bluuebunny/crossref_metadata_2025_split huggingface dataset:
NMR Studies on Imidines. III.1H and 13C Nuclear Magnetic Resonance Study on the Tautomerism and Geometrical Isomerism of 3‐Iminoisoindolinone and Some Alkylated Derivatives. Observation of E and Z Isomers About a Free Imino Grouping
Authors: Spiessens Luc I. , Anteunis Marc J. O. 
Published: September 2010

Abstract3‐Iminoisoindolinone (1) and some N‐alkyl derivatives (8, 9, 10, 11, 12, 16 and 17) have been fully examined by 1H and 13C NMR spectroscopy. 3‐(Methylimino) isoindolinone (12) cannot be obtained by reaction of 1 with methylamine, because it rearranges to 3‐imino‐2‐methylisoindolinone (11), which reacts further to 2‐methyl‐3‐(methylimino) isoindolinone (10). Both compounds have been shown to adopt the E configuration predominantly (88% E for 11 at‐55°C (CDCl3); 100% for 10). 3‐(Methylimino) isoindolinone (12) favours the Z configuration (96%).Analogous results are found for the butyl derivatives (16, 17). 3‐Imino isoindolinone (1) is present as the imino tautomer for 70% in DMSO‐d6 solution as established by comparison of 13C NMR chemical shift values of 1 with those of model compounds, 3‐imino‐2‐methyl isoindolinone (11) and 3‐(dimethylamino) isoindoleninone (8). The tautomeric equilibrium is more extreme towards the imino form for the N‐methyl and N‐butyl derivatives 12 and 16. 2, 3, 4, 5‐tetrahydroisoindolino [2,1‐a] pyrimidin‐6‐one served as the imino model compound together with 10. 1H and 13C NMR data are given for several phthalic acid derivatives.
Étude Du Spectre Électronique Des Trichlorures: (n‐C4H9)4NCl3 et ϕ4 AsCl3
Authors: De Meyer H. , Levert J. M. , Vanclef A. 
Published: September 2010

AbstractThe electronic spectra of organic trichlorides (n‐C4Hg)4NCl3 and ϕ4AsCl3) in acetonitrile and dichloromethane are studied and compared with spectra of other trihalide ions: Br3−, I3−, BrCl2−, ICl2−. The apparent constant of the equilibrium, Cl2 + Cl− − Cl3−, is evaluated in acetonitrile with lithium chloride and tetrabutylammonium chloride. Typical trichloride absorption bands in saturated chlorine brines of NaCl (or hydrochloride solutions) are not observed and thus no trichloride complex ions are formed in aqueous phase.
Pyridines. XII1 ‐ Métallation Régiosélective De La S‐Collidine: Influence Du Solvant et Du Cation Associé Sur L'Isomérisation Des Carbanions Formes. Application a la Benzylation et a la Benzoylation
Authors: Compagnon Paul‐Louis , Kimny Tan 
Published: September 2010

AbstractThe metalation of s‐collidine l by PhLi in Et2O, THF and DME leads to the kinetic anion (la,S); in Et2O la is also the thermodynamic product. In THF and DME, (la,S) isomerizes into the more delocalized thermodynamic anion (lb,S), without implication of a steric effect; halflife times T at 23°C are 122 mn in THF, 2 mn in THF + excess of l, < 1 mn in THF + TMEDA, at 22°C 28 mn in DME. In HMPT, PhLi deprotonates l giving within 2 mn an equilibrated mixture la + lb, but (lb,S) is still prevalent. In liquid NH3, with NaNH2 and LiNH2, (lb,S) is the only detectable anion. After the deprotonation step, the anions are trapped by PhCH2Cl (rate constant k3) or PhCN (k2). Note that the condensation with PhCN seems irreversible in DME, but reversible with protonation when liquid NH3 is evaporated and replaced by Et2O. With Li+ cation, a kinetic control is superimposed to the thermodynamic equilibrium la ‐ lb (k), the rate constants (Scheme 2) decreasing in the following order kb3 > kb3 > kb2 > kb2. These various results (selective metalation, isomerization, relative reactivities of la and lb versus PhCH2Cl and PhCN) are interpretable in terms of solvent donating effect DN and acceptor‐number AN (V. Gutmann13) and of the structure of la‐M and lb‐M (contact ion pair and solvent‐separated ion pair).
Polarographic Study of Mixed Ligand Complex Formation in the CD(II) ‐ Cl−‐2,2'‐Bipyridyl System
Authors: Mambetkaziev E. A. , Abilova M. U. , Shaldybaeva A. M. , Zhdanov S. I. , Jarkesheva Sh. A. 
Published: September 2010

