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An efficient synthesis of 3-phenyl-1-(6-phenyl-7H-[1,2,4] triazolo[3,4-b][1,3,4]thiadiazin-3-yl)-1H-pyrazol-5-amines was accomplished by a simple, atom-economical, and multicomponent approach. Reac...

Phenacyl bromides are used as a building blocks in synthetic organic chemistry, which serves as a key model for the development of various biologically important heterocyclic compounds and other in...

A greener approach for the synthesis of 4-oxo-4,5,6,7-tetrahydro indole derivatives has been achieved through Wang-OSO3H-mediated three-component reaction involving dimedone, phenacyl bromide, and ...

A series of novel 6-functionalized-5-amino-3-methyl-1-phenyl-1H-furo[3,2-e]pyrazolo[3,4-b]pyrazines (4a–c) was synthesized by the reaction of 3-methyl-6-oxo-1-phenyl-6,7-dihydro-1H-pyrazolo[3,4-b]pyrazine-5-carbonitrile (2) with α-halocarbonyl compounds such as: diethyl 2-bromomalonate, phenacyl bromide and chloroacetone. Cyclocondensation of the amino benzoyl 4b with diethyl malonate yielded the oxopyridine carboxylate derivative 5. Also, the starting intermediate amino ester compound 4a was allowed to react with ethanol amine to afford the hydroxyethyl caboxamide derivative 6. Furthermore, hydrazinolysis of the amino ester 4a afforded the corresponding amino carbohydrazide 7 which was used as a versatile precursor for synthesis of other heterocyclic compounds attached or fused to the furopyrazolopyrazine moiety. The chemical structures of the newly synthesized compounds were confirmed on the basis of elemental and spectral analyses containing FT-IR, 1H NMR, 13C NMR, and mass spectrometry hoping ...

The behavior of thioacetoacetanilide (1) and/or α-arylhydrazono-thioacetoacetanilides 4 toward many different α-halocarbonyl compounds was demonstrated. Thus, reactions of 1 with α-bromoketones (bromoacetone and phenacyl bromide) and hydrazonoyl bromides afforded the corresponding thiazole, thiophene and 1,3,4-thiadiazole derivatives, respectively. The synthesis and reactivity of thiazolidin-5-one 2 toward aromatic diazonium chlorides and aromatic aldehydes were described. Most of the synthesized compounds were screened for their antibacterial and antifungal activities and showed accepted antimicrobial activities with respect to the control drugs.

A convenient, one-pot, three-component regioselective synthesis of novel 2,2′-(1,4-phenylene)-bis-(3-aryl-2-substituted imino-4-aryl-3H-thiazole) derivatives from 1,4-phenylene diisothiocyanate, aryl amines, and various phenacyl bromide, and also the regioselective synthesis of 3-alkyl-2-(aryl imino)-4-cyclopropyl-5-(2′-fluorophenyl)-thiazole derivatives from alkylisothiocyanate, aryl amines, and 2-bromo-2-(2-fluorophenyl)-1-cyclopropylethanone in the presence of poly-4-vinyl pyridine as heterogenous basic catalyst are described. This efficient method produced the products at room temperature with excellent yields (82–96%). The structures of all products were characterized by spectral and elemental analyses. The antimicrobial activity of the synthesized compounds was evaluated against Salmonella enterica, Micrococcus luteus, Bacillus subtilis, and Pseudomonas aeruginosa.

A novel C 3-symmetric arsine was employed in the one-pot cyclopropanation of olefins with carbonyl-stabilized arsonium ylides formed in situ from phenacyl bromide in the presence of NaHCO3. This new arsine demonstrates good stereoselectivity and activity in the one-pot cyclopropanation of arylidenemalononitrile. [Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resource(s): Full experimental and spectral details.]

The article describes a convenient and efficient synthetic route for the construction of 2-aroylbenzofuran-3-ols from readily available diverse methyl salicylates and phenacyl bromides using K2CO3 as catalyst in dimethylformamide as solvent at room temperature. The reaction involves two steps, which occur in quick succession within 1 h to deliver the product with reasonably high yields. All the synthesized 2-aroylbenzofuran-3-ols (4a–u) were subjected for their antimicrobial studies, and some of these have shown prominent activity. [Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resource(s): Full experimental and spectral details.]

