The Reaction of Indole with Propiolic Acid

The reaction of indole with propiolic acid ia 1 : 1 mole ratio gave an adduct (I) of 2 : 1 addition with decarboxylation. The reaction of indole with propiolic acid methyl ester gave a 2 : 1 adduct (II). Hydrolysis of adduct II yield the corresponding carboxylic acid (IV). Decarboxylation of IV also gave I. The mechanism of title reaction were fully studied.     

The reaction of aroylhydrazines with N-phenylsulfonylarenehydrazonoyl chlorides. A route to substituted 4-amino-(4H)-1,2,4-triazoles and 1,3,4-oxadiazoles

Treatment of N-phenylsulfonylarenehydrazonoyl chlorides (II) with equivalent amounts of aroylhydrazines (III) in ethanol gave 3,5-diaryl-4-phenylsulfonylamino-1,2,4-triazoles (IV). Reaction of II with two equivalents of III in tetrahydrofuran gave 2,5-diaryl-1,3,4-oxadiazoles (V), in addition to IV. Addition of triethylamine to II or its mixture with III yielded only the tetrazenes (VIII). The possible pathways leading to IV-V and VIII are discussed. J. Chem. Soc., 14, 1089 (1977)     

Some derivatives of benzoin

Extension of the reaction time of benzoin (I) with anthranilamide (II) gave 2,3,5,6-tetraphenyl-pyrazine (IV) in addition to the expected benzamide III. Condensation of I with II in the presence of ammonium acetate or ammonium formate yielded IV, and IV with 4-quinazolinone (VII), respectively. Reaction of I with ammonium acetate only led to IV and 2,3,5,6-tetraphenylpyrrole (VIII). When I was heated with 2-aminothiazole, benzil, desoxybenzoin, and VIII were formed. A mechanism has been extended to explain the formation of IV and VIII.     

Tricyclic chemistry. Synthesis and chemistry of a novel polyheterocycle

The photochemical reaction of 1 with acrylonitrile gave the cyclobutane adducts II and III, which on treatment with base afforded a novel polycyclic structure IV. Reduction of IV with LAH followed by Eschweiler-Clarke methylation yielded the polyheterocyclic structure VI.     

Studies on the syntheses of heterocyclic compounds. Part CCLXXIII. Synthesis of C-nordihydrocorynantheol and its related compounds

Mannich reaction of tryptamine with 3,3,4-triethoxycarbonylhexaldehyde (IV) gave the cyclized product (VIII), whose hydrolysis, followed by decarboxylation, afforded the acid (IX). After esterification of IX, reduction of ester (X) with lithium aluminum hydride gave the C-nordihydrocorynantheol (II). The syntheses of IV and XV were also described. Furthermore, the Mannich reaction of L-N-benzyl-1-methyltryptophan methyl ester (XV) with IV was also examined. This reaction gave the ester (XVII), which was hydrolyzed and decarboxylated to give the acid (XVIII). Esterification of XVIII, followed by catalytic hydrogenation, gave the lactam (III).     

Cycloalkanes containing heterocyclic germanium,tin and lead

Treatment of the lithium reagent from 1,3-bis(trifluoromethyl)benzene (I) with carbon dioxide gave a 60/40 mixture of 2,4- and 2,6-bis(trifluoromethyl)-benzoic acids (IV) and (II). The lithiation/carbonation of 1,3-bis(trifluoromethyl)benzene-5-d (VIII) gave (II) and (IV) without loss of deutrium. This result indicates that (I), unlike trifluoromethylbenzene, does not lithiate meta to a CF₃ group.     

Manganese K-edge XANES studies of Mn speciation in Lac des Allemands as a function of depth

X-Ray absorbance near edge spectroscopy (XANES) was used to identify variations in oxidation states of Mn with depth in a core sample. The core sample was collected from a small lake (Lac des Allemands) located in southeastern Louisiana. Samples of core segments were split into subsamples, one dried prior to analysis and a second kept wet. Upper core segments in the wet subsample was found to have K-edge energies 1.5 eV below the lower core segments, suggesting the presence of Mn(II) and/or Mn(III). The dominant oxidation state in all core segments was Mn(IV), with the bottom core samples containing almost entirely Mn(IV). This change in oxidation state probably resulted from the depletion of water at depth and the presence of anaerobic conditions. Manganese oxidations states were also found to change in pre-treated (dried) samples. Significant concentrations of Mn(II)/Mn(III) were found in the wet core segments near the water/sediment interface but these states disappear after drying.     

