bluuebunny/crossref_metadata_2025_split huggingface dataset:
Residual stress and mechanical properties of polyimide thin films
Authors: Jang Wonbong , Seo Jongchul , Lee Choonkeun , Paek Sang‐Hyon , Han Haksoo 
Published: April 2009

AbstractFour different structure polyimide thin films based on 1,4‐phenylene diamine (PDA) and 4,4′‐oxydianiline (ODA) were synthesized by using two different dianhydrides, pyromellitic dianhydride (PMDA) and 3,3′,4,4′‐biphenyltetracarboxylic dianhydride (BPDA), and their residual stress behavior and mechanical properties were investigated by using a thin film stress analyzer and nanoindentation method. The residual stress behavior and mechanical properties were correlated to the morphological structure in polyimide films. The morphological structure of polyimide thin films was characterized by X‐ray diffraction patterns and refractive indices. The residual stress was in the range of −5 to 38 MPa and increased in the following order: PMDA‐PDA < BPDA‐PDA < PMDA‐ODA < BPDA‐ODA. The hardness of the polyimide films increased in the following order: PMDA‐ODA < BPDA‐ODA < PMDA‐PDA < BPDA‐PDA. The PDA‐based polyimide films showed relatively lower residual stress and higher hardness than the corresponding ODA‐based polyimide films. The in‐plane orientation and molecularly ordered phase were enhanced with the increasing order as follows: PMDA‐ODA < BPDA‐ODA < BPDA‐PDA ∼ PMDA‐PDA. The PDA‐based polyimides, having a rigid structure, showed relatively better‐developed morphological structure than the corresponding ODA‐based polyimides. The residual stress behavior and mechanical properties were correlated to the morphological structure in polyimide films. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Cure characterization of soybean oil—Styrene—Divinylbenzene thermosetting copolymers
Authors: Badrinarayanan Prashanth , Lu Yongshang , Larock Richard C. , Kessler Michael R. 
Published: April 2009

AbstractBio‐based resins are an alternative to petroleum‐based resins in the production of fiber‐reinforced polymers (FRPs) by processes such as pultrusion. A detailed understanding of the cure behavior of the resin is essential to determine the process variables for production of FRPs. In this work, the cure kinetics of soybean oil‐styrene‐divinylbenzene thermosetting polymers is characterized by differential scanning calorimetry (DSC) measurements. By varying the concentration of the cationic initiator from 1 to 3 weight percent (wt %), the most viable resin composition for pultrusion is identified. The ability of phenomenological reaction models to describe the DSC measurements for the optimum resin composition is tested and kinetic equations, which can be used to determine the degree of cure at any temperature and time, are determined. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Synthesis and characterization of in situ sodium‐activated and organomodified bentonite clay/styrene–butadiene rubber nanocomposites by a latex blending technique
Authors: Chakraborty S. , Sengupta R. , Dasgupta S. , Mukhopadhyay R. , Bandyopadhyay S. , Joshi Mangala , Ameta Suresh C. 
Published: April 2009

AbstractIn this article, we describe a method used to prepare an in situ sodium‐activated, organomodified bentonite clay/styrene–butadiene rubber nanocomposite master batch via a latex blending technique. The clay master batch was used for compound formulation. Octadecyl amine was used as an organic intercalate. The clay was purchased from local suppliers and was very cheap. Sodium chloride was used for in situ activation of the clay. The wide‐angle X‐ray diffraction data indicated that the in situ sodium activation helped to increase the intergallery distance from 1.28 to 1.88 nm. A transmission electron micrograph indicated intercalation and partial exfoliation. The thermal properties were relatively better in the case of the sodium‐activated, organomodified bentonite‐clay‐containing compound. A substantial improvement in physical properties such as the modulus, tensile strength, tear strength, and elongation at break was observed in the case of the in situ sodium‐activated compound. A cation‐exchange capacity equivalent (of the clay) of 1.5 times the octadecyl amine was the optimum dose for the modification. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Olefin Metathesis for Site‐Selective Protein Modification
Authors: Lin Yuya A. , Chalker Justin M. , Davis Benjamin G. 
Published: April 2009

