Characterization of all Six Mono -Methylchrysenes by NMR and MS

Complete assignment of the 1 H and 13 C resonances of the methylchrysenes ( 1 - 6 ) were accomplished using 1D and 2D NMR techniques. Shift increments were calculated for the six mono -methyl isomers, showing the similarity of the positions 1 and 6, 2 and 3, and 4 and 5 in these systems. Simulation of the 13 C NMR spectra gave large differences in chemical shifts compared to the experimental values. The mass spectra of chrysene ( 7 ) with methyl substituent in all six possible positions were similar and very simple, containing little structural information.     

Thiatriazole. VII. 3-Aroxy-5-imino-1,2,4-dithiazole aus 5-Amino-1,2,3,4-thiatriazol

Thiatriazoles. VII. 3-Aroxy-1,2,4-dithiazole-5-imids of 5-Amino-1,2,3,4-thiatriazole The unstable but isolable 3-aroxy-1,2,4-dithiazole-5-imids ( 2a – d ) has been found on chlorothioformate acylation of 5-amino-1,2,3,4-thiatriazole ( 1 ) in acetonitril. Further acylation and nucleophilic displacement reactions gave stable 3-amino-5-acylimino-1,2,4-dithiazoles ( 6a – c , 7 ). The structure of the prepared compounds was inferred from their ¹H and ¹³C-n.m.r., mass spectra and corroborated by comparison with the data of similar derivates as well as by chemical means.     

Addition of arylureas to aroyl isothiocyanates and the synthesis of 1-aroyl-5-aryl-2-thiobiurets and 2-aryl-5-aroylamino-2,3-dihydro-1,2,4-thiadiazol-3-ones

The hitherto unknown 1-aroyl-5-aryl-2-thiobiurets ( 5a – h ) were synthesized by addition of mono arylureas ( 4 ) to aroyl isothiocyanates ( 3 ). Treatment of 1-aroyl-5-aryl-2-thiobiurets ( 5a – h ) with alkali gave 5-aryl-2-thiobiurets ( 6a – e ). Oxidation of 1-aroyl-5-aryl-2-thiobiurets ( 5d , f , h ) with hydrogen peroxide in the presence of hydrochloric acid or bromine in chloroform gave 2-aryl-5-aroylamino-2,3-dihydro-1,2,4-thiadiazol-3-ones ( 7a – c ).     

Direct Synthesis of Pyrazoles via reaction of C-ethoxycarbonyl-N-arylnitrilimines with benzalmalononitriles and some α-cyanocinnamic acid derivatives

Reaction of C-ethoxycarbonyl-N-arylnitrilimines ( 2a–d ) with α, β-disubstituted acrylonitriles ( 3a–f ) in refluxing benzene affords the corresponding substituted pyrazoles 5a–f and 6a–c respectively in good yield. However, reaction of 2a–e with 3g gives the 2-pyrazoline derivatives 7a–d . The assigned structures for the products 5–7 were confirmed by their spectra (i.r., ¹H-n.m.r.) and elemental analyses. Also the structures of the pyrazoles 5 were substantiated by comparison with their regioisomeres 8 .     

Quinone–Quinoneimine Tautomerism of Some Aminonaphthoquinonoid Dyes

Quinone–quinoneimine tautomerism of 7, 10–dihydroxy–2, 3, 4–trihydrobenzo f quinoxalin–6–one derivatives has been investigated by means of their n. m. r. and visible absorption spectra. The quinonoid ring protons gave signals in the range 5. 6–6. 1 p. p. m., while the benzenoid ring protons showed signals in the range 6. 9–7. 0 p. p. m. These differences in chemical shift were valuable in identifying the structure of the tautomer. Tautomerism was found to be largely influenced by the nature of the substituents and the polarity of the solvent, and the equilibrium shift to the quinoneimine form in polar solvents. The quinone form absorbed visible light at much longer wavelengths (by about 100 nm) than does the quinoneimine form. The isosbestic point of the tautomerism was observed at about 510 nm. The calculated absorption maximum of each tautomer obtained using the PPP MO method was correlated with the observed values to predict the principal tautomer in solution.     

