bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spectrophotometric Studies of Nickel(II) Chelate of 2‐Picolylamine
Authors: Hseu Tong‐Ming , Tsai Yen‐Hsiang , Cheng Chi‐Wang 
Published: June 2015

AbstractNickel(II) chelate of 2–picolylamine has been studied spectrophotometrically in aqueous solution at 25°C and at an ionic strength of 0.3 M. The formation of pink color chelate was pH dependent, and the optimum pH range was between 7.0 to 8.5. Its mole ratio of ligand to nickel(II) ion was found to be 3 to 1 stoichiometry and the formation constant, logK, was determined as 13.31 ± 0.10. By using the wavelength 535 run, determination of trace amount of nickel(II) ion with the sensitivity of 5.28 τ/Cm2 was possible. Enthalpy and entropy changes characterizing the formation of the chelate have been calculated as follows: ΔG°=–8.15Kcal mole‐1, ΔH°=–9.65 Kcal mole‐1, ΔS°=28.5eu mole‐1.
Studies of Rare Earth Metal Complexes of Hydroxamic Acids
Authors: Liu Chuen‐Ying , Sun Peng‐Joung 
Published: June 2015

AbstractA cyclic hydroxamic acid, 2–hydroxyquinoline–N–oxide and an aromatic hydroxamic acid, benzohydroxamic acid were obtained in the form of free acids. Their acid dissociation constants and a total of seventy of the formation constants for twenty five complexes formed by these two hydroxamic acids with rare earth metals and yttrium in aqueous solution have been determined by Bjerrum potentiometric titration technique.
The Neutral Part of the Bark of Pinus Luchuensis Mayer
Authors: Cheng Yu‐Shia , Chen Eric Hsiang‐Tsun , Fang George Jim‐Min 
Published: June 2015

AbstractThe neutral part of the acetone extract from the bark of Pinus luchuensis Mayer has been investigated and found to consist of alkanes (C22–C34) and triterpenes of serratene type. The triterpenes are 3β–methoxyserrat–14–en–21–one, serrat–14–en–3, 21–dione, 3β–hydroxyserrat–14–en–21–one, 3β–21α–dimethoxyserrat–l4–ene and 3β–methoxyserrat–14–en–21α–ol.
Studies on the Alkaloids of Formosan Lauraceous Plants XVIII Alkaloids of Neolitsea Buisanensis Yamamoto Et Kamikoti and Neolitsea Aurata (Hay.) Koidz
Authors: Lu Sheng‐Teh , Su Tsang‐Long , Wang Eng‐Chi 
Published: June 2015

AbstractTwo alkaloids, laurolitsine (V) and litsericine (VII), were isolated from the woods of Neolitsea buisanersis. Six alkaloids were isolated from the woods of Neolitsea aurata and five of them were laurolitsine (V), litsericine (VII), N–methyllitsericine (VIII), (+)–anonaine (IX), and (–)‐roemerine (X) (Table I).
Kinetics of Solid State Reaction Between HgCl2(S) and Na2CO3(S)
Authors: Bassi P. S. , Sharma Indu Bhushan , Gupta B. R. 
Published: June 2015

AbstractThe kinetics of reaction between HgCl2 (s) and Na2CO3(s) have been studied by capillary technique in the temperature range of 75–150°C. The reaction follows a logarithmic law. The energy of activation of the overall reaction is 9.16 k. cal/mole. The microscopic study shows that the product formed is amorphous.
A Spectrophotometric Study of Fe(III) Chelates of Some Hydroxy Coumarin Derivatives
Authors: Paruthi H. K. , Tyagi J. S. , Taneja A. D. 
Published: June 2015

AbstractChelates formation of Fe(III) with 7–hydroxy–4–methyl coumarin–6–carboxylic acid (HMCCH)2 and 8–amino–7–hydroxy–4–methyl coumarin (AHMCH) have been studied. It has been observed that Fe(III) forms 1:2 (metal:ligand) chelates with HMCCH2 and AHMCH. The stability constants of these chelates at different ionic strengths and the effect of temperature on the stability constants of these chelates have been studied. The thermodynamic parameters such as entropy change (ΔS), free energy of formation (ΔG) and enthalpy change (ΔH) have also been calculated. The effect of dielectric constant oh the stability constants of these chelates have been studied. Estimation of nanogram quantities of Fe(III) with these ligands and the effect of diverse ions have also been studied and the results have been compared with other methods used for estimation of Fe(III).
Studies on the Constituents of Formosan Gentianaceous Plants: Part 1. Constituents of Swertia Randaiensis Hayata
Authors: Wu Tian‐Shung , Tlen Hsieh‐Ju , Lin Chung‐Nan 
Published: June 2015

