive dispersing agents, emulsifiers, and finelydivided inert solids. The concentration of the substituted l-thia-3-aza-4-one anti-fungal in these compositions may vary depending on whether the composition is intended for a direct application to plants or is intended to be subsequently diluted with additional inert carrier such as water to produce the ultimate treating composition. Treating compositions are most conveniently formulated by preparing liquid or solid concentrates, which are subsequently diluted to the desired level for use Emulsifiable liquid concentrates can be prepared by incorporating from about 1 to about 10 percent by weight of the active ingredient and an emulsifiable agent in a suitable water-immiscible organic liquid. Such concentrates may be further diluted with water to form spray mixtures in the form of oil-in-water emulsions. Such spray compositions then comprise active toxicant, water-immiscible solvent, emulsifying agent, and water. Suitable emulsifying agents can be of the nonionic or ionic types, or blends thereof, and include conden station products of alkylene oxides with phenols and organic acids, polyoxyethylene derivatives of sorbitan festers, complex ether alcohols, ionics of the arylalkyl sulfonate type, and the like. Suitable water-immiscible organic liquids to be employed include aromatic hydrocarbons, aliphatic hydrocarbons, cycloaliphatic hydrocarbons, and mixtures thereof such as petroleum distillates. Solid concentrate mixtures can be prepared by incorporating from about 10 to about 50% by weight of the substituted 1-thia-3-aza-4-one compound in a finely-divided solid carrier such as bentonite, Fuller's earth, diatomaceous earth, hydrated silica, diatomaceous silica, expanded mica, talc, chalk, and the like. Such concentrates can be formulated, if desired, for direct use as dusting compositions, or can be diluted, if desired, with additional inert solid carriers to produce dusting powders containing around 0.05 to 1% by weight of the substituted l-thia-3-aza-4-one. Alter natively, the surfactants, that is, dispersing and/or vetting agents, can be incorporated along with the substituted l-thia-3-aza-4-one in the solid carrier to form wettable powder concentrates ranging from about 10 to about 25% by weight concentration, which subse quently can be dispersed in water or other hydroxylated carrier to form spray compositions. Suitable surfactants include condensed aryl sulfonic acids and sodium salts thereof, sodium lignosulfate, sulfonate-oxide condensate blends, alkylaryl polyether alcohols, sulfonate/nonionic blends, anionic wetting agents, and the like. Further, the substituted l-thia-3-aza-4-one toxicant can be incorporated in solutions, simple dispersions, aerosol formulations, and other media acceptable to be employed for treating vegetation or applying to the soil. The antifungal composition is applied to infected or susceptible plant surfaces in any convenient fashion such as by spraying, dusting, dipping, or drenching. A spray method is considered preferable, especially when large numbers of plants are involved, because of the rapidity and uniformity of treatment possible. In spraying it is usually sufficient for the infected or susceptible surfaces to be thoroughly wet with the liquid dispersion employed. Good results have been obtained by employing spray compositions whether they be emulsions or aqueous dispersions of solid concentrates. Where the fungi to be controlled are in the soil, the antifungal compounds can be applied to the soil directly, or they can be diluted with various inert solid or liquid diluents, as described above, and then applied to the fungus-infested area. In one method of application to the soil, the soil surface is sprayed with a liquid dispersion or emulsion of the active ingredient. The application is