bluuebunny/crossref_metadata_2025_split huggingface dataset:
A new synthon in heterocycle synthesis
Authors: Sato M. , Stammer C. H. 
Published: April 2009

AbstractA tetraehlorobenzodioxinone, prepared from 2‐phenyl‐4‐benzyl‐2‐oxazolin‐5‐one and o‐chloranil was found to react with clhanol to give the ester 6. This compound reacted readily with various bis‐nucleophiles to form five‐ and six‐membered helerocyclic compounds.
Synthesis of 3,3′ ‐methylenediisoxazoles
Authors: Auricchio S. , Ricca A. , De Pava O. Vajna 
Published: April 2009

AbstractThe synthesis of new 3,3′‐methylenediisoxazoles (III), from 1,3‐dichloromalondioxime (IX) and acetylenic compounds is reported. We have studied the transformation of the chloronitroso compound (VII), obtained from malondioxime (V) in ether with gaseous chlorine at −70°, into IX. It was found that this was possible only by heating a DIYISO solution. The characteristics of the compounds which are described are reported.
Alumina‐catalyzed condensation of 2‐methylquinoline with methanol
Authors: Klemm L. H. , Hurtling Ross 
Published: April 2009

AbstractThe alumina‐catalyzed reaction of 2‐methylquinoline with excess methanol at 500° produced a mixture of 2‐ethyl‐, 2‐isopropyl‐, and 2‐isopropenylquinolines in yields of 10%, 7%, and 2%, respectively. A mechanistic interpretation of this reaction is presented.
Synthesis of new fundamental heterocycles. Part VII. Synthesis of 2‐azaxanthene
Authors: Sliwa H. , Cordonnier C. 
Published: April 2009

Abstract2‐Azaxanthone (5) has been conveniently prepared by condensation of the morpholine enamine of 1‐benzyl‐4‐piperidone witli salicylaldehyde followed by chromium trioxide oxidation and subsequent aromatization. Lithium aluminum hydride reduction of 5 afforded the new fundamental heterocycle 2‐azaxanlhene.
A new synthesis of fervenulin 4‐oxide
Authors: Ichiba Misuzu , Senga Keitaro , Nishigaki Sadao , Yoneda Fumio 
Published: April 2009

AbstractThe reaction of 1,3‐dimethyl‐6‐hydrazino‐5‐nitrosouracil (1) with Vilsmeier reagent (dimethylformamide‐phosphorus oxychloride) afforded fervenulin 4‐oxide (II) in good yield.
3‐Halo‐4‐imino‐2‐azetidinones via acykchloroformamidines
Authors: Brady William T. , Owens Robert A. 
Published: April 2009

Abstractα‐Haloacid Halides react with carbodimides to yield acylchloroformamidines which upon treatment with trithylamine undergo conversion to 3‐halo4‐imino‐2‐azetidinones in good yiels. Two pathways are possible for this conversion and these are discussed.
A convenient synthetic route to 5,5′‐Disubstituted 2,2′‐Bipyridines
Authors: Whittle C. P. 
Published: April 2009

AbstractSyntheses are described for a number of 5,5′‐disubstituted 2,2′‐bipyridines. In particular the benzidine analogue, (2,2′‐bipyridine]‐5,5′‐diamine and some of its derivatives have been prepared.
The effect of electron withdrawing croups on the stability of thiabenzenes
Authors: Pirelahi Hooshang , Abdoh Yahyo , Tavassoli Manoochehr 
Published: April 2009

AbstractThe reactions of p‐trifluoromethylphenyllithium with 2,4,6‐triarylthiopyrylium perehlorates (Ar = Ph, p‐CH3OC6H4, p‐NMe2C6H4) have been studied. The initially formed thiabenzenes were not slable enough to he isolated and rearranged readily to their corresponding 4‐(p‐tri‐fluoromethylphenyl)‐2,4,6‐triarylthiopyrans. The instability of the intermediate thiabenzenes reveals that, in contrast to the stabilization effect of the electron‐withdrawing p‐chloro‐ and pentalluorophcnyl groups attached to carbon atoms in sulfur ring, the electron‐withdrawing p‐lrilluoromethyl group on subsliluenls attached to sulfur decreases the stability of thiabenzenes.
Further studies on the structural determination of esters of 4‐Oxo‐4H‐1‐heiizopyran‐2‐carboxylic acids using the paramagnetic shift reagent eu(FOD)3
Authors: Cairns H. , Hunter D. 
Published: April 2009

