bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sur un transformation inattendue de l'amino‐3 nitro‐2 benzofuranne par l'acide acétique
Authors: Demerseman Pierre , Rissé Simone , Royer RenÉ 
Published: March 2009

AbstractL'acide acétique pur ou très concentré transforme lentement l'amino‐3 nitro‐2 benzofuranne en diazo‐3 dihydro‐2,3 benzofurannone‐2 dont la structure est confirmée par ses caractères spectroscopiques aussi bien que par sa réactivité chimique.
Electronic structure and molecular conformation of furan and pyrrole azomethines. An ab initio molecular orbital study
Authors: Millefiori S. , Millefiori A. 
Published: March 2009

AbstractSTO‐3G minimal basis set ab initio molecular orbital calculations were employed to study the electronic structure and conformational preferences in furan‐2‐N‐methylmethyleneimide (1) and pyrrole‐2‐N‐methylmethyleneimide (2). The theoretical results were examined by comparison with the parent molecular systems through a population analysis and molecular orbital interactions considerations. The OCCN‐trans and the NCCN‐cis forms were found to be the most stable structures in 1 and 2, respectively. Comparisons were made with available experimental data. The theoretical results indicate thatπ‐electron interactions and molecular orbital interactions are not significant factors in determining the conformational preferences which most likely depend on dipole‐dipole interactions.
The chemistry of carbazoles. VIII. Effect of methyl groups on the electronic spectra of carbazole
Authors: Tsunashima Yutaka , Kuroki Masatane 
Published: March 2009

AbstractElectronic spectra of a number of methylcarbazoles were measured. Spectral shifts of the longest wavelength absorption bands were evaluated by the HMO‐perturbation method. The calculated shifts of 1‐substituted (group II) and 4,5‐disubstituted carbazoles (group III) did not agree with the observed values. The effect of the methyl group on the direction and magnitude of the shift is closely additive except for 4,5‐disubstituted carbazoles. The additivity principle is a useful tool for determination of methylcarbazoles.
Linear free energy ortho‐correlations in the thiophene series. Part IX . Kinetics of esterification with diazodiphenylmethane of some 3‐, 4‐, and 5‐substituted thiophene‐2‐carboxylic acids in methanol
Authors: Noto Renato , Buscemi Silvestre , Consiglio Giovanni , Spinelli Domenico 
Published: March 2009

AbstractThe rate constants for the esterification of some 3‐, 4‐, and 5‐substituted thiophene‐2‐carboxylic acids with diazodiphenylmethane in methanol at 25° have been measured. The reactivity of some para‐ and ortho‐substituted benzoic acids has also been determined.Logarithmic kinetic constants for ortho‐, meta‐, and para‐like substituted thiophene‐2‐carboxylic acids furnish an excellent linear free energy relationship when plotted versus Δpka (β 0.89, r 0.989, C.L. > 99.9%, n 18, i 0.04), thus confirming the peculiar behaviour of five‐membered ring derivatives. The correlation with σH values offers an additional proof of the hyper‐ortho character of the 2,3‐relation in thiophene derivatives. para‐ and ortho‐Substituted benzoic acids show the usual behaviour of six‐membered ring derivatives.
Pyrrolo[1,2‐d]triazines‐1,2,4 III. Etude de la dioxo‐1,4 tetrahydro‐1,2,3,4 pyrrolo[1,2‐d]triazine‐1,2,4
Authors: Lancelot Jean‐Charles , Et MaxRobba Daniel Maume 
Published: March 2009

AbstractLa synthèse de la dioxo‐1,4 tétrahydro‐1,2,3,4 pyrrolo[1,2‐d]triazine‐1,2,4 (1) est réalisée par cyclisation du N‐carbéthoxyhydrazide de l'acide pyrrole‐carboxylique‐2 (2) et par réarrangement de la (pyrrolyl‐2)‐2 oxadiazolone‐5 (3). Les réactions de méthylation de la dione 1 effectuée avec le sulfate diméthylique et avec le diazométhane conduisent à des mélanges de dérivés O‐méthylés et N‐méthylés qui sont séparés par chromatographic en phase gazeuse et dont la structure est établie à l'aide des spectres ir et de rmn 1H.
Studies on the synthesis of heterocyclic compounds. Part VI. The action of methyl salicylate on some 5‐aminopyrazoles
Authors: Daidone Giuseppe , Plescia Salvatore 
Published: March 2009