AbstractComplex formation in the system, containing Cd2+, Cl− and 2,2'‐bipyridyl, was studied in the aqueous medium at 25°C using the classic polarographic method. The Schaap‐McMasters method was employed to calculate the stability constants of mixed ligand complexes. The formation of the complexes [CdCl bipy]+, [CdCl2bipy] and [CdCl bipy2]+ was established under the given experimental conditions.
Étude Rmn‐1H Des Hélicènes ‐ 2e Partie
Authors: Defay Nicole , Martin Richard H. 
Published: September 2010

AbstractThe proton chemical shifts of eight benzenoid helicenes, namely: [7], [8], [9], [10], [11], [12], [13] and [14] helicenes, have been assigned by the study of deuteriated or substituted derivatives. The evolution of the chemical shifts with the growth of the helix is discussed.
Some Ring‐Transformation Reactions of Desaurins
Authors: L'abbé Gerrit , Vangheluwe Patricia , Toppet Suzanne , King Geoffrey S. D. , Meervelt Luc Van 
Published: September 2010

AbstractThe desaurin 3, whose stereochemistry has now been established by an X‐ray crystal structure analysis, can be used as a thioketene equivalent (11). Reactions have been carried out with sodium azide/dimethyl sulfate, N,N‐diethyl‐aminopropyne, N‐methyl benzaldimine, tert‐butyl isonitrile and NaN3/CS2 to give the products listed in Schemes I, IV and V. Simple thioketenes (e.g. 16) react analogously with tert‐butyl isonitrile, but not with imines where C‐C adducts are formed instead of C‐S adducts.
Data Collection in X‐ray Single Crystal Diffractometry : Strategy and Error Sources
Authors: De Wolf M. , Lenstra A. T. H. 
Published: September 2010

AbstractA description is given of (i) tests for the stability and performance of the diffractometer, in particular the mechanical wear and tear, (ii) the influence of wavelength dispersion and mosaic spread on the determination of scan parameters and (iii) experiments showing the importance of multiple scattering on strong reflections. It is demonstrated that counting statistics seriously underestimates the error limits of intensities obtained in single crystal X‐ray diffractometry.
Four‐Membered Ring Peroxide Heterocycles: Photochemistry Through the Backdoor
Authors: Adam Waldemar , Baader Wilhelm J. , Babatsikos Chrisostomos , Schmidt Ernst 
Published: September 2010

AbstractThe unusual property of four‐membered ring peroxide heterocycles (1,2‐dioxetanes) to produce electronically excited carbonyl fragments on thermal decomposition is discussed. The synthetic tools for the preparation of such labile substances and the analytic methods for assessing excitation yields are covered. Using the complete series of methylated derivatives of the parent 1,2‐dioxetane, their thermal stability and excited state production is rationalized in terms of a modified diradical mechanism. With the help of bisdioxetanes, it is shown that generation of upper excited states is improbable, despite the fact that sufficient energy is available for this purpose. Attachment of dioxetanes to biomolecules via mild esterifications provides interesting opportunities for photobiological exploration.
Anchor Effect in HDS of Phenothiazine, Phenoxathiine, Thianthrene and Thioxanthene on Sulfided Nio‐Moo3/γ‐Al2o3Catalyst
Authors: Aubert C. , Durand R. , Geneste P. , Moreau C. 
Published: September 2010

AbstractThe rate constants of hydrodesulfurization of phenothiazine, phenoxathiine thianthrene and thioxanthene on sulfided NiO‐MoO3/γ‐Al2O3catalyst, at 340°C under 70 bar H2, are similar to one another and about 10‐fold higher than that of dibenzothiophene.From comparison with HDS of dibenzothiophene, the presence of a second heteroatom, N,S,O or of a methylene group has no or little effect on the HDS rates of the title compounds. The observed rate enhancement could result from differences in the strength of adsorption between the adsorbed state and the transition state (anchor effect) which depends on whether the molecules are planar or folded.The comparison of the rate constants of hydrodeoxygenation of homologous oxygenated compounds, xanthene and phenoxazine, with that of dibenzofurane leads to the same conclusion.
Transition Periods of the Activity of Co‐Mo/Al2o3 Catalysts in Thiophene Hydrodesulfurization
Authors: Dobrovolszky M. , Nagy Z. , Pall Z. , Tétényi P. 
Published: September 2010

