Synthesis of 1,2,4-triazole and thiazole analogs of ketoconazole

The synthesis of 1,2,4-triazole and thiazole analogs of ketoconazole is described in which one of the α azole ring carbons is linked to C-2 of the ketal by means of a three methylene tether. Lithiation of 1-methyl-1,2,4-triazole and thiazole and subsequent alkylation with 2-(2,4-dichlorophenyl)-2-(3-iodopropyl)-1,3-dioxolane produced, after an aqueous acidic workup, 2,4-dichlorophenyl 3-[5-(1-methyl-1,2,4-triazolyl) and 2-thiazolyl]propyl ketones, respectively. Ketalization with glycerol furnished the corresponding diastereomeric pairs of cis and trans 1,3- dioxolanes. The reaction of 2,4-dichlorophenyl 3-[5-(1-methyl-1,2,4-triazolyl)]propyl ketone with 3-mercapto-1,2-propanediol produced the corresponding diastereomeric cis and trans hydroxymethyl 1,3-oxathiolanes. The diastereomeric racemates were separated by column chromatography and their stereochemistry established by nOe nmr experiments. Some of these racemic cis ketal alcohols were converted by benzyl bromide to the corresponding benzyl ethers. Several of these racemic cis-ketals were reacted, first with methanesulfonyl chloride, then with 1-acetyl-4-(4-hydroxyphenyl)piperazine, to furnish the title compounds.     

1-(N-Arylthiocarbamoyl)amidino-3,5-dimethyl Pyrazoles-Preparation and Use in Heterocycle Synthesis

On reaction with α-haloketones or hydrazine, 1-(N-arylthiocarbamoyl)amidino-3,5-dimethylpyrazoles (1) afford 2,4-diaminothiazoles and 3,5-diamino-1,2,4-triazoles in good yield. A convenient route to 1 is also reported.     

Condensed as-triazines. Synthesis of 7-aryl-8H-[1,4]thiazino[2,3-e]-1,2,4-triazin-3(2H)-one

Ring closure of 6-amino-3-oxo-as-triazine-5-thione with α-haloketones provides the thiazino[2,3-e]-1,2,4-triazines which dehydrate via an unusual pathway to give 7-aryl-8H[1,4]thiazino[2,3-e]-1,2,4-triazin-3(2H)-ones.     

Synthesis and Antimicrobial Evaluation of Halogen-Containing Arylidene Thiazolo Triazinediones

A series of 7-substituted arylidene-1,3-thiazolo[2,3-c]-1,2,4-triazine-4,6-diones were synthesized in an one-pot multicomponent reaction of 6-arylmethyl-3-mercapto-1,2,4-triazin-5-ones with substituted benzaldehydes and monochloroacetic acid in the presence of acetic anhydride, acetic acid, and sodium acetate. The structures of the new compounds were supported by IR, ¹H NMR, MS, and analytical data. All the new compounds were tested for their antibacterial and antifungal activity. Arylidene thiazolo triazinediones with 1,3-benzodioxolo substituent at seventh and p-chlorophenyl or 2,4-dichlorophenyl substituents at third displayed good antibacterial and antifungal activity. And also compound bearing 2,3,5-trimethoxyphenyl substituent at seventh and 2,4-dichlorophenyl substituent at third displayed good activity.     

Analgesic and antimicrobial studies of some 2,4-dichloro-5-fluorophenyl containing arylidenetriazolothiadiazines

