Bildung von 5,6-Dihydro-1,3(4H)-thiazin-4-carbonsäure-estern aus 4-Allyl-1,3-thiazol-5(4H)-onen

Formation of Methyl 5,6-Dihydro-l, 3(4H)-thiazine-4-carboxyiates from 4-Allyl-l, 3-thiazol-5(4H)-ones . The reaction of N-[1-(N, N-dimethylthiocarbamoyl)-1-methyl-3-butenyl]benzamid ( 1 ) with HCl or TsOH in MeCN or toluene yields a mixture of 4-allyl-4-methyl-2-phenyl-1,3-thiazol-5(4H)-one ( 5a ) and allyl 4-methyl-2-phenyl-1,3-thiazol-2-yl sulfide ( 11 ; Scheme 3). Most probably, the corresponding 1,3-oxazol-5(4H)-thiones B are intermediates in this reaction. With HCl in MeOH, 1 is transformed into methyl 5,6-dihydro-4,6-dimethyl-2-phenyl-1,3(4H)-thiazine-4-carboxylate ( 12a ). The same product 12a is formed on treatment of the 1,3-thiazol-5(4H)-one 5a with HCl in MeOH (Scheme 4). It is shown that the latter reaction type is common for 4-allyl-substituted 1,3-thiazol-5(4H)-ones.     

Cyclocondensation of methyl 2-(1,3-benzothiazol-2-ylimino)-3,3,3-trifluoropropionate with C,N-binucleophiles

Reactions of methyl 2-(1,3-benzothiazol-2-ylimino)-3,3,3-trifluoropropionate with 1,3-C,N-binucleophiles, methyl 2-aminobut-2-enoate, 2-aminobut-2-enenitrile and N-substituted 6-aminouracils and 3-aminocyclohex-2-en-1-ones, led to the formation of trifluoromethyl-substituted heterocycles, dihydro-1H-pyrroles, hexahydro-1H-pyrrolo[2,3-d]pyrimidine-2,4,6-triones, and hexahydro-1H-indole-2,4-diones.     

Eine überraschende Ringerweiterung von 3-(Dimethylamino)-2,2-dimethyl-2H-azirin zu 4,5-Dihydropyridin-2(3H)-on-Derivaten

An Unexpected Ring Enlargement of 3-(Dimethylamino)-2,2-dimethyl-2H-azirine to 4,5-Dihydropyridin-2(3H)-one Derivatives The reaction of 3-(dimethylamino)-2,2-dimethyl-2H-azirine ( 1a ) and 4,4-disubstituted 2-(trifluoromethyl)-1,3-oxazol-5(4H)-ones 7 in MeCN at 70° afforded 5-(dimethylamino)-3,6-dihydropyrazin-2(1H)-ones 10 (Scheme 4), whereas no reaction could be observed between 1a and 2-allyl-4-phenyl-2-(trifluoromethyl)-1,3-oxazol-5(2H)-one ( 8a ) or 4,4-dibenzyl-2-phenyl-1,3-oxazol-5(4H)-one ( 9 ). The formation of 10 is rationalized by a mechanism via nucleophilic attack of 1a onto 7 . The failure of a reaction with 9 shows that only activated 1,3-oxazol-5(4H)-ones bearing electron-withdrawing substituents do react as electrophiles with 1a . The amino-azirine 1a and 2,4-disubstituted 1,3-oxazol-5(4H)-ones 2b – e in refluxing MeCN undergo a novel ring enlargement to 4,5-dihydropyridin-2(3H)-ones 11 (Scheme 5). Several side products were observed in these reactions. Two different reaction mechanisms for the formation of 11 are proposed: either 1a undergoes a nucleophilic addition onto the open-chain ketene tautomer of 2 (Scheme 6), or 2 reacts as CH-acidic compound (Scheme 7).     

Halocyclization of 2-(2-{4-[allylamino(thioxo)methyl]piperazin-1-yl}ethyl)-1<Emphasis Type="Italic">H</Emphasis>-benzo[<Emphasis Type="Italic">de</Emphasis>]isoquinoline-1,3(2<Emphasis Type="Italic">H</Emphasis>)-dione

Cyclization of 2-(2-{4-[allylamino(thioxo)methyl]piperazin-1-yl}ethyl)-1H-benzo[de]isoquinoline-1,3(2H)-dione by the action of iodine, bromine, or sulfuryl chloride gave 2-(2-{4-[4,5-dihydro-5-(halomethyl)-thiazol-2-yl]piperazin-1-yl}ethyl)-1H-benzo[de]isoquinoline-1,3(2H)-dione hydrohalides which were converted into 2-{2-[4-(5-methylthiazol-2-yl)piperazin-1-yl]ethyl}-1H-benzo[de]isoquinoline-1,3(2H)-dione.     

