Neue Azoolefine und deren saure Spaltung zu Aryldiiminen

New Azoolefines and their Acidic cleavage to Aryldiimines 3-Amino-1-aryl-3′,3′-dimethyl-pyrazolin-4-spiro-2′-oxiran-5-ones ( 3a – c ) undergo ring opening with methoxide forming methyl 3-amino-3-arylazo-propenoates ( 5a – c ). 5a – c are cleaved under acidic conditions. The main products of the cleavage of 5c with methanolic hydrochloric acid are nitrogen, 2, 4, 6-trichloro-benzen ( 6 ), 2, 4, 6-trichloro-aniline ( 9 ) and 2, 4, 6-trichlorophenylhydrazine ( 10 ). Intermediates of the cleavage of 5 are aryldiimines trapped with benzaldehyde as the corresponding benzhydrazides ( 12a , b ).     

Reactions with 5,6-Diphenyl-2,3-dihydro-imidazo[2,1-b]thiazol-3-ones and 6,7-Diphenyl-2,3-dihydro-4H-imidazo[2,1-b]1,3-thiazin-4-one

2-Methyl-5,6-diphenyl-2,3-dihydro-imidazo[2,1-b]thiazol-3-one 5 and 6,7-diphenyl-2,3-dihydro-4H-imidazo[2,1-b]1,3-thiazin-4-one 6 are prepared from 4,5-diphenyl-2-mercapto-imidazole 1 . Compounds 5 and 6 react with amines or hydrazines to give the 2-(4,5-diphenyl-imidazol-2-ylthio)acet(or propan) amides (hydrazides) 7a – g and the 3-(4,5-diphenyl-imidazol-2 ylthio) propanamides(hydrazides) 8a – e , respectively. The hydrazides 7a, 7b and 8a are condensed with aromatic aldehydes to the hydrazones 9a – h and 10a – d . Compound 5 couples with aryldiazonium salts to give 2-arylazo-2-methyl-5,6-diphenyl-2,3-dihydro-imidazo[2,1-b]thiazol-3-ones 11a – d .     

Synthesis and Structural Characterization of 5-Bromo-2,3-dimethylphenol

Bromination of the disubstituted 4,5-dimethyl-1,3-cyclohexanedione ( 6 ) followed by oxidation of the resulting 3-bromo-5,6-dimethyl-2-cyclohexen-1-ones ( 7 ) gave 5-bromo-2,3-dimethylphenol ( 1 ) together with its constitutional isomer 3 . The structure of 1 was secured by a x-ray analysis of its tosyl derivative 8 .     

Einige ungewöhnliche Umsetzungen des Dinatrium-2-oxo-1,3-dithiol-4,5-dithiolats mit Biselektrophilen

Some Unusual Reactions of Disodium 2-Oxo-1,3-dithiole-4,5-dithiolates with Biselectrophiles Reaction of disodium 2-oxo-1,3-dithiole-4,5-dithiolate (3) with dichloro-maleic anhydride (4) , Mucobromic acid (7) and its pseudoester 9 leads to the formation of the 1,3-dithiolo[4,5-b]-1,4-dithiins 6, 8 and 10. 3 condenses with cis-3,5-dibromo-cyclopentene (15) to yield the tricyclic compounds 16 and 17. 3 is silylated by trimethylsilyltriflate (19) to give the unstable bis(trimethylsilyl)-thioether 20 which reacts with aldehydes and ketones to furnish the 1,3-dithiolo[4,5-d]-1,3-dithiole-2-ones 22a–c .     