An efficient and convenient protocol of broad scope for the synthesis of quinoxaline by cyclization-oxidation of phenacyl bromide with equimolar amount of phenylenediamine at room temperature catalyzed by thiamine in the form of N-heterocyclic carbene (NHC). High efficiency, inexpensiveness, and non-toxicity are the interesting features of the catalyst, which make it eco-friendly and highly attractive.

An efficient and general method has been described for the synthesis of imidazo[2,1-b]-1,3,4-thiadiazole by the reaction of 2-aminothiadiazoles with phenacyl bromides in the presence of 1,4-diazabicyclo[2.2.2]octane (DABCO). The method is suitable for the synthesis of functionalized imidazothiadiazoles.

Silica phosphoric acid has been found to be an efficient catalyst for the synthesis of 2-amino/anilino-5-aryl-1,3,4-thiadiazine bromide derivatives from the reaction of thiosemicarbazide and α-bromoketones in acetonitrile at room temperature. The catalyst can be reused for four times without any significant loss of catalytic activity. The experimental procedure is simple, and the products are obtained in high yield.

A facile, one-pot, three-component bis heterocyclized reaction for the synthesis of hydrazonothiazolyl-pyrazolones has been described. Reaction of phenacyl bromides or 3-(2-bromoacetyl)coumarins, with thiosemicarbazide and ethyl 2-(2-arylhydrazono)-3-oxobutanoates in AcOH/NaOAc, gave the corresponding products in good yields. All the synthesized compounds were characterized by their analytical and spectral data.

5-Anthracenylidene- and 5-(4-benzyloxy-3-methoxy)benzylidene-hydantoin and 2-thiohydantoin derivatives 3a-g were prepared by condensation of anthracene-9-carboxaldehyde and 4-benzyloxy-3-methoxybenzylaldehyde with hydantoin and 2-thiohydantoin derivatives. Compounds 3a, b, f undergo Mannich reaction with formaldehyde and morpholine to give the corresponding Mannich products 4a–c. For the synthesis of alkylmercaptohydantoin 5a–o, the potassium salt of compounds 3a, b, e, f were reacted with an alkylhalide, either methyl iodide, phenacyl bromide, ethyl bromo acetate, allyl bromide, or methallyl bromide, under stirring at room temperature to afford the alkylmercaptohydantoins 5a–o. Acid hydrolysis of compounds 5a–c afforded the corresponding arylidene-hydantoin derivatives 3c, d, g. 2-Methylmercapto-hydantoin derivatives 5a, c were reacted with some secondary amines such as morpholine or piperidine to afford 5-(4-benzyloxy-3-methoxy)benzylidene-2-morpholino- or piperidino glycocyamidine derivatives ...

Stable derivatives of oxaphospholes were obtained from the reaction between electron-deficient acetylenic compounds and phenacyl bromide or its derivatives in the presence of triphenylphosphine in acetonitrile as the solvent in excellent yields. GRAPHICAL ABSTRACT

A novel, one-pot, multicomponent synthesis of 4-arylidene-3-methyl-1-(4-arylthiazol-2-yl)-1H-pyrazol-5(4H)-ones is described using phenacyl bromides, thiosemicarbazide, ethylacetoacetate, and aryl aldehydes. This synthesis involves simultaneous formation of two heterocycles like thiazole and pyrazolone along with condensation of active methylene group by aldehydes via Knoevenagel reaction. The methodology is mild, efficient, and high yielding. GRAPHICAL ABSTRACT

A simple and convenient protocol is described for the preparation of 2,4-disubstituted thiazoles via a condensation reaction of α -halo carbonyl compounds with thiourea or thioacetamide at room temperature, under grinding, in good yields.

The reaction between phenacyl bromide and 2-mercaptobenzimidazole has been studied in 12 different protic and aprotic solvents. The kinetic study shows that the reaction is second-order with first-order dependence each on (phenacyl bromide) and (2-mercaptobenzimidazole). Analysis of rate data shows that there is no direct correlation between the rate constant and dielectric constant of the solvent. Correlation of rate data with different solvent parameters like hydrogen bond acceptor basicity, polarizability and solvent electrophilicity, using linear multiple regression analysis shows that the reaction is influenced by these properties of the solvent. From the regression coefficients, information on the mode of solvation of the reactants and the transition state is obtained. The reaction has also been studied at different temperatures and the thermodynamic parameters Δ H #, Δ S # and Δ G # are evaluated.