AbstractOleanolic acid and gentianine have been isolated from Swertia randaiensis Hayata.
Chemical Studies on the Orient Plant Drugs‐II Structure of Glycoside‐P1, A Steryl Glucoside of Panax Ginseng Rhizoma
Authors: Lin Tzong‐Dann , Lin Mei‐Chao 
Published: June 2015

AbstractA new component of the steryl glucoside of Panax ginseng C.A. Meyer (Araliaceae) has been identified as sitosteryl–β–D–(6–O–fattyacyl)–glucopyranoside (1). Its gross structure, as a monoester of β–sitosteryl, campesteryl and stigmasteryl–β–D‐glucoside, was derived from a study of the products formed on methanolysis and on acid hydrolysis. The location of the fatty ester was established by comparison of the proton chemical shift for H2 C–6 in its tribenzoyl derivative with the chemical shifts for the corresponding protons in model benzoyl and acetyl derivation of sitosteryl–β–D–glucopyranoside.
Thermal Studies on Rare Earth Metal Ion Chelates of 8‐Hydroxyquinoline, 8‐Hydroxyquinaldine and Their Derivatives
Authors: Chang Tiao‐Hsu , Yang Tsong‐Jen , Yen Mei‐Wan 
Published: June 2015

AbstractThe thermal behaviors of chelates of oxine, 8‐hydroxyquinaldine and their derivatives (DCQ, 5, 7‐dichloro‐8‐hydroxyquinoline; DCQ', 5, 7‐dichloro‐8‐hydroxyquinaldine) in an air atmosphere have been studied. The order of heat stability of chelates, decreased with decreasing basicity of the ligand, i.e. oxine<DCQ<DCQ'. The presence of water or proton‐containing compounds in the chelates seemed to lower heat stabilities,
Kinetics of the Decomposition of Hydrogen Peroxide in the Presence of Aqua‐Pentacyanoferrate (II)
Authors: Girdhar K. K. 
Published: June 2015

AbstractThe decomposition of hydrogen peroxide has been studied in the presence of a large number of metal ions and their complexes1,2). Interest in radiation chemistry of aqueous solutions where hydrogen peroxide is one of the products and the use of acidic ferrous sulphate solutions as dosimeter in these studies has particularly stimulated the investigation on the kinetics of decomposition of hydrogen peroxide in the presence of Fe+2, Fe+3 and their complexes1,2). Ferrous sulphate solution can be used as a dosimeter under acidic conditions only, as at higher pH the hydrolysis of Fe+2 and Fe+3 interferes. Recent studies3‐6) have shown the possibility of using the aqueous solutions of ferro‐ and ferri‐cyanides over a range of pH as dosimeter. In the studies of ferrocyanide and ferricyanide catalysed decomposition of hydrogen peroxide7‐11), it is suggested that the catalytic properties of hexacyano ferrates are through their hydrated products. The present study aims at studying the interaction of aquapentacyanoferrate11) with hydrogen peroxide over a range of pH, concentration and temperature.
Temperature Effect on the Extraction of Uranyl and Thorium Nitrates by Tributylphosphate in Kerosene
Authors: Chen Chang‐Chyuan , Ting Gann 
Published: June 2015

AbstractTemperature effect on the extraction of uranyl and thorium nitrates by tributyl‐phosphate (TBP) has been investigated at different nitric acid concentration (–0.17 ∼ 3 N), and solvent composition from 10°C to 60°C. Thermodynamic quantities for the extraction of uranyl nitrate and thorium nitrate were also estimated.
Photoaddition of Iodoform with Norbornene
Authors: Wang Ching‐Bore , Hsu Ying‐Gev , Lin Lung Ching 
Published: June 2015

AbstractThe reaction of norbornene with iodoform in the inert solvent under irradiation resulted in Kharasch type addition to give endo‐3‐iodo‐exo‐2‐diiodomethyl‐bicyclo[2.2.1]heptane, and a carbene addition to give tricyclic compound, anti‐3‐iodo‐exo‐tricyclo[3.2.1.02,4]octane. The structural assignments of these adducts are based on elemental analyses, ir, nmr, and mass spectral studies.
The Reaction of Indole Magnesium Bromide with Ketones I. The Reaction of Indole Magnesium Bromide with Cyclohexanone
Authors: Zee Sheng‐Hsu , Kuo Kuang‐Ming 
Published: June 2015