Synthesis of Thiazolo(4,5-b)-quinoxalines and related compounds

The reaction of 2,3,7-trichloroquinoxaline ( 1 ) or 2,3-dichloro-7-bromoquinoxaline ( 2 ) with thiourea in DMSO gave 6,6′-dichloro- or 6,6′-dibromodiquinoxalino[2,3-b:2′:3′-e]1,4-dithiien ( 3 or 4 ). However, 1 or 2 reacts with thiourea in ethanol to give ( 3 or 4 ) beside 7-chloro- or 7-bromo-2-imino-2,3-dihydrothiazolo[4,5-b] quinoxaline ( 5 or 6 ) respectively. Interaction of 1 or 2 with acetone thiosemicarbazone gave 7-chloro- or 7-bromo-3-amino-2-imino-2,3-dihydro-thiazolo[4,5-b] quinoxaline hydrochloride ( 13 or 14 ) respectively. Cyclization of 7-chloro- or 7-bromo-3-amino-2-imino-2,3-dihydrothiazolo[4,5-b]quinoxaline ( 15 or 16 ) on treatment with aromatic acid chlorides or isothiocyanates succeeded to give 19—21 or 28 and 29 .     

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.     

Gamma-irradiation of individual cholesterol oxidation products

Cholesterol and seven of its oxidation products in aqueous suspensions of multilamellar vesicles or sonicated aqueous suspensions were subjected individually to γ-radiation (10 KGy) at 0–4°C in air, N₂ or N₂O. All compounds underwent some changes under the influence of radiation. β-Epoxide (cholesterol 5β,6β-epoxide) and, to a much lesser extent, α-epoxide (cholesterol 5α,6α-epoxide) were converted in low yield to 6-ketocholestanol (5α-cholestan-3β-ol-6-one). 7β-Hydroxycholesterol (cholest-5-ene-3β,7β-diol) and, to a lesser extent, 7α-hydroxycholesterol (cholest-5-ene-3β,7α-diol) gave low yields of 7-ketocholestanol (5α-cholestan-3β-ol-7-one). The latter compound also was obtained by irradiation of 7-ketocholesterol (cholest-5-ene-3β-ol-7-one). 6-Ketocholestanol and 7-ketocholestanol are potential biomarkers for irradiated meat and poultry.     

Synthesis of 2-Aryl-6-substituted quinolines and their use as fluorescent brightening agents

The condensation of 5-bromoisatin (1a) with aryl methyl ketones (2a–2d) gave 2-aryl-6-bromoquinolines (3a–3d), ammonolysis of which gave the 6-amino-2-arylquinoline derivatives (4a–4d), which were also converted to the corresponding acetyl derivatives 5a–5d by reaction with acetic anhydride. Diazotisation of 4a–4d and coupling with Tobias acid (6) gave o-aminoazo dyes (7a–7d), which were then oxidatively cyclised to the 2-aryl-6-triazoloquinoline derivatives (8a–8d). Treatment of 2-phenyl-6-bromoquinoline-4-carboxylic acid (3a) with cuprous cyanide and copper in quinoline gave 2-phenyl-6-cyanoquinoline (9) which on condensation with 2-aminophenol (10) and 1,2-diaminobenzene (11) yielded 2-phenyl-6-(benzoxazol-2-yl)- and 2-phenyl-6-(benzimidazol-2-yl)-quinolines (12a and 12b, respectively). The possible use of compounds 5a–5d, 8a–8d, 9 and 12a–12b as fluorescent brightening agents was studied.     

Structural Characterization and Luminescent Properties of a Red Phosphor Series: Y2−xEux(MoO4)3 (x=0.4–2.0)

A series of rare earth molybdates, Y_{2− x} Eu _x (MoO₄)₃ for x =0.4, 0.8, 1.2, 1.6 and 2.0 were prepared by solid-state method and their crystal structures, photo luminescent characteristics were investigated. The powders are mainly studied for their red light emission efficiency under near UV excitation. The crystal structures of the powders were found to depend on annealing temperature and the yttrium concentration. Mixtures of monoclinic ( C 2 /c ) and orthorhombic ( Pba 2, Pbna ) structures were formed in varying proportions depending on the value of x and annealing temperatures (700°–800°C). The luminescence behavior depended on the resultant composition of the crystal phase and the Eu³⁺ concentration. The excitation spectra showed the characteristic and broad O→Mo charge transfer (CT) band of the MoO₄ tetrahedra and the sharp intra-configurational 4 f –4 f transitions of Eu³⁺ in the host lattice. The integrated emission ratio (⁵D₀→⁷F₂/⁵D₀→⁷F₁) of Eu³⁺ depends on the annealing temperature and reveals that the local site symmetry of Eu³⁺ ions decreases with increasing concentration of Eu³⁺. The emission spectra obtained by exciting at 396 nm, gave highest red emission intensity for Y_0.4Eu_1.6(MoO₄)₃ annealed at 700°C/6 h among this series of samples.     