allowed to remain as a coating on the surface of the soil, or alternatively, incorporated into the soil by risking, hoeing, or other methods well known to those skilled in the art. Another method of application is to apply the active ingredient, in the form of a liquid dispersion or emulsion, to the soil as a drench. Thus, for the ccntrol- of soil-inhabiting fungi in the greennouse, the application rate varies from about 5 to about 200 ppm. active ingredient. When an acid addition salt of a l-thia-3-aza-4-one base is used, the rate of application will, of course, depend on the amount of base actually present. The salts themselves are employed chiefly for ease of handling and formulating. The fungicidally-actlve compounds of formulae (IV) and (V) have also been found effective when utilized as a seed soak for seeds prior to planting. Thus, where a fungicidal compound is applied as a seed soak, a seed soak formulation is prepared containing the fungicidal compound, together with other excipients such as a mixture of ethanol-acetone, polyoxyethylene sorbitan monooleate, and the like. When a compound of formula (IV) or (V) is utilized as a seed soak, satisfactory control has been accomplished at an application rate ot rom about 50 to about 400 ppm. of the fungicidal substituted l-thia-3-aza-4-one compound. The seeds are allowed to soak in the formulation for a period of up to about hours. The seeds are then removed and planted. The use cf the compounds of formula XS) or (V1, and acid addition salts thereof, as plant fungicidal agents, is illustrated by the following procedure. Trial 3 The evaluation of the effectiveness as a scil drench of some of the compounds of formula (IV) or (V) against Erysiphe cichoracearum, the causative organism of cucumber powdery mildew, was accomplished in the greenhouse in the following manner. Fungicidal compositions were prepared by dissolving the compound of formula (IV) or (V) in a 1:1 mixture of ethanol:acetone containing polyoxyethylene sorbitan monolaurate (Tween 20) and diluting with deionized water to a final concentration of 1% solvent and 0.1% surfactant. The most concentrated fungicidal composition was prepared first, that is, the one containing the highest concentration of active ingredient. The other fungicidal compositions containing lower concentrations of the active ingredient were then prepared by serial dilution technique from the highest concentration composition. A solvent-surfactant blank was used as a control. Five cucumber seeds (Cucumis sativus L., variety "Green Prolific") were planted in 4-inch square plastic pots containing soil and covered with sand. After the seeds had sprouted, the plants were thinned to 2 per pot. On day 15 after the seed was planted, 1 pot for each concentration of each test compound was soil drenched with 50 ml. of the formulated test compound. The pots containing the plants were then placed in the greenhouse and the leaves of the plants were inoculated by dusting them with conidia from infested cucumber plants. On day 23 after planting, the plants were observed to determine the incidence of cucumber powdery mildew on the cucumber plants. The results of the tests are recorded in Table 3, which follows. In the table, 0 percent = no powdery mildew incidence (infection). The compound column refers to the prior preparative example. Table 3 Appln. Rate Percent Incidence Powdery Compound ppm Mildew Infection on Cucumber 1 1 40 5 5 20 0 25 0 100 0 2 5 0 20 0 100 0 3 1 40 5 0 10 0 20 0 7 5 70 20 20 100 0 8 5 70 20 55 100 0 10 5 15 20 15 100 0 200 0 11 10 60 20 50 40 0 80 0 Table 3, Cont'd Appln. Rate Percent Incidence Powdery Compound ppm Mildew Infection on Cucumber 12 5 0 20 0 100 0 200 0 14 5 60 20 25 100 0 200 0 18 5 15 20 0 100 0 200 0 19 1 65 5 0-50 10 0-5 20 0 25 0 40 0 80 0 100 0 23 20 10 100 0 24 1 5 5 0 10 