AbstractThe effect of Eu(fod)3 on the signals of benzylic ruethvlene protons in the pmr spectra of 4‐oxo‐4H‐1‐benzopyran derivatives is described. Assignments were confirmed by decoupling experiments. The technique provides a method for distinguishing between structural isomers.
Reaction of ketenes with N,N‐Disubstituted 2‐Aminomethylenecyclo‐alkanones VI. Synthesis of N,N‐Disubstituted 4‐Amino‐3,4‐dihydro‐3,3‐dithioethyl‐5,6‐polyrnethylene‐α‐pyrones
Authors: Bargagna Alberto , Schenone Pietro , Cafaggi Sergio 
Published: April 2009

AbstractThe reaction of dithioethylketene, a new dithioalkylketene prepared in situ from dithio‐ethylacetyl chloride and triethylamine, with N,N‐disubstituted 2‐aminomethylenecycloalkanones gave the 1,4‐cycloadducts, namely N,N‐disubstituted 4‐amino‐3,4‐dihydro‐3,3‐dithioethyl‐5,6‐polymethylene‐α‐pyrones.
Régiospécificité et stéréosélectivité de la cycloaddition de l'oxyde de benzonitrile sur les pyrazolines‐3
Authors: Cibert J.‐P. , Pétrus C. , Pétrus F. 
Published: April 2009

AbstractLa régiospécificité et la stéréosélectivilé de la cycloaddition de l'oxyde de benzonitrile sur les pyrazolines‐3 sont dérnontrées. L'étude du comportement en milieu acide des différentes pyrazolidino[4,3‐d]isoxazolines‐2 obtenues est réalisée et les processus d'épimirisation et de dégradation observés sont discutés en fonction du substituant en 4 et du solvant utilisé.
Oxidation of fully substituted alkoxyoxazolcs with singlet molecular oxygen
Authors: Graziano M. L. , Iesce M. R. , Carotenulo A. , Scarpati R. 
Published: April 2009

AbstractDiacylcurbamatcs IV can be prepared from alkoxyoxazoles 1 by 1O2 oxidation. When the reaction is opportunely earried out a new heterocyclic system, namely the 3H‐1, 2, 4‐dioxazole III, is formed. A mechanistic interpretation of the results is suggested.
The reaction of β‐aminoaleohols with o‐Phthalaldehyde
Authors: Shipchandler M. T. 
Published: April 2009

AbstractThe reaction of o‐phthalaldehyde with β‐aminomonohydroxy compounds leads to ortho‐substituled phenyloxazolines. β‐Aminodiols or‐triols give tetracyelic bisoxazoiidines when reacted with o‐phthalaldchyde. These two type of ring systems are generated in one step under extremely mild conditions.
Studies on the oeearboxylation reactions. Note II. Kinetic study of the decarboxylation reaction of 5‐amino‐1,3,4‐thiadiazole‐2‐carboxylic acid (I) to 2‐amino‐1,3,4‐thiadiazole (III)
Authors: Spinelli Domenico , Noto Renato , Consiglio Giovanni , Buccheri Francesco 
Published: April 2009

AbstractThe rate constants of the deearboxylation reaction in water of 5‐amino‐1,3,4‐lhiadiazole‐2‐carboxylic acid (I) to 2‐amino‐1,3,4‐thiadiazole (III) over the pH range O.25‐3.91 have been measured and the activation parameters determined. The results obtained have been compared with previous results on the deearboxylalion of 5‐amino‐1,3,4‐oxadiazole‐2‐earboxylic acid (II) to gain information on the mechanism of the reaction studied.
Ozonolysis of 3,4‐dehydroproline
Authors: Nair V. , Kim K. H. , Walsh R. H. 
Published: April 2009

AbstractOzonolysis of protected 3,4‐dehydro‐DL‐proline (2) in methanol gives as the initially isolable product, a seven‐membered ring cyclic peroxide (5). Compound 5 undergoes rearrangement thermally to give methyl N‐tosylglycinate (8) and a stereochemical mixture of oxazolidine aldehyde esters (7). Structural evidence for 7 came from detailed 13C nmr studies of 7 and its reduction product (9).
Alkylation d'anions ambidents en catalyse par transfert de phase. Cas des hydroxypyridines
Authors: Dou Henri J.‐M. , Hassanaly Parina , Metzger Jacques 
Published: April 2009