Synthese und Polymerisation von 2-Aryl-5-methylen-1,3-dioxolan-4-onen und Arylbis(5-methylen-1,3-dioxolan-2-yl-4-on)en

Synthesis and Polymerization Behaviour of 2-Aryl-5-methylene-1,3-dioxolan-4-ones and Arylbis(5-methylene-1,3-dioxolan-2-yl-4-on)es Starting from 2,6-di(hydroxymethyl)-4-methylphen-ol-Na-salt-1-hydrate ( 1 ) a synthesis of 2-alkoxy-5-methyliso-phthaldialdehydes ( 3a,b ) is described via alkylation and oxidation. Condensation of aromatic aldehydes with 3-bromo-2-hydroxypropanoic acid (β-bromolactic acid) affords diastereoisomeric mixtures of new 2-aryl-5-bromomethyl-1,3-dioxolan-4-ones ( 6a–h ) as well as the corresponding bisdioxolanones ( 6i–l ). Dehydrobromination of 2-aryl-5-bromomethyl-1,3-dioxolan-4-ones ( 6a–d,i ) with DBU leads to 2-aryl-5-methylene-1,3-dioxolan-4-ones ( 8a–e ). Polymerization of compounds 8a , b , d and e proceed via opening of the dioxolanone ring.     

Darstellung und Reaktionen von 2-Arylazo-2-nitro-keten-aminalen

Synthesis and Reactions of 2-Arylazo-2-nitro-keten Aminals N,N′-Disubstituted 1-nitro-2,2-diamino ethylenes 1 undergo azo-coupling to form the title compounds 2 . Their treatment with oxalyl chloride yields the imidazolidin-4,5-dione-derivatives 4. 2 react with phosgene and thiophosgene to form 6-nitro-2,4-diaryl-5-arylimino−2,3,4,5-tetrahydro-1,2,4-triazin-3-ones 5 and -thiones 6 respectively. From 2 and N-(dichloromethylene)-arylsulfoamides the 6-nitro-2,4-diaryl-5-arylimino-3-aryl-sulfonylimino-2,3,4,5-tetrahydro-1,2,4-triazines 7 arise. The reduction of 2 yields the substituted oxalic amidines 9     

Chlormethyl-substituierte Heterocyclen aus Chlortetrolsäuremethylester

Chloromethyl Substituted Heterocycles from Methyl Chlorotetrolate Reaction of amidines, isothioureas or thioureas with methyl chlorotetrolate 1 leads to pyrimidin-4-ones 2 and 1,3-thiazines ( 3 ), respectively. Compounds 2 and 3 are starting materials for the synthesis of 6-chloromethyl-uracils ( 4 ), 1,3-thiazine-2,4-dione 5 and 6-benzylthiomethyl-thiazinone ( 6 ). 2-Aminothiazoles react with the ester 1 to yield 5-chloromethyl-thiazolo[3,2-a]pyrimidin-7-ones ( 7 ). The 5-oxo isomers 8 are obtained by reaction of thiazoles with ethyl γ-chloroacetoacetate. By reaction of 2-mercaptoimidazoles and 1 or chlorotetrolic acid the condensed 1,3-thiazinones ( 10 ) result. In the latter case the intermediate 9 is isolated. It can be cyclised to 10 by heating with acetic anhydride and sulphuric acid.     

Synthesis of 1,3-Oxazines and Furo[2,3-b]pyrans by reaction of 2-amino-4,5-dihydro-3-furancarbonitriles with dibenzoyldiazomethanes

2-Amino-4,5-dihydro-3-furancarbonitriles ( 1 ) react with a slight excess of dibenzoyldiazomethane in the presence of rhodium(II) acetate to give 1,3-oxazin-4-ones ( 2 ). With three equivalents of dibenzoyldiazomethane compounds 1 react to afford furo[2,3-b]pyran-3a-carbonitriles ( 3 ). Compound 3a was also obtained by treatment of 2a with two equivalents of dibenzoyldiazomethane.     