AbstractProtein compatible. Olefin metathesis has emerged as a viable strategy for site‐selective protein modification. This minireview traces its development from early peptide models and metathesis in water to its ultimate application to protein substrates. Prospects in chemistry and biology are also discussed.magnified imageFor a reaction to be generally useful for protein modification, it must be site‐selective and efficient under conditions compatible with proteins: aqueous media, low to ambient temperature, and at or near neutral pH. To engineer a reaction that satisfies these conditions is not a simple task. Olefin metathesis is one of most useful reactions for carbon–carbon bond formation, but does it fit these requirements? This minireview is an account of the development of olefin metathesis for protein modification. Highlighted below are examples of olefin metathesis in peptidic systems and in aqueous media that laid the groundwork for successful metathesis on protein substrates. Also discussed are the opportunities in protein engineering for the genetic introduction of amino acids suitable for metathesis and the related challenges in chemistry and biology.
Controlled‐release of Avermectin from Organically Modified Hydrotalcite‐like Compound Nanohybrids
Authors: QIU Depeng , LI Yonghai , FU Xiying , JIANG Zhen , ZHAO Xinyan , WANG Tian , HOU Wanguo 
Published: April 2009

AbstractThe intercalation of avermectin (AVM) into sodium dodecyl sulfate (SDS) modified hydrotalcite‐like compounds (HTlc) was carried out using an evaporating solvent enhanced intercalation method to obtain AVM‐SDS‐HTlc nanohybrids. It was found that the nanohybrids could well control the release of avermectin, showing the nanohybrids are a potential pesticide controlled‐release formulation. The release of avermectin from AVM‐SDS‐HTlc nanohybrids is dependent on the pH, temperature and the presence of electrolyte in release medium. Acidic medium and higher temperature and the presence of electrolytes may induce the higher release rate of avermectin. The release process of avermectin from AVM‐SDS‐HTlc nanohybrids can be described by pseudo‐first‐order release kinetics, and the activation energy of release is 279 kJ/mol.
SCOFF, the development of an eating disorder screening questionnaire
Authors: Hill Laura S. , Reid Fiona , Morgan John F. , Lacey J. Hubert 
Published: April 2009

AbstractObjective:This article describes the three‐stage development of the SCOFF, a screening tool for eating disorders.Method:Study 1 details questionnaire development and testing on cases and controls. Study 2 examines reliability of verbal versus written administration in a student population. Study 3 validates the test as a screening tool in primary care.Results:The SCOFF demonstrates good validity compared with DSM‐IV diagnosis on clinical interview. In the primary care setting it had a sensitivity of 84.6% and a specificity of 89.6%, detecting all true cases of anorexia nervosa and bulimia nervosa and seven of nine cases of EDNOS. Reliability between written and verbal versions of the SCOFF was high, with a kappa statistic of 0.82.Discussion:The SCOFF, which has been adapted for use in diverse languages, appears highly effective as a screening instrument and has been widely adopted to raise the index of suspicion of an eating disorder. © 2009 by Wiley Periodicals, Inc. Int J Eat Disord 2010
Click Multivalent Homogeneous Neoglycoconjugates – Synthesis and Evaluation of Their Binding Affinities
Authors: Perez‐Balderas Francisco , Morales‐Sanfrutos Julia , Hernandez‐Mateo Fernando , Isac‐García Joaquín , Santoyo‐Gonzalez Francisco 
Published: April 2009

AbstractMannose (α‐Man)‐containing neoglycoconjugates possessing aliphatic‐, aromatic‐, and carbohydrate‐centered architectures and differing in structural characteristics such as valency, topology, and nature of the linker have been synthesized using click chemistry that shows its value as an efficient and versatile methodology for accessing tailor‐made multivalent neoglycoconjugates. The binding behaviour of these glycomimics toward Concanavalin A (Con A) has been evaluated to determine the influence of the structural parameters. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Detection of benzo(a)pyrene diol epoxide‐DNA adducts in mononuclear white blood cells by CE immunoassay and its application to studying the effect of glutathione depletion
Authors: LeBlanc Adrienne , Shen Shengwen , Lew Kristi , Weinfeld Michael , Chris Le X. 
Published: April 2009