AbstractIndole magnesium bromide, produced by reacting indole with n‐butyl magnesium bromide in ether, was reacted with cyclohexanone at ice or room temperature to yield 1‐(indol‐I‐yl)‐cyclohexanol (I), which is unstable and may be decomposed easily into indole and cyclohexanone in acidic condition. Indole magnesium bromide reacted with cyclohexanone in refluxing benzene or in anisole at 80°C, to form two products, 1‐(indol‐3‐yl)‐cyclohexanol (II) and 1‐(indol‐3‐yl)‐cyclohexene (III). (II) could be converted to (III) by heating (II) in phosphoric acid. Reaction of III with maleic anhydride gave a Diels‐Alder adduct (IV). Reaction of indole magnesium bromide with cyclohexanone in anisole at 130°C yielded (III) and a trimolecular condensation product of cyclohexanone (V).
Lanthanons(III) Complexes of Bifunctional Tridentate Schiff's Bases
Authors: Kapoor R. N. , Mehrotra S. K. , Rajpurohit V. S. 
Published: June 2015

AbstractA systematic study of the reactions of isopropoxides of praseodymium, neodymium and samarium with bifunctional tridentate Schiff bases (acetylacetone‐O‐aminophenol and benzoylacetone‐O‐aminophenol) in equimolar ratios resulting in the formation of products with formula M(OPri) (SB), M(SB) (SBH) and M2(SB)3 (where SB is Schiff base anion, SBH is Schiff base and M is metal). The reactions have been found to be quite facile even at the room temperature as observed by immediate change of colour. The intensity of the colour of acetylacetone‐O‐aminophenol derivatives of rare earths decreased with the increasing stoichiometric ratio of the ligand i.e. from yellow to light yellow.
The Resolution of Amino Acids by Enzymes Part 1: Proteolytic Enzyme Bromelain for Hydrolysis of L‐Amino Acid Methyl Esters
Authors: Wong Chi‐Huey , Chen Shui‐Tien , Wang Kung‐Tsung 
Published: June 2015

AbstractPreparation of optically pure L‐amino acids from the corresponding methyl esters of racemic mixtures by treatment with proteolytic enzyme, bromelain, was investigated. The reaction was carried out at pH 6.0‐6.5, 25°C in a mixture containing 0.1M substrate, 5mM β‐mercaptoethanol, 0.05M potassium phosphate and 3mg/ml of crude enzyme. The product was isolated by ion exchange chromatography and the purity of product was established by m.p., tlc, ir spectrum, elemental analysis and optical rotation measurement.
Lanthanon (III) Complexes of Bifunctional Tridentate and Tetradentate Schiff Bases
Authors: Kapoor R. N. , Rajpurohit V. S. 
Published: June 2015

AbstractReactions of isopropoxides of praseodymium, neodymium and samarium with bifunctional tridentate and tetradentate schiff bases (i.e. salicylidene‐O‐aminophenol and bis‐salicylaldehyde ethylenediamine) have been carried out in benzene in different stoichiometric ratios resulting in the formation of products with the formula M(OPri)(C11H9NO2), M(C13H9NO2)(C13H10NO2). M2(C13H9NO2) M(OPri)(C15H14N2O2), M(C16H14N2O2)(C16H15N2O2) and M2(C16H14N2O2)3 (where M stands for Pr, Nd and Sm). The products were found to be yellow to orange solids soluble in benzene and alcohol. The absorption spectra of these complexes were also recorded in methanol.
Effect of Configuration Interaction on the G Values for Trigonally Distorted Octahedral Low Spin d5 System
Authors: Lo Chien‐Cho 
Published: June 2015

AbstractThe g values for trigonally distorted octahedral low spin d5 system is calculated, including configuration interaction. An appropriate set of five‐electron wave functions is employed. The portion of the g values calculated here without including configuration interaction is identical with that of Griffith and Hill.
Thermodynamic Studies on the Complexation Reactions of Copper(II) Macrocyclic Tetramine Complexes with Monodentate Ligands: Part II. A Spectrophotometric Study on the Reactions of Meso‐5, 7, 7, 12, 14, 14‐Hexamethyl‐1, 4, 8, 11‐Tetraazacyclotetradecane‐Copper(II) (Blue) with Halide Ions
Authors: Liou Ming‐Chung , Chao Kuo‐Hua , Liang Bih‐Fong , Chung Chung‐Sun 
Published: June 2015