AbstractHydrodesulfurization (HDS) of thiophene was studied over Co‐Mo/Al2O3 catalysts of various composition. Sulfidation was carried out by the reactant itself, alternating with dimethylsulfoxide. Mo‐rich catalysts reached their maximum activity level when the upper limit of sulfidation was not higher than 15%. From 50–60% sulfidation, a slow activity decrease appeared. Co‐rich catalysts reached very rapidly (2–3% sulfidation) a very low, very stable activity level. The C4‐selectivity was 80–96% at the quasi‐constant activity level. Butane yields were roughly proportional to the HDS activity. The predominance of cis‐2‐butenes permitted us to suggest a mechanism for thiophene HDS.
Influence of Reduction / Sulfidation Treatments on the Physico‐Chemical and Catalytic Properties of Unsupported Cobalt‐Molybdenum/Hydrodesulfurization Catalysts
Authors: Göbölös S. , Wu Q. , Ladriere J. , Delannay F. , Delmon B. 
Published: September 2010

AbstractUnsupported CoMo sulfide catalysts prepared by the homogeneous sulfide precipitation method were submitted to 3 MPa 4% H2S‐H2 at 573K, and 0.1 MPa H2 at 573 and 723K. The samples were characterized by MES, XPS, XRD and temperature‐programmed sulfur extraction. Their activity was measured in the HDS of thiophene and hydrogenation of cyclohexene. MES reveals the presence of Co9S8, CoS1+x, Co‐Mo‐S and two unidentified species. Treatment under H2 at 573K caused an increase of activity which was correlated with an increase of the Co9S8 concentration at the expense of all other species. Treatment under H2 at 723K caused a further increase of activity which was correlated with the sintering of the Co9S8 phase. Part of the sulfur extracted by treatment under H2 up to 733K cannot be recovered by subsequent treatment under H2S/H2. These results do not provide straightforward evidence for deciding between the current models used for explaining the synergetic effect, namely the existence of a Co‐Mo‐S phase or the remote control hypothesis. The sulfur deficiency of the catalyst appears to play a major role in the activity.
Catalysis by Polymers. V. Some Kinetic Aspects on the Polymer Catalyzed Reactions of Oxiranes
Authors: Oprea S. , Dumitriu E. , Hulea T. , Hulea V. 
Published: September 2010

AbstractThe esterification of epichlorohydrin with acrylic acid in the presence of various macro‐ and micromolecular catalysts has been investigated. The influence of concatenation of the catalytic functional groups on the reaction rate had been studied too.The previous studies1–4 in the field of polymer catalyzed reactions of oxiranes with organic acids have shown some interesting aspects related to the behaviour of catalytic functional groups which are attached to the polymer backbone. The aim of this paper was to study the concatenation effect of the catalytic functional groups both in the homopolymers and copolymers on the reaction rate of esterification; for the same purpose the small‐molecule analogues were used as references.
Improved Synthesis of 2‐Hydroxy‐4,4,6‐Trimethyl‐2,5‐Cyclohexadienone, Useful as a Flavoring Additive
Authors: Buyck Laurent De , Zi‐Peng Yao , Verhé Roland , Kimpe Norbert De , Schamp Niceas 
Published: September 2010

AbstractThe title dienone 1, useful for modification, improvement or increasing organoleptic properties of tobacco, sucrose syrups, flavored beverages, was prepared in 40–558 overall yield from isophorone, by chlorination of 2‐hydroxy‐isophorone (2), rearrangement into 6‐chloro‐2‐hydroxyisophorone (5) and de‐hydrochlorination. An excellent yield of 3‐chloro‐2‐hydroxy‐4,4,6‐trimethyl‐2,5‐cyclohexenone (12) was obtained by chlorination of 5 followed by dehydro‐halogenation.
Reaction of Titanium and Nickel‐Titanium Catalytic Heterogeneous Systems With Acetone
Authors: Malinowski Marek 
Published: September 2010