2-Cyano-N-(tetrahydrocarbazole)acetamide (1) was utilized for the synthesis of several new arylazocarbazole derivatives (2a–e). Compound (1) reacted with phenyl isothiocyanate to yield the corresponding non-isolable intermediate (3), which gave, upon treatment with dilute hydrochloric acid, thiocarbamoyl derivative (4). Compound (3) reacted with chloroacetone, chloroacetic acid, chloroacetyl chloride, ethyl bromoacetate, and phenacyl bromide to afford thiazolone derivatives (6), (8), and (10), respectively. Compound (1) was heated in the presence of pyridine and/or hydrazine hydrate and/or isatine to give the corresponding tetrahydrocarbazole derivatives (13), (14), and (18), respectively. Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.

A one-pot synthesis of functionalized benzofurans has been developed via O-alkylation, carbon–carbon coupling/cyclization, and dehydration/olefination tandem reactions from phenacyl bromide and phenols under microwave irradiation and solvent-free conditions in the presence of mineral-supported reagent and inorganic base. The best selectivity for forming benzofuran product has been achieved with Na2CO3 as a base. The order of activity of inorganic base is as follows: K2CO3 > NaHCO3 > Na2CO3 > KHCO3 > Na2SO3 > KOH > K3PO4 > NaOH > KH2PO4 > KOAc. This novel synthesis features three new bonds and one ring system assembled in a single step.

3,4-Dihydro-1,4,4a,6a-tetraaza-benzo[a]fluoren-2-one, a new tetracyclic heterocyclic framework, is designed through a simple and convenient synthetic sequence. Its 6-aryl derivatives are synthesized starting from 1H-indole-2-carboxylic acid. The reaction of differently substituted phenacyl bromides with 1H-indole-2-carboxylic acid and POCl3-mediated cyclization of the resultant 1H-indole-2-carboxylic acid phenacyl ester provided 2-oxa-4a-aza-fluoren-1-one, and its sequential reaction with hydrazine and 2-chloro-acetamide furnished the desired new heterocyclic compounds 7a–f.

2-Aminothiazole and 2-iminothiazolidine derivatives were synthesized from the reaction of phenacyl bromide, thiourea, and its derivatives in aqueous media catalyzed by diammonium hydrogen phosphate (10%) and DABCO (10%) at room temperature in an efficient and simple procedure.

Arylazothiocarbamoyl derivatives 4a–e were utilized for the synthesis of several new thiophene and pyrazole derivatives. Compound 4 reacted with phenacyl bromide, ethyl bromoacetate, chloroacetonitrile, chloroacetone and hydrazine hydrate to yield thiophene and pyrazole derivatives 7, 10, 12, 14, and 16, respectively.

The triphenylarsine-catalyzed approach for the highly stereoselective synthesis of trans-2,3-dihydro-spiro[cyclopropane-1,2′-indan-1′,3′-dione] with alkenes and phenacyl bromide in organic solvent is described. The triphenylarsine-catalyzed cyclopropanation in water was investigated. The mixture of cis/trans isomers is provided with water as a solvent. The cis isomer is formed using water as a solvent. The reactivity of the reaction in water is higher than that in the organic solvent.

A series of 4-aryl-2-(3-methyl-7-substituted quinoxaline-2-one-1-yl)-1,3-thiazoles ( 6a–l ) and 4-substituted alkyl-2-(3-methyl-7-substituted quinoxaline-2-one-1-yl)-1,3-thiazoles ( 8a–i ) were synthesized in good yield by condensing 2-(3-methyl-7-substituted l,2-oxoquinoxalin-1(2H)-yl)ethanethioamides ( 5a–c ) with substituted phenacyl bromide and dichloroacetone followed by treatment with secondary amines, respectively. The intermediates, 5a–c were conveniently obtained by reacting phosphorus pentasulphide with 2-(3-methyl-7-substituted-2-oxoquinoxalin-1(2H)-yl) acetamides ( 4a–c ) which in turn were synthesized from ethyl (3-methyl-7-substituted-2-oxoquinoxalin-1(2H)-yl) acetates ( 3a–c ) by aqueous ammonia treatment. The newly synthesized compounds were characterized by IR, 1 H NMR, 13 C NMR, and Mass spectral and elemental analyses. These compounds were screened for in vitro antibacterial activity against five pathogenic strains and antifungal activity against four fungi. Preliminary results revealed...