AbstractHigh levels of benzo(a)pyrene diol epoxide (BPDE)‐DNA adducts in white blood cells have been indicated as a risk factor for lung cancer. Sensitive, specific, fast and cost‐efficient techniques for the detection of BPDE‐DNA adducts in white blood cells are required for routine human biomonitoring. In the present study, an immunoassay based on CE/LIF was developed for the detection of BPDE‐DNA adducts in mononuclear white blood cells (MNCs). Although glutathione (GSH) conjugation catalyzed by glutathione‐S‐transferase (GST) is considered to be the major pathway for inactivating BPDE, the effect of GSH depletion on BPDE‐DNA adduct formation in MNCs has not been assessed. Therefore, we applied the newly developed method to study the effect of GSH depletion by d,l‐buthionine‐[S,R]‐sulfoximine (BSO) on the level of DNA adducts. We found that pretreatment of MNCs with 150 μM BSO for 2 h prior to BPDE exposure increased the level of BPDE‐DNA adducts appreciably (by ∼70%). Further investigations revealed that the 2‐h BSO treatment neither decreased the GSH level instantly nor affected GST activity; rather, it prevented the induction of GSH in response to subsequent BPDE incubation. The blocked synthesis of GSH might be responsible for the elevated level of BPDE‐DNA adducts in MNCs after BSO and BPDE treatment.
Capillary zone electrophoresis of Cowpea mosaic virus and peak identification
Authors: Liang Shucai , Schneider Rudolf J. 
Published: April 2009

AbstractCowpea mosaic virus (CPMV) was analyzed by CZE and the two separated subcomponents recorded at ∼2.2 and ∼2.7 min were respectively designated to be the slow electrophoretic form of CPMV (CPMVs) and the fast electrophoretic form of CPMV (CPMVf), the two electrophoretic forms of CPMV, by the following methods: first, CZE analysis of the biospecific complexes of CPMV and anti‐CPMV polyclonal antibody proved the properties of CPMV; second, isolation and CZE analysis of CPMVf and CPMVs. Because CPMVs was precipitated and CPMVf was left in the supernatant at pH 5.6, the only one peak at ∼2.7 min from the supernatant was assigned for CPMVf, while the peak at ∼2.2 min dominating for the precipite was deemed to be CPMVs. Third, viral characterization by directly analyzing the capsid proteins using MALDI‐TOF‐MS. Based on the theoretical molecular weights calculated from the sequence of the capsid proteins, the three peaks at m/z 21 516.75, 23 745.8 and 42 509.22 for natural CPMV were destined for the small (S) protein of CPMVf, the S protein of CPMVs and the large (L) protein of both of them, respectively. As expected, the non‐appearance of the peak at m/z 23 745.8 for the isolated CPMVf sample indicated the absence of CPMVs, and the peak at m/z 23 745.8 was predominant in the spectrum for the precipitated CPMVs sample. After the confirmation of CPMVs and CPMVf, the CZE separation of them was optimized. The developed analysis method has proven useful in investigating the stability of CPMV and the effect of 2,4‐dinitrophenyl‐decoration on the modification of the electrophoretical behavior of CPMV.
Syntheses du tri‐O‐benzyl‐3,4,6‐D‐glucal
Authors: Boullanger Paul , Martin Jean‐Claude , Descotes Gérard 
Published: April 2009

AbstractLe tri‐O‐benzyl‐3,4,6‐D‐glucal, intermédiaire de synthèse pour de nombreuses réactions d'addition, est obtenu, soit par benzylattion directe du glucal ou de son dérivé acétylé (Rendement), soit à partir de l'acétobromoglucose (Rendement 26%). Les caractéristiques physiques et spectrales sont décrites.
Mass spectra of 6‐ketononanolides and related ketolactones
Authors: Borowitz Irving J. 
Published: April 2009

AbstractThe mass spectral fragmentation of 6‐ketononanolides, 6‐ and 7‐ ketodecanolides, 7‐ketoundecanolides and 9‐ketotridecanolide has been partially correlated via high resolution measurements and the use of methyl substituted derivatives. Moities characteristic of the “lactone side” and the “non‐lactone side” of the ketolactones can be described. Metastable transitions and decoupled measurements are offered as additional evidence for some of these pathways.
A new synthesis of 2,1‐benzisothiazoles
Authors: Singerman Gary M. 
Published: April 2009

AbstractA novel synthesis of 2,1‐benzisothiazoles is described. When ano‐toluidine orN‐sulfinyl‐o‐toluidine is allowed to react with anN‐sulfinylsulfonamide, a 2,1‐benzisothiazole is formed.
Benzomorphan related compounds. IV. The stevens rearrangement of a trimethoxybenzyl‐1,2,5,6‐tetrahydropyridinium salt
Authors: Bosch J. , Canals J. , Granados R. 
Published: April 2009

