bluuebunny/crossref_metadata_2025_split huggingface dataset:
The synthesis of naphthothiopyranopyranones and naphthothiopyranopyranthiones
Authors: Takido Toshio , Tomizawa Nobuyuki , Tsukano Kazuo , Hayashi Takao , Itabashi Kunio 
Published: March 2009

AbstractThe synthesis of fused tetracyclic naphthothiopyranopyranones from dihydronaphthothiopyranones I or II has been studied. Compounds I or II have been cyclised in good yield to the corresponding dioxaborin difluoride complexes III, IV, XIII and XIV by treatment with acetic or propionic anhydride and boron trifluoride etherate. These complexes and the Vilsmeier reagent reacted to produce fused tetracyclic 3‐substituted naphthothiopyranopyranones V, VI, XV or XVI.The reaction of dioxaborin difluoride complexes III or IV with dimethylthioformamide (DMTF) afforded dimethylaminovinyldioxaborin difluoride complexes IX or X. Treatment of IX or X with hydrochloric acid solution gave naphthothiopyranopyranones VII or VIII.The reaction of VII, VIII, XV or XVI with DMTF/acetic anhydride yielded new products, which was identified as naphthothiopyranopyranthions XI, XII, XVII or XVIII.
Synthesis of novel substituted spirohydantoins
Authors: Carrera George M. , Garvey David S. 
Published: March 2009

AbstractThe synthesis of novel N‐1‐alkylspirohydantoins (1‐alkyl‐1,3,8‐triazaspiro[4.5]decanes) is reported. The key hydantoin intermediates 3 were prepared using standard hydantoin methodology. This synthesis allows for differential substitution of all three nitrogens.
The meyer‐schuster rearrangement and hydrohalide addition of 3‐alkynyl‐3‐hydroxy‐1H‐isoindol‐1‐ones
Authors: Omar Enouri A. , Tu Chi , Wigal Carl T. , Braun Loren L. 
Published: March 2009

AbstractTreatment of N‐methyl and N‐phenylphthalimide with appropiate lithium acetylides in tetrahydrofuran obtained the acetylenic alcohols 2a through 2h. These compounds, when subjected to mildly acidic hydrolysis conditions in aqueous organic solvents, underwent Meyer‐Schuster rearrangement to yield the α,β‐unsaturated carbonyl compounds 4a through 4h which were determined to have the E configuration. The phenyl ethynyl analogs of series 4 underwent hydrohalide addition when treated with hydrogen halides in water solution.
New synthesis of 4,5‐dihydro‐1,2,4‐triazin‐3(2H)‐one derivatives through cyclic transformation of 1,3,4‐oxadiazol‐2(3H)‐one derivatives
Authors: Milcent René , Yver Béatrice , Barbier Géo 
Published: March 2009

AbstractSome 5‐aryl(or benzyl)‐2‐oxo‐1,3,4‐oxadiazole‐3(2H)‐acetones or acetophenones 2 were easily prepared. These compounds reacted with hydrazine derivatives to give 4,5‐dihydro‐1,2,4‐triazin‐3(2H)‐one derivatives 3, 4 and 6 in good yields. With phenylhydrazine, the intermediate hydrazones 5 were obtained. Their conversion into triazinones necessitated the presence of sodium ethylate.
Conformational analysis of benzoannulated nine‐membered rings. Part 3. 1,4,5,7‐Tetrahydro‐3H‐2,6‐benzodiselenine and its 4‐spiro derivatives
Authors: Rys Barbara , Duddeck Helmut , Hiegemann Monika 
Published: March 2009

AbstractThe 1H and 13C nmr spectra of 1,4,5,7‐tetrahydro‐3H‐2,6‐benzodiselenine (1) and three 4‐spiro derivatives 2–4 as well as the 77Se nmr spectra of 2 have been recorded at different temperatures in order to investigate their conformational behavior. It was found that in analogy to corresponding dithionins the molecules adopt a chiral ground state conformation (Figure 2), and coalescence effects are due to racemization.
Synthesis of 3‐hetaryl‐4,5,6,7‐tetrahydrobenzo[b]thiophenes
Authors: Sabnis R. W. , Rangnekar D. W. 
Published: March 2009

