bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis of sulfur‐bridged piperazinediones by reaction of 3,6‐dibromo‐1,4‐dimethyl‐2,5‐piperazinedione with geminal dithiols
Authors: Srinivasan Ananthachari , Kolar Aldean J. , Olsen Richard K. 
Published: March 2009

AbstractThe reaction of several geminal dithiols with 3,6‐dibromo‐1,4‐dimethyl‐2,5‐piperazinedione gave in good yields piperazinedione derivatives substituted at the 3,6‐position with a geminal dithiol‐bridging group. These sulfur‐bridged piperazinediones formally represent derivatives of the 2,4‐dithia‐6,8‐diaza‐7,9‐dioxobicyclo[3.2.2]nonane ring system. Attempts to transform these sulfur‐bridged piperazinediones to 3,6‐epidithiopiperazinediones by removal of the bridging group common to the sulfur functionality were unsuccessful. Studies also are reported of addition of thioacetic acid to 3,6‐dimethylene‐2,5‐piperazinedione to give 3,6‐diacetylthio‐3,6‐dimethyl‐2,5‐piperazinedione. Conversion of the 3,6‐diacetylthio derivative to the epithiopiperazinedione ring system yielded a mixture of epimono‐ and epidithiopiperazinediones.
A convenient synthesis of 9H‐dibenz[c,f]imidazo[1,2‐a]azepin‐9‐ones
Authors: Houlihan William J. , Parrino Vincent A. 
Published: March 2009

AbstractA convenient three step synthesis of 9H‐dibenz[c,f]imidazo[1,2‐a]azepin‐9‐ones from readily available 2‐phenylimidazoline and a methyl benzoate is described.
Mutagenic heterocyclic nitrogen compounds related to protein pyrolysates. 1. Derivatives of dipyrido[1,2‐a:3′,2′‐d]imidazole
Authors: Saint‐Ruf G. , Loukakou B. , N'Zouzi C. 
Published: March 2009

Abstract2‐Amino‐6‐methyldipyrido[1,2‐a:3′‐2′‐d]imidazole is one of the mutagenic principles of L‐glutamic acid and casein pyrolysates. We prepared several isomeric amines of this compound, as well as their homologues methylated in different positions on the heterocyclic ring, either by nitration of the ring followed by reduction or from appropriate 4‐azidodipyrido[1,2‐a:3′,2′‐d]imidazoles. The latter compounds, the heterocyclic ring itself and various functional derivatives (hydroxylated, carboxylated, hydrazinic) were synthesized from 2‐aminoimidazo[1,2‐a]pyridines via various reactions which are described herein.
Thermal decompositions of dinitropyridyl and dinitrothienyl dithiocarbamates and t‐butyl trithiocarbonates
Authors: Rasheed Khalid , Warkentin James D. 
Published: March 2009

AbstractThe title compounds on heating cyclized to yield 7‐nitro‐1,3‐dithiolo[4,5‐c]pyridin‐2‐one (III), 6‐nitro‐1,3‐dithiolo[2,3‐c]pyridin‐2‐one (VIIa), 6‐nitrothieno[2,3‐d]‐1,3‐dithiol‐2‐one (XIVa) and 6‐nitrothteno[2,3‐d]‐1,3‐dithiole‐2‐thione (XIVb).
Studies in the heterocyclic series. XXI. A novel tetraaza‐analog of phenothiazine
Authors: Okafor Charles O. , Uche Imaga O. , Akpanisi Leonard E. S. 
Published: March 2009

AbstractAs a continuation of our search for new pharmaco‐active phenothiazine compounds, the synthesis of 1,4,6,8‐tetraazabenzo[b]phenothiazine ring system is described. Derivatives of this new heterocycle were prepared by converting 4,5‐diamino‐6‐hydroxypyrimidine to 4,5‐diaminopyrimidine‐6‐(1H)thione followed by the action of 2,3‐dichloroquinoxaline in refluxing DMF or DMAC. The reaction of mixed nitric and sulfuric acids with 9‐amino‐12‐chloro‐1,4,6,8‐tetraazabenzo[b]phenothiazine gave 9‐amino‐12‐chloro‐13‐nitro‐1,4,6,8‐tetraazabenzo[b]phenothiazine 5‐oxide in satisfactory yields. Diazotization of 9‐amino‐1,4,6,8‐tetraazabenzo‐[b]phenothiazine led to 1,4,6,8‐tetraazatriazolo[4,5,1‐kl]benzo[b]phenothiazine which is a new heterocyclic compound and the parent compound of this ring system. The mechanistic pathways to these compounds are also proposed.
Preparation of N‐aryl‐2,4‐diaminopentanes by the ring opening reaction of 1‐aryl‐3,4,5,6‐tetrahydro‐2‐(1H)pyrimidinones
Authors: Kashima Choji , Katoh Akira , Yoshiwara Nobutoshi , Omote Yoshimori 
Published: March 2009