AbstractThe reaction of acetone with a low‐valent titanium species anchored on silica gel was studied in heterogeneous media. Aldol type condensation products, mesitylene and mesityloxide, were observed as main products. The influence of nickel and cyclopentadienyl ligands on the reaction was observed.
Non‐Catalytic Reduction of α‐Oximinoketones and α‐Oximinoalcohols to erythro‐2‐Amino‐1‐Arylalkan‐1‐Ols
Authors: Oppong‐Boachie Francis Kwabena 
Published: September 2010

AbstractA non‐catalytic reduction of α‐oximinoketones 1 and α‐oximinoalcohols 2 to erythro‐2‐amino‐1‐arylalkan‐1‐ols 3 with lithium aluminium hydride is reported. The erythro‐2‐amino‐1‐arylalkan‐1‐ols are isolated as their hydrochlorides 5 and characterised as the erythro isomers by benzoylation.
Infrared Study of the Interaction Between Esters and Hydrogen Chloride or Bromide In the Liquid State
Authors: Vanderheyden L. , Zeegers‐Huyskens TH. 
Published: September 2010

AbstractThe interaction between six esters and hydrogen chloride or bromide is studied by infrared spectrometry. The formation constants determined in carbontetrachloride are much lower than those expected from the gas phase acidities of the hydrogen halides. This effect is ascribable to an entropy effect connected with a freezing of rotation of the acid molecules. With HCl, only normal hydrogen bonds are formed and the relative frequency shifts of the νHCl band and of the νC=O vibrations are linearly related, independently of the polarity of the medium and of the temperature. The infrared spectra of the HBr complexes show the characteristics of strong hydrogen bonds
Characterisation of Chromium Doped Raney Nickel Catalysts
Authors: Kordulis C. , Doumain B. , Damon J. P. , Masson J. , Dallons J. L. , Delannay F. 
Published: September 2010

AbstractTwo chromium‐doped Raney nickel catalysts have been prepared from Al‐Ni‐Cr alloys where Cr was introduced in such a way as to substitute for nickel in the Ni2Al3 intermetallic phase. In comparison with the undoped catalysts, the BET and metallic surface areas remain little affected but more aluminium is retained after etching. X.P.S. shows that aluminium and nickel are in the metallic state whereas chromium is completely oxidized. Very large amounts of chromium are found on the surface, which suggests migration of chromium to the surface during leaching. Analytical electron microscopy indicates that the local chromium concentration is not perfectly uniform. Electron probe microanalysis of the precursor alloy reveals the segregation of part of chromium in a separate phase. These results are evaluated in the framework of the available literature data on the microstructure of Raney nickel catalysts.
A High‐Yield Selective N(3)‐Alkylation Process of Hydantoins Using Dimethylformanide Dialkyl Acetals
Authors: Poupaert Jacques H. , Smeyers Claude , Böttcher Patrick 
Published: September 2010

AbstractA selective N(3)‐alkylation process of 5‐substituted hydantoins is described. Treatment of hydantoins with excess of dimethylformamide dialkyl acetals at 100°C results in N(3)‐alkyl derivatives in 69–90% yield.
Asymmetric Hydrogenation of Dehydrovalyl Peptides
Authors: Calderón S. , Cativiela C. , Mayoral J. A. , Meléndez E. 
Published: September 2010

AbstractBoth N‐benzoyl‐Δ‐valyl‐L and D‐phenylalanine aethyl esters were hydrogenated at atmospheric pressure in quantitative yield, using 5% Pd/C suspended in n‐propanol. Diastereoselectivity is low but in line of expectations.
Synthesis of 5‐Diazomethyl Substituted V‐Triazolo [4,5‐D] Pyrimidines
Authors: L'abbé Gerrit , Godts Françoise , Toppet Suzanne 
Published: September 2010

AbstractABSTRACT. The condensation of 5‐azido‐4‐cyano‐1‐substituted‐1,2,3‐triazoles with active methylene nitriles in the presence of a strong base yields the title compounds 6 which exist in equilibrium with the tricyclic systems 5. The equilibrium position is shifted towards the diazo forms for X‐H and for X‐COOEt in non‐polar solvents, thus giving the first examples of open‐chain diazo functions attached to a pyrimidine ring at the 2‐position.
Diazoverbindungen‐671) Elektrophile Diazoalkansubstitution Mit Donorsubstituierten Kationen
Authors: Regitz M. , Weise G. , Lenz B. , Förster U. , Urgast K. , Maas G. 
Published: September 2010