Preparation and Luminescence Spectra of Calcium- and Rare-Earth (R = Eu, Tb, and Pr)-Codoped α-SiAlON Ceramics

Rare-earth-doped oxynitride or nitride compounds have been reported to be luminescent and may then serve as new phosphors with good thermal and chemical stabilities. In this work, we report the photoluminescence (PL) spectra of europium-, terbium-, and praseodymium-doped Ca-α-SiAlON ceramics. The highly dense ceramics were prepared by hot pressing at 1750°C for 1 h under 20 MPa in a nitrogen atmosphere. Europium-doped Ca-α-SiAlON displayed a single broad emission band peaking at λ= 550–590 nm depending on the europium concentration. The emission bands in the spectra of europium-doped Ca-α-SiAlONs were assigned to the allowed transition of Eu²⁺ from the lowest crystal field component of 4 f ⁶5 d to ⁸S_7/2 (4 f ⁷) ground-state level. The emission spectra of terbium- and praseodymium-doped Ca-α-SiAlON ceramics both consisted of several sharp lines, which were attributed to the ⁵D₄→⁷F _j ( j = 3, 4, 5, 6) transitions of Tb³⁺ and ³P₀→³H _j ( j = 3, 4, 5) transitions of Pr³⁺, respectively. In particular, the terbium-doped α-SiAlON ceramics showed a strong green emission among these phosphors.     

New phenothiazine dyes and pigments

The synthesis of three new azaphenothiazine ring systems and an evaluation of their use as intermediates for new dyes and pigments is described. 2-Amino-5-bromopyrazine-3[4H]-thione (11) was prepared and converted to the novel 1,4,6,9-tetraazaphenothiazine ring system. The reaction of 4,5-diaminopyrimidine-6[1H]-thione (15) with 2,3-dichloropyrazines gave the isomeric 1,4,6,8-tetraazaphenothiazine ring system, another new heterocycle in this series. With 2,3-dichloroquinoxaline a previously unknown tetracyclic tetraazaphenothiazine ring system was isolated in satisfactory yields. The properties and reactions of these new heterocyclic systems are presented. Mixed nitric and sulphuric acids convert them to their 5-sulphoxides. Structural assignments were based on chemical evidence and their UV, IR, NMR and mass spectra. Mechanistic pathways to these compounds are also proposed.     

Selective cyclisation of 2, 3, 4, 5-tetra-O-acetyl-galactaric acid bis-[Alkylthio(thiocarbonyl)]hydrazide to Saccharide 1, 3, 4-Oxadiazole,Thiadiazole, and thiadiazoline derivatives

The synthesis of galactaric acid acetate bis[alkylthio(thiocarbonyl)]hydrazide ( 1 , 2 ) is described. Selective cyclisation of both hydrazides 1 and 2 was investigated. Phosphorous oxychloride as cyclising agent led to dehydrative cyclisation and produced 1, 2, 3, 4-tetra-O-acetyl-1, 4-bis(5-S-methyl or — benzyl) 1, 3, 4-thiadiazol-2-yl galactotetritol ( 3 ) or ( 4 ). While thionyl chloride led to dehydrosulfurization and gave 1, 2, 3, 4-tetra-O-acetyl-1, 4-bis(5-S-methyl or -benzyl)-1, 3, 4-oxadiazol-2-yl galactotetritol ( 5 ) or ( 6 ). Finally with triethyl orthoformate as cyclising agent, compounds 1 or 2 , gave 3, 3′-(2, 3, 4, 5-tetra-O-acetyl-galactar-1.6 dioyl)bis[2-ethoxy-2, 3-dihydro-5-S-methyl or benzyl 1, 3, 4-thiadiazole] ( 7 ) or ( 8 ).     

三苄基锡炔基膦酸酯的合成及波谱分析

合成了6个新的三苄基锡炔基瞵酸酯[(PhCH2)3Sn]2O2P(O)C≡CR(R=n-C5H11,n-C6H13,n-C7H15,Ph,CH2OCH3,CH2OC2H5),对产物进行了红外光谱及核磁共振氢谱分析。     

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.     

Sulphur Analogues of Deoxyvasicinone

The synthesis of the 2-thioanalogue of deoxyvasicinone ( 1 ) 5 and some higher analogues 6 and 7 are described. Oxidation of these heterocycles with 3-chloroperoxybenzoic acid gave the sulphoxides 12 , 13 and 14 which underwent facile Pummerer rearrangement to yield, after deacetylation, the alkanols 18 , 19 and 20 . Under more vigorous oxidising conditions 5 and 6 were oxidatively ring opened to yield the sulphonic acids 21 and 22 whereas 7 gave the sulphone 23 .     