2-Methylpyridine (1a), 2,6-dimethylpyridine (1b), 2-methylpyrazine (1c) and 2-methylquinoline (1d) were treated with lithium diisopropylamide (LDA) in THF at low temperature followed by carbon disulfide to give the dianion (5). Reactions of dianion (5) with iodomethane, 1,2-dibromoethane, ethyl chloroacetate, α -chloroacetonitrile or phenacyl bromide gave 6a–c, 6e, 9, 10, 11, 12 and 13, respectively. Reactions of dianion (5) with 1,2-dibromoethene gave the dithiocarboxylic acids (14a–c) rather than a dithiolene, and reaction of dianion (5a) with aqueous ammonium persulfate gave 15. Treatment of 2-methylpyridine (1a) with lithium diisopropylamide (LDA) and 2-bromopyridine afforded tetra-2-pyridylmethane (18) as the main product.

An expeditious, solvent-free, and high yielding synthesis of nitrogen containing heterocycles from 1,2,4-s-triazole, benzoin, chloroacetic acid or phenacyl bromide under microwave irradiation is described. This improved greener synthetic methodology provides a simple and straightforward one-pot approach for the synthesis of a variety of heterocycles.

1,3-diphenyl-1H-pyrazole-4-carboxaldehyde (1) reacted with ethyl cyanoacetate and thiourea to give the pyrimidinethione derivative 2. The reaction of 2 with some alkylating agents gave the corresponding thioethers 3a–e and 7. Thione 2 was cyclized to 5 and 6 upon a reaction with chloroacetic acid and with benzaldehyde, respectively. Thioether 3c was cyclized to 4 upon boiling with sodium acetate in ethanol, and 7 was cyclized to 8 upon boiling in an acetic anhydride-pyridine mixture. The hydrazino derivative 9 was prepared either by boiling 2 and/or 3a with hydrazine. The reaction of 9 with nitrous acid, acetylacetone, triethyl orthoformate, acetic anhydride, and carbon disulfide gave 10–14. The alkylation of 14 with ethyl iodide, phenacyl bromide, and ethyl chloroacetate afforded the alkythiotriazolo pyrimidinone derivatives 15a–c. The dialkyl derivative 16 was produced upon the treatment of 2 with two equivalents of ethyl iodide. Boiling 16 with hydrazine afforded the hydrazino 17. The reaction of 17 wi...

The reaction of DL-malic and succinic acids with thiocarbohydrazide afforded 1,2-bis[4-amino-5-mercapto-1,2,4-triazol-3-yl]-ethane derivatives 3a and 3b. The reaction of 3a,b with phenacyl bromide and benzoin afforded 1,2-bis-1,2,4-triazolo [3,4-b][1,3,4]thiadiazine derivatives 4 and 5. The carboethoxymethylation of 3a and 3b gave 6a and 6b, respectively, and their reactions with carbon disulfide and benzoylisothiocyanate gave the 1,2-bis-1,2,4-triazolo[3,4-b][1,3,4]thiadiazole 7 and 9, and with p-nitrobenzaldehyde gave a Schiff's base and dihydrothiadiazole 8. The structures were confirmed by using 1 H and 13 C NMR spectra. Selected members of these compounds were screened for antimicrobial activity.

Condensation of thiazolidin-5-one derivative 1 with different aromatic aldehydes gave the corresponding arylidenes 2a–e. Compound 2e was reacted with urea and thiourea to give the corresponding thiazolo[5,4-d]pyrimidine derivatives 3a, b, respectively. Treatment of compound 1 with phenyl isothiocyanate in basic DMF gave the nonisolable potassium salt of the adduct 4, which underwent heterocyclization upon treatment with chloroacetyl chloride and phenacyl bromide to give the corresponding [2,4′] bisthiazolidinylidenes 5 and 8. Moreover, the reactions of compound 1 with a variety of reagents, e.g., ninhydrin and isatin, were investigated. The structures of these compounds were established by analytical and spectral data.