AbstractThe imidazolinium chloride 8 reacts with diazomethyl compounds 3 (in the presence of an amine) or with metal derivatives of 3 under the formation of the 2‐(diazomethyl) imidazolidines 9. Compounds of the same type are received by treatment of the electron‐rich olefine 10 with 3 at elevated temperature. An analogous substitution process at 3 with the donor‐stabilized salts 13 and 17 produces stable 2‐(diazomethyl) benzthiazolines (14) and 6‐(diazomethyl) hexahydro‐1,3,5‐triazines (18) respectively.Thermolysis and photolysis of 9 mainly yield tetrahydro‐1,4‐diazines (21) by 1,2‐N‐shift of the carbene precursors 20; moreover the hitherto unknown isomerization reaction of the diazo compounds 9 to the azines 25 has been observed. In the thermal decomposition of 14 the formation of 2‐methylenbenzthiazolines (28) is preferred whereas photolysis of the same diazo compounds affords mixtures of 28 and 1,4‐benzothiazines 30. The olefines 28 are characterized by protonation (31) and reaction with the cyclic azo compound 32 (34).
Polarographic Study of the Catalytic Prewave of Co(II) in the Presence of 5,5‐Dimethyl‐1,3‐Cyclohexanedione Dithiosemicarbazone Analytical Applications
Authors: Misiego A.Sánchez , Guiberteau Cabanillas A. , Garcia‐Moncó Carra R. , Caro Gámez C. , Garcia Garcia P. 
Published: September 2010

AbstractThe dissolutions containing Co(II) in a Tris‐HCl medium and in the presence of perchlorate of 5,5‐dimethyl‐1,3‐cyclohexanodione dithiosemicarbazone (DYDT‐HClO4) produce a prewave that has been studied by means of classical polarography (DC) and differencial pulse polarography (DPP). The catalytic nature of the prewave has been established and the possible electrode mechanism proposed. The analytical possibilities of the mentioned prewave have also been analyzed in order to determine the DYDT, Hg(II) and Ag(I).
Synthèse Des Pyrazolyl‐1 Benzimidazoles A Partir Des Dihydro‐1,3(2H) Benzo[2,3‐b] Diazepine‐1,5 Ones‐2
Authors: Essassi E. M. , Salem M. 
Published: September 2010

AbstractHydrazinolysis of 4‐phenyl 1,5‐benzodiazepine 2‐thiones 2a‐2b gives N‐(5 (3)‐phenyl 3(5)‐pyrazolyl) 1‐amino 2‐aminobenzene 3a‐3b. The compounds 3a‐3b have been used as precursors to prepare the 1‐[(5)3‐phenyl (3)5‐pyrazolyl] benzimidazoles 5a‐5h.
NMR Imaging Machine Using Components of Commercial HR Spectrometers
Authors: Dereppe J. M. , Lemercinier X. , Moreaux C. , Haut H. 
Published: September 2010

AbstractTwo dimensional mapping of H spin densities in test objects were obtained using a projection reconstruction method. The experiments were carried out on a modified commercial spectrometer. The spatial distorsions of the system are discussed and illustrated.
Comportements Chimique et Électrochimique dans les Hydroxydes Alcalins Fondus. I. Si(IV) ET Ge(IV)
Authors: Claes P. , Peeters G. , Glibert J. 
Published: September 2010

AbstractThe study of the dissolution reaction of the silicium and germanium dioxides was carried out in the NaOH‐KOH (49 mole%) eutectic mixture at 210°C and in pure NaOH at 350°C. The initial acidobasicity of these solvents as well as the CO2‐ and CO modifications after addition of the Si(IV) and Ge(IV) solutes were measured by an original method using linear sweep voltammetry at a platinum electrode. This procedure was nevertheless ineffective in acidic NaOH medium because of the distortion of the water reduction peak by the cathodic front. In this case, the water liberated by the reaction was eliminated by a flow of dry nitrogen and collected in a cell containing anhydrous MgClO4. The equilibrium conditions obtained by addition of minute amounts of SiO2 and GeO2 were determined by aging of the solutions. The SiO44‐ and GeO44‐ oxyani ons were formed in the respective acidic or basic melts according to the reactions:
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Theoretical Study of the Electronic Structure of Ketene, Ketenimine, Keteniminium Ion and Related Cumulenes. Evaluation of a 1,2 Dipolar Model
Authors: Sonveaux E. , André J. M. , Delhalle J. , Fripiat J. G. 
Published: September 2010