0 Table 3, Cont'd Appln. Rate Percent Incidence Powdery Compound ppm Mildew Infection on Cucumber 25 20 60 100 0 26 20 65 100 0 27 20 50 100 0 37 5 80 20 70 100 0 200 0 54 5 80 20 20 100 0 200 0 88 5 45 20 0 100 0 89A 20 0 200 0 Control 0 70-95 Trial 4 A test to establish the efficacy cf selected compounds of formula (IV) or (V) as fungicides in the control of Erysiphe graminis tritici, the causative organism of powdery mildew of wheat, was carried out in the greenhouse in the following manner. Fungicidal compositions were prepared in the same manner as described in Experiment 3. Thirty to forty wheat seeds (variety Monon) were planted in 4-inch square plastic pots containing soil and covered with sand. After about 6 to 8 days, when the seedlings are 4-6 inches tall, 1 pot was soil drenched with a volume of the formulated test chemical. The plants were then placed in the greenhouse and the leaves were inoculated by dusting them with conidia from infested wheat plants. About 14 to 16 days after planting the plants were observed to determine the percent incidence of the wheat powdery mildew on the wheat plants, The results are recorded in Table 4, which follows. In the table, 0 percent = no powdery mildew incidence (infection). The compound column refers to the prior preparative examples. Table 4 Appln. Rate Percent Incidence Powdery Compound ppm ¯ Mildew on Wheat 1 60 5 20 20 0 25 0 100 0 10 5 60 20 25 100 0 200 0 11 5 60 20 45 100 0 12 5 40 20 0 100 0 200 0 17 5 60 20 55 100 5 200 0 18 5 70 20 65 100 5 200 5 Table 4, Cont'd Appln. Rate Percent Incidence Powdery Compound ppm Mildew on Wheat 19 1 60 5 25 10 0 20 0 25 0 40 0 37 5 70 20 70 100 10 200 5 64B 400 0 64C 400 0 100 0 25 25 Control 0 60-80 Trial 5 The evaluation of the effectiveness of some of the compounds of formula (IV) or (V) against Erysiphe graminis hordei, the causative organism of powdery mildew of barley, was accomplished in the greenhouse in the same manner as that described in Experiment 4. The results are recorded in Table 5, which follows. The compound column refers to the prior preparative example. Table 5 Appln. Rate Percent Incidence Powder Compound ppm Mildew on Barley 2 .5- 0 20 0 40 0 80 0 100 0 3 20 0 40 0 80 0 19 5 60 20 20 100 0 24 2.0 0 40 0 80 0 88 0.295 60 1.18 15 5.90 0 Control 0 60-75 Trial 6 The further evaluation of the effectiveness of some of the compounds of formula (IV) or (V) against the powdery mildew disease of barley was carried out in the greenhouse in the following manner. Fungicidal compositions were prepared by dissolving the compound to be tested in 2% ethanol:acetone (1:1) plus 0.1 polyoxyethylene sorbitan monolaurate in deionized water. Each test compound was prepared in concentrations of 200, 400 and 800 ppm. Five milliliters of each concentration was sprayed onto 3 cups of soil in a tumbler to thoroughly incorporate the compound. This resulted in rates of 1,2 and 4 mg./3 cups of soil, respectively. In plastic pots measuring 20.32 cm. in diameter and 25.4 cm. in depth, there was placed 5 cups of untreated greenhouse soil. The 3 cups of treated soil was used to fill the top 6 c. of each pot. twenty seeds of Larker variety barley were planted in the treated soil at a depth of 1 cm. The pots were top watered as needed. When the plants were 6 days old, all the plants were inoculated with powdery mildew conidia from infected plants. Beginning 12 days after planting (DAP), the plants were observed for the incidence of powdery mildew. The observed results were recorded and are shown in Table 6, which follows. In the table, 0% = no powdery mildew incidence and thus 100% control. The compound colurrm refers to the prior preparative examples. Table 6 Appln. Powdery Mildew Incidence rate On Barley at DAP Compound kg. /ha 12 15 19 25 2 0.28 0 0 2 10 0.56 0 0 0 2 1.12 0 0 0 2 3 0.28 50 60 70 