Synthesis via pummerer intermediates. III. Rearrangements of 3-(methylsulfinyl)quinolinones, 3-(methylsulfinyl)cinnolinones, 3-(methylsulfinyl)chromanones and 3-(methylsulfinyl)chromones with acetic anhydride and with thionyl chloride

The reaction of 1-methyl-3-(methylsulfinyl)-4(1H)quinolinone ( 1 ) with acetic anhydride and thionyl chloride gave 3-[[(acetyloxy)methyl]thio]]-1-methyl-4(1H)quinolinone ( 2 ) and 3-[(chloromethyl)thio]-1-methyl-4(1H)quinolinone ( 3 ) respectively. 3-(Methylsulfinyl)-4(1H)cinnolinone ( 4 ) gave the corresponding products when treated under similar conditions. Treatment of 8-methoxy-3-(methylsulfinyl)-4H-1-benzopyran-4-one ( 11 ) with acetic anhydride and thionyl chloride gave bis addition vinyl Pummerer products 2,3-bis(acetyloxy)-2,3-dihydro-8-methoxy-3-(methylthio)-4H-1-benzopyran-4-one ( 12 ) and 2,3-dichloro-2,3-dihydro-8-methoxy-3-(methylthio)-4H-1-benzopyran-4-one ( 13 ), respectively.     

Sur la synthèse de chloro-3 indolinones a partir de β-nitrostyrènes diversement substitués

When treated with acetyl chloride and ferric chloride in methylene chloride, at 0°, monosubstituted β-nitrostyrene derivatives such as 2,3 or 4-methyl, -chloro or -fluoro and 3-nitro-β-nitrostyrenes cyclize into the new corresponding 3-chloro-1,3-dihydro-2H-indol-2-one. Reaction with other metal chlorides such as aluminum chloride and titanium tetrachloride does not lead to these heterocyclic derivatives but only produces N-acetyl-N-hydroxy-α-chlorobenzeneacetamides and/or N-(acetyloxy)-α-chlorobenzeneethanimidoyl chlorides.     

Reactions of 2-isocyanatobenzoyl chloride and 2-carbomethoxyphenyl isocyanate with 5-aminotetrazole

Treatment of 2-isocyanatobenzoyl chloride ( 4 ) with 5-aminotetrazole (5-AT) gave 3-(5-tetrazolyl)quinazoline-2,4(1H,3H)-dione ( 1 ) directly. Treatment of 2-carbomethoxyphenyl isocyanate ( 5 ) with 5-AT gave 2-[((5-amino-1H-tetrazol-1-yl)carbonyl)amino]benzoic acid methyl ester ( 6 ) as a kinetic product, which was thermally isomerized to 2-[((1H-tetrazol-5-ylamino)carbonyl)amino]benzoic acid methyl ester ( 7 ), the thermodynamically more stable urea. Cyclization of 7 with polyphosphoric acid gave 2-(1H-tetrazol-5-ylamino)-4H-3,1-benzoxazin-4-one ( 2 ). Urea 6 was quite labile in solution, as shown by nmr, and readily reacted with methanol to give 2-[(methoxycarbonyl)amino]benzoic acid methyl ester ( 10 ).     

Synthesis of nitrogen-containing heterocycles on the basis of 3-(4-acetylphenyl)-1-methylquinolin-2(1<Emphasis Type="Italic">H</Emphasis>)-one

The Meerwein reaction of 1-methylquinolin-2(1H)-one with 4-acetylbenzenediazonium chloride gave 3-(4-acetylphenyl)-1-methylquinolin-2(1H)-one which was brominated to 3-[4-(2-bromoacetyl)phenyl]-1-methylquinolin-2(1H)-one. The latter reacted with pyridine, 4-methylpyridine, quinoline, benzo[f]quinoline, and triphenylphosphine to afford the corresponding quaternary salts, and its reactions with thioacetamide, thiourea, 2-aminopyridine, and 2-aminopyrimidine led to the corresponding thiazole, imidazo[1,2-a]pyridine, and imidazo[1,2-a]pyrimidine derivatives containing a 2-oxoquinoline fragment. 3-(4-{2-[2-(Arylmethylidene)-hydrazinyl]-1,3-thiazol-4-yl}phenyl)-1-methylquinolin-2(1H)-ones were obtained by condensation of 3-[4-(2-bromoacetyl)phenyl]-1-methylquinolin-2(1H)-one with thiosemicarbazide and aromatic aldehydes.     

