Reaction of ethyl N-(6-ethoxycarbonyl-2-methylthiothieno[2,3-d]-pyrimidin-5-yl) formimidate with alkyl- and arylhydrazines: Formation of modified thieno[2,3-d]pyrimidines and thieno[2,3-d:4,5-d]dipyrimidin-4-ones

The reaction of ethyl N-(6-ethoxycarbonyl-2-methyl-thiothieno[2,3-d]pyrimidin-5-yl)formimidate ( 1 ) with methyl-hydrazine, N,N′-dimethyl- and N,N′-diphenylhydrazines separately in refluxing ethanol resulted in hydrolysis of formimidate group to give ethyl 5-amino-2-methylthiothieno[2,3-d] pyrimidine-6-carboxylate ( 2 ). The reaction on 1 with methyl-hydrazine without solvent afforded ethyl 5-amino-2-(1-methyl-hydrazino)thieno[2,3-d]pyrimidine-6-carboxylate ( 3 ), which underwent hydrazone formation with p-nitrobenzaldehyde to give 4 . Treatment of 1 with N,N-dimethylhydrazine afforded a mixture of 3-dimethylamino-7-methylthiothieno[2,3-d:4,5-d']dipyrimidin-4(3H)-one ( 5 ) and 2 . Displacement of methylthio group in 5 with morpholine, piperidine and 4-methylpiperazine gave the corresponding 7-substituted derivatives 6a-c . The reaction of 1 with para-substituted phenylhydrazines resulted in the formation of 3-(p-substituted phenylamino)7-methylthiothieno[2,3-d:4,5-d']dipyrimidin-4 (3H)ones ( 7a-c ).     

Synthesis of pyrazolo[4′,3′:5,6]pyrazino[2,3-c]pyrazoles and pyrazolo[4′,3′:5,6]pyrazino[2,3-d]pyrimidines and their application to polyester fibres

4-Nitroso-1-phenyl-3-methyl-5-aminopyrazole ( 1 ) was condensed with ethylcyanoacetate ( 2 ), malononitrile ( 4a ) and 2-cyanomethylbenzimidazole ( 4b ) to yield 6-hydroxy-5-cyano, 6-amino-5-cyano and 6-amino-5-(benzimidazol-2-yl)-3-methylpyrazolo [3,4-b]pyrazines 3, 5a and 5b , respectively. 5-Cyano-6-chloro derivative 6 obtained from 3 was converted to 3-aminopyrazolo[4′,3′:5,6]pyrazino[2,3-c]pyrazoles 8a and 8b by the treatment with hydrazin hydrate ( 7a ) and phenylhydrazine ( 7b ), respectively. Compound 5a was treated with formamide ( 9a ), urea ( 9b ) and thiourea ( 9c ) to give 4-aminopyrazolo[4′,3′:5,6]pyrazino[2′3′-d]pyrimidines 10a–10c. With refluxing acetic anhydride compounds 8a, 8b and 10a gave corresponding acetamido derivatives 8c, 8d and 10d. Compound 5a was treated with ethylorthoformate ( 11 ), acetic anhydride ( 12 ) or benzoylchloride ( 13 ) to give fused benzimidazopyrazolo[4′,3′:5,6]pyrazino[2′,3′-d]pyrimidines, viz., benzimidazol[1,2-c]pyrazolo[4,3-g]pteridines ( 14a–14c ). Some of the compounds 8, 10 and 14 were applied to polyester as disperse dyes and their fastness properties were studied.     

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 .     