AbstractThe potassium hydroxide‐induced (Stevens) rearrangement of 1,3,4‐trimethyl‐1‐(3,4,5‐trimethoxybenzyl)‐1,2,5,6‐tetrahydropyridinium chloride (I) gives the desired 1,3,4‐trimethyl‐2‐(3,4,5‐trimethoxybenzyl)‐1,2,5,6‐tetrahydropyridine (III) and the Hofmann elimination product, N‐methyl‐N‐(3,4,5‐trimethoxybenzyl)‐2,3‐dimethyl‐2,4‐pentadienamine (II). In the presence of ethereal phenyllithium, the salt I undergoes rearrangement giving the expected tetrahydropyridine III in about 17% yield and four other products, N‐(3,4,5‐trimethoxybenzyl)methylamine (VI), 1,3,4‐trimethyl‐2‐(6‐methyl‐2,3,4‐trimethoxyphenyl)‐1,2,5,6‐tetrahydropyridine (IV), 1,3,3‐trirnethyl‐2‐(3,4,5‐trimethoxyphenyl)‐4‐rnethylenepiperidine (V) and 1,3,4‐trimethyl‐4‐(3,4,5‐trimethoxybenzyl)‐1,4,5,6‐tetrahydropyridine (VII), the latter being the 1,4‐Stevens rearrangement product which cyclizes easily to β‐2′,3′,4′‐trimethoxy‐2,5,9‐trimethyl‐7,8‐benzomorphan (VIII). Their structures have been proved both by analytical and spectral data. A possible route for VIII and its stereochemical aspects are discussed.
Synthesis of 1,2,3‐thiadiazoles
Authors: Peet Norton P. , Sunder Shyam 
Published: April 2009

AbstractSeveral methods were explored for preparing certain 4,5‐disubstituted‐1,2,3‐thiadiazoles. The reaction of phenoxyacetyl chlorides with diazoacetylamides yielded α‐diazo‐β‐ketoacetamides which were cyclized, with hydrogen sulfide and ammonium hydroxide, to 4‐carboxamido‐5‐phenoxymethyl‐1,2,3‐thiadiazoles. However, treatment of α‐diazo‐α‐benzoylacetamides with hydrogen sulfide and ammonium hydroxide yielded hydrazones rather than thiadiazoles. The reaction of α‐[(ethoxycarbonyl)hydrazono]benzenepropanoic acid (25) with thionyl chloride yielded 5‐phenyl‐1,2,3‐thiadiazole‐4‐carbocylic acid (26a), the corresponding acid chloride 26b, and 5‐(phenylmethyl)‐2H‐1,3,4‐oxadiazine‐2,6(3H)dione (27). The yields of 26a, 26b, and 27 were dependent on the reaction conditions employed. Oxadiazine 27 could also be converted to acid chloride 26b with thionyl chloride. Reduction of 1‐([5‐(4‐chlorophenoxy)methyl‐1,2,3‐thiadiazol‐4‐yl]‐carbonyl)piperidine (10b) with diborane yielded a boron complex which produced 1‐([5‐((4‐chlorophenoxy)methyl)‐1,2,3‐thiadiazol‐4‐yl]methyl)piperidine (31) upon recrystallization from ethanol.
2,3,7,8‐Tetraazaspiro[4.4] nonane, 2,3,7,8‐tetraazaspiro‐[4.4] nona‐2,7‐diene and derivatives
Authors: Nielsen Arnold T. 
Published: April 2009

AbstractSynthetic routes to the title compounds (4, 12) are described. Chiral derivatives of these, 2,7‐bis(phenylcarbamoyl)‐2,3,7,8‐tetraazaspiro[4.4]nonane (7) and 3,8‐dicarbomethoxy‐2,3,7,8‐tetraazaspiro[4.4]nona‐1,6‐diene (10) were prepared. Synthetic routes to diketo derivatives of other tetraazaspiro[4.4]nonanes were explored. 3,3‐Dicarbethoxy‐1‐pyrazoline (24) and 3,3‐dicarbethoxypyrazolidine (25) were prepared and their reactions with hydrazine examined. Proton and 13C nuclear magnetic resonance spectra of new compounds, including some 5‐substituted 3‐hydroxypyrazoles, are discussed in relation to structure.
Selenium heterocycles. XIX. Synthesis of selenophenes and triarylbenzenes from 2,5‐diaryl‐1,4‐dithiin 1,1,4,4‐tetroxides
Authors: Lalezari I. , Shafiee A. , Rashidbaigi A. 
Published: April 2009