AbstractSome 1‐phenyl‐3‐R‐5‐aminopyrazoles reacted with methyl salicylate to give N‐(1‐phenyl‐3‐R‐pyrazol‐5‐yl)‐2‐methoxybenzamides (3a,b,c), 1‐phenyl‐2‐methyl‐3‐R‐salicyloilimino‐3‐pyrazolines (4a,b,c) together with 1‐phenyl‐3‐R‐5‐methylamino pyrazoles (5a,b,c). The structures of the new compounds 3 and 4 were determined on the basis of analytical and spectroscopic data as well as on the acid hydrolysis products.
Transformation thermique des β‐(méthyl‐2 furyl)‐3 acryloylazides: Nouveau mode de formation de certaines pyrimidines
Authors: Bisagni Emile , Lhoste Jean‐Marc , Hung Nguyen Chi 
Published: March 2009

AbstractPar chauffage à 240° dans le diphényléther, les β‐(méthyl‐2 furyl)‐3 acryloylazides ne conduisent paus aux furo[3,4‐c]pyridones attendues suivant la réaction d'Eloy et Deryckere mais à des pyrimidines‐diones‐2,4 résultant de la dimérisation des vinylisocyanates formés intermédiairement.
Synthesis of 3‐substituted 7‐(3,3‐dimethyl‐1‐triazeno)‐10‐methylphenothiazines as potential antitumor agents
Authors: Lin Ai Jeng , Kasina Sudhaka 
Published: March 2009

AbstractA series of 3‐substituted (chloro, bromo, fluoro or methyl) 7‐(3,3‐dimethyl‐1‐triazeno)‐10‐methylphenothiazines were synthesized as potential antitumor agents. Treatment of p‐substituted anilines with ammonium thiocyanate in the presence of bromine gave 6‐substituted 2‐aminobenzthiazoles which, after methylation with methyl iodide were hydrolyzed in 50% potassium hydroxide to give 5‐substituted 2‐methylaminothiophenols in moderate yield. Condensation of methylaminothiophenols with 3,4‐dichloronitrobenzene in ethanol under an atomsphere of nitrogen gave adducts which were cyclized in dimethylformamide under the catalysis of copper and cuprous iodide to give 3‐substituted 7‐nitro‐10‐methylphenothiazines. The nitro group was reduced to the amino function with stannous chloride. Diazotization of the amines followed by coupling with dimethylamine gave the corresponding triazenes.
Selenium heterocycles. XXXII . Synthesis of [1]benzoxepino[3,4‐d]‐thiazole, [1]benzothiepino[3,4‐d]thiazole, [1]benzoxepino[3,4‐d]selenazole, and [1]benzothiepino[3,4‐d]selenazole. four novel heterocycles
Authors: Shafiee A. , Kiaeay G. , Vosooghi M. 
Published: March 2009

AbstractStarting from the readily available ethyl 2‐phenyl‐4‐methyl‐thiazole‐5‐carboxylate (III), 2‐phenyl‐4‐chloromethyl‐thiazole (VIII) and 2‐aryl‐4‐chloromethylselenazole (XIV), 2‐phenyl‐4,10‐dihydro‐10‐oxo‐[1]benzoxepino[3,4‐d]thiazole (Ia), 2‐phenyl‐4,10‐dihydro‐10‐oxo[1]benzothiepino[3,4‐d]thiazole (Ib), 2‐aryl‐4,10‐dihydro‐10‐oxo[1]benzoxepino[3,4‐d]selenazoles (IIa‐IIe) and 2‐aryl‐4,10‐dihydro‐10‐oxo[1]benzothiepino[3,4‐d]selenazoles (IIf‐IIj) were prepared.
Substituent effects in heterocyclic systems by carbon‐13 nuclear magnetic resonance. Isoxazoles
Authors: Chrisope Douglas R. , Keel Rebecca A. , Baumstark Alfons L. , Boykin David W. 
Published: March 2009