Potentiometric titration of gold, platinum, and some other precious metals with cetylpyridinium chloride

Summary The precipitation titration of some precious metal halides vs. cetylpyridinium chloride was investigated, with emphasis on tetrachloroaurate and hexachloroplatinate. The optimum pH for titration of the latter anions was from 0.5 to 1.0. Differentiation of AuCl ₄ ^– and PtCl ₆ ^2– with this titrant is not feasible; their sum can, however, be determined. Titration vs. tetraphenylarsonium chloride at the same pH is successful only for AuCl ₄ ^– which can, thus, be determined in the presence of PtCl ₆ ^2– . Tetrachlororuthenate(IV), hexachlororhodate(III) and hexachloroiridate(III) did not yield analytically useful titration curves. Hexachloroosmate(IV), tetrachloropalladate(II), hexachloropalladate(IV), hexachloroiridate(IV) and tetrachloroplatinite(II) gave good titration curves.

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Potentiometrische Titration von Gold, Platin und einigen anderen Edelmetallen mit Cetylpyridiniumchlorid

Zusammenfassung Die Fällungstitration einiger Edelmetallhalogenide mit Cetylpyridiniumchlorid wurde untersucht, wobei besonders Tetrachloraurat und Hexachlorplatinat von Interesse waren. Der optimale pH-Wert für die Titration war 0,5–1,0. Eine Unterscheidung zwischen AuCl ₄ ^– und PtCl ₆ ^2– war nicht möglich, jedoch kann deren Summe erfaßt werden. Die Titration mit Tetraphenylarsoniumchlorid bei demselben pH-Wert ist nur für AuCl ₄ ^– anwendbar; eine Bestimmung neben PtCl ₆ ^2– ist dadurch möglich. Für Tetrachlorruthenat(IV), Hexachlorrhodat(III) und Hexachloriridat(III) wurden keine analytisch brauchbaren Titrationskurven erhalten. Hexachlorosmat(IV), Tetrachlorpalladat(II), Hexachlorpalladat(IV), Hexachloriridat(IV) und Tetrachlorplatinit(II) ergaben jedoch gute Titrationskurven.

     

手性炔基亚砜作为二碳合成子在生物卤介不对称合成中的应用

本文报导了手性炔基亚砜的制备及其在四氢异喹啉及四氢咔啉生物碱对映体选择性合成中的应用。     

Intramolecularly Coordinated Organotin Tellurides: Stable or Unstable?

The step-wise oxidation of an organotin(I) compound with elemental tellurium gave a variety of unprecedented organotin tellurides containing tin atoms in the oxidation states +II and +IV.     

5,5,5-Trifluorolaevulic acid and some derived compounds

5,5,5-Trifluorolaevulic acid (II) has been prepared by the acidic hydrolysis of the Claisen condensation product (I) of ethyl trifluoroacetate and diethyl succinate. Dehydration of the acid (II) with phosphoric oxide gave 4-hydroxy-5,5,5-trifluoropent-3-enoic acid lactone (III). Reduction of either this lactone or the acid (II) with lithium aluminium hydride gave 5,5,5-trifluoropentane-1,4-diol (IV), from which 5,5,5-trifluoropenta-1,3-diene (VI) has been obtained by acetylation followed by pyrolysis.     

Ion chromatography of chloro complexes of the platinum group metals and gold using bonded phase silica substrates

The ion chromatography of chloro complexes of Au(III), Ir(IV), Ir(III), Os(IV), Pd(II), Pt(IV), Rh(III) and Ru(III) was investigated using anion-exchange and ion-interaction techniques involving silica-based phases. Chloride was either absent or at a very low level and the pH was high enough to enable steel-fabricated liquid chromatography equipment to be used. With anion exchange, Ir(IV), Ir(III), Os(IV) and Pt(IV) gave good stable chromatography and all produced linear calibration plots, except Ir(IV) owing to instability of the sample solution. The detection limits were Ir(III) 5, Os(IV) 10 and Pt(IV) 2 ng ml^?1. The ion-interaction technique was not so successful, only Au(III) and Pd(II) giving stable chromatography. The calibration plots were slightly curved, although acceptable, and the detection limits were 10 and 30 ng ml^?1 for Au (III) and Pd(II), respectively.     

Heterocycles. Part V. Reaction of α,β-unsaturated carbonyl compounds with arylacetamides. A synthesis of 2-pyridone derivatives

The reaction of 1,3-diaryl-2-propene-1-ones I with arylacetamides II, in the presence of sodium ethoxide under reflux, for two hours, gave the corresponding 3,4,6-triaryl-3,4-dihydro-2(1H)-pyridones IV. However, when the reaction of these ketones was carried out in the presence of sodium hydride, they gave the corresponding 3,4,6-triaryl-2(1H)-pyridones VI or a mixture of IV and VI. When 1,3-diaryl-2-propyne-1-ones V were reacted with arylacetamides, in the presence of sodium hydride, they yielded the corresponding 2-pyridones VI. Treatment of compounds IV with selenium produced the corresponding 2-pyridones VI. Acetylation of the latter compounds gave the corresponding 2-acetyl derivatives VIII. The structure of all products was confirmed by chemical and spectroscopic evidence, and the mechanism of the reactions was discussed.     