Novel magnesium and zinc porphyrazines containing galactose moieties: Synthesis via click reaction and characterization

In this study, galactose conjugated new magnesium and zinc porphyrazines were synthesized by the cyclotetramerization reaction of 2,3-bis[1-(2,2,7,7-tetramethyltetra-hydro-bis[1,3]dioxolo[4,5-b;4′,5′-d]pyran-5,methyl)-1H-[1,2,3]triazol-4-yl methylsulfanyl]-but 2-enedinitrile. This substituted dicyano compound was prepared via two different routes. One started from cis-1,2-dicyano-1,2-ethylenedithiolate disodium, [1-(2, 2, 7,7-tetramethyltetrahydrobis[1,3]dioxolo[4,5-b;4′,5′-d]pyran-5-yl-methyl)-1H-[1,2,3]triazo-l-4-yl]methanol and ended in a multi-step reaction sequence via Click procedures. The other reaction was between 5-azidomethyl-2,2,7,7-tetramethyltetrahydro-bis[1,3]dioxolo[4,5-b;4′,5′-d]pyran and (2Z)-2,3-bis(prop-2-yl-1-yl-thio)but-2-enedinitrile. A very soluble galactose linked magnesium porphyrazine derivative in common polar solvents and water was achieved by the deprotected isopropylidene groups in TFA and water media. It is first time, zinc porphyrazine complex has been achieved at one-step reaction by using Zn(BuO)₂ as template agent. The new compounds have been characterized by a combination of elemental analysis, ¹H, ¹³C NMR, IR, UV–vis and MS spectral data.     

Über neue Pyrazolverbindungen. IV Darstellung und Cyclisierungsverhalten einiger akzeptorsubstituierter N-(Pyrazol-3-yl)-thioharnstoffe

New Pyrazol Derivatives. IV. Preparation and Cyclization of Some Acceptor-Substituted N-(Pyrazol-3-yl)-thioureas . 3-Aminopyrazol-4-carboxylic acid derivatives ( 1 , 2 ) were transformed by reaction with different isothiocyanates R²NCS to N-(pyrazol-3-yl)-N^. -substituted thioureas ( 5 , 6 ). Ethyl 3-amino-1-benzylpyrazol-4-carboxylate reacts with CSCl₂ to form ethyl 1-benzyl-3-isothiocyanatopyrazol-4-carboxylate ( 3 ) which yields with amines the corresponding N-(pyrazol-3-yl)-N^. -substituted thioureas ( 5 ). As a byproduct in the reaction with CSCl₂ N,N^. -di-(pyrazol-3-yl)-thiourea ( 4 ) is formed. With hydrazine or phenylhydrazine N-(pyrazol-3-yl)-thiosemicarbazides ( 7a , b ) are obtained. The thioureas ( 5 , 6 ) can be cyclized in basic solution to 4,5,6,7-tetrahydropyrazolo[3,4-d]pyrimidin-4-on-6-thiones ( 8 ) which on alkylation form 6-alkylthio-4,5-dihydropyrazolo[3,4-d]pyrimidin-4-ones ( 9 ). Methyl-N-(pyrazol-3-yl)-N^.-benzoylisothiourea ( 10 ) reacts with ethylamine to form N-benzoyl-N^. -ethyl-N^‥-(pyrazol-3-yl)-guanidine derivative ( 11 ) which on treatment with NaH in dimethylformamide yields 6-benzoylamino-5-ethyl-4,5-dihydropyrazolo[3,4-d]pyrimidin-4-one ( 12 ). By treatment with sulfuric acid the N-(pyrazol-3-yl)-thiourea derivatives ( 5 , 6 ) form new 6-amino substituted pyrazolo[3,4-d][1,3]thiazin-4-ones ( 13 ).     