AbstractThe carbon‐13 nmr spectra of a series of 3‐aryl‐5‐phenylisoxazoles (I) and 3‐phenyl‐5‐arylisoxazoles (II) have been recorded and the signals assigned. Carbon‐13 data for series I show little effect of substituent on the chemical shift of the isoxazole ring carbons. However, a plot of the carbon‐13 chemical shift of carbon‐5 in the isoxazole system I versus the chemical shift of carbon‐3 in the 3‐(4′‐aryl)‐1‐phenylpropenones gives a straight line (r = .989) with a slope of 0.35. In series II, the chemical shifts of both carbon‐4 and ‐5 are relatively sensitive to substituent effects. Fair correlations between Hammett sigma values and the chemical shifts of these two carbons are found; dual substituent parameter treatment improves the correlations. The results obtained from correlations with carbon‐4 in series II are similar to those obtained from β‐carbons of a number of styrene systems. The data show that carbon‐4 in series II is approximately 20% less sensitive to substituent effects than the previously reported data for carbon‐3 of 2‐arylfurans. Transmission of substituent effects in the isoxazole system compare well with those of the benzothiazole system.
Reactions of benzothiohydrazide as a bidentate nucleophile
Authors: Elliott Arthur J. 
Published: March 2009

AbstractBenzothiohydrazide acts as a 1,4‐bidentate nucleophile under basic conditions, and condenses with suitably substituted pyridines, pyrimidines and quinoxalines to yield ring‐fused‐1,3,4‐thiadiazines un‐substituted on the 4‐nitrogen position.
Alkylation et acylation d'acridanones‐9
Authors: Blanchard Christiane , Montginoul Claude , Torreilles Eliane , Giral Louis 
Published: March 2009

AbstractNous décrivons les N‐alkylations et les N‐acylations d'acridanones‐9 substituées en position 2 ou 3 par des groupements nitro et méthoxy. Les caractéristiques physiques des nouveaux composés ainsi obtenus sont données.
Functional derivatives of thiophene. I. Synthesis and 1H‐NMR spectra in the 2‐aminothiophene series
Authors: Galvez C. , Garcia F. 
Published: March 2009

AbstractThe preparation of 2‐amino‐5‐nitrothiophene, 2‐formamido‐5‐nitrothiophene, 2‐acetamido‐5‐nitrothiophene and 2‐t‐butyloxycarbonylamino‐5‐nitrothiophene are described. Abnormal values of the coupling constants J3.4 had been observed in the 1H‐nmr spectra of compounds obtained.
Facile deacylation of N‐acyl‐2,3‐dihydrobenzo‐1,4‐thiazine 1‐oxide and 1,1 dioxide
Authors: Florio Saverio , Leng John L. , Stirling Charles J. M. 
Published: March 2009

AbstractThe title amides react easily with methanolic sodium methoxide at room temperature affording 2,3‐dihydrobenzo‐1,4‐thiazine 1‐oxide and 1,1‐dioxide and methylacetate. An unusual mechanism of deacylation is proposed.
Synthesis of a non‐flexible analog of chlorpromazine
Authors: Elliott Arthur J. , Guzik Henry 
Published: March 2009

Abstract9‐Chloro‐2‐dimethylaminomethyl‐1,2‐dihydropyrrolo[3,2,1‐kl]phenothiazine (3b), a conformationally restricted analog of chlorpromazine, has been synthesised and has been found to be devoid of neuroleptic activity.
Some 2‐(dialkylamino) substituted chromenylium salts
Authors: Mazzei M. , Ermili A. , Sottofattori E. , Roma G. 
Published: March 2009

AbstractThe reaction of 2‐(dialkylamino)‐7‐methoxychromones with malononitrile in the presence of acetic anhydride afforded [2‐(dialkylamino)‐7‐methoxy‐4H‐chromen‐4‐ylidene]malononitriles. When these compounds were refluxed with concentrated hydrochloric (or hydroiodic) acid, 2‐(dialkylamino)‐7‐methoxy(or hydroxy)‐4‐methylchromenylium salts were obtained. The use of concentrated sulfuric acid or polyphosphoric acid in the hydrolysis was also investigated. The preparation of ethyl [2‐(dialkylamino)‐7‐methoxy‐4H‐chromen‐4‐ylidene]cyanoacetates and their behavior when treated with acids are also described, as well as the synthesis of some 3‐(dialkylamino)‐1‐methylnaphtho[2,1‐b]pyrylium salts.
The reaction of nitriles with mercaptoacetic acid. A new synthesis of thiazole derivatives
Authors: Elnagdi Mohamed Hilmy , Khalifa Mohamed Ali Elsayed , Ibraheim Mohamed Kamal Ahmed , Elmoghayar Mohamed Riffat Hamza 
Published: March 2009