Reaction of vinylcyclopropanes with butyllithium

Vinylcyclopropanes III and IV gave mainly allyl anions I, II, and XIII respectively under strong metalating conditions. Cyclopropyllithiums V and XV were also formed unexpectedly in significant quantities and were further explored.     

Reactions of tetrafluoroethylene oligomers. Part 1. Some pyrolytic reactions of the pentamer and hexaher and of the fluorine adducts of the tetramer and pentamer

Pyrolyses of these highly branched fluorocarbons over glass beads caused the preferential thermolyses of CC bonds where there is maximum carbon substitution. Fluorinations of perfluoro-3,4-dimethylhex-3-ene (tetramer) (I) and perfluoro-4-ethyl-3,4-dimethylhex- 2-ehe (pentamer) (II) over cobalt (III) fluoride at 230° and 145° respectively afforded the corresponding saturated fluorocarbons (III) and (IV), though II gave principally the saturated tetramer (III) at 250°. Pyrolysis of III alone at 500—520° gave perfluoro-2-methylbutane (V), whilst pyrolysis of III in the presence of bromine or toluene afforded 2-bromononafluorobutane (VI) and 2H-nonafluorobutane (VII) respectively. Pyrolysis of perfluoro-3-ethyl-3, 4-dimethylhexane (IV) alone gave a mixture of perfluoro-2-methylbutane (V), perfluoro-2-methylbut-1-ene (VIII), perfluoro-3-methylpentane (IX), perfluoro-3,3-dimethylpentane (X), and perfluoro-3,4- dimethylhexane (III). Pyrolysis of IV in the presence of bromine gave (VI) and 3-bromo-3-trifluoromethyl-decafluoropentane (XI): with toluene, pyrolysis gare VlI and 3H-3-trifluoromethyldecafluoropentane (XII). Pyrolysis of II at 500° over glass gave perfluoro-1,2,3-trimethylcyclobutene (XIII) and perfluoro-2,3-dimethylpenta-1,3(E)- and (Z)-diene (XIV) and (XV) respectively. The diene mixture (XIV and XV) was fluorinated with CoF₃ to give perfluoro-2,3-dimethylpentane (XVI) and was cyclised thermally to give the cyclobutene (XIII). Pyrolysis of perfluoro-2- (1′-ethyl-1′-methylpropyl)-3-methylpent-1-ene (XVII) (TFE hexamer major isomer) at 500° gave perfluoro-1-methyl-2-(1′-methylpropyl)cyclobut-1-ene (XVIII) and perfluoro-2-methyl-2-(1′-methylpropyl)buta-1,3-diene (XIX). Fluorination of XVIII over CoF₃ gave perfluoro-1-methyl-2- (1′-methylpropyl)cyclobutane (XX), which on co-pyrolysis with bromine gave VI. XIX on heating gave XVIII. Reaction of XVIII with ammonia in ether gave a mixture of E and Z 1′-trifluoromethyl-2-(1′-trifluoromethyl- pentafluoropropyliden-1′-yl)tetrafluorocyclobutylamine (XXI) which on diazotisation and hydrolysis afforded 2-(2′trifluoromethyl- tetrafluorocyclobut-1-en-1′-yl)-octafluorobutan-2-ol (XXII).     

Some 4-quinazolinones

The acid catalyzed reaction of anthranilamide with benzoin was studied under two conditions. Condensation at 150° gave known J plus unexpected quinazolinone H. In refluxing benzene (azeolropic water removal), the reactants yielded imine III. The acid catalyzed and uncatalyzed 150° reaction of III was examined by both ir and tlc. Both benzoic acid and II were formed in each case. Triethyl ortholormate with I gave quinazolinone IV while this ester with III formed II, benzaldehyde and benzoic acid.     

Insect pheromones and their analogues. XVIII. Regiospecific synthesis of (±)-15,19-dimethyltritriacontane — A component of the pheromone of Stomoxys calcitrans

(±)-15,19-Dimethyltritriacontane (II) — a component of the pheromone of the stable fly — has been obtained by a five-stage synthesis from dimethylcyclooctadiene (I). The coupling of 1,1-dimethoxy-4-methyl-8-oxonon-4Z-ene [the product of the ozonolysis of (I)] with n-C₁₃H₂₇CH=PPh₃ (THF; ?30°, 2 h; 25°, 15 h; Ar) gave 1,1-dimethoxy-4,8-dimethyldocosa-4Z,8Z(E)-diene (III). The hydrolysis of (III) (TsOH·Py, H₂O-Ac, boiling, 4 h) gave the corresponding aldehyde (IV). The condensation of (IV) with n-C₁₀H₂₁CH=PPh₃ (THF; ?60° to ?30°C, 2 h, 25°C, 15 h) led to 15,19-dimethyltritriaconta-11Z(E),15Z,19Z(E)-triene (V), the exhaustive hydrogenation of which (ethanol, H₂, 5% Pd/C, 25°C) gave (II). The substance, the yield in %, and R_f values are given, respectively: (II), 95, 0.92; (III), 29, 0.74; (IV), 80, 0.72; (V) 50, 0.8. The IR and PMR spectra of compounds (II)–(V) and the mass spectra of (II) and (III) are given.     