METHODS FOR AROMATIC AND HETEROCYCLIC AMINE CARCINOGEN-DNA ADDUCT ANALYSIS BY LIQUID CHROMATOGRAPHY-TANDEM MASS SPECTROMETRY

Xenobiotic-DNA adducts are used as biomarkers to assess the genotoxic effects of carcinogens. Rats were dosed with 4-aminobiphenyl (4-ABP), 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx), or 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP). DNA was isolated from the colons of vehicle and carcinogen-treated rats and digested using different nucleases and alkaline phosphatase. Deoxyribonucleoside adducts were quantified by capillary liquid chromatography-tandem mass spectrometry (LC-MS/MS) using isotope dilution methods with deuterated internal standards. Major adducts were those bound to the C8 position of deoxyguanosine. 3′- and 5′- Exonucleases were the most efficient nucleases at isolating dG-C8-ABP adducts. However, bulky adducts such as dG-C8-MeIQx and dG-C8-PhIP were better isolated using nuclease P1 rather than a combination of micrococcal nuclease and spleen phosphodiesterase. The use of DNase I enhanced the detection of all three adducts. We describe LC-MS/MS methods for DNA adduct detection and support the testing of different nucleases that increase DNA digestion efficiency and make available more DNA adducts for detection.     

Synthesis of 2 and 6-triazolylthiazolo[4,5-b]quinoxaline derivatives and their application as fluorescent disperse dyes

Synthesis of 2-triazolylthiazolo[4,5-b]quinoxaline derivatives was achieved by diazotisation of 2-aminothiazolo[4,5-b]quinoxaline and its 6-nitro derivative using orthophosphoric acid and sodium nitrite with a trace of nitric acid, coupling with suitable aromatic amines and subsequent cyclisation of the resulting ortho amino azo compounds. Diazotisation of 2,6-diaminothiazolo[4,5-b]quinoxaline with concentrated hydrochloric acid and sodium nitrite and subsequent coupling and cyclisation resulted in the 6-triazolylthiazolo[4,5-b]quinoxaline derivatives. These compounds were applied on polyester as fluorescent disperse dyes.     

Heterocyclic quinones. XVI. The Reaction of acid Amides with 2,3- Dichloro-1,4-naphthoquinone,a novel route to naphth[2,3-d]oxazole-4,9-diones

Heating acid amides 2 with 2,3-dichloro-1,4-naphthoquinone 1 in solvents like glycerol or ethylene glycol gave readily naphth [2,3-d] oxazole-4,9-diones 4 . The reaction was enhanced by addition of catalytic amounts of sodium hydrogencarbonate, but failed to proceed at all when attempted in low boiling polar or nonpolar solvents. 2-Amido-3-chloro-1,4-naphthoquinones 3 were produced as intermediates in these reactions.     

Quinoxaline derivatives as long wavelength photosensitizers in photoinitiated cationic polymerization of diaryliodonium salts

The present paper is focused on visible light initiated cationic polymerizations. Photoinitiated polymerization of representative vinyl ether and oxirane monomers using two quinoxaline derivatives; namely (2-(2,3-dihydrobenzo [b][1,4]dioxin-6-yl)-3-(2,3-dihydrobenzo[b]-[1,4]dioxin-7-yl)-5-(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)-8-(2,3-dihydrothieno[3,4-b][1,4]dioxin-7yl) quinoxaline) (DBQEd) and 2,3,5,8-tetra(thiophen-2-yl)quinoxaline (TTQ) are studied. Novel dyes based on the quinoxaline skeleton are employed as efficient photosensitizers in cationic photopolymerizations. Polymerizations were initiated at room temperature upon irradiation with long-wavelength UV and visible lights in the presence of diphenyliodonium hexafluorophosphate (Ph₂I⁺PF₆^?). The progress of the polymerizations was monitored by optical pyrometry (OP). Solar irradiation is also employed to carry out the cationic polymerization of a diepoxide monomer in the presence of air.     