75 0.56 5 10 20 30 1.12 0 2 10 20 12 0.28 60 75 80 85 0.56 2 g 5 15 20 1.12 0 0 2 10 19 0.28 2 5 20 30 0.56 0 0 5 15 1.12 0 0 2 10 24 0.28 55 60 70 80 0.56 25 30 35 45 1.12 5 10 20 30 Control 0 60 75 80 90 Trial 7 This test was run to further evaluate the efficacy of one of the compounds of formula (IV) as a fungicide in the control of the causative organisms of wheat and barley powdery mildew. Five hundred milligrams of the test compound was dissolved in 10 ml. of acetone and sprayed on 50 g. of tumbling Florex 30/60 granules and allowed to air dry. The granules as sprayed thereby contained 1.0% active ingredient. Three replicate weighings each of 0, 400 and 200 mg. of the 1% granules, containing 8, and 2 mg. of the test compound, respectively, were de. Three weighings of untreated granules were also aae. The granules were added to 3 cups of tumbling *,oíl per treatment and mixed thoroughly. The 3 cups of soil containing the granules were placed on top of untreated soil in pots as in Experiment 6 above. Twenty seeds per pot of either Larker barley, Proctor barley or Logan wheat were planted in the treated soil at a depth of 1 cm. The pots were top watered as needed. Six days after planting, the plaits were inoculated with the respective powdery mildew conidia from already infected wheat and barley plants. Beginning 12 days after planting (DAP), observations were made to determine the incidence of powdery mildew. The results are recorded in Table 7. The compound column refers to the prior preparative example. Table 7 Powdery Mildew Incidence at DAP on: Appln.* Logan wheat Compound rate 12 15 19 23 19 200 5 10 20 30 400 2 5 10 20 800 0 0 1 2 Control 0 50 55 60 65 Larker barley 12 15 19 23 19 200 0 2 10 20 400 0 0 5 15 800 0 0 1 5 Control 0 55 60 65 65 Proctor barley 12 15 19 23 19 200 2 5 15 30 400 0 0 5 20 800 0 0 2 15 Control 0 55 60 65 65 *Mg. of 1% granules per pot. Trial 8 The efficacy of the compounds of formula ( or (V) against the causative organisms of four fungal diseases of wheat was determined in the greenhouse by foliar and soil drench application of the test compounds according to the following procedure. Wheat, variety Monon, was planted in round plastic pots measuring 6.25 om. in diameter, containing soil covered with sand. Two pots per disease, together with 4 check pots per disease were prepared, for a total of 24 pots. When the seedlings were about 4-5 inches tall, that is, at about 5-7 days after planting the seeds, depending on the time of year the test was run, the plants in each of two test pots were sprayed with a single formulated test compound (application rate of 400 ppm. a.i.), while the soil in each of two other test pots was drenched with 10 ml. per pot of the same formulated test compound (application rate 12.32 kg./ha.). This procedure was carried out for each formulated test compound, employing two pots each test compound for the spray application and two pots each for the soil drench application for each disease. As checks In each disease test, the plants in two check pots were sprayed with the water-diluted solventemulsifier solution, and the soil in two more check pots was drenched with the water-diluted solventemulsifier solution, for a total of four check pots for each disease. Within 24 hours after application of the formulated test compounds and the solvent-surfactant solution as described above, all the pots were placed in the greenhouse and inoculated respectively with the conidia of the test organisms. The plants were then observed at 4-8 days after transfer to the greenhouse for symptoms of the diseases and the disease ratings recorded. The disease ratings are as follows: 1 -- Severe 2 -- Moderately Severe 3 -- Moderate 4 -- Slight 5 -- No Disease (100% control) The test organisms were the following: Helminthosporium Leaf Spot (H) (Helminthosporium sativum) Leaf Rust (LR) (Puccinia recondita trilici) Powdery mildew (PM) (Erysiphe graminis tritici) Septoria Leaf Blotch (S) (Septoria tritici) The results are set forth in Table 8, which follows, the compounds being identified by the numbers of their preparative examples. Table 8 Disease Control Ratings Appln. Foliar Application Appln. Soil Drench Rate Rate Compound ppm. PM LR H S kg./ha. PM LR H S 22 400 4 -- -- -- -- -- -- -- -29 400 5 1 3 5 12.32 5 3 3 4 30 400 1 1 4 5 12.32 4 1 1 5 31 400 4 1 1 4 12.32 4 1 1 4 32 400 5 1 5 5 12.32 5 5 5 5 35 400 5 1 5 5 12.32 4 5 1 5 36 400 4 1 4 1 12.32 5 4 1 5 50 400 5 1 4 4 12.32 5 5 5 4 57 400 4 1 4 5 12.32 5 4 4 4 64C 400 5 5 4 5 -- -- -- -- -64C 100 3 -- 3 3 -- -- -- -- -65 400 5 1 5 1 12.32 5 4 1 4 66 400 5 1 1 5 12.32 1 1 1 1 Table 8 (cont'd) Disease Control Ratings Appln. Foliar Application Appln. Soil Drench Rate Rate Compound ppm. PM LR H S kg./ha. PM LR H S 69 400 4 3 4 4 12.32 4 1 1 1 76 400 3 1 5 4 12.32 5 3 1 5 79 400 4 1 3 4 12.32 5 3 1 5 79 400 5 1 1 1 12.32 5 1 1 4 86 400 4 4 5 4 12.32 5 5 1 4 89A 400 4 1 3 1 -- -- -- -- -89B 400 4 1 1 1 -- -- -- -- -90 400 5 1 4 4 12.32 5 1 1 1 Control 0 1 1 1 1 0.0 1 1 1 1 Trial 9 Following the same general testing procedure as described in Trial 8, additional testing of the efficacy of the compounds of Trial 8 was accomplished at the same application rates, as well as at lower application rates. The results are recorded In Table 9. Table 9 Disease Control Ratings Appln. Foliar Application Appln. Soil Drench Rate Rate Compound ppm. PM LR H S kg./ha. PM LR H S 29 400 5 -- 4 4 - 100 5 -- 1 1 - 25 4 -- 1 1 - Not Tested 30 400 -- -- 4 5 - 100 -- -- 1 3 - 25 -- -- 1 1 - 31 400 5 -- -- 4 12.32 5 -- -- 5 100 4 -- -- 2.5 3.36 2.5 -- -- 3 25 2.5 -- -- 1 0.78 1 -- -- 1 32 400 5 -- 4 5 12.32 5 5 3 5 100 4 -- 3.5 3 3.36 5 5 1 4.5 25 4 -- 2 2.5 0.78 4 1 1 2.5 Table 9 Disease Control Ratings Appln. Foliar Application Appln. Soil Drench Rate Rate Compound ppm. PM LR H S kg./ha. PM LR H S 35 400 5 1 3 5 12.23 5 4 -- 4 100 4.5 1 1 4 3.36 5 1 -- 4 25 3.5 1 1 2.5 0.78 4.5 1 -- 1 36 400 4 -- 5 -- 12.32 5 4 -- 5 100 4.5 -- 4.5 -- 3.36 5 3 -- 5 25 3.5 -- 3 -- 0.78 5 1 -- 1 50 400 5 -- 5 4 12.32 5 -- 3 5 100 5 -- 4 4 3.36 5 -- 1 4 25 4.5 -- 3 1 0.78 5 -- 1 1 6 3 -- 1 -- 0.22 5 -- -- - 57 400 4 -- 5 5 12.32 5 -- 4 4 100 4 -- 4 4 3.36 5 -- 1 1 25 3.5 -- 1 4 0.78 3.5 -- 1 1 6 3 -- 1 3 0.22 1 -- 0 0 Table 9 (Cont'd) Disease Control Ratings Appln. Foliar Application Appln. Soil Drench Rate Rate Compound ppm. PM LR H S kg./ha. PM LR H S 69 400 1 3 5 5 12.32 4 1 -- - 100 1 1 4 4 3.36 4 1 -- - 25 1 1 1 1 0.78 1 1 -- - Control 0 1 1 1 1 0.0 1 1 -- -- Trial iO The terrestrial plant growth regulator activity of the compounds of formula (VI) was determined in the greenhouse according to the following procedure. The plants used in this study were soybean, variety Chippewa; barley, variety Larker; ryegrass, variety Manhattan; and cucumber, variety Green Prolific. All plants- were grown in soil in 10 cm. plastic pots. The soil in one-half of the number of pots was covered with vermiculite after the sees were sown, and those pots used for a Coliar spray application of the test compounds. The soil in the other half of the number of pots was covered with soil after the seeds were planted, and those pots used for a soil drench application of the test compounds. The seedling plants were fertilized bi-weekly until termination of the test with a solution containing 6.7 g. cf Rapid-Gro (a commercially-available fertilizer) per gallon. After the plants became established, and before the treatment date, the plants in each pot were thinned to the desired number of plants per pot. Thus, there were two soybean plants per pot, five barley plants per pot, an estimated 100 ryegrass plants per pot, and one cucumber plant per pot. The