Abstract1‐Aryl‐3,4,5,6‐tetrahydro‐2‐(1H)pyrimidinones (I) underwent reductive ring opening reaction with lithium aluminum hydride to afford N‐aryl‐2,4‐diaminopentanes (II) in good yields. On the other hand, 3,4,5,6‐tetrahydro‐3,4,6‐trimethyl‐1‐phenyl‐2‐(1H)‐pyrimidinone (V) gave only cyclic diamine, 3,4,6‐trimethyl‐1‐phenylhexahydropyrimidine (VI), in 60% yield.
Synthesis of nitrobenzothiazolinethiones and related compounds via intramolecular displacement of nitro groups
Authors: Rasheed Khalid , Warkentin James D. 
Published: March 2009

AbstractA number of dinitroanilines on reaction with sodium hydride in dimethylformamide produced the sodium salt which, on further reaction with carbon disulfide, cyclized to nitrobenzothiazolinethiones. In several cases benzothiazolinethione sulfides and benzothiazolinethione disulfides were also isolated.
A reinvestigation of the cyclodesulfurization of thiosemicarbazides
Authors: Sunder Shyam , Peet Norton P. , Barbuch Robert J. 
Published: March 2009

AbstractA recent report describing the preparation of 2‐(substituted‐amino)‐3,4‐dihydro‐5H‐1,3,4‐benzotriazepin‐5‐ones (3), by the cyclodesulfurization of hydrazides prepared from o‐aminobenzoylhydrazine (1) and isothiocyanates, is erroneus. The products resulting from this reaction sequence are, instead, 2‐(substituted‐amino)‐5‐(o‐aminophenyl)‐1,3,4‐oxadiazoles (4). Alternate syntheses of the oxadiazoles led to the correct structural assignments.
The preparation of selenium‐containing aromatic and heterocyclic C‐substituted α‐amino acetic acid derivatives of potential biomedical application
Authors: Sadeh Tsvi , Davis Michael A. , Gil Ran , Zoller Uri 
Published: March 2009

AbstractModel selenium‐containing aromatic and heterocyclic C‐substituted α‐amino acid compounds have been synthesized as potential biomedical organ scanning application (external imaging) agents. The synthesis is based on the amidoalkylation of aromatic and heterocyclic compounds with α‐hydroxyglyoxylic acid‐primary amide adducts (2). The procedure is simple and straightforward, the overall yields are good, and the method appears to be of general use for the preparation of a wide variety of selenium‐containing amino acids (4).
Functionalization of substituted 2‐(1H)pyridones. II. Synthetic pathways to c‐6 modified 3‐cyano‐ and 3‐carboxy‐2‐(1H)pyridones from a common precursor
Authors: Showalter H. D. Hollis , Domagala John M. , Sanchez Joseph P. 
Published: March 2009

AbstractStarting from readily available 1,2‐dihydro‐6‐methyl‐2‐oxo‐3‐pyridinecarbonitrile, 1, viable synthetic pathways to a number of C‐6 functionalized 1,2‐dihydro‐2‐oxo‐3‐pyridinecarbonitriles and corresponding acids are presented. Through the utilization of dianion chemistry, the C‐6 methyl substituent is selectively functionalized to three different oxidation levels.
Metal‐chelating 1,3‐bis(2′‐pyridylimino)isoindolines
Authors: Siegl Walter O. 
Published: March 2009