Amino-thieno[2,3–c]pyrazole und Amino-thieno[2,3–b]pyrrole

Amino-thieno[2,3–c]pyrazoles and Amino-thieno[2,3–b]pyrroles The synthesis of thieno[2,3–c]pyrazoles and thieno[2,3–b]pyrroles is described. From the dithioliumsalt ( 1 ) and potassium hydroxide the potassium-(2,2-dicyan-1-methylthio-ethen-1-yl)-thiolate ( 2 ) is formed. This reacts with hydrazine hydrate to form the 3-amino-5-thioxo-pyrazol-4-carbonitrile ( 3 ) S-Alkylation with α-chlorocarbonyl compounds yielding ( 6a–c ) leads via Thorpe-Ziegler-cyclization to 3,4-diamino-thieno[2,3–c]pyrazoles ( 9 ) if the position 1 is alkylated ( 8 ). Acetyl acetone yields 2-mercapto-pyrazolo[1,5–a]pyrimidine ( 5 ). After S-alkylation ( 10a–d ) are immediately cyclized to thieno [2′,3′:3,4]pyrazolo[1,5-a]pyrimidine ( 11a–d ). The ketone ( 6a ) can be cyclized to the pyrazolo [5,1–b]thiazole ( 12 ). 3 reacts with oxalyl chloride to form the 2,3-dioxo-6-thioxo-imidazo[1,2-b]pyrazole ( 13 ) of which S-phenacyl derivative ( 14 ) because the NH-proton cannot be cyclized. The 5-amino-3,4-dicyano-pyrrol-2-thiolate ( 16 ) shows the analogous behaviour. The S-alkylation is followed by cyclization, and 3,5-diamino-thieno[2,3–b]pyrroles ( 18a–b ) arise. Reaction of 5-amino-2-alkylthio-pyrrol-3,5-dicarbonitrile ( 17 ) with acetyl acetone provides pyrrolo[1,2-a]pyrimidine ( 20a–c ) which can be cyclized to form thieno[3′,2′:4,6]pyrimidines ( 21a–c ) very easily.     

Action of acrylonitrile on 4-cyano- and 4-carbethoxy pyridazin-3(2H)-ones and their 3-mercapto derivatives. A novel Synthesis of Pyrano and Thiinopyridazines

Reaction of acrylonitrile with 4-cyano-5,6-diphenyl pyridazin-3(2H)-one and 3(2H)-thione derivative ( 1a, b ) at elevated temperature gave 7H-5-amino-6-cyano-3,4-diphenylpyrano and thiino [2,3-c] pyridazines ( 2a, b ), respectively. However, the reaction of 4-carbethoxy pyridazine derivatives ( 1c, d ) with the same reagent, under the same conditions afforded 6H, 7H-6-cyano-3,4-diphenyl-5-oxopyrano ( 3a ) and thiino [2,3-c] pyridazine ( 3b ), respectively. In addition, treatment of ( 1a, c ) and ( 1b, d ) with acrylonitrile ar reflux in alkaline medium give the respective 3-(2′-cyanoethyloxo) ( 7a, c ) and 3-2′-cyanoethylthio ( 7b, d ) pyridazine derivatives. Prolonged alkaline hydrolysis of either ( 1a, c ) or ( 7a, c ) yielded the same product ( 8a ). Also hydrolysis of ( 1b, d ) and ( 7b, d ) afforded one and the same product ( 8b ). The structures of the products were assigned on the basis of satisfactory analytical and spectroscopic data.     

Synthesis and structure of new alkynyl derivatives of phenothiazine and phenoxazine

New alkynyl derivatives of phenothiazine and phenoxazine were obtained via Sonogashira cross-coupling reactions. This was achieved by first synthesizing the intermediates 6-chloro-5H-benzo[a]phenothiazin-5-one, 6-chloro-5H-benzo[a]phenoxazin-5-one and 6-chloro-5H-naphtho[2,1-b]pyrido[2,3-e][1,4]oxazin-5-one by anhydrous base-catalyzed condensations between 2,3-dichloro-1,4-naphthoquinone and 2-aminothiophenol, 2-aminophenol and 2-aminopyridinol, respectively .The cross-couplings of these electron-rich chlorophenothiazine and chlorophenoxazine intermediates with terminal alkynes, employing 4?mol% Pd and 7?mol% XPhos in the presence of base in acetonitrile at 80°C, afforded the highly colored alkynylated derivatives in good yields. These reaction conditions allowed the incorporation of both unprotected N-H and carbonyl groups. Structural assignments were established by spectroscopic (UV, IR, ¹H and ¹³Cnmr), ms and elemental analytical data.     