AbstractA novel efficient synthesis of 3‐hetaryl‐4,5,6,7‐tetrahydrobenzo[b]thiophenes was achieved by the cyclocondensation of ethyl 2‐amino‐4,5,6,7‐tetrahydrobenzo[6]thiophene‐3‐carboxylate with selected o‐substituted aromatic amines or with alifatic, aromatic and heterocyclic acid hydrazides in the presence of polyphosphoric acid.
A convenient and versatile synthesis of 4‐trifluoromethyl‐substituted pyrazoles
Authors: Meazza Giovanni , Zanardi Giampaolo , Piccardi Paolo 
Published: March 2009

AbstractTrifluoromethyl‐substituted pyrazoles were synthesized via 1,3‐dipolar cycloaddition from sydnones 2a‐j and 1‐aryl‐3,3,3‐trifluoro‐propynes 5a‐f. The regioselectivity of the reaction and the spectroscopic characteristics of the products are discussed.
New derivatives of 4,4,5,5‐tetramethyl‐4,5‐dihydro‐1‐H‐imidazol‐1‐oxyl 3‐oxide as monomers for polyradicals with special magnetic properties
Authors: Saf Robert , Swoboda Petra , Hummel Klaus , Czaputa Rainer 
Published: March 2009

AbstractThe preparation of new derivatives of 4,4,5,5‐tetramethyl‐4,5‐dihydro‐1H‐imidazol‐1‐oxyl 3‐oxide as monomers for purely organic polymers with special magnetic properties is described. 3,5‐Diethynylbenzaldehyde and 3,5‐bis(trimethylsilylethynyl)benzaldehyde were converted to the corresponding 1,3‐dihydroxy‐4,4,5,5‐tetramethylimidazolidine derivatives which were oxidized to stable nitronyl nitroxide radicals.
Preparation of 3‐hydroxy‐ and 3‐methoxy‐N‐heteroaryl‐2‐methyl‐4‐pyridones
Authors: Jakopčić Krešimir , Mintas Mladen , Isufi Islam 
Published: March 2009

AbstractA number of new 3‐hydroxy‐ and 3‐methoxy‐2‐methyl‐4‐pyridones substituted on the nitrogen atom with selected heterocycles has been prepared. Novel chelating properties of the hydroxy‐compounds are expected.
Synthesis of 3‐substituted 5‐arylisoxazoles from α,β‐unsaturated oximes
Authors: Alberola Angel , Manuel Bañez J. , Calvo Luis , Rodríguez Rodríguez M. Teresa , Carmen Sañudo M. 
Published: March 2009

AbstractThe synthesis of 3‐substituted 5‐arylisoxazoles from oximes of α,β‐unsaturated ketones is studied. The formation of the isoxazole derivatives takes place by cyclization of oximes in the presence of iodine and potassium iodide. The presence of isoxazoline is detected. On the basis of the results a plausible mechanism is suggested.
Synthesis of a new 1,4‐dihydropyridine containing the imidazo[1,5‐α]pyridine nucleus
Authors: Fos Empar , Boscá Francisco , Mauleón David , Carganico Germane 
Published: March 2009

AbstractThe synthesis of the new dihydropyridine diethyl 1,4‐dihydro‐4‐(imidazo[1,5‐α]pyridin‐8‐yl)‐2,6‐dimethyl‐pyridine‐3,5‐dicarboxylate (1) is described. After many attempts to prepare the key intermediate aldehyde 2a by different approaches, this compound has been obtained in good yields from methyl 2‐cyano‐3‐pyridinecar‐boxylate (10). A three‐step procedure involving reduction to the amine, formylation with concomitant cyclization and reduction of the ester group was used.
Anticancer anthrapyrazoles. The synthesis of 2‐substituted 5‐nitro and 5‐aminoanthra[1,9‐cd]pyrazol‐6(2H)‐ones
Authors: Hollis Showalter H. D. , Turner William R. 
Published: March 2009

AbstractSynthetic methodologies for the preparation of substituted 5‐nitro‐ and 5‐aminoanthra[1,9‐cd]‐pyrazol‐6(2H)‐ones, 4 and 5 respectively, substituted with a basic side at N‐2 and dioxy substitution in the A‐ring, are reported. These compounds are essentially devoid of activity against in vitro L1210 leukemia and in vivo murine P388 leukemia.
Studies on isocyanides and related compounds. Investigation on the reaction between (Z)‐alkyl 3‐dimethylamino‐2‐isocyanoacrylates and acyl chlorides
Authors: Bossio Ricardo , Marcaccini Stefano , Pepino Roberto , Paoli Paola , Polo Cecilia 
Published: March 2009