AbstractA variety of novel chelating 1,3‐bis(2′‐pyridylimino)isoindoline ligands were prepared and characterized including ligands substituted on both the pyridyl and isoindoline ring systems. Noteworthy are the first iso‐indoline ligands with solubility in aqueous media. A convenient preparation of 4‐alkoxyphthalonitriles is reported; these compounds are readily obtained from 4‐nitrophthalonitrile and are suitable starting materials for alkoxy‐substituted ligands.
Synthesis of 6‐chloro‐1,5‐dimethylbenzimidazole
Authors: Criddle W. J. , Ellis G. P. , Jones R. T. 
Published: March 2009

AbstractThe title compound 6‐chloro‐1,5‐dimethylbenzimidazole (VI) has been synthesized from 5‐chloro‐4,N‐dimethyl‐2‐nitroaniline (X) which was prepared by two independent methods.
The synthesis and stereochemical assignment of exo‐7‐phenyl‐2,5‐dioxabicyclo[4.1.0]heptane
Authors: Hobbs Gregory D. , Woodyard James D. , Curtis John R. 
Published: March 2009

AbstractThe synthesis and stereochemical assignment of exo‐7‐phenyl‐2,5‐dioxabicyclo[4.1.0]heptane is reported. The stereochemical assignment was made based on data obtained from variable temperature nmr spectra.
On the reaction of 5‐aminopyrimidine with diazonium salts
Authors: Swistun Zofia , Van Der Plas Henk C. 
Published: March 2009

AbstractThe reaction of 5‐aminopyrimidine with benzenediazonium chloride, p‐methylbenzenediazonium chloride and p‐bromobenzenediazonium chloride is described. The reaction leads to a mixture of compounds, i.e. 1‐aryl‐3‐(pyrimidin‐5‐yl)triazene (6), 5‐amino‐4‐aryl‐6‐arylazopyrimidine (7) and 4‐aryl‐6‐arylazo‐5‐hydroxypyrimidine (8). The yields are found to be strongly dependent on the substituent present in the diazonium salt. Attempts to rearrange 1‐(p‐bromophenyl)‐3‐(pyrimidin‐5‐yl)triazene (6c) under basic and acidic conditions into a 1,2,3‐triazole derivative failed.
Synthesis of (E)‐8‐aza‐11‐deoxy‐15α‐ and 15β‐hydroxyprost‐13‐en‐1‐ol
Authors: Zoretic P. A. , Bhakta C. , Sinha N. D. , Jardin J. 
Published: March 2009

AbstractThe synthesis of a prostaglandin E1 analog, (E)‐8‐aza‐11‐deoxy‐15α‐ and 15β‐hydroxyprost‐13‐en‐1‐ol, is reported.
N‐(2‐hydroxyethyl)‐4‐(p‐nitrobenzylidene)‐1,4‐dihydropyridine (DHP) from the reaction of 4‐(p‐nitrobenzyl)pyridine (NBP) with ethylene oxide
Authors: Morrill Terence C. , Friedrich Louis E. , Machonkin Mary A. , Whitbourne James E. , Eastman Carolyn A. 
Published: March 2009

AbstractThe title reaction was carried out and characterization of the alkylation product (DHP, II) lead to the conclusion that it had a 1,4‐dihydropyridine structure, rather than a pyridinium ion structure. The 13C‐ and 1H‐nmr spectra, and the colors were especially important in establishing the structure.
Fluorine containing bioactive heterocycles. PartII. Synthesis of some new fluorine containing arylglyoxals, their hydrates and 1,5‐disubstituted hydantoins
Authors: Joshi Krishna C. , Pathak Vijai N. , Goyal Mahendra K. 
Published: March 2009

AbstractEight new fluorine containing arylglyoxals have been synthesized by the oxidation of the active methyl group of fluorinated acetophenones by selenium dioxide in dioxan‐water medium. The corresponding hydrates were obtained by dissolving arylglyoxals in minimum amounts of benzene and adding hot water. Seventeen new fluorine containing 1,5‐disubstituted hydantoins were subsequently prepared by the condensation of these arylglyoxals with arylureas in ethanol and characterized by ir, pmr and mass spectral studies. Representative compounds have been screened for their possible anticonvulsant and analgesic activities. None of the compounds show significant analgesic acitivity.
Determination of the anomeric configuration of 2′‐deoxy‐D‐ribonucleosides by 1H NMR and by crystallographic studies of a novel 2′‐deoxy C‐nucleoside
Authors: Srivastava Prem C. , Robbins Roland K. , Takusagawa F. , Berman H. M. 
Published: March 2009