Réactions de Friedel et Crafts de dérivés aromatiques sur les composés dioxo-1,4,2,3-non saturés. IV. Réactions des hydroxy-5-ouchloro-5-diméthyl-3,5- ou diméthyl-4,5-dihydro-2,5-furannones-2

Friedel-Crafts reactions of aromatic derivatives with 1,4-dicarbonyls 2,3-éthylenic compounds. Part IV. Reactions of 5-hydroxy or 5-chloro 3,5-dimethyl or 4,5-dimethyl 2 (5 H) furanones We studied the Friedel-Crafts reactions of 2-(5H)-furanones. In the presence of sulfuric acid and of an aromatic derivative, 5-hydroxy- or 5-chloro-5-methyl-2-(5H)-furanones with one methyl group either in the 3 position, or in the 4 position generally give the corresponding 5-aryl-2-(5H)-furanones, while with aluminium chloride, it is possible to obtain, when a reaction takes place, isomeric 1H-indenecarboxylic acids. However, in a particular case, an addition to the substrate's double bond is observed. The 3-aryl-5-hydroxy-tetrahydrofuran-2-one obtained is methylated in two ways and gives either a cyclic product, or a linear one. In two cases tautomerism between 1H-1-indenecarboxylic acid and 1H-3-indenecarboxylic has been shown by ¹H-NMR.     

A clean synthesis of oxazino[5,6-<Emphasis Type="Italic">f</Emphasis>]quinolinone and naphtho[1,2-<Emphasis Type="Italic">e</Emphasis>]oxazinone derivatives

A clean, simple, one-pot, and efficient synthesis of 1,2-dihydro-1-aryl[1,3]oxazino[5,6-f]quinolin-3-one and 1,2-dihydro-1-arylnaphtho[1,2-e]-[1,3]oxazine-3-one derivatives was accomplished in good yields via reaction between 6-quinolinol or 2-naphthol, aromatic aldehydes, and methyl carbamate in aqueous medium catalyzed by TEBA (triethylbenzylammonium chloride). Correspondence: Mohammad Hossein Mosslemin, Department of Chemistry, Islamic Azad University, Yazd 8916871967, Iran.     

Synthese von 4-Benzylthio- und 4-(Arylthio)-1,3-oxazol-5(2H)-onen

Synthesis of 4-(Benzylthio)-and 4-(Arylthio)-1,3-oxazole-5(2H)-ones Following a known procedure, 4-(benzylthio)-1,3-oxazol-5(2H)-one ( 4a ) was synthesized starting from sodium cyanodithioformate ( 1 ) and cyclohexanone (Scheme 1). The structure of the intermediate 4-(benzylthio)-1,3-thiazol-5(2H)-one ( 3a ) was established by X-ray crystallography. An alternative route was developed for the synthesis of 4-(arylthio)-1,3-oxazol-5(2H)-ones which are not accessible by the former reaction. Treatment of ethyl cyanoformate ( 5 ) with a thiophenol in the presence of catalytic amounts of Et₂NH and TiCl₄, followed by addition of a ketone and BF₃.Et₂O in a one-pot-reaction, gave 4f–i in low-to-fair yields (Scheme 3). Both synthetic pathways-complementary as for benzyl–S and aryl-S derivatives–seem to be limited with respect to variation of substituents of the ketone.     

Poly(<Emphasis Type="Italic">N</Emphasis>-vinylimidazole) as an efficient and recyclable catalyst of the aza-Michael reaction in water

Poly(N-vinylimidazole) effectively catalyzed Michael addition of 1H-1,2,4-triazole, 3,5-dimethyl-1H-1,2,4-triazole, uracil, oxazolidin-2-one, and succinimide to but-3-en-2-one, cyclohex-2-en-1-one, methyl acrylate, and methyl vinyl sulfone in water at room temperature. The catalyst can readily be regenerated and repeatedly used at least five times without loss in activity, as shown in the reaction of 1H-1,2,4-triazole with but-3-en-2-one as an example.     