2,4-Dichloro-5-fluorophenyl containing 7-arylidenetriazolothiadiazines were obtained by the reaction of 4-amino-3-(2,4-dichloro-5-fluorophenyl)-5-mercapto-1,2,4-triazole with 2,3-dibromo-1,3-diarylpropan-1-ones, and also by the reaction of 4-amino-3-(2,4-dichloro-5-fluorophenyl)-5-mercapto-1,2,4-triazole with α-bromopropenones in the presence of a base. The structure of the 7-arylidenetriazolothiadiazines was confirmed by an alternative synthesis. A plausible mechanism for the formation of 7-arylidenetriazolothiadiazines is proposed. All newly synthesized compounds were screened for their analgesic and antimicrobial activities. Compounds bearing 4-chlorophenyl or 3,4-methylenedioxyphenyl moieties at position 7 of the arylidenetriazolothiadiazines showed excellent analgesic activity. Arylidenetriazolothiadiazines carrying a phenyl, 4-chlorophenyl, 4-methylphenyl, 3,4-dimethoxyphenyl, and 2,4-dichlorophenyl moieties at position 7 showed excellent antibacterial and antifungal activities. Correspondence: Mari Sithambaram Karthikeyan, Department of Chemistry, Mangalore University, Mangalagangothri 574199, Karnataka, India.     

Synthesis of aryl ω-(1-methyl-5-imidazolyl and 1H-5-tetrazolyl)alkyl ketones

Successful syntheses of 2,4-dichlorophenyl 2-(1-methyl-5-imidazolyl)ethyl and 2,4-dichlorophenyl 3-(1-methyl-5-imidazolyl)propyl ketones are described. In addition, syntheses of 2,4-dichlorophenyl and 4-chlorophenyl 3-(1-methyl-1H-5-tetrazolyl)propyl ketones are reported.     

Synthesis of s-triazolocycloalkyl-, s-triazolobenzocycloalkyl-, and s-triazolocycloalkylhydrothiadiazines

The reaction of cyclic-α-haloketones with 5-subslituted-4-amino-4H-1,2,4-triazole-3-lhiols gave s-triãzolocycloalkylhydrothiadiazines and s-triazolobenzocycloalkylthiadiazines. Reduetion of the 5,5a-imine bond of the s-triazoloeycloalkylthiadiazines gave s-triazolocycloalkylhydrothia-diazines.     

Synthesis of 1-halophenyl 4-(2-imidazolyl)-1-butanones and 5-(2-imidazolyl)-1-pentanones and their ketalization with glycerol

An alternate synthesis of 1-(2,4-dichlorophenyl)-4-(2-imidazolyl)-1-butanones 5d is presented after 1-[(dimethylamino)methyl- and 1-methyl]-2-lithioimidazole failed to be substituted satisfactorily by 2-(2,4-dichlorophenyl)-2-(3-iodopropyl)-1,3-dioxolane ( 3b ). The Pinner addition of ethanol to 2-(2,4-dichlorophenyl)-2-(3-cyanopropyl)-1,3-dioxolane yielded the corresponding imidate which was reacted with 1-amino-2,2-dimethoxyethane to form an amidine. Hot dilute hydrochloric acid converted this ami-dine to the 2-imidazolyl ketone 5b . Syntheses of homologous 1-(4-chloro- and 2,4-dichlorophenyl)-4-(2-imidazolyl)-1-pentanones 20 are described. Ketalizations of 5 and 20 with glycerol formed imidazolyl 1,3-dioxolanyl alcohols. Selective N- and O-alkylations of some of these imidazolyl alcohols are described.     

Synthesis of 5-(6-Methyl-2,4-dioxo-1,2,3,4-tetrahydro-3-pyrimidinyl)-methyl-4-amino-1,2,4-triazole-3-thione and its Reactions with Polyfunctional Electrophiles