The aminolysis and esterification of unsymmetrical epoxides

The reactions of 1,2-epoxypropane (I) and 2-methyl-2,3-epoxypentane (II) with various primary and secondary amines and with hexahydrophthalic anhydride in the presence of hydroxylic catalysts have been studied. The direction of ring opening of the epoxides on reaction with the amines is unaltered by the presence of phenol as catalyst, and involves attack at the least substituted carbon atom of the epoxide ring. The structures of the piperidino adducts (viz. IV and V) derived from the phenol-catalysed reaction of piperidine with I and II, respectively, were proved by unambiguous syntheses of IV and V by the interaction of the corresponding chlorhydrin with piperidine. With hexahydrophthalic anhydride in the presence of water, I gave a low molecular weight polymeric ester whereas II afforded mainly a diadduct derived from the reaction of two molecules of II with one molecule of the anhydride. Reaction mechanisms are discussed briefly.     

Electrometric titrations of Cr(VI), Mn(IV), V(V), Co(III) and U(VI) with a standard iron(II) solution in alkaline media containing hexitols

Direct and indirect potentiometric, bipotentiometric and biamperometric titrations with a standard iron(II) solution are described for some inorganic compounds in alkaline media containing hexitols (mannitol, dulcitol and sorbitol). The optimal conditions for titrations based on the Cr(VI) → Cr(III), Mn(IV) → Mn(III) → Mn(II), V(V) → V(IV), Co(III) → Co(II) and U(VI) → U(IV) systems are discussed. Of the hexitols studied, sorbitol has the greatest effect on the value of the redox potential of the Fe(III)/Fe(II) system; the E_f° value is about —1.10 V vs. SCE.     

Binuclear cyclometalated organoplatinum complexes containing 1,1'-bis(diphenylphosphino)ferrocene as spacer ligand: kinetics and mechanism of MeI oxidative addition

The binuclear complex [Pt2Me2(ppy)2(mu-dppf)], 1, in which ppy = deprotonated 2-phenylpyridyl and dppf = 1,1'-bis(diphenylphosphino)ferrocene, was synthesized by the reaction of [PtMe(SMe2)(ppy)] with 0.5 equiv of dppf at room temperature. In this reaction when 1 equiv of dppf was used, the dppf chelating complex 2, [PtMe(dppf)(ppy-kappa1C)], was obtained. The reaction of Pt(II)-Pt(II) complex 1 with excess MeI gave the Pt(IV)-Pt(IV) complex [Pt2I2Me4(ppy)2(mu-dppf)], 3. When the reaction was performed with 1 equiv of MeI, a mixture containing unreacted complex 1, a mixed-valence Pt(II)-Pt(IV) complex [PtMe(ppy)(mu-dppf)PtIMe2(ppy)], 4, and complex 3 was obtained. In a comparative study, the reaction of [PtMe(SMe2)(ppy)] with 1 equiv of monodentate phosphine PPh3 gave [PtMe(ppy)(PPh3)], A. MeI was reacted with A to give the platinum(IV) complex [PtMe2I(ppy)(PPh3)], C. All the complexes were fully characterized using multinuclear (1H, 31P, 13C, and 195Pt) NMR spectroscopy, and complex 2 was further identified by single crystal X-ray structure determination. The reaction of binuclear Pt(II)-Pt(II) complex 1 with excess MeI was monitored by low temperature 31P NMR spectroscopy and further by 1H NMR spectroscopy, and the kinetics of the reaction was studied by UV-vis spectroscopy. On the basis of the data, a mechanism has been suggested for the reaction which overall involved stepwise oxidative addition of MeI to the two Pt(II) centers. In this suggested mechanism, the reaction proceeded through a number of Pt(II)-Pt(IV) and Pt(IV)-Pt(IV) intermediates. Although MeI in each step was trans oxidatively added to one of the Pt(II) centers, further trans to cis isomerizations of Me and I groups were also identified. A comparative kinetic study of the reaction of monomeric platinum(II) complex A with MeI was also performed. The rate of reaction of MeI with complex 1 was some 3.5 times faster than that with complex A, indicating that dppf in the complex 1, as compared with PPh 3 in the complex A, has significantly enhanced the electron richness of the platinum centers.