AbstractThe reaction between (Z)‐methyl 3‐dimethylamino‐2‐isocyanoacrylate (1a) and acyl chlorides 2a,b did not afford methyl 2‐acyl‐1‐methyl‐1H‐imidazole‐4‐carboxylates 3a,b, as previously reported, but 2‐acyl‐4‐dimeth‐ylaminomethyleneoxazol‐5(4H)‐ones 4a,b.
9,9‐diphenyl‐1,9,10,10a‐tetrahydro‐2H‐phenaleno[1,9‐bc]pyrans
Authors: Beswick John R. , Cotterill W. David , Iqbal Muhammad , Livingstone Robert 
Published: March 2009

AbstractReaction between some naphtho[2,1‐b]pyrans and 1,1‐diphenylethene affords 9,9‐diphenyl‐1,9,10,10a‐tetrahydro‐2H‐phenaleno[1,9‐bc]pyrans.
Synthesis of C‐nor‐4,6‐secocamptothecin and related compounds
Authors: Kurihara Takushi , Tanno Hirokatsu , Takemura Shigetaka , Harusawa Shinya , Yoneda Ryuji 
Published: March 2009

AbstractC‐nor‐4,6‐Secocamptothecin 2, 4‐ethyl‐4‐hydroxy‐6‐(2‐quinolinyl)‐1H‐pyrano[3,4‐c]pyridine‐3,8(4H,7H)‐dione, lacking the C‐ring of camptothecin 1, and its related compounds 3 and 4 were prepared from ethyl quinoline‐2‐carboxylate 7. By an analogous reaction sequences, synthesis of 6‐(2‐pyridinyl)‐1H‐pyrano[3,4‐c]‐pyridine‐3,8(4H7H)‐dione derivatives 5 and 6, which contain the B, D, and E ring of 1, were achieved.
Condensation reactions of activated picolines with anthranilate esters and o‐nitrobenzaldehyde: Improved syntheses of the antiarrhythmic drug encainide
Authors: Dillon John L. , Spector Richard H. , Madding Gary D. , Wire Mary E. 
Published: March 2009

AbstractTwo new and improved syntheses of the antiarrhythmic drug Encainide, 1, are presented. The first approach is based on the condensation of 2‐picolyllithium with the p‐anisoyl amide of methyl anthranilate, 3, followed by a series of catalytic hydrogenations and methylation. The second route relies on a particularly facile condensation reaction between N‐methylpicolinium methyl sulfate and o‐nitrobenzaldehyde to produce the alcohol 17c in high yield which is converted to the olefin 18c by a novel dehydration procedure and then to the final molecule, by catalytic hydrogenation over platinum followed by acylation.
Synthesis and NMR characterization of a novel heterologue of pyrene: The naphtho[1,8‐bc;4,5‐b'c']dipyran (1,8‐dioxapyrene)
Authors: Buisson J.‐P. , Kotzyba J. , Lièvremont J.‐P. , Demerseman P. , Platzer N. , Bideau J.‐P. , Cotrait Michel 
Published: March 2009

Abstract1,8‐Dioxapyrene, a novel unsubstituted dioxa‐analog of pyrene was synthesized from 4‐methoxy‐1‐naphthol in a ten‐step reaction involving two peri‐heterocyclizations. 1H and 13C nmr indicated a disruption of extended delocalization of π electrons, like that observed with the 1,6‐isomer.
Synthesis of new thienocyclopenta[3,2‐d]‐oxazole and thiazole derivatives
Authors: Dallemagne Patrick , Boulouard Michel , Rault Sylvain , Robba Max 
Published: March 2009

AbstractSynthesis of thieno[2′,3′:5,4]cyclopenta[3,2‐d]oxazole and thiazole derivatives are achieved by insertion of carbon dioxide and disulfide into 4‐amino‐5‐chloro‐5,6‐dihydro‐4H‐cyclopenta[b]thiophen‐6‐one.
Synthesis of 6‐aminobenzo[b]naphtho[2,1‐d]thiophene
Authors: Tominaga Yoshinori , Castle Lyle W. , Castle Raymond N. 
Published: March 2009