AbstractThe reaction of mercaptoacetic acid with nitriles was investigated. Whereas 4‐hydroxythiazole derivative could be obtained from the reaction of benzoylacetonitrile and of ethyl cyanoacetate with mercaptoacetic acid, a bithiazole derivative was obtained on treatment of benzonitrile with the same reagent. The behaviour of the synthesised thiazole derivatives towards aromatic aldehydes and hydrazines is reported.
Synthesis of 1H‐[1,2]diazepino[4,5‐b]indole derivatives
Authors: Vega A. Monge , Martinez M. T. , Palop J. A. , Mateo J. M. , Fernández‐Alvarez E. 
Published: March 2009

AbstractA synthesis of four 1H‐[1,2]diazepino[4,5‐b]indole derivatives and some preliminary information about their biological activity are presented. The starting materials were 2‐ethoxycarbonylindoles and 2‐ethoxy‐carbonyl‐3‐formylindoles, la, b and 2a, b, respectively. 2‐Ethoxycarbonyls la, b reacted with 1‐dimethylamino‐2‐nitroethylene and ‐2‐ethoxycarbonyl‐3‐formylindoles 2a, b in the presence of nitroalkanes (nitromethane or nitroethane) giving 3‐(2‐nitrovinyl)indoles 3a, b. Reduction of 3a, b yielded β‐(2‐oxoalkyl)indoles 4. On reaction with an excess of hydrazine hydrate, compounds 4 gave satisfactory yields of 5‐oxo‐1H‐[1,2]diazepino[4,5‐b]indoles 5.
Transformations in the 2‐quinolone series
Authors: Coppola Gary M. , Hardtmann Goetz E. 
Published: March 2009

AbstractThe treatment of 1‐substituted‐1,2‐dihydro‐4‐hydroxy‐2‐oxo‐3‐quinoline carboxylic acid esters and 4‐hydroxy‐1‐methyl‐3‐nitro‐2‐(1H)quinolinone with phosphorus oxychloride resulted in the formation of the corresponding 4‐chloro‐2‐quinolones. Their reactions with a variety of carbon, nitrogen, oxygen, and sulfur nucleophiles is described.
Napthyridines. IV. Synthesis of benzo[f]‐1,7‐naphthyridines
Authors: Baumgarten Henry E. , Barkley Raymond P. , Chiu Shuet‐Hing Lee , Thompson Robert D. 
Published: March 2009

AbstractBenzo[f]‐1,7‐naphthyridines have been synthesized from 3‐nitrolepidine (3) by a sequence involving monobromination of the methyl group of 3, oxidation of the bromomethyl group to the carboxyladehyde group by Franzen's trimethylamine N‐oxide procedure, and conversion of the resultant 3‐nitro‐1‐quinoline‐carboxaldehyde (6) to the benzo[f]‐1,7‐naphthyridine by the Borsche modification of the Friedlander cyclization.
Kinetic study on the alkaline hydrolysis of 1‐aryl‐2‐phenyl‐2‐imidazolines. Basicity‐rate of hydrolysis and structure relationships
Authors: Fernádez Beatriz M. , Reverdito Ana M. , Lamdan Samuel 
Published: March 2009

AbstractRate constants (kobs) of hydrolysis in boiling alkaline ethanolic solution for six 1‐aryl‐2‐phenyl‐2‐imidazolines were determined. The influence of substituents in the phenyl group at N‐1 upon rate of hydrolysis was studied. When the imidazoline ring is considered to be a substituent of the benzene ring at N‐1, a good correlation with the Hammett equation is found. It was observed that reaction rates were enhanced by electron‐releasing phenyl substituents of N‐1 and reduced by electron‐withdrawing groups, providing a change in the mechanism of the reaction in the first case that was not observed in the second. Agreement with the Hammett equation allowed comparison between experimental and “calculated” rate constants which are nearly equal. An equation relating the rate constants with the ionization constants of imidazolinium ions is given.
Reaction of 4‐aryl‐1,2,4‐triazines with hydrazine
Authors: Ibrahim Y. A. , Eid M. M. , Badawy M. A. , Abdel‐Hady S. A. L. 
Published: March 2009