AbstractL'alkylation d'ions ambidents dérivés de la 2‐ et 4‐pyridones en catalyse par transfert de phase, conduit à 80% de N‐substitution et 20% de O‐substitution. Les changements de temperature, solvants, sels, halogénures d'alkyle, n'introduisent que de faibles variations dans le pour‐centage de N‐ et O‐ alkylation. Les rendements globaux varient entre 40 et 80% pour les halogénures d'alkyle primaires et secondaires.
Synthesis of some 3‐Hydroxy‐5‐pyridylpyrrole derivatives
Authors: Campaigne E. , Shutske G. M. , Payne John C. 
Published: April 2009

AbstractEthyl sarcosinate adds to 2, −3‐ and 4‐pyridylmethylidenemalonates to produce the Michael adducts, which can be conveniently cyclized to oxopyrrolidine diesters under Dieckmann conditions. Mild oxidation converted the crude adducts to the isomeric 1‐methyl‐3‐hydroxy‐5‐pyridylpyrrole‐2,4‐dicarboxylates. Addition of ethyl glycinate to ethyl picolinoylacetate or ethyl nicotinoylacetate produced the corresponding enaminoesters, but these azadiesters were not cyclized under the usual Dieckmann conditions.
Fused s‐triazino heterocycles. V. 1,3,4,6,9b‐Pentaazaphenalenes. Reactions of a carboxylic acid side chain
Authors: Shaw John T. , Miller Deborah A. , Holodnak J. Larry 
Published: April 2009

AbstractProcedures were developed to convert 4‐(2‐methyl‐1,3,4,6,9b‐pentaazaphenalene‐5‐yl)butanoic acid (Ia) and 3‐(2‐methyl‐1,3,4,6,9b‐pentaazaphenalene‐5‐yl)propanoic acid (IIa) to a series of esters and amides.
Synthèse de nouveaux composés hétérocycliques: Les diaza‐4,5 pyrène, diaza‐4,5 pyrène‐4 N‐oxyde et diaza‐4,9 pyrène‐4,9 di N‐oxyde
Authors: Mugnier Y. , Laviron E. 
Published: April 2009

AbstractLe diaza‐4,5 pyrène a été obtenu par cyclisation électrochimique à partir du dinitro‐4,5 phénanthrène, lui‐měme préparé par cyclisation du dinitro‐2,2′ diformyl‐6,6′ bipliényle. La cyclisation électrochimique de ce dernier composé conduit au diaza‐4,9 pyrène‐4,9 di N‐oxyde.
Catalytic desulfurization of condensed thiophenes by means of methanol
Authors: Klemm L. H. , Karchesy Joseph J. 
Published: April 2009

AbstractDesulfurization of dibenzothiophene, two methyldibenzothiophenes, and phenanthro[4,5‐bcd]‐thiophene to give 60‐80% yields of hydrocarbon products was effected by means of a sulfided molydena catalyst plus methanol at 450° and a pressure of ca. one atmosphere. The methanol functions both as an in situ hydrogen donor and as a methylating agent.
Synthesis of substituted 2‐amino‐3‐cyano‐4‐methylpyrroles
Authors: Johnson Ronald W. , Matlson Ronald J. , Sowell J. Walter 
Published: April 2009

AbstractA facile route for the synthesis of substituted 2‐amino‐3‐cyano‐4‐methylpyrroles fromN‐acetyl‐α‐amino ketones and malononitrile is reported.
A single crystal X‐Ray diffraction analysis of 1,9‐dihydro[1] benzothiopyrano[4,3‐c] pyrazole 5,5‐dioxide
Authors: Ealick Steven E. , Van Der Helm Dick , Ramalingam K. , Thyvelikakath George X. , Berlin K. D. 
Published: April 2009