AbstractThe stability constants for the formation of [Cu(tet a)X]+(blue) from [Cu(tet a)]2+(blue) and X‐ (where X=Cl, Br, I) were determined by spectrophotometric method at 15°, 25° and 35°C. The corresponding ΔH° and ΔS° values were obtained from the variations of the stability constants between 15° and 35°C. For the same halide ion, the stability constant of [Cu(tet b)X]+ (blue) is larger than that of [Cu(tet a)X]+(blue).
Peptization of Thorium Hydroxide and Thorium Oxide Sols with Nitrate
Authors: Wen Tung‐Jen , Huang Theresa S. C. Chen 
Published: June 2015

AbstractThe peptization of thorium hydroxide and thorium oxide sol on the preparation of microsphere of nuclear fuels are studied. These sols are prepared mainly by dispersing hydrated thorium oxide in nitric acid. A main character of ThO2 sol is its NO3−/Th mole ratio. After peptization, the nitrate is presented as two forms; i. e., sorbed by particles of the sol and free in the aqueous solutions. The adsorbed NO3−/Th mole ratio depends on the average crystallite size of thorium oxide. In certain size range, the adsorbed NO3−/Th of ThO2 sol prepared from thorium oxalate is inversely proportional to the crystallite size. The different series of thorium oxide are made by different methods. In this paper the crystallite size is obtained from 33 to 84 A by changing calcination temperatures.
Preparation of Complexes of Nickel(II) Aryl Carboxylates with Morpholine and Piperidine
Authors: Kumar N. , Gandotra A. K. 
Published: June 2015

AbstractComplexes of nickel(II) aryl carboxylates with a general formula Ni(RC6H4COO)2L2 where R=H, p‐CH3. p‐Cl, m‐ & p‐NO2; and L = morpholine and piperidine; have been prepared by the interaction of nickel(II) aryl carboxylates with a large excess of appropriate amine. Unlike parent anhydrous nickel(II) aryl carboxylates all these complexes are soluble in common organic solvents.
Complexes of Copper(II) Chloroacetates with Pyridine and Picoline N‐Oxides
Authors: Kumar N. , Suri A. K. , Kant Rama 
Published: June 2015

Abstract1:1 Adducts of composition Cu(CH3‐xClxCOO)4L and 1:2 adducts of composition Cu(CH3‐xClxCOO)2L2 where x=1‐3 and L is pyridine N‐Oxide (PyNO), 2‐picoline N‐oxide (2‐PicNO) or 3‐picoline N‐oxide (3‐PicNO) have been isolated by the interaction of copper(II) chloroacetates with the appropriate N‐oxide ligands. The adducts are soluble in methanol.
The Stabilities and Thermodynamic Properties of Manganese(II) and Nickel(II) Chelates of Trans‐1,2‐Diaminocyclohexane‐N, N, N', N'‐Tetraacetic Acid
Authors: Hseu Tong‐Ming , Farng Li‐Pau , Siew Pi‐Yuen , Tsai Ing‐Ing 
Published: June 2015

AbstractThe interaction between trans‐1,2‐diaminocyclohexane‐N, N, N', N'‐tetraacetic acid (H1DCTA or H4Z) and Mn(II) and Ni(II) ions has been investigated. The formation constants of the hydrogen chelates (MHZ−), and of the normal chelates (MZ2−), have been measured at 20, 30 and 40°C, and an ionic strength of 0.10 (KNO3). The former was done by a titration technique and the latter by a mercury indicator electrode method. Enthalpy and entropy changes characterizing the formation of the normal chelates have been calculated at 25°C.
A Convenient Regiospecific Syntheses of (E)‐1‐Alkanesulfonyl‐ and (E)‐1‐Arylsulfonyl‐2‐Phenylethenes
Authors: Liu Lilian Kao , Hong C. T. 
Published: June 2015

Abstract(E)‐1‐Alkanesulfonyl‐ and (E)‐1‐arylsulfonyl‐2‐phenylethenes (styryl sulfones) were obtained from good to excellent yields by the base‐catalyzed elimination of the corresponding β‐chlorosulfones. The latter were obtained, respectively, by additions of the alkanesulfonyl‐ and the arylsulfonyl chlorides to styrene under the catalytic action of copper chlorides.
Complexes of Copper(II) Aryl Carboxylates with Picoline N‐Oxides
Authors: Kumar N. , Gandotra A. K. , Suri A. K. , Kant Rama 
Published: June 2015