Abstract2′‐Deoxy‐D‐ribonucleoside analogs of biologically active 2‐β‐D‐ribofuranosylthiazole‐4‐carboxamide were synthesized and the structure of the β anomer was determined by X‐ray crystallography and ′1H nmr. 2′‐Methylene protons of α‐ and β‐deoxyribonucleosides were observed to exhibit characteristic patterns in the 1H nmr which was used to distinguish between the two anomers. The method could be used to determine the anomeric configuration of both N‐ and C‐2′‐deoxyribonucleosides.
4‐substituted‐1,2,3,4‐tetrahydro‐3,3‐dimethylisoquinolines. II.
Authors: Bobowski George , Gottlieb Jeffrey M. 
Published: March 2009

AbstractA practical synthesis (Scheme I) is described for the preparation of a series of 4‐substituted‐3,3‐dimethyl‐1,2,3,4‐tetrahydroisoquinolines (3). Treatment of α‐(1‐amino‐1‐methylethyl)arylmethanols or α‐(1‐amino‐1‐methylethyl)heteroarylmethanols (5) with aromatic aldehydes gave imines7from which amino alcohols8were derived by reduction with potassium borohydride. Acid catalyzed cyclization of8yielded3. An acyl substituent was installed by Friedel‐Crafts acylation as a final step. The biological activities of3a(1) are briefly described.
Reactions of 1,4‐dihydro‐3‐(2H)benzoisoquinolinones with aldehydes in the presence of a strong base. Condensation and aromatization as competing reactions
Authors: Hazai L. , Deák Gy. , Tóth G. , Volford J. , Tamás J. 
Published: March 2009

AbstractIn reactions of 1‐phenyl‐1,4‐dihydro‐3‐(2H)benzoisoquinolinones with benzaldehyde in the presence of a strong base, the final result can be ring substitution with aromatization or only aromatization of the starting isoquinolinone, depending on the position of the ring junction ([f] or [h]), in the 5‐methyl derivative the latter process becomes predominating. In the system sodium hydride‐dimethylformamide, containing no aromatic aldehyde, methylation at site 4 occurs. Using compounds labelled with deuterium, it has been established that the 4‐benzyl or 4‐methyl derivatives with aromatic structures are formed through hydride ion migrations.
Synthesis and properties of thiazolo[5,4‐d]pyrimidine 1‐oxides
Authors: Senga Keitaro , Ichiba Misuzu , Kanazawa Hashime , Nishigaki Sadao 
Published: March 2009

AbstractSynthesis and properties of hitherto unknown thiazolo[5,4‐d]pyrimidine 1‐oxides are described. For example, the reaction of 6‐chloro‐1,3‐dimethyl‐5‐nitrouracil (I) with methyl thioglycolate in the presence of excess triethylamine afforded 2‐methoxycarbonyl‐4,6‐dimethylthiazolo[5,4‐d]pyrimidine‐5,7‐(4H,6H)dione 1‐oxide (IIIa), which is a versatile intermediate for the preparation of various thiazolo[5,4‐d]pyrimidine derivatives.
Indolizidine synthesis by transannular cyclization
Authors: Wilson Stephen R. , Sawicki Robert A. 
Published: March 2009

AbstractBeckmann rearrangement of alkylcyclooctenone oximes VIa and VIb gave corresponding nine‐membered lactams 1,3,4,5,8,9‐hexahydro‐3‐methyl‐2H‐azonin‐2‐one (VIIIa) and 1,3,4,5,8,9‐hexahydro‐3‐butyl‐2H‐azonin‐2‐one (VIIIb), respectively. A stereospecific transannular cyclization was induced by mercuric acetate leading to alkyl indolizinones Xa and Xb. Temperature and solvent dependent nmr spectra of the medium ring lactams indicates the stereochemical control is caused by steric interactions of the alkyl side chain. Lithium aluminum hydride reduced Xa/Xb to cis‐octahydro‐6‐methylindolizidine (XIa) and cis‐octahydro‐3‐n‐butylindolizidine (XIb).
Action de O‐ et N‐nucléophiles sur les sels de phényl‐3 benzopyrylium‐1
Authors: Deschamps‐Vallet Colette , Ilotsé Jean‐Baptiste , Meyer‐Dayan Michèle , Molho Darius 
Published: March 2009