AbstractThe structure of 1,4‐rlihydro[1 ]benzothiopyrano[4,3‐c ]pyrazole 5,5‐dioxide was determined by single crystal x‐ray diffraction. The molecule crystallizes in space group P21/c with a = 13.4378(6), b = 5.5938(3), c = 12.9837(6)Å, and β = 103.831°. The final R value is 0.083. Surprisingly, the tautomer with N(2)‐H exists in the crystal with the pyrazole ring being planar. The entire system is not planar as the benzene ring is rotated about C(9a) and C(9b) with respect to the pyrazole ring. In the crystal structure the pyrazole exists as hydrogen‐bonded dimers with two molecules related by a center of symmetry.
Synthesis of 7‐amirio‐2H, 4H‐vic‐triazolo[4,5‐c]‐[1,2,6]thiadiazine 5,5‐dioxides
Authors: García‐Muñoz C. , Ochoa C. , Stud M. , Pfleiderer W. 
Published: April 2009

Abstract7‐Amino‐2H,4H‐vic‐triazolo[4,5‐c][1,2,6]thiadiazine 5,5‐dioxide was prepared by two different ways from 3,4,5‐triamirio‐1,2,6‐lhiadiazine 1, 1‐dioxide and 3,5‐diamino‐4H‐1,2,6‐thia‐diazine 1, 1‐dioxide respectively. 7‐A:nino‐2‐phenyl‐4H‐vic‐triazolo[4,5‐c] [1,2,6]thiadiazine 5,5‐dioxide was obtained by lead telraacetate oxidation of 3,5‐diamino‐4‐phenylazo‐1, 2, 6‐thiadiazine 1, 1‐dioxide.
New derivatives of 3‐methylisoxazolo[5,4‐b]pyridine
Authors: Camparini Alfredo , Ponticelli Fabio , Tedeschi Piero 
Published: April 2009

AbstractThe synthesis and properties of 4,6‐dichloro‐ (IV), 4‐chloro‐ (XII) and 6‐chloro‐3‐methyl‐isoxazolo[5,4‐b]pyridine (XI) are described. Depending on the reaction conditions compound IV with hydrazine or methoxide gave mono‐ or bi‐substituted products. The halogen atom at the 4‐position was shown to be the more mobile.
Chemical, physicochemical and crystallographical studies in the 1,2,4‐triazole series
Authors: Hénichart J. P. , Houssin R. , Lablanche B. , Baert F. , Devos L. 
Published: April 2009

AbstractThe structure of the condensation product of 1,2,4‐lriuzole and morpholinochloroethane was determined by comparison of its chemical, physicoehemieal and erystallographical characteristics with those of two isomeric compounds prepared by an univocal synthesis.
Synthesis of some N,1‐ and N′,1‐diaryl‐1H‐1,2,4‐triazole‐3,5‐diamines
Authors: Wu M. T. 
Published: April 2009

AbstractTwo novel methods for the preparation of N, 1‐ and N′,1‐diaryl‐1H‐1,2,4‐lriazole‐3,5‐(Hamines are described.
Reactions of epoxy‐1,1,2‐trichloroethane with nudeophiles
Authors: Kline Stanley A. , Van Duuren Benjamin L. 
Published: April 2009

AbstractEpoxy‐1,1,2‐triehloroethane (1) was synthesized by the autuoxidation of trichloroethylene and was characterized. It was shown to react readily with 2‐mercaptobenzirnidazole (2), 1 ‐melhyl‐2‐mercaptoimidazole (3), p‐nitrolhiophenol (4), and 3,4‐dichlorolhiophenol (5) forming 2‐chloro‐2‐(benzirnidazole‐2‐thio)acelie acid (6), 2‐ehloro‐2‐(1‐methylirnidazole‐2‐thio)aeetic acid (characterized as methyl ester (8)), 2‐chloro‐2‐(4‐nitrolhiothiophenoxy)‐4‐nilrophenylthioaeetate (9), and 2‐chloro‐2‐(3,4‐dichlorothiophenoxy)‐3,4‐dichlorophenylthioaeetale (10), respectively. Base hydrolysis of 9 yielded 2,2‐di(4‐nilrothiophenoxy)acetie acid (11). Adducl 9 decomposed on silica gel yielding p‐nitrophcnyldisulfide (12).
The role of solvent in conjugate additions leading to cis and trans‐1‐Alkyl‐2‐aryl‐3‐carbo(aroyl)aziridines
Authors: Tarburton Phillip , Woller Paul B. , Badger Robert C. , Doomes Earl , Cromwell Norman H. 
Published: April 2009