5-Benzylidene-2-thiohydantoin (1) and 5,5-dimethyl-2,4-dithiohydantoin (6) undergo Mannich reaction with formaldehyde and morpholine to give the corresponding Mannich products 2 and 7, respectively. Subsequent reaction of the product 2 and 7 with phenacyl bromide gives the corresponding 2-benzolmethylthiohydantoin Reaction of 5-benzylidene-2-carbomethoxythiohydantoin (5b) with P2S5 afforded 4-benzylideneimidazo[2,1-b]-thiazole-2-thione-5-one (13) as the sole product. Reaction of 2-thio and 2,4-dithiohydantoin derivatives 2 and 7 with (2,3,4,6-tetra-O-acetyl-α –D-gluco- or galgcto- pyranosyl) bromide or (2,3,4-tri-O-acetyl-α -xylopyranosyl) bromide afforded the corresponding S-gluco- galacto- or xylosides (14–19). Many attempts to deacetylation of the resulting S-nucleosides and to get N-nucleosides were tried.

Pyrazolo[3,4-b]pyridine derivative 3a was prepared and reacted with methyl iodide to give 4 or 5 depending on reaction conditions. Oxidation of 3a with iodine produced the corresponding disulphide derivative 6 , whereas oxidation with KMnO 4 gave the corresponding oxo derivative 7 . Oxidation of 4 afforded the corresponding sulphone derivative 8 , which on boiling in NaOH solution gave 7 . The reaction of compound 3a with chloroacetonitrile, ethyl chloroacetate, phenacyl bromide, and chloroacetanilide afforded 9a , b , 11 , and 12 respectively. Cyclication of the products 9a , b , 11 , and 12 yielded 10a , b , 13 , and 14 respectively. The reaction of compound 14 with ethyl orthoformate, nitrous acid, acetic anhydride, benzaldehyde, urea, CS 2 , and phenyl isothiocyanate afforded compounds 15-21 respectively.

Treatment of 3-methyl 1-phenyl-5-amino pyrazole 1 with 4-acetyl benzene sulfonyl chloride in pyridine gave the sulfonamide 2 . Condensation of 2 with aromatic aldehydes, semicarbazide, and thiosemicarbazide furnished the f , g -unsaturated ketones 3a-c , the semicarbazone 4a and the thiosemicarbazone 4b respectively. Reaction of 3a-c with hydrazine hydrate, phenyl hydrazine, hydroxylamine, thiourea afforded the pyrazoles 5a-f , isoxazoles 6a-c , and pyrimidinethiones 7a-c . Reaction of 3a-c with malononitrile in ethanol containing piperidine provided the pyran derivatives 8a-c , while, when the reaction was carried out in boiling acetic acid in presence of ammonium acetate, the pyridine derivatives 9a-c were formed. When 4a reacted with thionyl chloride and with selenium dioxide, 1,2,3-thiadiazole and 1,2,3-selenadiazole 10 , 11 were formed respectively. Allowing 4b to react with f -halocarbonyl compounds such as phenacyl bromide, chloroacetone, 2-bromomethyl propionate, chloroacetic acid, and bromo dieth...

A [1,2,4]triazino [3,4-b]thiadiazine was prepared by cyclization of 4-amino-3-phenacylmer-capto [1,2,4] triazin-5-one 2 in the presence of solid acid via an unusual pathway.

The reaction of benzopyrano[2,3-c]pyrazol-3-one (1) with some active halo compounds, afforded compounds 4, 8 and 12, respectively. The cyanoethyl derivative 19 was synthesized and treated with active methylenes and sulfur or benzoylisothiocyanate and phenacyl bromide, to give compounds 24a,b and 27. Compounds 25a,b and 28 were obtained through the reaction of compounds 24a,b with acrylonitrile or compound 27 with maleic anhydride. Thiation of compound 1 afforded the corresponding thio derivative 29. The reaction of 4-benzylidene-2-methyloxazolin-5-one with compounds 1 or 29 gave products 30a,b , respectively.