AbstractThe action of hydrazine on 3,5‐dioxo‐4‐aryl‐2,3,4,5‐tetrahydro‐1,2,4‐triazines gave 4‐amino‐3,5‐dixo‐2,3,4,5‐tetrahydro‐1,2,4‐triazines. The intermediates of this reaction were isolated and shown to be α‐ketoacidhydra‐zide 4‐arylsemicarbazones and not the α‐ketoanilidecarbohydrazones. The realtive rates of cyclization of the latter isomeric derivatives provide a support for a proposed intermediates which were not isolated in the reaction of 3‐mercapto and 3‐methylmercapto‐4‐aryl‐5‐oxo‐4,5‐dihydro‐1,2,4‐triazines with hydrazine.
1‐Aminopyrazolin‐5‐ones. Synthesis and reactivity
Authors: Adembri Giorgio , Camparini Alfredo , Ponticelli Fabio , Tedeschi Piero 
Published: March 2009

AbstractA synthesis of 1‐aminopyrazolin‐5‐ones (I) by chloramine attack on the 2‐benzylpyrazolones (IVd‐e) has been accomplished. Nucleophilic substitution reactions of aminopyrazolones (I) are investigated; with 1,4‐diketones, N,N'‐pyrrolylpyrazolones (XVIIa‐c) are obtained. Chlorination of acetylaminopyrazolones (VII) led to the corresponding 1‐amino‐5‐chloropyrazoles (XXI) via the isolable pyrazolo[3,2‐b]oxadiazoles (XIX).
Synthesis of anthra[b]thiophenes and benzo[b]naphtho[d]thiophenes
Authors: Tominaga Yoshinori , Lee Milton L. , Castle Raymond N. 
Published: March 2009

AbstractAll isomers of the parent anthra[b]thiophenes and benzo[b]naphtho[d]thiophenes, namely anthra[2,3‐b]thio‐phene, anthra[2,1‐b]thiophene, anthra[1,2‐b]thiophene, benzo[b]naphtho[2,3‐d]thiophene, benzo[b]naphtho[2,1‐d]thiophene and benzo[b]naphtho[1,2‐d]thiophene were synthesized using a new procedure.
Synthesis of benzo[3,2]phenanthro[4,5‐bcd]thiophene and chryseno[4,5‐bcd]thiophene
Authors: Thompson Robert Douglas , Iwao Masatomo , Lee Milton L. , Castle Raymond N. 
Published: March 2009

AbstractBenzo[2,3]phenanthro[4,5‐bcd]thiophene and chryseno[4,5‐bcd]thiophene were synthesized, so that their mutagenic and carcinogenic activity can be determined.
Substituent, solvent and steric effects on the electrochemical reduction of aziridinium salts
Authors: Crist Delanson R. , Borsetti Arnold P. , Kass Mary Beth 
Published: March 2009

AbstractThe polarographic behavior of a series of N,N‐dimethyl‐2‐arylaziridinium fluorosulfonates was investigated as another example of ring‐opening reactions of this important class of compounds. Half‐wave potentials showed that in water reduction was facilitated by electron‐donating groups. This unusual result was explained in terms of electron transfer to an aminocarbonium ion‐like species. In methylene chloride, however, two one‐electron waves were observed, with the first showing a normal substituent effect (ϱ = 0.17 ± 0.03 V). This result indicated direct electron transfer to the aziridinium ion itself to form a radical species which was detected by cyclic voltammetry. Reasons for the change in mechanism are presented, and E1/2 values for selected aziridinium salts illustrate the importance of steric effects on the reduction process.
The mass spectra of some substituted thiophene‐2‐carboxanilides
Authors: Fisichella Salvatore , Occhipinti Salvatore , Alberghina Gaetano , Amato Maria Emanuela 
Published: March 2009