AbstractIn the formation of cis‐ and trarn‐1‐alkyl‐2‐aryl‐3‐carbo(aroyl)aziridines a change in solvent from benzene to rnethanol in the α‐bromochalone‐primary amine reaction produced an increase in cic isotner. However, the same solvent change resulted in a decrease in the cis/trans ratio when these same aziridines were prepared by the ehalcone‐halogen‐primary amine reaction. These results are rationalized in terms of both an open and chelated enol intermediate thought to be crucial in the relative product formations. Other mechanistic considerations in the product formations are presented.
On the behavior of α‐brominated dimethyl o‐benzenediacetate toward nitrogen nucleophiles. Part II. Reaction of dimethyl α‐bromo‐o‐benzenediacetate with hydrazines
Authors: Cignarella G. , Cerri R. , Savelli F. , Maselli A. 
Published: April 2009

AbstractDimethyl α‐bromo‐o‐benzenediacetate (1) condensed with hydrazine and acetylhydrazine to give respectively 1‐carbomethoxy‐2‐amino‐1,4‐dihydro‐3‐(2H)isoquinolinone (2) and its N‐acetyl derivative (9). Replacement of the bromine atom of 1 with the N‐1‐methylhydrazino (3) and the N‐1‐phenylhydrazino (5) groups occurred by allowing 1 to react respectively with methylhydrazine and phenylhydrazine. In the latter case alkylation by 1 at the N‐2 also occurred which led to the formation of the 2‐phenylaminoisoquinolinone (8). Derivatives 3 and 5 smoothly cyclized to the 1‐earbomethoxy‐5(H)‐1,2,3,4‐tetrahydro‐2,3‐benzodiazepin‐4‐ones 4 and 6. A series of derivatives of 2 were also pharmacologically tested as antiinflammatory and CNS depressant agents.
Synthesis in the diazasteroid group VI. A synthesis of 2,3‐dimethoxy‐15‐methyl‐8,15‐diazaestra‐1,3,5(10)triene
Authors: Yamazaki Takao , Nagata Masanori , Matoba Katsuhide , Takahata Hiroki , Castle Raymond N. 
Published: April 2009

AbstractHomoveratrylamine (II) was condensed with 3‐(2‐carbomethoxyethyl)‐1,3‐dimethyl‐2‐pyrrol‐idone (Ib) to furnish the corresponding amide (III), which was subjected to the Bischler‐Napieralski reaction to afford the corresponding dihydroisoquinoline derivative (IV). Compound V was obtained by the reductive ring closure of Vila which was obtained by the hydrogena‐tion of IV. The stereochemistry of V is proposed to have the anti‐trans‐trans quinolizidine conformation.
Studies on the synthesis of chemotherapeutics. I. Synthesis of 1‐(2‐tetrahydrofuryl)‐5‐fluorouracil [ftorafur] (studies on the syntheses of heterocyclic compounds. Part 703)
Authors: Kametani Tetsuji , Kigasawa Kazuo , Hiiragi Mineharu , Wakisaka Kikuo , Kusama Osamu , Kawasaki Kumeo , Sugi Hideo 
Published: April 2009

AbstractSynthesis of 1‐(2‐tetrahydrol'uryl)‐5‐fluorouracil [Ftorafur] (1) which is well known as an antitumor agent from 5‐fluorouracil (2) with 2‐alkoxytetrahydrofurans (4) is described. Among these reactions, the best yield was obtained by using 2‐t‐butoxytetrahydrofuran (4h).
Synthetic studies on chemotherapeutics. II. Synthesis of phenyl‐substituted 1,4‐dihydro‐4‐oxonicotinic acid derivatives. [Studies on the syntheses of heterocyclic compounds. Part 704]
Authors: Kametani Tetsuji , Kigasawa Kazuo , Hiiragi Mineharu , Wakisaka Kikuo , Kusama Osamu , Sugi Hideo , Kawasaki Kumeo 
Published: April 2009

AbstractThe thermal cyclization of the arninomethylenemalonates (8) gave the 4‐hydroxynicotinates (9), ethylation of which yieldedN‐ethylated (11) and O‐ethylated products (12). Hydrolysis of 9, 11, and 12 led to the desired nicotinic acids (10, 4, and 13), respectively.
Pyrazolopyrimidine nucleosides. Part VIII The synthesis of certain 4‐substituted pyrazolo[3,4‐d]pyrimidine nucleosides
Authors: Montero Jean Louis G. , Bhat Ganapati A. , Panzica Raymond P. , Townsend Leroy B. 
Published: April 2009