AbstractLes perchlorates de phényl‐3 benzopyrylium‐1 (1a) et (1i) réagissent exclusivement en position 2 avec l'éthanol et l'alcool isopropylique pour donner les acétals mixtes 2a, 3a et 3i. En présence de N‐nucléophiles, les sels 1a et 1b donnent avec l'ammoniaque les amines secondaires symétriques 4a et 4b ou bis(phényl‐3 2H benzopyranne‐1 yl‐2)amines, tandis qu'avec les amines aliphatiques en solution aqueuse il se forme les bis‐acétals 5a et 5b ou oxy‐2,2′ bis(phényl‐3 2H benzopyrannes‐1). Ces mêmes dérivés 5a et 5b sont obtenus dans diverses autres conditions acides.
Mass spectral fragmentation patterns of 1,5‐benzodiazepines. I. ortho effects of R2‐substituent on 2‐(ortho‐R2‐aniline)‐4‐(para‐R1‐phenyl)‐3H‐1,5‐benzodiazepines
Authors: Maza M. E. , Galindez M. , Martinez R. , Cortés E. 
Published: March 2009

AbstractThe 70 eV electron impact mass spectra of twenty‐five 1,5‐benzodiazepines are discussed in detail with the aid of metastable ions and by comparison with the fragmentation patterns of known compounds. The fragmentation is markedly influenced by ortho‐substituents on the aniline group.
Carbon‐13 nuclear magnetic resonance spectra of N‐substituted 2‐amino‐4H‐3,1‐benzoxazin‐4‐ones and 3‐substituted 2,4‐(1H,3H)quinazolinediones
Authors: Petridou‐Fischer J. , Papadopoulos E. P. 
Published: March 2009

Abstract13C chemical shifts of nine N‐substituted 2‐amino‐4H‐3,1‐benzoxazin‐4‐ones, the isomeric 3‐substituted 2,4‐(1H,3H)quinazolinediones, and the parent compounds of the two series are reported. Support is provided for the endocyclic position of the C=N bond in the former series of compounds.
Synthesis of 2H‐1,4‐thiazin‐3(4H)‐one 1‐oxide and 2H‐1,4‐thiazin‐3‐(4H)‐one 1,1‐dioxide, structural analogs of uracil
Authors: Bobek M. 
Published: March 2009

AbstractThe synthesis of 1,4‐thiazine 1‐oxide and 1,1‐dioxide analogs of the antibiotic emimycin is described. Reaction of methylthioglycolate with 1‐bromo‐2,2‐diethoxyethane gave methyl (2,2‐diethoxyethylthio)acetate (2). Treatment of 2 with methanolic ammonia followed by cyclization furnished 2H‐1,4‐thiazin‐3(4H)‐one (5). Oxidation of 5 with m‐chloroperoxybenzoic acid converted it to 2H‐1,4‐thiazin‐3(4H)‐one 1‐oxide (6). Oxidation of 2 with potassium permanganate, followed by treatment with methanolic ammonia, and cyclization gave 2H‐1,4‐thiazin‐3(4H)‐one 1,1‐dioxide.
1,3‐benzoxathioles. Electrophilic aromatic substitution
Authors: Cabiddu Salvatore , Cerioni Giovanni , Cocco Maria Teresa , Maccioni Antonio , Plumitallo Antonio 
Published: March 2009

AbstractSome electrophilic substitution reactions on 1,3‐benzoxathiole derivatives are described. Bromination and acylation reactions take place in position 5, i.e., para to the oxygen atom. 1,3‐Benzoxathiole nitration yields a mixture of the corresponding sulfoxide and of the 6‐nitro derivative when performed with 33% nitric acid, while, using a mixture of 40% nitric acid and acetic acid or acetyl nitrate, the 6‐nitroderivative is obtained together with large amounts of gummy products. 2,2‐Dimethyl‐1,3‐benzoxathiole nitration with 33% nitric acid yields disulfide XI, while with 33% nitric acid and acetic acid or with acetyl nitrate a mixture of disulfide XI and XII is obtained. The structure of the products have been determined by spectroscopic methods.
Réaction de l'azaallyllithium en série acétylénique: Une méthode directe de préparation de phényléthynyl pyrrolidines, ‐pyrrolines et ‐pyrroles N‐non substitués et N‐alkylés
Authors: Vo‐Quang Liliane , Vo‐Quang Yen 
Published: March 2009