AbstractMolecular orbital and configuration interaction calculations have been performed by ab initio methods for allene, ketene, ketenimine and keteniminium ion. Vinylketene and vinylketenimine were also investigated. The electronic populations, the frontier orbital energies and coefficients were deducted. A 1,2‐dipolar model of heterocumulenes is proposed. The experimental results related to the cycloadditions of these heterocumulenes are discussed on the basis of this model.
Ring Enlargement of the β‐Lactam Nucleus of Penicillins
Authors: Marchand‐Brynaert J. , Ghosez L. 
Published: September 2010

AbstractUsing penicillins as starting materials, a general synthetic route to the bicyclic compounds 7 has been established; they formally result from a ring enlargement of the ß‐lactam with insertion of one nitrogen atom. The key‐step of the procedure is a very mild Lossen rearrangement of hydroxamic acids intermediates upon treatment with N,N‐diethylaminopropyne.
Pyridines. XIII1‐Acylation de Pyridyl‐Lithioènamines Primaires Synthèse de Pyridyl‐Ènamides et de Naphtyridin‐1, 6 Ones‐5
Authors: Compagnon Paul‐Louis , Gasquez Françoise , Kimny Tan 
Published: September 2010

AbstractThe primary lithioenamine 4a is an ambivalent nucleophile resulting from the condensation of benzonitrile with 2‐s‐collidyllithium. Acylation of 4a by acetyl, benzoyl, N, N‐dimethylcarbamoyl chlorides, ethyl chloroformate or methyl benzoate leads to β‐C‐acylated 5, N‐acylated 6 (enamides) and β‐C, N‐diacylated 7 compounds. N‐acylation predominates upon C‐acylation with the studied aliphatic acid chlorides, contrary to benzoylation. 4, 6‐Dimethyl‐2‐pyridyl‐acetate 17 and‐acetamide 18 are formed and their origin is discussed. Thermocyclization of certain enamides, carbamates 6c, 7c and urea 6d leads to 2, 4‐dimethyl‐7‐phenyl‐1, 6‐naphthyridin‐5 (6H)‐ones 9a and 9b, and not to pyrido [1, 2‐c]pyrimidones 8.
Ba(OH)2 as the Catalyst in Organic Reactions‐Part VI Influence of Catalyst Structure and Basicity in the Alcohol Condensation of Acetone
Authors: Barrios J. , Marinas J. M. , Sinisterra J. V. 
Published: September 2010

AbstractThe aldol condensation of acetone in solid‐liquid system catalyzed by a family of barium hydroxide catalysts has been carried out. The C‐200 is more active and selective than the commercial barium hydroxide in the aldol condensation of acetone. The structure of the catalysts were analyzed by IR, TGA, TDA and X‐ray powder diagrams. The basic sites of the catalysts were titrated by benzoic acid (BA). The crystalline structure and the number of basic sites are related to the catalytic activity. Ba(OH)2.H2O is shown to be the active compound.
Thallium (I), Uranyl (II) and Vanadyl (II) complexes of 1–2‐amino‐3 Hydroxy Butanoic acid‐a Polarographic Study
Authors: Saxena R. S. , Parikh Reshma D. 
Published: September 2010

AbstractComplexation of Tl+1, UO22+ and VO+2 with 1–2‐amino‐3 hydroxy butanoic acid (AHB) has been studied polarographically in aqueous media. The reduction has been found to be reversible and diffusion controlled involving a one electron transfer process in the case of Tl+ and a two electron transfer process in the case of UO22+ and VO2+. The plot of ‐E1/2 vs‐log Cx yielded a straight line indicating the formation of a 1:1 complex in the case of UO22+ and VO+2 and hence the method of Lingane was adopted for the evaluation of coordination number and stability constants. However, in the case of Tl+ the plots of potential vs concentration data revealed the formation of 1:1 and 1:2 (M:L) complexes, whose stability constants were determined by employing DeFord and Hume's method.