Synthesis of 4,4′-aryldihydrazono-3-(3′-pyridyl)-2-pyrazolin-4,5-diones and 1-aryl-3-(3′-pyridyl)-4,4′-arylbisazo-5-aryliminopyrazoles and their application as disazo disperse dyes. Part II

3-(3′-Pyridyl)-2-pyrazoline-4,5-dione 4,4′(4,4′-biphenylenedihydrazone and p-phenylenedihydrazone) and its derivatives ( IIa-e, IIIa-e ) were obtained by the coupling reaction of tetrazotised benzidine and p-diamonobenzene with 3-(3′-pyridyl)-2-pyrazolin-5-ones ( Ia-e ). Similarly, bis-azo compounds containing pyrazole nucleous as, 1-aryl-3-(3′-pyridyl)-4,4′-arylbisazo-5-aryliminopyrazoles ( VIa-i and VIIa-i ) were prepared by the interaction of the corresponding chloro compound ( IV and V ) with aromatic amines. The compounds so obtained ( II, III, VI and VII ) are used as disazo disperse dyes for dyeing polyester fibres fast yellow-orange shades. Their fastness properties towards washing, rubbing, acid-alkaline perspiration and light were investigated.     

Efficient asymmetric TADDOLs-organocatalyzed cycloaddition for the synthesis of allyltin derivatives

We report here the results obtained in the study of organocatalytic asymmetric Diels–Alder reactions to optimize the synthesis of stereo defined allyltin derivatives using (Z)-2-(1-cyclohexenyl)-1-ethenyl(trineophyl)stannane (1) as diene and substituted dienophiles in the presence of (4R,5R)-α,α,α′,α′-tetraphenyl-1,3-dioxolane-4,5-dimethanol (TADDOL, I) and analogs (4R,5R)-α,α,α′,α′-tetra(1-naphtyl)-1,3-dioxolane-4,5-dimethanol (II) and (4R,5R)-α,α,α′,α′-tetra(9-phenantryl)1,3-dioxolane-4,5-dimethanol (III) as chiral catalysts to enhance stereoselectivity through hydrogen bond activation of the dienophile. Catalyst II provided excellent results and ultrasonic radiation at low temperature showed the shorter reaction times.     

Regioselective synthesis of new 5-methyl-5H-pyrimido[4′,5′:4,5][1,3]thiazino [3,2-a]perimidines

A convenient and efficient regioselective synthesis of new pyrimido[4′,5′:4,5] [1,3]thiazino[3,2-a]perimidines is described through intermolecular heterocyclization of 2,4-dichloro-5-(chloromethyl)-6-methylpyrimidine and 1H-perimidine-2(3H)-thione in short reaction times under mild conditions.     

Cyclisierungsreaktionen β,γ-ungesättigter Kohlensäurederivate. IX. Regiochemie der elektrophilen Cyclofunktionalisierung β,γ-ungesättigter Carbamidsäureester mit Brom – Synthese von Oxazolidin-2-onen und Tetrahydro-2H-1,3-oxazin-2-onen

Cyclization Reactions of β,γ-Unsaturated Derivatives of Carbonic Acid. IX. Regiochemistry of Electrophilic Cyclofunctionalization of β,γ-Unsaturated Carbamic Acid Esters with Bromine – Synthesis of Oxazolidine-2-ones and Tetrahydro-2H-1,3-oxazine-2-ones N,N-Disubstituted β,γ-unsaturated urethanes ( 1 ) and bromine react in methylene chloride at room temperature. The crotyl urethanes ( 1a – 1c and 1e ) and bromine give mixtures of corresponding saturated urethanes (dibromine adducts) ( 2a – 2c and 2e ), the oxazolidine-2-ones ( 3a – 3c and 3e ), and the tetrahydro-2H-1,3-oxazine-2-ones ( 4a – 4c and 4e ). The reaction of γ,γ-dimethylallyl urethanes ( 1f – 1h ) with bromine gives similar results. A useful synthetic route to N-substituted tetrahydro-2H-1,3-oxazine-2-ones ( 4l – 4q ) is demonstrated by the reaction of cinnamyl urethanes ( 1l – 1q ) with bromine.     