ryegrass was clipped to a height of 2.5 cm. on the day before treatment. The plants in one-half the number of ots were treated with a soil drench at the rate of 5.6 kg./ha. of test compound. The plants in the other one-half the number of pots were treated with a foliar spray at an application rate of 2000 ppm. The fcliar spray applications were made with a DeVilbiss atomizer at 10-12 psi., the foliage of all the plants being sprayed to wetness. The test compounds were formulated in the following manner. A solution was prepared of 50 mg. of the test compound in 3 ml. of a mixture of ethanol and acetone (1:1 by volume), and diluted to a total volume of 25 ml. with Toximul R and S water (300 ppm Toximul R and 400 ppm Toximul S in deionized water). [Toximul R and Toximul S are general purpose matched pair emulsifiers and are a liquid sulfonate/nonionic blend produced by Stepan Chemical Company, orthfield, Illinois, U.S.A.] Fourteen ml. of the solution was used for the foliar application. For the soil drench, 11 ml. was diluted to 100 ml., with a 20 ml. aliquot then being poured into each pot. The age of the plants at time of treatment varied as follows: Soybean - 16 days Barley - 7 days Ryegrass - 10 days Cucumber - 17 days After treatment, the soybean and ryegrass were maintained in the greenhouse for 15 days, at the end of which time visual evaluations were made of growth regulator effects and injury. The barley and cucumber plants were maintained in the greenhouse for 20 days, at the end of which time the visual evaluations of growth regulator effects and injury were made. A scale of 0, 1, 2, and 3 was used. Zero is no effect and 3 is distinct or severe effect. A "+" is used for growth promotion, while a "-" indicates inhibition or depression. The results are set forth in Table 10. The compound column refers to the prior preparative examples. Table 10 Plant Growth Regulator Effects Soybean Cucumber Appln. Treat Compound Rate ment H BR IÚ# H F IÚ# 1 2000 ppm. Foliar 0 0 0 0 0 0 5.6 kg./ha. Drench 0 0 0 0 0 0 29 2000 ppm. Foliar -1 0 1Mê# 0 0 0 5.6 kg./ha. Drench 0 0 0 0 0 0 35 2000 ppm Foliar -1 0 2M -1 0 0 5.6 kg./ha. Drench -2 0 0 0 0 0 Control 0 Foliar 0 0 0 0 0 0 Drench 0 0 0 0 0 0 Ú#H = height; BR = branching; I = injury; F = flowering; T = tillering; M = morphological effects; B = burn; C = chlorosis Table 10 (cont) Plant Growth Regulator Effects Barley Ryegrass Appln. Treat Compound Rate ment H T F IÚ# H T IÚ# 1 2000 ppm. Foliar 0 0 0 0 0 0 0 5.6 kg./ha. Drench -3 0 -3 2CB -1 0 0 29 2000 ppm. Foliar 0 0 0 0 0 0 0 5.6 kg./ha. Drench -3 0 -3 2C -1 0 1B 35 2000 ppm Foliar -1 0 0 0 0 0 0 5.6 kg./ha. Drench -3 0 -3 2BC -1 0 1B Control 0 Foliar 0 0 0 0 0 0 0 Drench 0 0 0 0 0 0 0 Ú#H = height; BR = branching; I = injury; F = flowering; T = tillering; M = morphological effects; B = burn; C = chlorosis The results obtained in the experiments described and reported above show the novel substituted l-thia-3-aza-4-one derivatives of formula (I) disclosed herein are effective in the disclosed and claimed methods of regulating the growth of submerged and floating aquatic plants, of protecting plants from phytopathogenic fungi, and of regulating the growth of terrestrial plants such as wheat and barley.

Claims: CLAIMS 1. A compound of the formula EMI111.1 wherein R is C3-C10 alkyl, C3-C8 cycloalkyl, methallyl, phenyl halophenyl, trifluoromethylphenyl, benzyl, methoxybenzyl, methylbenzyl, halobenzyl, dimethyl- aminoethyl, methylcyclohexyl, C3-C8 cycloalkyl(Cl-C3)- alkyl, &alpha;-methylbenzyl, 2-thiazolyl, nitrophenyl, phenoxyphenyl, (tetrahydro-2-furanyl)methyl, haloanilyl, trifluormethylthiophenyl, methylthiophenyl, 2-norbornyl, furfuryl, 2-(1-methoxypropyl), methoxyphenyl, fluoro (C1-C2) alkoxyphenyl, 3,4-(methylenedioxy) phenyl, xylyl biphenylyl, tolyl, or halo tolyl; X is oxygen or