AbstractMixtures of 2,5‐diaryl‐1,4‐dithiin 1,1,4,4‐tctroxides and selenium were subjected to heat and afforded 2,5‐diarylselenophenes. Pyrolysis of 2,5‐diaryl‐1,4‐dithiin 1,1,4,4‐tetroxides led to the formation of a mixture of 1,2,4‐ and 1,3,5‐triarylbenzenes.
Unexpected formation of a 10H‐Pyrido[2,3‐h]pyrazolo[3,4‐b]quinoline derivative, a new ring system
Authors: Crenshaw R. R. , Luke G. M. , Whitehead D. F. 
Published: April 2009

AbstractTreatment of N‐(1,3‐dimethylpyrazol‐5‐yl)‐4‐anthranilic acid with phosphorus oxychloride gave an intermediate which was condensed with 3‐dimethylaminopropylamine to yield 10,8‐dimethyl‐7‐(3‐dimethylaminopropylamino)‐10H‐pyrido[2,3‐h]pyrazolo[3,4‐b]quinoline (IV). The structure of IV, which represents a previously undescribed ring system, was confirmed by an independent synthesis.
Ring‐opening and a novel ring expansion in the reactions of 1‐Alkyl‐2‐carbomethoxyazetidine with hydrazine
Authors: Leung Hiu‐Kwong , Phillips Barry A. , Cromwell Norman H. 
Published: April 2009

AbstractThe mechanism of the reactions of 1‐t‐butyl‐2‐carbomethoxyazelidine and 1‐benzyl‐2‐carbomethoxyazetidine with hydrazine hydrate was investigated. Treatment of 1‐alkyl‐2‐earbomethoxyazetidine with hydrazine hydrate in cold ethanol yielded 1‐alkylazetidine‐2‐carhohydrazide. Depending on the sterie bulkiness of the alkyl group of the amino functionality, reactions of 1‐alkylazetidine‐2‐carbohydrazides in methanol gave the appropriate aminoester or the appropriate pyrrolidone, or a mixture of both. The intermediacy of the diimide in these transformations was confirmed by the concurrent reduction of azobenzene to hydrazobenzene.
Acetylenic ketones. Part III . Reaction of acetylenic ketones with nucleophilic sulfur compounds
Authors: Haddar F. G. , Al‐Hajjar F. H. , El‐Rayyes N. R. 
Published: April 2009

AbstractAroylphenylacetylenes reacted with ammonium dithiocarbamate and ammonium hydrogen sulfide in 60% dioxane‐waler mixture at 15° to give mainly a mixture of the corresponding β‐hydroxy‐α‐thiobenzoylstyrene derivatives (III) and (E,Z)‐β,β'‐di(α‐aroylstyryl) sulfides (IV), whereas with sodium xanthate and sodium sulfide they gave only (III). However, when benzoyl‐(Ia) or p‐ehlorobenzoyl‐(Id)phenylacetylenes was refluxed with ammonium dithiocarbamate in ethyl alcohol, it gave a mixture of (IIIa or d) and the (E,E)‐β,β'‐di(α‐aroylstyryl) sulfide (VIa or d).β‐Hydroxy‐α‐thiobenzoylstyrene derivatives (III), (E,Z)‐(IV) and (E,E)‐(VI)‐β,β'‐di(α‐aroylstyryl) sulfides reacted with hydrazine hydrate and phenylhydrazine to give 3(5)‐aryl‐5(3)‐phenyl‐(IX)‐ and 5‐aryl‐1,3‐diphenyl‐(X)pyrazoles, respectively. The former compounds (III) reacted with guanidine and ethyl hydrazinecarboxylate to give the corresponding aminopyrimidines (XIII) and acetophenone‐N‐ethoxycarbonyl hydrazones (XI), respectively.
12H‐naphtho[1′,2′:5,6]pyrano[2,3‐d]pyrimidine derivatives
Authors: Roma Giorgio , Ermili Aldo , Mazzei Mauro 
Published: April 2009

AbstractReaction of 1‐oxo‐2‐formyl‐3‐dimethylamino‐1H‐naphtho[2,1‐b]pyran with amidines, guanidine, O‐methylisourea, S‐methylisothiourea afforded 9‐substituted 12‐oxo‐12H‐naphtho[1′,2′:5,6]pyrano[2,3‐d]pyrimidines.When the reaction with O‐methylisourea was carried out in anhydrous pyridine, 10,20‐dioxo‐10H,20H‐dinaphtho[1,2‐e:1′,2′‐e′][1,5]diazocino[2,3‐b:6,7‐b′]dipyran was formed.
Studies on quinoline derivatives and related compounds. IV. Synthesis of 4‐substituted 1‐alkyl‐1,4‐dihydro‐3‐quinolinecarboxylic acid
Authors: Agui Hideo , Nakagome Takenari 
Published: April 2009