The reaction of compound 1 with triethyl orthoformate afforded 2, which in turn reacted with CS2 and active methlyene compounds or malononitrile to give dithiolane and 4-malononitrile methylene derivatives 3,4, respectively. Treatment of compound 4 with active methylene compounds afforded spiro cyclopentene derivatives 5a-c. Compound 1 was reacted with bromomalononitrile or CS2 and halocompounds to afford furo-. thieno- and dithiolano-pyrazole derivatives 6–11, respectively. The reaction of compound 12 with phenacyl bromide or benzylidenemalononitrile furnished oxathiol-2-ylidene and pyridinethione derivatives 13,14, respectively. The dibromo derivative 16 was reacted with CS2 and active methylenes or malononitrile to obtain spiro dithietanes 17a-e and 4-dicyano-methlyene derivative 22, respectively. Compounds 17 underwent a cycloaddition reaction with thioglycolic acid, N-phenylbenzohydrazindoyl bromide, 2,5-dimethylfuran and 1-phenyl-3,5-pyrazolidinedi one to give cycloadducts 18–21, respective...

Treatment of 5-substituted-4-amino-3-mercapto-1,2,4-triazoles (1), with triethyl orthoformate or acetyl chloride gave the corresponding triazolo[3,4-b]thiadiazoles (2) and (3), respectively. Reaction of (1) with phenacyl bromide, DMAD and DEAD afforded the corresponding thiazololo[3,4-b][1,3,4] thiadiazines (4), (5) and (6), respectively. Reaction of (1) with propargyl bromide in the presence of sodium methoxide gave the corresponding sulfide (7) which upon treatment with LiH gave the corresponding 1,2,4-triazolo[3,4-b][1,3,4]thiadiazine (8). Reaction of (1) with 2,4-dinitrochlorobenzene gave substituted 5H-1,2,4-triazolo[1,3,4-b] benzothiadiazine(9).

The reaction of 3(4-amino-5-mercapto-1,2,4-triazol-3′-yl)quinoxalin-2(1H)-one 4 with phenacyl bromide, 2,3-dichloroquinoxaline, benzoine, chloroacetic acid, and α-chloroacetonitrile to give triazolothiadiazino derivatives 5–10. Reaction of 4 with phenyl isothiocyanate, aromatic aldehydes, formic acid, aromatic carboxylic acid, benzoyl chloride, and carbon disulphide gave triazolothiadiazino derivatives 11–17.

The addition of enolate anions obtained from substituted aryl methyl ketones in the presence of NaH and DMF to phenyl isothiocyanate on subsequent alkylation with phenacyl bromide or α-bromo propiophenone underwent intramolecular cyclization involving the ketene-N, S-acetal moiety and carbonyl group to afford 2-phenylamino-3-aroyl-4-phenyl-5-methyl/unsubstituted thiophenes. Reaction of enolates derived from acetyl acetone and ethyl acetoacetate under similar conditions underwent intramolecular aldol condensation resulting in the formation of substituted thiophenes.

Thieno[2,3-b]pyridines 5a,b, 2-S-methylacetyl pyridine derivative 7 , 2-S-methyldiaetyl pyridine derivative 7b, 2-S-methylethoxycarbonyl pyridine derivative 12a, 2-S-methylacetylethoxycarbonyl pyridine derivative 12 and 2-S-methyl pyridine derivative 28 , had been obtained via the reaction of pyridinethione 3 with phenacyl bromide derivatives, chloroacetone, α-chloroacetylacetone, chloroethylacetone, α-chloroethylacetoacetate and methyl iodide respectively. Several cyclization reactions were performed with 10% KOH, nitrous acid, hydrazine hydrate, formic acid, acetic anhydride and acetic acid to give an additional ring on the previously obtained new ring system.

Reaction of tetrasubstituted cyclopentadienones 1,1a with phenacyl bromide 2, dichloroacetophenone 3, ethyl bromomalonate 4, bromomethyl-p-tolylsulphone 5 in 50% NaOH and in the presence of benzylt...