Abstract1‐(β‐D‐Ribofuranosyl)pyrazolo[3,4‐b]pyrimidine‐4‐thione (6), obtained by a three‐step synthesis from allopurinol riboside (3), was treated with certain alkyl and aryl halides to provide the corresponding 4‐alkylthio derivatives. The nucleoside 4‐methylthio‐1‐(β‐D‐ribofuranosyl)pyra‐zolo[3,4‐d]pyritnidine (7) has served as the precursor for the preparation of the 4‐methylamino (11), 4‐dimethylamino (12), 4‐hydrazino (13), and the 4‐hydroxylamino (14) analogs.
Synthesis of polycyclic fused benzimidazole derivatives
Authors: Giannola Liberohalo , Bajardi Maria Luisa , Palazzo Salvatore 
Published: April 2009

AbstractAm easy method for the synthesis of tetraeyclie systems containing an imidazole and an iso‐thiazole or an imidazole and a thiazine ring, by reacting 2H‐1,3‐benzothiazine‐2‐thion‐4(3H)one with aromatic primary diarnines is reported. The structures were assigned based upon mass spectra and modes of cleavage of the compounds. The most important fragments are described.
Oxindoles from α‐acyloxyamides
Authors: Barker Marvin W. , Sung Hsiu‐Sun 
Published: April 2009

AbstractOxindoies have been obtained in good yields from the reaction of several a‐acyloxy‐α,α‐diphenylacetanilides and boron trifluoride etherate. The reaction probably occurs by hydrolysis of the ester followed by electrophilic substitution of the resultant carbonium ion on the anilide ring.
Reaction of 3‐(o‐chlorobenzylidene)‐2,4‐dioxopentanoic acid with hydroxylamine hydrochloride. Revised structure tor azeto[3,2‐d]isoxazoline
Authors: Kurihara Takushi , Mori Masanobu , Sakamoto Yasuhiko 
Published: April 2009

AbstractReaction of 3‐(o‐ehlorobenzylidene)‐2,4‐dioxopentanoic acid (1) with hydroxylamine hydro‐chloride in acetic acid gave 5‐(o‐chlorophenyl)‐3‐methyl‐4‐(α‐hydroxyimino)isoxazolineglyo‐xylic acid (5) and 3‐(o‐chlorobenzylidene)‐4‐hydroxyimino‐2‐oxopentanoic acid (2) in 57% and 7% yields. Pyrolysis of 5 afforded 5‐(o‐chlorophenyl)‐3‐methylisoxazole‐4‐carbonitrile (8), cis‐ and trans‐5‐(o‐chlorophenyl)‐3‐methylisoxazoline‐4‐carbonitriles (9,10), and 5‐(o‐chloro‐phenyl)‐3‐methylisoxazoline‐4‐carboxamide (11).
Mass spectral fragmentation pattern of 2,2′‐Bipyridyls. Part IX. 6‐Alkoxy‐2,2′‐bipyridyls
Authors: Keats N. G. , Summers L. A. 
Published: April 2009

AbstractThe mass spectral fragmentation patterns of 6‐methoxy‐, 6‐ethoxy‐ and 6‐propoxy‐2,2 ′‐bipyridyls are reported. The base peaks in the spectra of both the 6‐methoxy and 6‐ethoxy compounds are due to the M‐lion of 6‐methoxy‐2,2′‐bipyridyl, while the base peak with 6‐propoxy‐2,2‐ bipyridyl is due to a species formed by loss of C3H6 from the molecular ion.
Mass spectral fragmentation pattern of 2,2′‐Bipyridyls. Part X. trans‐1,2‐Di‐(2‐pyridyl)ethylene
Authors: Keats N. G. , Summers L. A. 
Published: April 2009

AbstractThe base peak in the mass spectrum of trans‐1,2‐di‐(2‐pyridyl)ethylene is due to the M‐1 ion. A major fragmentation route involves loss of HCN from the M‐1 ion. Another important pathway involves rupture of one of the bonds linking a pyridine ring with the central CHCH group.
Synthesis of 5H‐Tetrazolo[1,5‐d] [1,4]benzodiazepin‐6(7H)ones
Authors: Peet Norton P. , Sunder Shyam 
Published: April 2009