Summary.  In the reaction of 5-(6-methyl-2,4-dioxo-1,2,3,4-tetrahydro-3-pyrimidinyl)-methyl-1,3,4-oxadiazole-2-thione with hydrazine hydrate, 5-(6-methyl-2,4-dioxo-1,2,3,4-tetrahydro-3-pyrimidinyl)-methyl-4-amino-1,2,4-triazole-3-thione was formed. The reactions of the latter with ethyl bromoacetate and chloroacetonitrile in the presence of triethylamine proceeded under formation of the corresponding S-alkylated derivatives, whereas from its reaction with ω-bromoacetophenone and ethyl 4-chloroacetoacetate triazolothiadiazines were obtained. Treatment of the title compound with ethyl 2-chloroacetoacetate led to the formation of 5-(6-methyl-2,4-dioxo-1,2,3,4-tetrahydro-3-pyrimidinyl)-methyl-4-N-acetylamino-(3-ethoxy-carbonylmethylthio)-1,2,4-triazole. Performing of the latter reaction without basic catalyst gave a triazolothiadiazine. Treatment of the S-alkylated derivatives with sodium methoxide resulted in triazolothiadiazines via a cyclocondensation reaction. Received November 20, 2000. Accepted January 15, 2001     

Synthesis of 5,5′[[[3-(dimethylamino)propyl]imino]]bis[3-(trichloromethyl)-1,2,4-thiadiazole] and related thiadiazoles as antimalarial agents

The condensation of 5-chloro-3-(trichloromethyl)-1,2,4-thiadiazole (VIII) with N,N-dimelhyl-1,3-propanediamine gave 5-¶ [3-(dimethylammo)propyl]amino¶-3-(trichloromethyl)-1,2,4-thia-diazole(5) and 5,5′-¶[3-(dimethylamino)propyl]imino)¶bis[3-(triehloromethyl)-1,2,4-tliiadiazole] (14), together with 5,5′-[(3-¶ methyl[ 3-(trichloromethyl)-1,2,4-thiadiazol-5-yl ]amino Jpropyl)-imino]bis[3-(trichloromethyl)-1,2,4-thiadiazole] ( 17 ) which was formed via an unusual displacement of the distal methyl group of 14. The remarkable antimalarial activity of 14 prompted the synthesis of an array of 5-amino-3-(trichloromethyl, methyl, and 3,4-dichlorophenyl)-1,2,4-thiadiazoles and 5,5′-¶[(dialkylamino)alkyl]imino¶bis[3-(trichloromethyl, methyl, and 3,4-dichlorophenyl)-1,2,4-thiadiazoles] from an amine and the requisite 5-chloro-3-substituted-1,2,4-thiadiazoles, which were prepared from the appropriate amidine and trichloromethylsull'enyl chloride. 5-¶3-[(Diethylamino)methyl]-p-anisidino ¶-3-(triehloromethyl)-1,2,4-thiadiazole ( 13 ) was active against a chloroquine-resistant line of Plasrnodium berghei in the mouse, and compound 14 , the most promising member of the series overall, was designated for expanded antimalarial and toxicological studies. Structure-activity relationships against P. berghei in mice and P. gallinaceum in chicks are discussed.     

Synthesis of 4-(4-phenyl-3-pyrazolyl)-4H-1,2,4-triazoles

4-(4-PhenyI-3-pyrazolyl)-4H-1,2,4-triazoles and 4-phenyl-5-(4H-1,2,4-triazol4-yl)-3-pyrazolols were prepared by the reaction of formylhydrazine on α-phenyl-α-cyanoacetaldehydes and ethyl α-phenyl-α-cyanoacetates.     

Desulfurization reaction of cis-1,2-diphenyl-3-aryl-1,4,2-diazaphospholidin-5-thione-2-oxides utilizing an Ag+−H2O or ROH system

A desulfurization reaction of the title compounds, as cyclic substrates, utilizing an Ag⁺−H₂O or ROH system, is described in this article. The diastereoisomerism of ring-opening products and the possible reaction mechanism are also discussed. Themolecular structure of α-(3-phenylureido)-α-(2,4-dichlorophenyl)methylphenylphosphinic acid (4a) was determined by X-ray diffraction. © 1998 John Wiley & Sons, Inc. Heteroatom Chem 9: 585–590, 1998     