Abstract6‐Aminobenzo[b]naphtho[2,1‐d]thiophene has been prepared by two different routes, one, a one‐pot synthesis.
Synthesis of 3‐acylamino‐2‐oxazolidinone derivatives through cyclic transformations of 5‐aryl (or benzyl)‐1,3,4‐oxadiazol‐2(3H)‐one derivatives
Authors: Milcent René , Yver Beatrice , Barbier Géo 
Published: March 2009

AbstractNew 3‐acylamino‐2‐oxazolidinone derivatives 3 were obtained in good yields by reaction of 5‐aryl (or benzyl)3‐(2‐hydroxyethyl)1,3,4‐oxadiazol‐2(3H)ones 1 with sodium ethylate. Treatment of ethyl 5‐aryl‐2‐oxo‐1,3,4‐oxadiazole‐3(2H)‐acetates 7 with aromatic aldehydes in the presence of sodium ethylate or sodium hydride afforded 3‐acylamino‐5‐aryl‐4‐ethoxycarbonyl‐2‐oxazolidinone derivatives as two trans‐5 and cis‐6 racemics. Only RS,SR‐racemates were obtained with acetophenone under the same conditions.
Crystal and molecular structure and spectra of 2′,2′,5,5,5′,5′,7,7‐octamethyl‐2′,5,5′,7‐tetrahydrofuro[3,4‐d]‐1‐oxa‐3,4‐disele‐nin‐2‐spiro‐3′‐furan‐4′(3′H)‐one from selenium dioxide oxidation of 2,2,5,5‐tetramethyltetrahydrofuran‐3‐one. A novel six‐membered heterocyclic ring system in the chalcogen series
Authors: Kuronen Pirjo , Laitalainen Tarja , Orama Olli 
Published: March 2009

AbstractWhen 2,2,5,5‐tetramethyltetrahydrofuran‐3‐one 1 was oxidized with selenium dioxide in ethanol, the title heterocycle 4 was formed along with 2,2,5,5‐tetramethyltetrahydro‐3,4‐furandione 2. The diselenide 4 represents a novel six‐membered heterocycle in the chalcogen series.
Natural product chemistry. Part 159. Two methods for the synthesis of 4‐azaacronycine as a potential antitumor agent
Authors: Reisch Johannes , Dziemba Peter , La Mura Marco , Rao Akkinepalli Raghu Ram 
Published: March 2009

AbstractTwo different methods for the synthesis of 4‐azaacronycine (10) have been described. One route with a fusion reaction between 1,3‐dihydroxy‐10‐methyl‐9(10H)‐acridinone (1) and 2‐amino‐2‐methyl‐3‐butyne in a glass ampoule and the other by a reaction of 3‐amino‐1‐methoxy‐10‐methyl‐9(10H)‐acridinone (9) with 2‐chloro‐2‐methyl‐3‐butyne.
Investigation into the diastereomeric composition of a pyruvamide dimer
Authors: Stewart Kent D. , Bailey Charles , Hall William R. , Crouch Ronald 
Published: March 2009

AbstractN‐Benzylpyruvamide cyclized under basic conditions to give a 70:30 trans:cis mixture of diastereomers of N,1‐dibenzyl‐2,4‐dihydroxy‐4‐methyl‐5‐oxo‐2‐pyrrolidinecarboxamide.
Reaction of amines on 3‐ureidomethylenecoumarins. A new route to N‐(methylene‐4‐oxocoumarinyl)amines
Authors: Hamdi Maâmar , Granier Patrick , Sakellariou Reine , Spéziale Vincent 
Published: March 2009

AbstractN‐(Methylene‐4‐oxocoumarinyl)amines were prepared in good yield by reacting aliphatic and aromatic amines bearing functional groups with the relevant 3‐ureidomethylenecoumarins.
The synthesis of 6,9‐difluorobenzo[g]quinoline‐5,10‐dione. Displacements of the fluorides by diamines which lead to 6,9‐bis[(aminoalkyl)amino]benzo[g]quinoline‐5,10‐diones
Authors: Krapcho A. Paul , Petry Mary E. , Landi John J. , Stallman John , Polsenberg Johanna F. , Hacker Miles P. , Spinelli Silvano , Oliva Ambrogio , Di Domenico Roberto , Menta Emesto 
Published: March 2009