Umsetzung von (Z/E)-1-Aryl-4-arylmethylen-pyrrolidin-2,3,5-trionen mit Enaminocarbonylverbindungen

Reaction of (Z/E)-1-Aryl-4-arylmethylene-pyrrolidine-2,3,5-triones with Enaminocarbonyl Compounds Treatment of the α, β-unsaturated ketones (Z/E)- 1a–e with alicyclic or aliphatic enamines afforded cyclic Michael adducts 2 and 3a–e , respectively. By dehydration of the N,O-hemiacetals 3b–d the corresponding 1,4-dihydropyridines 4a–c were obtained. The acid-catalyzed reaction of aminosubstituted maleimides with (Z/E)- 1e , aldehydes or indan-1,2,3-trione led to 5a–c , 6a–c , 7a–c and 8 . O-Methylation of the aryl-bis(maleinimidyl)methanes 5c , 6c by using diazomethane gave 5d , 6d , whereas 5a cyclized spontaneously to the 1,4-dihydropyridine 9a . Further 1,4-dihydropyridines were prepared by cyclocondensation of 6a , b in the presence of ammonium acetate and oxidized to the pyridine derivative 10 .     

Reactions of Ring C in Glycyrrhetic Acid Derivatives

The chemistry of the relatively unreactive glycyrrhetic acid (1) ring C was investigated. The enone group in this ring was reduced by diborane to allylic alcohols (6, 7), which can be readily converted into the corresponding homoannular dienes (2, 5). These dienes were also prepared by NaBH₄ reduction of the enone group. The epoxidation of the diene 2 leads to the mono-( 12 ) and di-( 14 ) epoxides. A new ring C enone system ( 13 ) was also obtained. Treatment of the two different tosylhydrazones derivatives ( 16, 20 ) with methyllithium gave the conjugated methylene compounds ( 17, 21 ). The NMR spectrum of the latter compound was also studied with a shift reagent — Eu(FOD). The mass spectra of the homoannular dienes ( 2, 5 ), allylic alcohols ( 6, 7 ) and 11-methylene compounds ( 17, 21 ) were studied and some new types of fragmentation were suggested.     

铽-樟脑酸-α,α′联吡啶配合物的合成及荧光性能研究

合成了稀土铽-α,α′联吡啶三元配合物,通过元素分析、红外光谱分析,确定了配合物的组成为Tb2(CA)3(dipy)2(CA:樟脑酸根,dipy:α,α′联吡啶),另外,又合成了不同比例铽、钇异核混配三元配合物。在室温下测定了配合物的荧光激发光谱,最佳波长为313 nm,即在313.0 nm光的激发下,测定了四种稀土配合物的发射光谱,发射光谱图显示了Tb3+离子的特征光谱,产生四条谱线,分别是5D4-7F6(490.0 nm),5D4-7F5(544.0 nm),5D4-7F4(584.0 nm),5D4-7F3(620.0nm),最强峰为544 nm处Tb3+离子绿色荧光发射峰。对四种配合物荧光发射峰强度变化的研究表明,钇的掺入并没有降低铽离子的荧光强度,说明不发光稀土离子钇对铽离子的荧光发射有敏化作用。     

Synthesis and reactions of 2-(p-chloroanilino)-5- (D-galacto-1,2,3,4,5-pentahydroxypentyl)-1,3,4-thiadiazole

Oxidative cyclization of D -galactose (p-chlorophenyl)thiosemicarbazone gave 2-(p-chloroanilino)-5-( D -galacto-1,2,3,4,5-pentahydroxypentyl)-1,3,4-thiadiazole ( 1 ), whose acetylation afforded 2-[N-acetyl-N-(p-chlorophenyl)]-amino-5-( D -galacto-1,2,3,4,5-pentacetoxypentyl)- 1,3,4-thiadiazole ( 3 ). Its periodate oxidation of the glycol groups gave 2-(p-chloroanilino)-1,3,4-thiadiazole-5-carboxaldehyde ( 4 ), which can be transformed into 1,2-[2-(p-chloroanilino)-1,3,4-thiadiazol-5-yl]-1-hydroxy-2-oxoethane. A number of hydrazones of the formyl thiadiazole was prepared and its reduction with sodium borohydride gave 2-(p-chloroanilino)-5-hydroxymethyl-1,3,4-thiadiazole ( 6 ), whose acetylation gave a mono-O-acetyl derivative ( 7 ). Oxidation of the formyl thiadiazole gave 2-(p-chloroanilino)-1,3,4-thiadiazole ( 9 ). The spectral data of the compounds were discussed.