Kinetics of rearrangement of 2,4-dichlorophenyl-(1H-1,2,4-triazol-1-ylmethyl)ketone enol acetate

The kinetics of rearrangement of 2,4-dichlorophenyl(1H-1,2,4-triazol-1-ylmethyl)ketone enol acetate into 2,4-dichlorophenyl(5-acetyl-1H-1,2,4-triazol-l-ylmethyl)ketone were investigated by¹H NMR spectroscopy. It was shown that this rearrangement is a first-order reaction. The rate constant was measured in the 129–156°C range and the activation parameters of the reaction were determined. A hypothesis concerning the intramolecular character of the observed rearrangement was drawn based on the kinetic data.Institute of Chemistry, Academy of Sciences of the Moldovian Republic, 277014 Kishinev. All-Union Scientific-Research Institute of Chemical Agents for the Protection of Plants, Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 10, pp. 2284–2287, October, 1992.     

Electrochemical Detection of Host–Guest Interactions of Dicarboximide Pesticides with Cyclodextrins

Electrochemical methods sensitively detect the formation of host–guest complexes of cyclodextrins and three redox-active pesticides: vinclozoline (3-(3,5-dichlorophenyl)-5-methyl-5-vinyl-1,3-oxazolidine-2,4-dione), iprodione (3-(3,5-dichlorophenyl)-N-(1-methylethyl)-2,4-dioxo-1-imidazolidinecarboxamide), and procymidone (3-(3,5-dichloro-phenyl)-1,5-dimethyl-3-azabicyclo[3.1.0]hexane-2,4-dione). The protecting environment of the CD cavity allows a four-electron heterogeneous reaction leading to a preferential cleavage of the C–Cl bonds and conservation of the heterocycle structure for a further second electron transfer step. This interpretation is supported by numerical simulation of the voltammetric curves and by quantum-chemical calculations of the LUMO changes of vinclozoline. Electrochemical detection of these host–guest interactions is far superior to the spectral methods.     

Synthesis, 1H- and 13C-NMR spectra,crystal structure and ring openings of 1-methyl-6,9-epoxy-9-aryl-5,6,9,10-tetrahydro-1H-imidazo [3,2-e] [2H-1,5] oxazocinium methanesulfonate

The methanesulfonic acid catalyzed reaction of 1-(4-chloro- and 2,4-dichlorophenyl)-2-(1-methyl-2-imida-zolyl)ethanones 1a and 1b with glycerol produced cis- and trans-{2-haloaryl-2-[(1-methyl-2-imidazolyl)methyl]-4-hydroxymethyl}-1,3-dioxolanes 2a and 2b with a 2:1 cis/trans ratio. Besides these five-membered ketals, the reaction of 1a with glycerol afforded a small amount of trans-{2-(4-chlorophenyl)-2-[(1-methyl-2-imidazolyl)methyl]-5-hydroxy}-1,3-dioxane ( 3a , 7%). The reaction of methanesulfonyl chloride with cis-1 formed the corresponding methanesulfonates, cis- 4 , which rapidly cyclized to the title compounds 5 . Base-catalyzed ring opening of 5 furnished 1-methyl-5,6-dihydro-6-hydroxymethyl-8-(4-chloro- and 2,4-dichlorophenyl)-1H-imidazo[3,2-d][1,4]oxazepinium methanesulfonates 7 . Acid-catalyzed hydrolyses of 5 or 7 provided 1-methyl-2-[(4-chloro- and 2,4-dichloro)phenacyl]-3-[(2,3-dihydroxy)-1-propyl]imidazolium salts 12 . Structure proofs were based on extensive ¹H and ¹³C chemical shifts and coupling constants and structures of 3a and 5a were confirmed by single crystal X-ray crystallography.     