AbstractThe synthesis of 6,9‐difluorobenzo[g]quinoline‐5,10‐dione (3b) is described. Facile ipso substitutions of the fluorides from 3b by diamines readily yield the corresponding 6,9‐bis[(aminoalkyl)amino]benzo‐[g]quinoline‐5,10‐diones 2. The analogue 2d has been synthesized by side arm modifications of dione 8a.
A new approach for the synthesis of fused pyrroles. The synthesis of acyl substituted pyrrolo[1,2‐x]azines
Authors: Čopar Anton , Stanovnik Branko , Tišler Miha 
Published: March 2009

AbstractN‐Acetonyl‐ and N‐phenacyl quaternary salts of α‐methyl substituted heterocycles 16, 17, 21, 23 and 26 were converted with DMFDMA into the corresponding 3‐acylpyrrolo[1,2‐a]pyridine 18, 7‐benzoylpyrrolo‐[1,2‐c]pyrimidine 22, and 6‐benzoylpyrrolo[1,2‐a]pyrazine derivatives 24 and 27. A concurrent reaction produced methyl and phenyl substituted pyrrolo[1,2‐x]azines 19, 20, 25 and 28.
Reactions of 4‐Methoxy‐3‐quinolinyl and 1,4‐Dihydro‐4‐oxo‐3‐quino‐linyl Sulfides Aiming at the Synthesis of 4‐Chloro‐3‐Quinolinyl Sulfides
Authors: Maślankiewicz Andrzej , Boryczka Stanislaw 
Published: March 2009

AbstractThe preparation of 1,4‐dihydro‐4‐oxo‐3′‐alkylthio‐3,4′‐diquinolinyl sulfides 3 or 1,4‐dihydro‐4‐oxo‐3‐(alkylthio)quinolines 4 by acid catalysed hydrolysis of 4‐methoxy‐3′‐alkylthio‐3,4′‐diquinolinyl sulfides 1 or 4‐methoxy‐3‐(alkylthio)‐quinolines 2 is described. The reactions of 4‐methoxy‐3′‐alkylthio‐3,4′‐diquinolinyl sulfides 1 or 1,4‐dihydro‐4‐oxo‐3′‐alkylthio‐3,4′‐diquinolinyl sulfides 3 with phosphoryl chloride in DMF afforded 4‐chloro‐3′‐alkylthio‐3,4′‐diquinolinyl sulfides 5. Treatment of the title compounds 1 or 3 with boiling phosphoryl chloride systems:leads to 4‐chloro‐3‐(alkylthio)quinolines 6 and thioquinanthrene but those of alkoxy‐ or oxo‐quinolines 2 or 4 lead to 4‐chloro‐3‐(alkylthio)quinolines 6. The reactions of N‐methyl‐4(1H)‐quinolinones 3n and 4n with phosphoryl chloride directed to 4‐chloro‐3‐(alkylthio)quinolines 6 were studied as well.
Heteroarylation of 6‐Aryl‐2,3‐dihydroimidazo[2,1‐b]thiazole with N‐(Ethoxycarbonyl)heteroaromatic Salts
Authors: Shilcrat Susan , Lantos Ivan , Mcguire Michael , Pridgen Lendon , Davis Louisa , Eggleston Drake , Staiger David , Webb Lee 
Published: March 2009

AbstractThe ethyl chloroformate salts of a variety of benzo‐fused six membered π‐deficient heteroaromatics, including quinoline, isoquinoline, 4‐chloroquinoline, 3‐bromoquinoline, phthalazine, and quinazoline, reacted with 6‐aryl‐2,3‐dihydroimidazo[2,1‐b]thiazole at the 5‐position. The dihydroheteroaromatic adducts were oxidized by o‐chloranil, sulfur, or electrochemical methodology to form the 5‐heteroaromatic‐6‐aryl‐2,3‐dihydroimidazo[2,1‐b]thiazoles, 10‐15. In each example, the regiochemistry of addition to the heteroaromatic ring was established.
Synthesis and spectroscopic characterizations of both 4b,5‐dihydro‐4b‐methyl‐11H‐isoindolo[2,1‐a]benzimidazol‐11‐ones and 2,3,3a,4‐tetrahydro‐3a‐methyl‐1H‐pyrrolo[1,2‐a]benzimidazol‐1‐ones
Authors: Louvet Philippe , Thomasson FrançOis , Luu‐Duc Cuong 
Published: March 2009