sulfur; EMI111.2 R1 is hydrogen, methyl, or -S(C1-C6 alkyl); R2 is hydrogen, C1-C6 alkyl, or -S(C1-C6 alkyl; ; R3 is hydrogen or methyl; R4 is hydrogen or C1-C6 alkyl; and R5 is hydrpgen or methyl 2. A compound of Claim 1 of the formula EMI112.1 wherein R1 is hydrogen, methyl, or -S(C1-C6 alkyl); R2 is hydrogen, C1-C6 alkyl, or -S(C1-C6 alkyl); and R6 is C3-C10 alkyl, C3-C8 cycloalkyl, methallyl, halophenyl, phenyl, fluoro(Cl-C2)alkoxyphenyl, nitrophenyl, tolyl, methoxyphenyl, furfuryl, 3,4-(methylenedioxy)phenyl, (tetrahydro-2-furanyl) methyl, trifluoromethylphenyl, methylcyclohexyl, C3-C8 cycloalkyl(C1-C3)- alkyl, biphenylyl, phenoxyphenyl, 2-norbornyl, halobenzyl, 2-thiazolyl, trifluoromethylthiophenyl, halotolyl, or methylthiophenyl. 3. A compound of Claim 1 of the formula EMI112.2 wherein X is oxygen or sulfur; R7 is C5-C6 alkyl, C5-C6 cycloalkyl, halobenzyl, xylyl, halophenyl, methylthiophenyl, tolyl, halotolyl, trifluoromethylphenyl, l-(2-cyclopentyll-methyl)ethyl, or methoxyphenyl; R8 is hydrogen or methyl; and R9 and R10 are the same or different and are hydrogen or methyl. 4. Any one of the following compounds: 3-(4-Chlorophenyl)-5-methyl-2-(3-pyridyl)4-thiazolidinone, 3-(4-Chlorobenzyl)-2-(3-pyridyl)-4-thiazolidinone, 3-Cyclohexyl-5-methyl-2-(3-pyridyl)-4-thiazolidinone, -(4-Chlorophenyl)-2-(3-pyridyl)-4-thia- zolidinone, 3-(2-Cyclopentyl-l-methyl)ethyl-5-methyl 2-(3-pyridyl)-4-thiazolidinone, 3-(4-Chlorophenyl)-5,5-dimethyl-2-(3pyridyl)-4-thiazolidinone, 3-(4-Chlorophenyl)-5-(n-butyl)-5-methyl-2 (3-pyridyl) -4-thiazolidinone, 3-[(4-Chlorophenyl) methyl] tetrahydro-2 (3-pyridyl)-4H-1,3-thiazin-4-one, 3-[(2-Cyclopentyl-1-methyl) ethyl] tetrahydro2-(3-pyridyl)-4H-1,3-thiazin-4-one, 3-(4-Chlorophenyl) tetrahydro-5-methyl-2 (3-pyridyl)-4H-1,3-thiazin-4-one, or 3-(3,4-Dimethylphenyl) tetrahydro-2-(3pyridyl)-4h-1,3-thiazin-4-one. 5. A process for preparing the 4-thiazol- idinone compounds of the formula EMI114.1 wherein RÚ and Rê are defined in Claim 1, which comprises reacting 3-pyridylcarboxaldehyde of the formula EMI114.2 with a substituted amine of the formula R-NH2 herein R is defined as in Claim 1, followed by re cting with thioglycolic acid or thiolactic acid. 6. A process of Claim 5 which comprises urther reacting the compounds of formula (VII) when R1 or Rê is hydrogen with an alkylating agent to provide the compounds or formula (VII) wherein RÚ is methyl or -S(C1-C6 alkyl) or Rê is C1-C6 alkyl or -S(C1-C6 alkyl), or both RÚ and Rê are other than hydrogen. 7. A process of Claim 5 which comprises further reacting the compounds of formula (VII) with 2S5 to provide the compounds of formula (I) as defined in Claim 1 wherein X is sulfur. 8. A process of Claim 5 which comprises the presence of a cyclizing agent when R-NH2 is a sterically hindered amine. 9. A process for preparing the thiazinone compounds of the formula EMI115.1 wherein S R3, R and R are defined as in Claim 1, RÚ, is C3-C10 alkyl, C5-C6 cycloalkyl, C3-C8 cycloalkyl(C1-C3)alkyl, halophenyl, trifluoromethylphenyl, halobenzyl, haloanilyl, methoxyphenyl, xylyl, tolyl, or methylthiophenyl, which comprises reacting a compound of the formula EMI115.2 wherein R3, R4, R5 and R17 are defined as before, with a cyclizing agent. 10. A process of Claim 9 which comprises further reacting the compounds of formula (VIII) when P3 or R4 is hydrogen or when R3 is methyl and is C1-C6 alkyl and R5 is hydrogen with an alkylating agent to provide the compounds of formula (VIII) where either R3is methyl or R4 is C1-C6 alkyl, or where R is methyl and R is C1-C6 alkyl, then R5 is methyl. 11. A process of Claim 9 which comprises further reacting the compounds of formula (VIII) with P2S5 to provide the compounds of formula (I) as defined in Claim 1 wherein X is sulfur. 