Picryl derivatives of 5-nitro-2,4-dihydro-3H-1,2,4-triazol-3-one

Treatment of 5-nitro-2,4-dihydro-3H-1,2,4-triazol-3-one ( 1 ) with picryl fluoride (PkF) in 1-methyl-2-pyrrolidinone (NMP) gave a mixture of a monopicryl and a dipicryl derivative of 1 in a ratio of 2 :1 , respectively, regardless of the initial concentrations of 1 and PkF. The products were identified as 5-nitro-2-picryl-2,4-dihydro-3H-1,2,4-triazol-3-one ( 2 ) by X-ray crystallography and 5-nitro-2,4-dipicryl-2,4-dihydro-3H-1,2,4-triazol-3-one ( 4 ) by ¹⁵N labeling experiments.     

Extraction of hydrochloric and nitric acid with 1-{[2-(2,4-Dichlorophenyl)-4-propyl-1,3-dioxolan-2-yl]-methyl)-1H-1,2,4-triazole and (RS)-1-(4-Chlorophenyl)-4,4-dimethyl-3-(1H-1,2,4-triazol-1-yl-methyl)-pentan-3-ol

Extraction of hydrochloric and nitric acid with 1-{[2-(2,4-dichlorophenyl)-4-propyl-1,3-dioxolan-2-yl]-methyl}-1H-1,2,4-triazole (propiconazole) and hydrochloric acid with (RS)-1-(4-chlorophenyl)-4,4-dimethyl-3-(1H-1,2,4-triazol-1-yl-methyl)-pentan-3-ol (tebuconazole) was studied. It is established that extraction of acids proceeds with the formation of monosolvates as an exothermic process. Effective extraction constants of acids are evaluated. By means of the IR and ¹H NMR spectroscopy it was shown that the protonaccepting center of tebuconazole is N⁴ atom of the triazole ring.     

Synthesis of the methanesulfonates of α-(4-chlorophenyl)-α-[1-(2-chlorophenyl)emenyl]-1H-1,2,4-triazole-1-ethanol and α-[1-(2-chlorophenyl)ethenyl]-α-(2,4-difluorophenyl)-1H-1,2,4-triazole-1-ethanol,alpha styryl carbinol antifungal agents

The methanesulfonates of (α-(4-chlorophenyl)-α-[1-(2-chlorophenyl)ethenyl]-1H-1,2,4-triazole-1-ethanol and α-[1-(2-chlorophenyl)ethenyl]-α-(2,4-difluorophenyl)-1H-1,2,4-triazole-1-ethanol ( 1a, b ) are orally effective α-styryl carbinol derivatives developed for the treatment and prevention of systemic fungal infections. Practical new processes amenable for the large-scale production of these compounds are described. Of note is the selection of dichlorostyrene as a convenient precursor of the styryl portion, modification of a sensitive Grignard addition into a realistic preparative reaction and the use of 1,2,4-triazole simultaneously as a base transfer agent and nucleophile.     

An efficient protocol for solid phase aminothiazole synthesis

An efficient synthesis of 2,4-diamino-5-ketothiazoles under solid phase conditions has been achieved by the reaction of polymer supported amidinothioureas with α-haloketones. This novel synthetic approach involving traceless cleavage from the support is suited for automation, and allows solid phase combinatorial synthesis of 2,4-diamino-5-ketothiazoles in good yields and purities.     

Extraction of palladium(II) with 1-{[2-(2,4-Dichlorophenyl)-4-propyl-1,3-dioxolan-2-yl]-methyl}-1<Emphasis Type="Italic">H</Emphasis>-1,2,4-triazole from nitrate-nitrite solutions modeling the composition of raffinates formed in the PUREX process

Extraction of palladium(II) with 1-{[2-(2,4-dichlorophenyl)-4-propyl-1,3-dioxolan-2-yl]-methyl}-1H-1,2,4-triazole in toluene from nitrate-nitrite solutions modeling in a number of components the composition of raffinates formed in the PUREX process was studied. Conditions of a tenfold concentration of palladium(II) into an ammonia extract were found.