AbstractThe complete assignment of the 1H and 13C nmr spectra of some derivatives of both 4b,5‐dihydro‐4b‐methyl‐11H‐isoindolo[2,1‐a]benzimidazol‐11‐one I and 2,3,3a,4‐tetrahydro‐3a‐methyl‐1H‐pyrrolo[1,2‐a]‐benzimidazol‐1‐one II was herein reported by the combined use of one and two‐dimensional nmr techniques. Eight compounds, three of which are novel, 2a, 3, 6, were thus prepared. Their uv and ir spectra were also obtained. In addition, the mass spectra of compounds 1, 2a, 2b, 3 and 6 are reported.
Reactions of 4,6‐bis(acetyl)resorcinol with alkoxycarbonylalkylidene(triphenyl)phosphoranes. Preparation of coumarin derivatives
Authors: Nicolaides D. N. , Fylaktakidou K. C. , Bezergiannidou‐Balouktsi C. , Litinas K. E. 
Published: March 2009

AbstractReaction of compound 1 with ylide 2a affords compounds 3a, 3b and coumarins 4a, 5a, 5b, 6a in 77% total yield. Reaction of 1 with ylide 2b affords coumarin 4b. The acetylderivatives obtained, react further with ylides 2a‐c to give pyrano[3,2‐g]chromene‐2,8‐diones 6b‐d.
Synthesis of 2,7‐disubstituted‐5,6‐dimethylpyrrolo‐[2,3‐d]‐1,3‐oxazin‐4‐ones as antifungal agents
Authors: Player Mark R. , Sowell J. Walter , Williams Glenn R. , Cowley Gerald T. 
Published: March 2009

AbstractA series of novel 5,6‐dimethylpyrrolo[2,3‐d]‐1,3‐oxazin‐4‐ones were synthesized from 2‐amino‐3‐tert‐butoxy‐carbonyl‐4,5‐dimethylpyrroles. Two methods were used, cyclodehydration of 2‐acylamino‐3‐carboxypyrroles with acetic anhydride and direct conversion of the 5,6‐dimethylpyrrolo[2,3‐d]‐1,3‐oxazin‐2,4‐diones to the title compounds with an anhydride directly providing the 2 substituent. Molecular modeling techniques revealed that these pyrrolo[2,3‐d]oxazinones were rigid analogues of the allylamine antifungals. The compounds were tested for in vitro activity against Tricophyton and Scopulariopsis sp.
Photodimerization of 1H‐azepine‐2,7‐dione
Authors: Takabatake Tohru , Hasegawa Minoru 
Published: March 2009

Abstract1H‐Azepine‐2,7‐dione 2 afforded photodimer 8 by irradiation using a high or low pressure mercury lamp. Photodimer 8 had a unique structure which must have formed with the prototropy in one of the two molecules of compound 2. Measurement of the fluorescence spectra of 2 indicated a spectrum of the excimer during the dimerization of 2. Irradiation of the dimer of 2 at its wave‐length of maximal absorption failed to cause it to change into a monomer of 2.
Structures of abnormal‐ and normal‐addition 1‐pyrazolines produced from 2‐cyano‐3,3‐di‐(or mono‐)‐substituted‐acrylates with diazoalkanes
Authors: Nagai Wakatu , Hirata Yumiko , Hosomi Keiji , Higuchi Taiichi 
Published: March 2009

AbstractReactions of methyl 2‐cyano‐3‐methyl‐3‐(p‐substituted‐phenyl)acrylates (1) with 1‐phenyldiazoethane (2) produced the stable abnormal‐addition 1‐pyrazolines, AP, 4 [1]. The structure of cis‐syn‐4a (X = NO2) was determined by X‐ray crystallography. Thermal decomposition of 4 results in “true cycloreversion” to the starting materials. Stereochemistry and decomposition of the normal‐addition 1‐pyrazolines, NP, produced in situ from 2‐cyano‐3‐(p‐substituted‐phenyl)acrylates and diazoalkanes, are also discussed.
Synthesis of c‐17 trans β‐lactams of the androstane series
Authors: Siddiqui A. U. , Satyanarayana Y. , Srinivas M. , Siddiqui A. H. 
Published: March 2009