AbstractCopper(II) aryl carboxylates on interaction with 2‐picoline N‐Oxide (2‐picNO), 3‐picoline N‐Oxide (3‐picNO) and 4‐picoline N‐Oxide (4‐picNO) in acetone or ethyl acetate yield 1:1 adducts. These are regarded as binuclear bridged complexes of composition Cu2(RC6H4COO)2L2 where R is o‐, m‐, p‐CH2; o‐, m‐Cl: o‐NO2; m‐, p‐CH2O; and L is 2‐, 3‐, and 4‐picNO ligand. With 4‐picNO some 1:2 adducts have also been obtained.
Linear Correlation of the Basicity of Aromatic Compounds with Σσ+ Constants in the Hydrogen Chloride‐Aluminum Chloride System
Authors: Rei Min‐Hon 
Published: June 2015

AbstractIn an automatic hydrochlorinator, twenty‐four aromatic compounds including halogen and methoxy substituted compounds were complexed with hydrogen chloride and aluminum chloride. Relative basicities of these compounds to toluene were measured. Except those methoxy substituted compounds and few weakly basic compounds, the relative basicities of nineteen compounds were found to correlate linearly with the summation of σ+ constants. Thus, this technique provide a simple approach to the analysis of aromatic basicity.While hexamethylbenzene was found to be 15 × 100 time more basic than was toluene, benzene was found to be only FIVE time less basic than was toluene. From the rate of chlorination, benzene was estimated to be 1300 time less basic than was toluene according to the literature report.Moreover, the resultant complexes are composed of three types of structures. In the weakly basic region, a π‐complex is proposed. In the medium basic range, the σ‐complex is attributed to. the formation of a dimeric aluminum chloride‐hydrogen chloride complex. In the strongly basic region, the aromatic compound complexes with a monomeric aluminum chloride‐hydrogen chloride to form a stable σ‐complex.
Photolysis of Isoniazid
Authors: Chiang Hung‐Cheh , Lin Long‐Jin 
Published: June 2015

AbstractThe UV light irradiation of isoniazid (I) in methanol four products, isonicotinic acid (II), isonicotinamide (III), N, N′‐bis(isonicotinic acid)hydrazide (IV) and isonicotinaldehyde isonicotinyl hydrazone (V), in ethanol three products, (III), (IV) and acetaldehyde isonicotinyl hydrazone (VI) were isolated and identified. Also, the photoreaction mechanism of isoniazid in methanol and ethanol were discussed.
Some 4(1h) Pyridylidene Compounds II Synthesis and Structure of N,N‐Conjugated‐4‐Pyridine Compounds
Authors: Kuo Kung Tu 
Published: June 2015

AbstractThe reaction of 4‐methylpyridine and its methiodide with p‐N, N‐dimethylamino‐benzaldehyde gave 4‐p‐N, N‐dimethylaminostyrylpyridine (I) and 4‐p‐N, N‐dimethylaminostyrylpyridine methiodide (II), respectively, II was also prepared by methylation of I with methyl iodide in methanol. The pyridylidene structure of II, N‐benzyl‐4‐(p‐N, N‐dimethylaminophenyl) pyridinium chloride (IVa) and its methiodide (Va) was discussed in terms of UV, NMR and mass spectra.
Studies on the Photodimerization of Isoeugenol
Authors: Chiang Hung‐Cheh , Li Shyh‐Yuan 
Published: June 2015

AbstractUnder the irradiation of the ultraviolet light, Isoeugenol (I) undergoes dimerization in acetone to give diisoeugenol (II) and dehydrodiisoeugenol (III). The structures are determined by the comparison of the mixed m. p., I. R. spectra and T. L. C. with synthesized authentic samples. Also the photoreaction mechanism is discussed in detail. The reaction represents a new type and as an exception of photochemical process for the C=C double bond in conjugation with aromatic ring that generally dimerizes to produce cyclobutane type derivatives.
Liquid Chromatography of Adenine, Caffeine, Theobromine, Theophylline, Tannic Acid, Xanthine and its Application to Tea Analysis
Authors: Hsu Tong‐Jung , Liao Chi‐Chow , Chen Mei‐Yun 
Published: June 2015

AbstractA polystyrenesulfonic acid resin in the hydrogen form is a useful stationary phase for chromatographic separation of adenine, caffeine, theobromine, theophylline, tannic acid, xanthine and tea components with aqueous ethanol as eluent. The results indicated that caffeine, theophylline, theobromine, adenine, xanthine and tannic acid could be separated on a column of Dowex‐50W‐X8(H)+ by elution with 25% ethanol as eluent.
Nitro, Nitrito and Nitrato Derivatives of Dicyclopentadienyl Thallium(III) Chloride and Bis Indenyl Thallium(III) Chloride
Authors: Hari S. C. , Arora R. S. , Bhalla M. S. , Multani R. K. 
Published: June 2015