五氟磺草胺中间体2-氨基-5,8-二甲氧基[1,2,4]三唑[1,5-c]嘧啶的合成研究

以甲氧基乙酸甲酯、甲酸乙酯和尿素为原料,经缩合、环化、三氯氧磷氯化、氨水取代得到2-氯-4-氨基-5-甲氧基嘧啶,然后与N-乙氧基羰基异硫氰酸酯反应、盐酸羟胺环化、甲氧基化得到目标产物2-氨基-5,8-二甲氧基[1,2,4]三唑[1,5-c]嘧啶。总收率27.2%。     

氯虫苯甲酰胺的合成

以顺丁烯二酸酐、2,3-二氯吡啶为起始原料经8步反应合成中间体3-溴-1-(3-氯吡啶-2-吡啶基)-1H-吡唑-5-甲酸(9);以2-氨基-3-甲基苯甲酸为原料经1步反应合成中间体5-氯-2-氨基-3-甲基苯甲酸(10).中间体9与10反应生成氯虫苯甲酰胺.目标化合物经1H NMR确证.反应总收率36.3%(以2,3-二氯吡啶计),产品含量(HPLC)不小于95%.     

吡啶并吡嗪/咪唑杂环化合物的合成研究

以2,3-二氨基吡啶或2,3,5,6-四氨基吡啶盐酸盐等为原料合成了吡啶并吡嗪、吡啶并咪唑及吡啶并二咪唑氮杂环衍生物。探讨了反应条件对产物收率的影响,初步确定了优化反应条件。对2,3-二甲基吡啶并吡嗪及2,3-二乙基吡啶并吡嗪的合成,氯化铵-甲醇体系具有明显的催化效果。使用4,5-二羟基咪唑烷-2-酮代替乙二醛与2,3-二氨基吡啶反应,可显著提高吡啶并吡嗪的合成收率;对于吡啶并咪唑和2-甲基吡啶并咪唑的合成,以2,3-二氨基吡啶与原甲酸三乙酯或原乙酸三甲酯为原料,在磷钼酸催化下反应,收率达50%以上;对于吡啶并[2,3-b:5,6-b']二咪唑和2,6-二甲基吡啶并[2,3-b:5,6-b']二咪唑的合成,分别以2,3,5,6-四氨基吡啶盐酸盐与原甲酸三乙酯和原乙酸三甲酯为原料在磷钼酸催化下反应,收率可达68.7%和66.5%。     

2,3-Heterokondensierte Thiophene aus substituiertem 2-Aminothiophen-3-thiol

2,3-Heterocondensed Thiophenes from Substituted 2-Aminothiophen-3-thiole Ethyl 5-amino-4-mercapto-3-methyl-thiophen-2-carboxylate ( 2 ), obtainable from the appropriate thienylthiocyanate 1 by reduction, undergoes reactions in analogy to the 2-aminobenzenthiole. Thus, with formic acid or trimethylorthoacetat the thieno [2,3-d]thiazoles 4 and 5 are formed. Aromatic aldehydes yield the thieno[2,3-d]thiazolines ( 6 ) which can be dehydrogenated by sulphur to form 9 . From carbon disulfide and 2 the thieno[2,3-d]thiazol-2-thione ( 7 ) is formed. With phenacylbromide or ethyl bromoacetate 2 can be converted into the thieno[3,2-b] thiazine derivatives 11 or 12 . Diazotation of 2 yields the thieno[2,3-d]1,2,3-thiadiazole derivative ( 14 ).     