AbstractLa cycloaddition du diphényl‐1,3 aza‐2 allyllithium au tolane, au diphénylbutadiyne et au diphényl‐1,4 butényne E conduit quantitativement au tétraphényl‐2,3,4,5 pyrrole, à la phényléthynyl‐3 triphényl‐2,4,5 pyrroline‐3 et à la phényléthynyl‐3 triphényl‐2,4,5 pyrrolidine respectivement. En traitant le milieu réaction‐nel par le bromure de benzyle ou le sulfate de méthyle avant hydrolyse, on obtient directement les dérivés alkylés correspondants. La structure des pyrrolines‐3 est établie sur des bases spectroscopiques et des corrélations chimiques. La stéréochimie de cette nouvelle méthode de synthèse des pyrrolines‐3 est discutée.
The photochemical reactions of 5H‐benzo[a]phenothiazin‐5‐one with alkylthiols and thiophenol
Authors: Ueno Yoshio , Takeuchi Yutaka , Koshitani Jinya , Yoshida Takatoshi 
Published: March 2009

Abstract6‐Alkylthio‐ and 6‐phenylthio‐5H‐benzo[a]phenothiazin‐5‐ones were prepared by the photochemical reaction of 5H‐benzo[a]phenothiazin‐5‐one with alkylthiols and thiophenol. The structures of newly prepared compounds were determined by elemental analysis, spectroscopic methods (ir, nmr and ms) and comparison with a sample prepared by an alternate route.
1‐(β‐D‐ribofuranosyl)imidazo[4,5‐d]pyridazin‐4(5H)‐one: A new analogue of inosine
Authors: Gagnier R. Paul , Halat Michael J. , Otter Brian A. 
Published: March 2009

AbstractImidazo[4,5‐d]pyridazine‐4(5H)‐one, which normally forms the N‐6 nucleoside, can be induced to form the N‐1 and N‐3 nucleosides when a benzyloxymethyl substitutent is incorporated at N‐5. The N‐5 blocking group can be removed under mild conditions with boron trichloride.
Selenium heterocycles. XXXIII. Synthesis of thieno[3,4‐b]furan, seleno[3,4‐b]furan, thieno[3,4‐b]indole and seleno[3,4‐b]indole. four novel heterocycles
Authors: Shafiee A. , Sattari S. 
Published: March 2009

AbstractStarting from the readily available 2‐methyl‐3‐benzoylfuran, 1‐phenylthieno[3,4‐b]furan and 1‐phenyl‐seleno[3,4‐b]furan were prepared. Also, starting from phenyl 3‐methylindol‐2‐yl ketone and aryl 2‐methyl‐indole‐3‐yl ketones a series of substituted thieno[3,4‐b]indoles and substituted seleno[3,4‐b]indoles were prepared.
Synthesis and reactivity of 4‐substituted‐2,3‐dihydrobenzo‐1,4‐thiazines
Authors: Florio Saverio , Leng John L. , Stirling Charles J. M. 
Published: March 2009

AbstractA series of derivatives of 4H‐2,3‐dihydrobenzo‐1,4‐thiazine has been prepared. 4‐Acetyl‐2,3‐dihydrobenzo‐1,4‐thiazine undergoes self‐condensation by n‐butylmagnesium bromide affording the corresponding 4‐aceto‐acetyl‐2,3‐dihydrobenzo‐1,4‐thiazine, which, is converted to 5H‐1,4‐thiazino[2,3,4‐if]quinolin‐5‐one. Halogena‐tion of the acetyl derivative takes place at the position 2 of the heterocyclic ring and oxidation leads to 1‐oxides and 1,1‐dioxides.
Synthesis of heterocycles. Part V. The synthesis of substituted indenopyridines
Authors: Eweiss N. F. 
Published: March 2009