AbstractSix new complexes of thallium(III) of the formula (π‐D)2Tl(L) (where D= cyclopentadienyl or indenyl group and L=nitro, nitrito or nitrato group) have been prepared and characterised on the basis of I. R. studies and some thermal properties of these complexes.
Contribution of P‐O and P‐N Linkages in Phosphorylated Histone H1
Authors: Wang L. Y. , Fricke O. , Lin Y. C. 
Published: June 2015

AbstractIn studies of the phosphorylated proteins in Walker‐256 carcinosarcoma, it was established that the ratio of P‐N linkages to P‐O linkages on histone H1 varied between 0.6 to 1.0. Histone H1 was phosphorylated in vivo and isolated under all neutral conditions employing a dextran/polyethylene glycol two‐phase system and Bio‐Rex 70 chromatography.
Proton Magnetic Resonance Studies of Heterocyclic Aromatic Amine Adducts of Nickel(II) and Cobalt(II) Acetylacetonate
Authors: Wang Wen‐Jwu , Wei Ho‐Hsiang 
Published: June 2015

AbstractThe proton nmr isotropic shifts of pyridine type ligands coordinated to paramagnetic nickel(II) and cobalt(II) acetylacetonate are reported, and the mechanisms of unpaired electron spin delocalization in these complexes are discussed. It is found that a σ‐delocalization mechanism is in dominant, but the π‐contribution can not be rule out. The calculations of the geometric factor for Co(II) complexes are done. It is used in the ratio method to separate the contribution of pseudo‐contact shift from isotropic shift for Co(II) complexes. The effect of pseudoaromatic chelate ring on contact shift is not so large as previously reported.
The Natural Optical Activity of Tris(Ethylenediamine)Metal(II) Nitrates V. The Single Crystal Circular Dichroism Spectrum of Ni(en)3 (NO3 )2
Authors: Yang Mark Chin‐Lan , Palmer Richard Alan 
Published: June 2015

AbstractThe axial CD spectra of single crystal of Zn(en)3(NO3)2 doped with 1‐50% Ni(en)3(NO3)2 have been observed at temperatures from ambient to 5 K. The increase in R of the 3E[3T3g(F)] transition as the temperature decreases is consistent with the magnetic dipole allowed character of the parent octahedral transition. The electric and magnetic dipole forbidden transition to the 3T1g(F) octahedral level gives rise to a relatively weak axial CD band with an unusual temperature dependent splitting. This structure is attributed to electric quadrupole intensity, which is allowed for transitions to both the E and 3A2[3T1g(F)] levels in D3 symmetry.
The Mutual Resoluton of Dl‐ephedrine and N‐Benzyloxycarbonyl‐Dl‐Amino Acids
Authors: Wong Chi‐Huey , Wang Kung‐Tsung 
Published: June 2015

AbstractD(‐)‐Ephedrine was prepared by resolving the racemate through its N‐benzyloxycarbonyl‐L‐phenylalanine salt in ether solution. The L(+)‐ephedrine in mother liquid was recovered and precipitated exclusivly with N ‐benzyloxycarbonyl‐L‐alanine in ethyl acetate. The amino acid derivatives were recovered from the salts by acid decomposition and the optically pure ephedrine was also recovered, which was again useful for the resolution of racemic amino acid derivatives synthesized chemically. Other amino acid derivatves are also tested for the mutual resolution.Mutual resolution was also effected by dissolving DL‐ephedrine and N ‐benzyloxycarbonyl‐DL‐alanine in ethyl acetate to obtain the optically pure D(‐)‐ephedrine and N ‐benzyloxycarbonyl‐D‐alanine.
Liquid Chromatography of Benzoic Acid and Phthalic Acid on Ion‐Exchange Resin
Authors: Hsu Tong‐Jung , Liao Chi‐Chow , Chen Mei‐Yun 
Published: June 2015

AbstractThis is to report a study in which cation ion‐exchange resin serves as the stationary phase for liquid chromatography of benzoic acid and phthalic acid and aqueous ethanol acts as the mobile phase. No ion. exchange phenomenon is involved. It is rather a solvent action on the polymer matrix for the organic solutes. It was found that the elution volumes depend on the pKa values of the acids; the higher the pKa value the more the retention volume.