AbstractBy the displacement reactions of 1‐ethyl‐4‐chloro‐3‐carboethoxy‐6,7‐methylenedioxyquinolinium iodide (3a), several 4‐substituted derivatives including the 4‐thioxo (1c) and 4‐amino derivatives (6) of oxolinic acid were prepared. The acid 1c and its N1‐substituted derivatives (18a‐h) were prepared alternatively by alkylation of ethyl 4‐ethylmercapto‐6,7‐methylenedioxy‐3‐quinolinecarboxylate (15) followed by treatment with sodium hydrosulfide and hydrolysis.
Heterocyclic compounds. VII. Synthesis of thiadiazasteroid analogs
Authors: Manhas M. S. , Rao V. V. , Amin S. G. 
Published: April 2009

AbstractThe synthesis of a number of β‐northiadiaza steroid analogs has been described. Suitable o‐aminonitriles were acylated with γ‐chlorobutyryl chloride. These amidonitriles were cyclized to substituted γ‐lactams and subsequently to the tetracyclic products. To functionalize the “17‐position” in these steroids, the intermediate γ‐lactams were converted to arylidene derivatives before cyclization to the tetracyclic derivatives.
Synthesis of the carbocyclic analogs of uracil nucleosides
Authors: Shealy Y. Fulmer , O'Dell C. Allen 
Published: April 2009

AbstractTreatment of the required hydroxyl derivatives ofcis‐3‐aminocyclopentanemethanol with 3‐ethoxyacryloyl isocyanate gaveN‐(3‐ethoxyacryloyl)‐N′‐[hydroxy‐ or dihydroxy(hydroxy‐methyl)cyclopentyl]ureas. Cyclization of the ureas in dilute sulfuric acid afforded high yields of the carbocyclic analogs of uridine, 2′‐deoxyuridine, and 3′‐deoxyuridine. The uridine and 3′‐deoxyuridine analogs were also obtained in good yields by cyclizing the ureas in concentrated aqueous ammonia. None of the three analogs showed activity in testsversusKB cells in culture or L1210 leukemiain vivo.
Nucleophilic substitutions on the pyridine ring with enolate anions
Authors: Smith Francis X. , Evans Gordon G. 
Published: April 2009

AbstractThe enolate anions of 5‐alkylbarbituric acids and isopropylidene alkylmalonates are demonstrated to readily displace chloro, pyridinio, and acetoxy substituents from the 4‐position of simple pyridine derivatives under conditions in which the ring nitrogen carries a positive charge.
The synthesis of some benzo[4,5]cyclohept[1,2,3‐ij]isoquinolines
Authors: Santroch George , Humber Leslie G. 
Published: April 2009

AbstractA facile synthesis and spectroscopic properties of various oxidation states of the novel benzo[4,5]cyclohept[1,2,3‐ij]isoquinoline system are described. The synthesis involves the condensation of 5H‐dibenzo[a,d]cyclohepten‐5‐one, or of its 10,11‐dihydro derivative, with amino‐acetaldehyde diethylacetal, followed by treatment of the resultant imines with polyphosphoric acid to afford the novel tetracyclic system in high yields.
Synthesis of 2‐substituted‐5‐rnethylthiazolo[ 3,2‐b ] ‐1,2,4‐lriazoles and acylatcd 3‐amino‐2‐imino‐4‐methyl‐2‐thiazolines
Authors: Pilgram Kurt , Pollard G. E. 
Published: April 2009

Abstract3‐Amino‐2‐imino‐4‐mcthyl‐2‐thiazoline, 1, underwent ring closure with ethyl formate, cyanogen bromide and carbon disulfide, giving moderate yields of 2‐substituted‐5‐methylthiazolo[ 3,2‐b ]‐1,2,4‐triazoles, II. Reaction of I‐HCl with acid anhydrides (acetic, propionie, trifluoroacetic) resulted in the formation of the corresponding II compounds, whereas other anhydrides (benzoic, perfluoropropionic, perfluorobutyric) gave high yields of 3‐aeylamido‐2‐acylimido‐4‐melhyl‐2‐thiazolines. With acid chlorides and I‐HCl, in the presence of trielhylamine, mixtures of 2‐acyl‐irnino‐3‐aniino‐4‐methyl‐2‐thiazolines and 2‐aeylimino‐3‐(diacylamido)‐4‐methyl‐2‐thiazolines are formed. Spectral characteristics are reported.