Preparation and crystal structure determination of adducts of copper(II) chloride with 3-aryl-1-(imino-pyridin-2-yl-methyl)-5-hydroxy-5-trifluoromethyl-4,5-dihydro-1H-pyrazoles

1,1,1-Trifluoro-4-methoxy-4-aryl-but-3-en-2-ones react with 2-pyridylcarboxamidrazone to produce the corresponding 1,1,1-trifluoro-4-aryl-4-(N¹-pyridine-2-carboxamidrazone)-3-buten-2-ones. The butenones react with copper(II) chloride to give 1:1 adducts, in which the donor molecules were shown to isomerize to their cyclic pyrazolic forms. The crystal structure of the 4-fluoro-phenyl derivative, dichloro-[3-(4-fluorophenyl)-1-(imino-pyridin-2-yl-methyl)-5-hydroxy-5-trifluoromethyl-4,5-dihydro-1H-pyrazole]-copper(II), was solved by X-ray crystallography. The structural results are compared with those of other copper(II) chloride adducts of similar ligands containing the amidrazone pharmacophore, which have been tested as anticancer drugs.     

Beiträge zum Reaktionsverhalten von Derivaten der Imidodithiokohlensäure. II [1]. 7-Hydroxythiazolo[4,5-b]pyridone-(5)

Contributions to the Reaction Behaviour of Derivatives of Imidodithiocarbonic Acid. II. 7-Hydroxythiazolo[4,5-b]pyrid-5-ones Derivatives of cyanimidocarbonic acid 1 react with ethyl γ-bromoacetoacetate to ethyl thiazolylacetates 2 which are converted into 7-hydroxythiazolo[4,5-b]pyrid-5-ones 3 by acid or base catalyzed cyclisation. These compounds can be alkylated as well as acylated. The 7-hydroxy group is exchangeable for chlorine. Furthermore in position 6 electrophilic sulfonation can take place.     

Geschützte Aminooxazoline der Arabinose und Ribose

Protected Aminooxazolines of Arabinose and Ribose The reaction of D-arabinose or D-ribose with cyanamide afforded 2-amino-1,2-oxazolines 1 which were treated with dihydropyran or ethylvinylether. In the presence of PTS the 3′,5′-di-THP- or 3′,5′-di-O-ethoxyethyl-D-arabino-(ribo)-furo-[1′,2′:4,5]-2-oxazolines 2 and 3 could be isolated as useful intermediates for the preparation of nucleosides. When the 2-aminooxazolines are treated with benzyloxycarbonylchloride or its p-substituted derivatives the N-3 atom of the oxazoline ring is preferentially substituted. Under these conditions the exocyclic amino function is always replaced and 2-oxo-3-benzyloxycarbonylderivatives 4 are obtained; only traces of the corresponding 2-aminoderivatives 5 are formed. Treatment of 4 with acetic anhydride, benzoylchloride, and benzoylcyanide, respectively, results in the 3′-, 5′-di-O-acyl derivatives 6 . Mild hydrolysis of the benzyloxycarbonyl group with trifluoroacetic acid yields the 3′,5′-di-O-acyl-D-arabino-(ribo)-furo-[1′,2′:4,5]-2-oxooxazolidines as further intermediates for the synthesis of nucleosides.     

Synthese von 2-aminosubstituierten 4,5-Dihydro-1,3-thiazolen

Synthesis of 2-Amino-Substituted 4,5-Dihydro-1,3-thiazoles . The reaction of 2-substituted 4-methallylthiosemicarbazides 1 with carbonyl compounds catalyzed by weak acids gives thiosemicarbazones 2 and 1,2,4-triazolidine-3-thiones 3 . By contrast under strong acidic conditions the reaction occurs by electrophilic cyclisation with participation of the methallyl and thiono groups, and 4,5-dihydro-1,3-thiazoles 5 are formed after neutralisation. The electrophilic cyclisation of N-methallyl substituted thioureas 6 and 1,4-disubstituted thiosemicarbazides 7 is also described.     