Abstract2‐Arylmethylene‐l‐indanones (I) and 2‐arylmethylene‐1,3‐indanediones (VII) react with active methylene compounds in the presence of ammonium acetate as a basic catalyst to afford substituted pyridines. The postulated routes to the formation of the reported compounds are given.
Synthesis and biological evaluation of certain 4‐alkylamino and 4‐arylalkylamino derivatives of the imidazo[4,5‐d]pyridazine and v‐triazolo[4,5‐d]pyridazine ring systems
Authors: Chen Shih‐Fong , Panzica Raymond P. , Dexter Daniel L. , Chu Ming‐Yu Wang , Calabresi Paul 
Published: March 2009

AbstractCertain 4‐alkylamino and 4‐arylalkylamino derivatives of the imidazo‐ and v‐triazolo[4,5‐d]pyridazine ring systems were prepared and evaluated against two human colon carcinomas (DLD‐1 and HCT‐15) and one human lung carcinoma (LX‐1), in vitro. 4‐Methylthioimidazo[4,5‐d]pyridazine (1) and 4‐methylthio‐v‐triazolo‐[4,5‐d]pyridazine (9) served as precursors to the title compounds. Treatment of these heterocycles with the appropriate amine (ammonia, methylamine, dimethylamine, benzylamine and hydrazine) provided the desired derivatives of that ring system. 4‐AIP (2) and 2‐aza‐4‐AIP (10) served as precursors to the 4‐dimethylaminomethyleneamino derivatives 6 and 14, respectively. Likewise, the 4‐hydrazino analogs (7 and 15) served as intermediates in the syntheses of benzaldehyde‐p‐[bis(2‐chloroethyl)amino]amino[4,5‐d]‐pyridazin‐4‐yl‐hydrazone (8) and benzaldehyde‐p‐[bis(2‐chloroethyl)amino]amino‐v‐triazolo[4,5‐d]pyridazin‐4‐yl‐hydrazone (16), respectively.
Synthesis of 2H‐chromeno[2,3‐d]pyrimidine‐2,4‐(3H)‐diones (10‐Oxa‐5‐deazaflavins) and their use in the oxidation of benzyl alcohol
Authors: Yoneda Fumio , Hirayama Ryoichi , Yamashita Machiko 
Published: March 2009

AbstractTreatment of 6‐phenoxyuracil derivatives with the Vilsmeier reagent (dimethylformamide‐phosphorus oxy‐chloride) gave the corresponding 5‐formyl‐6‐phenoxyuracil derivatives or their equivalents (5‐dimethylamino‐methylene‐6‐phenoxyuracil derivatives). Dehydrative cyclization of the above 5‐formyluracils or 5‐dimethyl‐aminomethyleneuracils with polyphosphoric acid gave the corresponding 2H‐chromeno[2,3‐d]pyrimidine‐2,4(3H)‐diones (10‐oxa‐5‐deazaflavins). These 10‐oxa‐5‐deazaflavins showed strong oxidizing power in oxidizing benzyl alcohol even under neutral conditions (without base) to give benzaldehyde, while they were hydro‐genated to 1,5‐dihydro‐10‐oxa‐5‐deazaflavins.
Mass spectral fragmentation patterns of 3,3‐dimethyl‐2,3,4,5,10,11‐hexahydro‐11‐(o‐ and p‐R‐phenyl)‐1H‐dibenzo‐ [b,e][1,4]diazepin‐1‐ones. II
Authors: Arellano M. del R. , Martínez R. , Cortés E. 
Published: March 2009

AbstractA study has been made of the fragmentation upon electron impact of 3,3‐dimethyl‐2,3,4,5,10,11‐hexahydro‐11‐phenyl‐1H‐dibenzo[b,e][1,4]diazepin‐1‐one and fifteen of its derivatives containing chloro, bromo, methyl, methoxy, hydroxy, nitro, amino, carboxyl and carboxymethyl substituents on ortho and para positions of the 11‐phenyl ring. All the spectra analyzed contain molecular ions and the principal fragmentation routes takes place either from the molecular or from (M+‐1) ion. There are, however, some deviations from the general fragmentation pattern in the case of 1,4‐dibenzodiazepin‐1‐ones with o‐nitro, o‐hydroxy and o‐carboxyl substituents caused by direct interactions of these groups with the benzodiazepine ring.