12. A composition for use in agriculture which comprises as active ingredient a compound of formula (I) as defined in Claim 1 and an agriculturallyacceptable excepient. 13. A fungicidal composition of Claim 12 which comprises as active ingredient a compound of the formula EMI116.1 wherein R11 is C3 C10 alkyl, phenyl, halophenyl, methallyl, C3-C8 cycloalkyl, nitrophenyl, methylcyclohexyl, fluoro (C1-C2) alkoxyphenyl, tolyl, xylyl, methoxyphenyl, trifluoromethylphenyl, halotolyl, halobenzyl, 3,4- (methylenedioxy) phenyl, or biphenylyl; R12 is hydrogen or methyl; R13 is hydrogen or C1-C6 alkyl; and a fungicidally-acceptable excepient. 14. A fungicidal composition of Claim 12 which comprises as active ingredient a compound of the formula EMI117.1 wherein R14 is C3-C6 alkyl, C5-C6 cycloalkyl, halobenzyl, trifluoromethylphenyl, halophenyl, tolyl, or methoxyphenyl; R15 is hydrogen or methyl; and a fungicidally-acceptable excepient. 15. An aquatic growth regulator composition of Claim 12 which comprises as active ingredient a compound of the formula EMI117.2 wherein R16 is C3-C10 alkyl, C3-C8 cycloalkyl, methallyl, phenyl, halophenyl, trifluoromethylphenyl, methoxybenzyl, methylbenzyl, halobenzyl, benzyl, dimethylaminoethyl, C3-C8 cycloalkyl (C1-C3) alkyl, methylcyclohexyl, 2-thiazolyl, a-methylbenzyl, phenoxy- phenyl, (tetrahydro-2-furanyl) methyl, haloanilyl, xylyl, trifluoromethylthiophenyl, methylthiophenyl, methoxy phenyl, fluoro (C±-C2) alkoxyphenyl, 3,4-(methylenedioxy)phenyl, biphenylyl, 2-norbornyl, furfuryl, 2 (1-methoxypropyl), halotolyl, or tolyl; X is oxygen or sulfur; EMI118.1 R1 is hydrogen, methyl, or -S(C1-C6 alkyl); R2 is hydrogen, C1-C6 alkyl, or -S(C1-C6 alkyl); ; R is hydrogen or methyl; R4 is hydrogen or C1-C6 alkyl; R5 is hydrogen or methyl; and an aquatically-acceptable excepient. 16. A method for regulating the growth of submerged and floating aquatic weeds which comprises adding to the water containing said weeds an amount sufficient to provide a growth-regulating and nonherbicidal concentration of a compound of the formula EMI118.2 wherein R16 is C3-C10 alkyl, C3-C8 cycloalkyl, methallyl, phenyl, halophenyl, trifluoromethylphenyl, methoxybenzyl, methylbenzyl, halobenzyl, benzyl, dimethylaminoethyl, methylcyclohexyl, C3-Cb cycloalkyl(C1-C3)alkyl, 2thiazolyl, a-methylbenzyl, phenoxyphenyl, (tetrahydro 2-furanyl)methyl, haloanilyl, xylyl, trifluoromethylthiophenyl, methylthiophenyl, methoxyphenyl, fluoro(C1-C2)alkcphenyl, 3,4-(methylenedioxy)phenyl, biphenylyl, tolyl, 2-norbornyl, furfuryl, 2-(1- methoxypropyl), or halotolyl; X is oxygen or sulfur; EMI119.1 R1 is hydrogen, methyl, or -S(C1-C6 alkyl); R2 is hydrogen, C1-C6 alkyl, or -S(C1-C6 alkyl; R is hydrogen or methyl; R4 is hydrogen or C1-C6 alkyl, and R5 is hydrogen or methyl. 17. The method of Claim 16 which comprises having the growth-regulating and non-herbicidal concentration of the active compounds range from about 0.25 to about 10 ppm. 18. A method of protecting plants from phytopathogenic fungi which comprises contacting the fungi with a fungicidally-effective and non-herbicidal amount of a compound of the formula EMI119.2 wherein 11 is C3-C10 alkyl, phenyl, halophenyl, methallyl, C3-C cycloalkyl, nitrophenyl, methylcyclohexyl, fluoro (C1-C6) alkoxyphenyl, tolyl, xylyl, methoxyphenyl, trifluoromethylphenyl, halotolyl, halobenzyl, 3,4-(methylenedioxy) phenyl or biphenylyl; R12 is hydrogen or methyl; R13 is hydrogen or C1-C6 alkyl; R14 is C3-C6 alkyl, C5-C6 cycloalkyl, halobenzyl, trifluoromethylphenyl, halophenyl, tolyl, or methoxyphenyl; and R15 is hydrogen or methyl. 19. The method of Claim 18 which comprises having said compound applied at a rate within the range of from about 5 to about 1000 ppm.

Inventors: KRUMKALNS, ERIKS VICTOR
Applicants: ELI LILLY AND COMPANY
Application year: 1979
Main classification: C07D417
IPC codes: A01N47, C07D417, A01P3, A01P21, A01N43