Benzimidazole condensed ring systems. 5. Studies on the Synthesis of Pyrimido[1,6-α]benzimidazole-1,3(2H,5H)-diones

The reaction of ethyl 1H-benzimidazole-2-acetate (1) with methyl or ethyl isocyantes 2a,b resulted in excellent yields of the respective 2-methyl- or 2-ethylpyrimido[1,6-a]benzimidazole-1,3(2H,5H)-diones 3a,b , while the reaction of 1 with phenyl isocyanate (2c) gave, unexpectedly, ethyl 2-(1-phenylcarbamoyl-1H,3H-benzimidazol-2-ylidene)-2-phenylcarbamoylacetate (4). Alkylation of 3 with trimethyl or triethyl phosphates 5a,b led to the 5-methyl or 5-ethyl derivatives 6a-d . Chlorination of 6 with sulfuryl chloride afforded the 4-chloro derivatives 7a-d.     

Reactions of derivatives of anthranilic acid with 3-chloropropyl isocyanate

The urea 1 obtained from anthranilonitrile and 3-chloropropyl isocyanate is converted into 3-(3-chloropropyl)-2,4(1H,3H)quinazolinedione ( 4 ) when heated with hydrochloric acid, whereas it undergoes a double cyclization to form 2,3,4,7-tetrahydro-6H-pyrimido[1,2-c]quinazolin-6-one ( 3 ) upon heating, or treatment with ammonia. On the other hand, the urea 5 formed from methyl anthranilate and 3-chloropropyl isocyanate cyclizes in three different ways, when treated with ammonia, potassium bicarbonate, or concentrated sulfuric acid, to yield compound 4 , 3,4-dihydro-2H,6H-[1,3]oxazino[2,3-b]quinazolin-6-one ( 9 ), or 2-[(3-chloropropyl)amino]-4H-3,1-benzoxazin-4-one ( 6 ), respectively. Acid-catalyzed reactions of compound 9 with nucleophilic reagents proceed with opening of the oxazine ring and readily yield various 3-substituted 2,4(1H,3H)-quinazolinediones.     

Cyanamides in the synthesis of 1,3-thiazole and 1,3-thiazine derivatives

Hetaryl, aroyl, and aryl cyanamides react with 2-sulfanylbenzoic acid, 2-aminobenzenethiol, and 2-aminoethanethiol to give derivatives of 2-amino-4H-1,3-benzothiazin-4-one, 1,3-benzothiazol-2-amine, and 4,5-dihydro-1,3-thiazol-2-amine.     

Synthesis and electronic spectra of new low-molecular weight compounds with possible application in electroluminescent layers

Two new low-molecular weight compounds — (Z)-4-(4-(dimethylamino)benzylidene)-1-(9-ethyl-9H-carbazol-3-yl)-2-phenyl-1H-imidazol-5(4H)-one and 2-(6-hydroxyhexyl)-6-(pyrrolidin-1-yl)-1H-benzo[de]isoquinoline-1,3(2H)-dione) — with possible application in organic light-emitting devices were synthesized. Their photophysical properties in solution and in polymer films were investigated. The determined relative fluorescence quantum yields in solution for both compounds were 0.003 and 0.51, while those in poly(methyl methacrylate) films were around 0.10 and 1.0, respectively. For 1H-imidazol-5(4H)-one derivative, single-layer organic displays with one emitting layer were prepared by spin-coating technology. The applied voltage was 40 V (AC) with 1–3 KHz frequency. The emission maximum of the experimental AC display structures was at 600–630 nm. For displays with 2-(6-hydroxyhexyl)-6-(pyrrolidin-1-yl)-1H-benzo[de]isoquinoline-1,3(2H)-dione) the applied voltage was 60 V (AC) with 6-9 KHz frequency, but its future success will require more appropriate binding polymers. Based on the obtained experimental results, it is concluded that the investigated compounds could be applied for preparation of color electroluminescent structures.      