A novel procedure for the synthesis of heterocycles 5, 7 have been developed from the acid catalysed condensation-cyclization of benzylidene and benzylmalononitriles with thiosemicarbazide. Base catalysed cyclization of 2 with dicyandiamide led to the formation of pyrimidine 3. Reaction of 5 and 7 with phenacyl bromide separately afforded 6 and 8 while interaction of 7 with ethyl acetoacetate gave a mixture of 9 and 10.

5-Cyano-4-oxo-6-phenyl-2-thioxo-1,2,3,4-tetrahydropyrimidine (I) reacts with P2S5 in pyridine to give pyrimidine-2,4-dithione (II). Further reaction of II with ethyl chloroacetate, chloroacetanilide, phenacyl bromide, bromoacetone and chloroacetonitrile gave the corresponding thieno[2,3-d]pyrimidine derivatives (III-VI). Interaction of compound IVa with hydrazine hydrate in ethanol or diluted ethanol gave the hydrazide and hydrazino derivatives (VII, IX), which reacted with aromatic aldehydes to give the corresponding hydrazones (VIIIa-c, Xa-c ). Alkaline hydrolysis of IV, using KOH gave the acid XI with extrusion of thioglycolic acid.

3,5-Dicyano-6-mercapto-4-phenylpyridin-2(1H)-one (1) was reacted with ethyl chloroacetate to give compound (II) which on reaction with hydrazine hydrate gave the corresponding hydrazide derivative (III). Acylation of (III) with acetic acid, phenylisocyanate, or phenylisothiocyanate gave different monoacyl derivatives (IV-VI). Condensation of III with aromatic aldehydes and acetylacetone gave compounds VIIa-c, VIII respectively. Compound I was reacted with chloroanilides, bromoacetone and phenacyl bromide to yield the IX-XI; these and compound II gave thieno[2,3-b]-pyridines (XU-XV) on treatment with sodium ethoxide solution. Reaction of XII with acetic anhydride gave the diacetyl derivative XVI. Hydrolysis of compound XII with sodium hydroxide gave the corresponding acid (XVII) which on treatment with acetic anhydride gave the oxazine derivative (XVIII). Reaction of oxazine compound XVIII with ammonium acetate and hydrazine hydrate gave pyrido[3′,2′:4,5] thieno[3,2-d]pyrimidin-4.7-dione derivativ...

A new method for the separation and quantification of monohydroxy-eicosatetraenoic acids has been developed. The 5-, 12-, and 15-hydroxylated acids were esterified with p-(9-anthroyloxy) phenacyl bromide and subjected to reversed-phase high-performance liquid chromatography. 12-HETE and 15-HETE were readily separated. 5-HETE eluted in 2 peaks, the second co-eluting with 15-HETE. Sensitivity of the assay was 2.81 nM for both the 12- and 15-hydroxylated acids, and 6.25 nM for the 5-hydroxylated acid. This technique lends itself to analysis of biological samples.

Reaction of 3,4-trimethylene-6-amino-5-ethoxycarbonylthiopyrane-2-thione (1) with hydrazine hydrate gave the corresponding o-diaminocyclopentapyridine-2-thione (2). Ring closure of 2 with some reagents, namely, formic acid, aromatic aldehydes, carbon disulphide. phenacyl bromide, ethyl chloroformate, ethyl chloroacetate, nitrosylsulfuric acid, and pyruvic acid gave tricyclic compounds (2–14) by direct or indirect pathways, respectively.

10-Phenylphenoxaphosphine (2) undergoes quaternization with phenacyl bromide in nitromethane five times more slowly than triphenylphosphine and almost twenty times more slowly than o-methoxyphenyldiphenylphosphine. It is argued that stabilization of the developing phosphonium centre by interaction with the ortho-oxygen atom, previously suggested as being involved in the quaternization of the latter (McEwen et al. 1), is not significant for the quaternization of the phenoxaphosphine (2), and that the predominant role of the ether oxygen is electron-withdrawal from phosphorus. This conclusion is supported by an X-ray structural study of the title compound (3). Crystals of (3) are orthorhombic, a = 18.954(11), b = 25.715(14), c = 9.322(5) a, Z = 8, in space group P b c a (D 15 2h , No. 61). The structure was determined by Patterson and electrondensity methods, and refined by least squares techniques to R = 0.045 for 1505 independent reflections. The fused ring system of the phenoxaphosphonium cation...