Abstract3,3′‐Ethylenedioxyandrost‐4‐en‐17β‐ol 1 was converted into the ethyl ester 2 by reaction with potassium metal and ethyl chloroacetate. The ethyl ester 2 on reaction with hydrazine gave the hydrazide 3. Condensation of 3 with aryl aldehydes gave the Schiff bases 4. The reaction of Schiff bases 4 with mono‐chloroacetyl chloride in the presence of triethylamine afforded the β‐lactams 5.
Synthesis of benzyl and tert‐butyl 3‐(2‐methoxycarbonylethyl)‐4‐methylpyrrole‐2‐carboxylates from methyl 4‐oxobutanoate
Authors: Drinan Martin A. , Lash Timothy D. 
Published: March 2009

AbstractCondensation of methyl 4‐oxobutanoate with nitroethane in the presence of 4‐dimethylaminopyridine, followed by treatment with acetic anhydride, afforded a nitroacetoxyester 10b. Subsequent reaction with isocyanoacetate esters and DBU in refluxing tetrahydrofuran gave the synthetically valuable pyrroles 1a and 1b.
Synthesis of a novel cyclic sulfone dihydropyridine: An investigation of the isomerization reaction converting an exocyclic double bond isomer into a 1,4‐dihydropyridine
Authors: Fenk Christopher J. , Conley Richard A. , Lindabery Gregory C. , Stefanick Stephen M. , Royster Thomas E. , Dodd John H. , Schwender Charles F. 
Published: March 2009

AbstractAn eight membered cyclic sulfone 1,4‐dihydropyridine, RWJ 22726, 1, with remarkable cardiovascular activity was prepared by isomerization of an exocyclic double bond isomer using various reaction conditions. Under acidic and thermal isomerization conditions, an equilibrium mixture of products in an optimum ratio of 1:3.5 in favor of the desired 1,4‐dihydropyridine was obtained. Equilibration using basic reaction conditions could not be effected. Complete conversion to the 1,4‐dihydropyridine during the isomerization reaction was ultimately achieved by selective precipitation of the hydrochloride salt of the desired isomer.
Intramolecular [4 + 2] cycloaddition reactions of pyridazino‐[4,5‐d]pyridazines with acetylenic side‐chain dienophiles: Synthesis of f‐annelated phthalazines
Authors: Haider Norbert , Loll Claudia 
Published: March 2009

AbstractStarting from the thione 1, a series of 1‐(alkynyl‐X)‐4‐phenylpyridazino[4,5‐d]pyridazines 4–8 (X = 0, NH, S) was prepared. Thermally induced intramolecular [4+2] cycloaddition reactions of the ethers 4, 5 and the thioether 8 afforded f‐annelated phthalazine derivatives.
3‐(Thiazolidin‐3‐yl)rhodanines. A novel class of rhodanine derivatives
Authors: Hanefeld Wolfgang , Schlitzer Martin 
Published: March 2009

Abstractα‐Bromoacetylaminorhodanines 1 were reacted with NH4SCN yielding 3‐(thiazolidin‐3‐yl)rhodanines 4, a novel type of rhodanine derivatives bearing a uncommon N‐N ring‐connection.
Condensations of brominated products of o‐acetylbenzophenone with several primary amines
Authors: Nan'Ya Seiko , Ishida Hirofumi , Moiji Ester J. , Butsugan Yasuo , Bajji Ashok C. 
Published: March 2009

Abstract2‐Bromo‐3‐phenylinden‐1‐one 2 reacted with phenylthiourea to produce 2‐phenylimino‐8‐phenylindeno[1,2‐d]thiazole (heteropentalene) 4 in moderate yield and bis‐substituted‐indenyl sulfide 5 in low yield. Whereas, from the reaction of 2 with thiourea or its methyl derivative only 5 was obtained in moderate yield. Another brominated compound, dibromoacetylbenzophenone and several primary amines afforded iminoindanone derivatives 6.
Synthesis and mass spectra of some 1‐aroylamino‐5‐arylaminomethyl‐1,2,3‐triazoles
Authors: Laskos Efstathios , Lianis Pygmalion S. , Rodios Nestor A. 
Published: March 2009

AbstractThe title compounds 2 are prepared from the reaction of 1‐(N, N‐diaroyl)amino‐5‐bromomethyl‐1,2,3‐triazoles with aromatic amines. The fragmentation pattern upon electron impact at 70 eV of compounds 2 is studied. The molecular ion peak is present in all the spectra examined. Besides the [M‐28]++, there is also a more abundant [M‐29]+ peak, corresponding to a N2H loss of the molecular ion. The ion Ar2NH = CH2 is the base or the most prominent peak.