4H-Chromenone Glycosides from Eranthis hyemalis (L.) SALISBURY

Investigation of the tubers of Eranthis hyemalis (Ranunculaceae) afforded six chromenone glycosides. Their structures have been elucidated mainly by spectroscopic (FAB-MS, 2D-NMR techniques) and chemical methods (acidic and enzymatic hydrolysis) as 9-{[(β-D -glucopyranosyl)oxy]methyl}-8,11-dihydro-5-hydroxy-2-methyl-4H-pyrano[2,3-g][1]benzoxepin-4-one ( 1 ), 9-{[(β-D -gentiobiosyl)oxy]methyl}-8,11-dihydro-5-hydroxy-2-methyl-4H-pyrano[2,3-g][1]benzoxepin-4-one( 2 ), 9-{[(β-D -glucopyranosvl)oxy]melhyl}-8,11-dihydro-5-hydroxy-2-(hydroxy-methyl)-4H-pyrano[2,3-g][1]benzoxepin-4-one( 3 ), 8-{(2E)-4-[(β-D -glucopyranosyl)oxy]-3-methylbut-2-enyl}-5,7-dihydroxy-2-methyl-4H-1-benzopyran-4-one ( 4 ), 8-{(2E)-4-[(β-D -glucopyranosyi)oxy]-3-methylbut-2-enyl}-5,7-dihydroxy-2-(hydroxymethyl)-4H-1-benzopyran-4-one ( 5 ), and 7-{[(β-D -glucopyranosy1)oxy]methyl}-2,3-dihydro-2-(l-hydroxy-1-methylethyl)-4-methoxy-5H-furo[3,2-g][1]benzopyran-5-one ( 6 ). Compound 2 exhibited negative inotropic activity.     

Simple procedure for preparation of quinoxalin-2(1H)-one 3-[Oxo(cyclo)alkyl(idene)] derivatives

A simple preparative procedure was developed for 3-(2-oxoalkylidene)-3,4-dihydroquinoxalin-2(1H)-ones, 4,5-dihydroxy-1-[3-oxo-3,4-dihydroquinoxalin-2(1H)-ylidene]-3,5-octadiene-2,7-dione, and 3-(2,3-dihydroxy-4-methyl-5-oxo-1,3-cyclopentadien-1-yl)quinoxalin-2(1H)-one by reaction of methyl ketones first with diethyl oxalate in the presence of sodium, and then with o-phenylenediamine.     

Synthesis and microbial screening of 8-(benzyloxy)-5-(2-[1,3-diphenyl-1H-pyrazol-4-yl]thiazol-4-yl)quinolin-2(1H)-one derivatives

The present investigation describe the synthesis of 8-(benzyloxy)-5-(2-[1,3-diphenyl-1H-pyrazol-4-yl]thiazol-4-yl)quinolin-2(1H)-one derivatives. Quinolin-8-ol was transformed by five step synthetic procedures into 8-Benzyloxy-5-(2-bromo-acetyl)-1H-quinolin-2-one. Subsequently, 8-Benzyloxy-5-(2-bromo-acetyl)-1H-quinolin-2-one condensed with 1,3-Diphenyl-1H-pyrazole-4-carbothioic acid amide in the presence of acetonitrile to afford 8-(benzyloxy)-5-(2-[1,3-diphenyl-1H-pyrazol-4-yl]thiazol-4-yl)quinolin-2(1H)-one derivatives. Synthesized compounds were screened for their antimicrobial activity against gram-positive and gram-negative bacteria. Most of the synthesized compounds are found to be active against tested bacterial strains and fungal strain.     

2H-1,2,4,6-thiatriazin-3(4H)-one 1-oxides and their regioselective N4-methylation and -amination

The syntheses of 2H-1,2,4,6-thiatriazin-3(4H)-one 1-oxides and 1,1-dioxides is described. The reaction of 1-carbamoyl-2-methylisothioureas 2 with thionyl chloride gave 2H-1,2,4,6-thiatriazin-3(4H)-one 1-oxides 3 in high yields. The treatment of 3 with either diazomethane or O-(2,4-dinitrophenyl)hydroxylamine furnished regioselectively N⁴-methylated and N⁴-aminated 2H-1,2,4,6-thiatriazin-3(4H)-one 1-oxides, respectively. Subsequent dimethylamination of 4 followed by oxidation with m-chloroperoxybenzoic acid led to 2H-1,2,4,6-thiatriazin-3(4H)-one 1,1-dioxides 6a-c .