Vergleich der thermischen,photochemischen und massenspektrometrischen Fragmentierung von Schwefelheterocyclen mit cis-Dithioethylenstruktur

Comparison of the Thermal, Photochemical and Mass Spectrometric Fragmentation of Sulphur Heterocycles with cis-Dithioethene-Structure The mass spectrometric primary fragmentation of 3-methylthio-1,4,2-dithiazines 1 , 1,4-dithiins 2 , 2,3-dihydro-1,4-dithiin-2-ones 4 , 1,3-dithiole-2-ones 5 , 2-imino-1,3-dithioles 6 and 1,3-dithiole-2-thiones 7 is compared with their thermolytical and photochemical reaction. In the mass spectra an intense peak of the dithiete radical ion is observed, if in the compounds an energetically favourable neutral molecule is preformed: in 1 methyl rhodanide, in 3 ethene, in 4 ketene, in 5 carbon monoxide and in 6 hydrogen cyanide. The substances 1, 3–6 – with the restriction by 3 – yield photochemically the dithiete, too. The photolysis of dithiazines 1 is wave length dependent. Mass spectrometrically, thermally and photochemically the dithiins 2 form thiophenes. The dithiolethiones 7 decompose mass spectrometrically and thermally into carbon disulfide, sulfur and ethynes, but photochemically they form tetrathiafulvalenes. The fragmentation of the compounds 1–6 is analogous in mass spectrometry and photolysis; 2, 3, 5 and with reservation 1 show similar mass spectrometric, thermal and photochemical reactivity. Possible reasons for these analogies are discussed. The dithietes, generated by photolysis of the compounds 1, 4, 5 or 6 react with iron penta-, nickel tetra-, molybdenum hexa- and tungsten hexacarbonyl in preparative scale to the corresponding dithiolene complexes.     

Alkylthio-substituierte Bis(benzol-1,2-dithiolato)zinkate,Benzol-1,2-dithiole und -1,2-dithiolate – Edukte für Dibenzo[c,g](1,2,5,6)tetrathiocine und Benzo[c](1,2,3)-trithiole; Untersuchungen zu Benzodithieten und ortho-Dithiobenzochinonen

Alkylthiosubstituted Bis(benzene-1,2-dithiolato)zincates, Benzene-1,2-dithioles, and -1,2-dithiolates – Educts for Dibenzo[c,g](1,2,5,6)tetrathiocins, and Benzo[c](1,2,3)trithioles; Investigations on Benzodithietes and ortho-Dithiobenzochinones Using benzenehexathiolate 1 it is possible to synthesize alkylthio-substituted benzo-1,3-dithiole-2-thiones 2 , or -ones 3 and benzo-di(1,3-dithiole-2-thiones) 4 , or -ones 5 , resp., which were cleaved under basic conditions. The generated benzene-1,2-dithiolates 7 were isolated as benzene-dithiolato zincates 8 , benzene-1,2-dithioles 11 , and benzene-1-thiole-2-thiolates 10 . Dibenzo[c,g](1,2,5,6)-tetrathiocins 9 were synthesized by oxidation of 7 or 8 in good yields. For the per(methylthio)-substituted tetrathiocin 9a the twist conformation was proved by x-ray structure analysis. The tetrathiocin 9a was probably formed via the orthodithiobenzoquinone 13a . Photolysis of 3a at room temperature in solution led to 9a and tetrakis(methylthio)benzo[c] (1,2,3)trithiole 12a as the main product, which was also formed by irradiation of 9a . The trithioles 12 were formed from 8 by reaction with sulfur dichloride. 12a was investigated by x-ray structure analysis. ortho-Dithiobenzoquinone 13c can be claimed as an intermediate upon irradiation of benzo-1,3-dithiol-2-one 3c in an argon matrix at 10 K. Depending on the wavelength the equilibrium lies either on the side of dithiobenzoquinone 13c or benzodithiete 14c . The same is true for system 15/16 , which can be reached by flash vacuum pyrolysis of 3c .