Ring closure reaction of 5-hydroxy-pyrido[2,3-d]pyrimidine-2,4,7-triones to benzo[b]pyrimido[4,5-h]1,6-naphthyridine-1,3,6-triones

N-Substituted aminouracils ( 1 ) react with malonates by cyclocondensation to 5-hydroxy-pyrido[2,3-d]pyrimidine-2,4,7-triones ( 2 ), which give with triethylorthoformate and aniline 6-(phenylaminomethylene)-pyrido[2,3-d]pyrimidine-tetraone ( 3 ). Halogenation of 2a - d (with R² = Me) with phosphorylchloride leads to 5,7-dichloro-pyrido[2,3-d]pyrimidine-2,4-diones ( 4 ) by cleavage of the methyl group at N-8, whereas Vilsmeier reaction of 2 affords 5-chloro-6-formyl derivatives ( 6 ), which cyclize with arylamines to give benzo[b]pyrimido[4,5-h] 1,6-naphthyridines ( 9 ). Compounds 9 were obtained independently by amination of the tosylates 5 to the 5-arylamino compounds 8 , and Vilsmeier formylation to yield 9 .     

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.     

Dyes for synthetic-polymer fibres: I72 I72 V 2 14H-naphtho[2,3-a]phenothiazine-8,13-diones I72 I72 V 3 and 1H-2,3-dihydroanthra[2,1-b][1,4]-thiazine-7,12-diones I72 I72 V 3

Condensation of 1-amino- or 1-hydroxy-2-bromoanthraquinones with 2-amino-benzenethiol, I72 I72 V 2 or of 1-amino-2-bromoanthraquinones with 2-nitrobenzenethiol I72 I72 V 3 gives 14H-naphtho[2,3-a]-phenothiazine-8,13-diones. The related 1H-2,3- I72 I72 V 3 dihydroanthra[2,1-b][1,4]thiazine-7,12-diones result from interaction of 1- I72 I72 V 3 amino-2-mercaptoanthraquinones with 1,2-dibromoethane or of 1-hydroxy-2- I72 I72 V 3 bromoanthraquinones with 2-aminoethanethiol. The colour, dyeing and fastness I72 I72 V 3 properties of these compounds on synthetic-polymer fibres are described. I72 I72 V 3     

The synthesis of fused and pendant pyrazole heterocyclic compounds from 5-amino-3-methyl-1-phenylpyrazole and their evaluation as fluorescent brightening agents

5-Amino-3-methyl-1-phenylpyrazole ( 1 ) has been condensed with EMME ( 2 a) and EMCA ( 2 b) and the resulting ethyl 5-aminoacrylates ( 3 a–b) cyclized to pyrazolo[3,4,-b]pyridines ( 4 a–b). 3-Methyl-1-phenylpyrazol-5-yl diazonium salt ( 7 ), prepared from ( 1 ) was coupled with tobias acid ( 8 ) and 2-methoxy-6-aminoquinoxaline ( 9 ) to get the corresponding O-aminoarylazo and heterylazo dyes ( 10 ) which were oxidatively cyclized to 2-N-(3-methyl-1-N-phenylpyrazol-5-yl)-1,2,3-triazolo[4,5-a] naphthalene and [4,5-f] quinoxaline derivative ( 11 ). The spectral properties of the compounds ( 4 a–b, 5 , 6 , 11 a–b) were studied.     

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 .     

Two-component,one-pot synthesis of pyrimido[1,2-b] [1,2,4,5]tetrazines

Derivatives containing the cyclohepta4′,5′thieno[2′,3′:4,5]pyrimido[1,2-b][1,2,4,5]-tetrazin-6-one system were prepared from the reaction of 3-amino-2-thioxo-1,2,3,5,6,7,8,9-octahydro-4H-cyclohepta[4,5]thieno[2,3-d]pyrimidin-4-one (5) or its 2-methylthio derivative 6 with hydrazonoyl chlorides 9. The mechanism of the studied reactions has been discussed and the biological activity of the isolated products has been evaluated.