AbstractSyntheses of 5H‐tetrazolo [1,5‐d] [1,4 ]benzodiazepin‐6(7H)ones 2a‐d from 5‐(o‐aminophenyl)‐tetrazoles 1a‐d and bromoacetyl bromide are described. Compounds 2a‐d are representatives of a novel tricyclic ring system. Several alternate methods for the synthesis of 2a‐d were attempted without success. Spectral evidence for structural assignments 2a‐d is presented. Chemical evidence for these assignments includes the transformation of 2a to 6‐(2,2‐dimethylhydrazino)‐5H‐tetrazolo[1,5‐d] [1,4]benzodiazepine (19) via the thione analog of 2a (18).
3‐Monosubstituted and 3,6‐Unsymmetrically disubstituted 1,2,4,5‐Tetrazines. A general method of synthesis
Authors: Mangia Alberto , Bortesi Fulvio , Amendola Umberto 
Published: April 2009

AbstractA stepwise procedure has been developed for the synthesis of 3,6‐unsymmetrically disubstituted‐ or 3‐monosubstituted‐1,2,4,5‐tetrazines, based upon the facile substitution either of an alkylthio group in 3,6‐bis(alkylthio)‐1,2,4,5‐tetrazines (1) and (2) by nitrogen nucleophiles, particularly by hydrazine, or of a bromo group, obtained by oxidation of a hydrazino group or by an independent synthesis, by carbon nucleophiles. The ultraviolet‐visible spectra and some nuclear magnetic resonance properties are discussed.
Synthesis and conformational analysis of isomeric 3‐propananilidotropanes
Authors: Bagley Jerome R. , Riley Thomas N. 
Published: April 2009

AbstractThe isomeric 3‐anilino and 3‐propananilidotropanes have been synthesized and obtained in isomerically pure form. The configurations and solute conformations of these isomers were studied via glc and nrar analysis. The 3β‐isomers have been shown to exist in the normal piper‐idine chair conformation whereas the 3α‐anilino tropane exists in a flattened piperidine chair conformation and the 3α‐propananilidotropane isomer preferentially exists in a conformation in which the piperidine ring system is a boat.
Studies on the chemistry of 2,3,5,6‐tetrahydro‐6‐phenylimidazo[2,1‐b]‐thiazole II. Reaction with nucleophiles
Authors: Bigg D. C. H. , Purvis S. R. 
Published: April 2009

AbstractThe title compound behaves as an ambident electrophile which reacts with alkylthiols, thio‐phenols, and sodium diethyldithiocarbamate to give 1‐(2‐substituted ethyl)‐4‐phenylimidazolidine‐2‐thiones by attack at C‐2. In contrast, the reaction with pyrrolidine involves attack at the bridgehead carbon atom, followed by elimination of thiirane, to give 4‐phenyl‐2‐(1‐pyrrolidino)‐imidazoline.
Pyrimido[5,4‐b]quinolines. II. Reactions at the heterocyclic ring‐carbon and nitrogen atoms
Authors: Levine E. M. , Chu C. K. , Bardos T. J. 
Published: April 2009

Abstract10‐Chloro‐7,8‐dimethylpyrimido[5,4‐b]quinolin‐2,4(1H,3H)dione (I) was unreactive toward ammonia but it reacted with 2 molecules of n‐butylamine, presumably via Dimroth‐type ring‐opening and closure, to give the N3‐butyl, N10‐butylamino derivative (IV). In similar reactions of 10‐chloro‐2,4‐dimethoxy‐7,8‐dimethylpyrimido[5,4‐b]quinoline (II) only the 4‐meth‐oxyl was displaced by either ammonia or n‐butylamine. Alkyllithium reagents also displaced the 4‐methoxyl as well as added to the 3,4 double bond of II to yield the corresponding gem‐dialkyl substituted (C4) derivatives; the C10 chlorine remained unreactive. 2,4‐Dimethoxy‐7,8‐di‐methylpyrimido[5,4‐b]quinoline‐10‐one (III) could be alkylated only in the form of the thallium salt. Treatment of the benzyl derivative of III with methylmagnesium bromide led only to the displacement of the 4‐methoxyl by a methyl group.