AbstractThe mass spectra of some substituted thiophene‐2‐carboxanilides at 70 eV are reported. The primary degradation reaction of these compounds involves cleavage of the amide bond, followed by elimination of CO. The effect of substituents on the mass spectra are related by the Hammett equation. The correlation against σ and σ+ is poor.
Synthesis of anhydro‐3‐mercapto‐5‐pyrazinyl‐1,2,4‐triazolium hydroxides
Authors: Shutske Gregory M. 
Published: March 2009

AbstractThe synthesis of some novel anhydro‐3‐mercapto‐5‐pyrazinyl‐1,2,4‐triazolium hydroxides 5 is described. The appropriate 1‐methylhydrazides 3 were condensed with isothiocyanates to give the thiosemicarbazides 4 which were cyclized to 5 under mildly basic conditions. A few 1,2,4‐triazole‐3‐thiones 8 were synthesized for comparison, starting with the 2‐methylhydrazides 6 and then carrying out analogous synthetic transformations.
8β‐Substituted dihydrocodeinones having heteroatoms in the side chain
Authors: Kotick Michael P. , Polazzi Joseph O. 
Published: March 2009

AbstractA series of 8β‐substituted dihydrocodeinones, having hetero atoms in the side chain, were prepared. Michael addition of methanol or ethanol to 1 was accomplished under basic conditions, while the nitromethane adduct was prepared by a fluoride ion catalyzed reaction. The 8β‐diethylmalonyl adduct 7 was converted in several steps to an 8β‐tertiary carbinol analog 12. Alternatively, 8β‐vinyldihydrocodeinone 13 was transformed, via the dimethyl ketal, to 8β‐hydroxymethyl or ‐ethyl compounds which were fluorinated in the side chain by use of diethylaminosulfur trifluoride.
Epimerization at C‐2 of 2‐substituted thiazolidine‐4‐carboxylic acids
Authors: Nagasawa H. T. , Goon D. J. W. , Shirota F. N. 
Published: March 2009

Abstract2(R,S)‐5,5‐Trimethylthiazolidine‐4‐(S)‐carboxylic acid (1a), with a 3.3 to 1 predominance of the 2S (cis) isomer, was shown to epimerize at the C‐2 position in neutral, protic solvents. This was manifested by mutarotation concomitant to changes in the ratios of the C‐4 methine proton resonances in the nmr spectrum. Compound 1a was stable in dilute sodium carbonate solution, but underwent rapid equilibration in 1N hydrochloric acid.Acetylation of 1a gave an acetyl derivative (2a) with exclusively 2S,4S stereochemistry. Chiral integrity at C‐2 was proved by conversion of both 2a and its enantiomer 2b via their munchnone derivatives to enantiomeric dimethyl 1,1,3,5‐tetramethyl‐1H,2H‐pyrrolo[1,2‐c]thiazole‐6,7‐dicarboxylates (4a and 4b).Acetylation of 2‐(R,S)‐phenyl‐5,5‐dimethylthiazolidine‐4(S)‐carboxylic acid, afforded both the 2S,4S (6a) and 2R,4S (6b) epimers. Epimerization of 6a at C‐4 gave the 2S,4R isomer (6c) which was enantiomeric with 6b.
Synthesis of some 2‐alkyl‐4‐quinolone and 2‐alkyl‐4‐methoxyquinoline alkaloids
Authors: Somanathan Ratnasamy , Smith Kevin M. 
Published: March 2009

AbstractAcid‐catalyzed condensation of a series of 3‐oxoalkanoic acid esters with aniline affords the corresponding 2‐alkyl‐4‐quinolones in good yield. Treatment of these compounds with methyl iodide affords 2‐alkyl‐4‐methoxyquinolines and 2‐alkyl‐N‐methylquinolones. Three of the compounds are naturally‐occurring alkaloids which are synthesized here for the first time.
Studies on 2,1‐benzisoxazoles. Behaviour towards electrophilic substitution and cycloaddition reactions
Authors: Boruah R. C. , Sandhu J. S. , Thyagarajan G. 
Published: March 2009

AbstractThe behaviour of 2,1‐benzisoxazoles (anthranils) towards electrophilic substitutions has been studied. Nitration of 5‐chloro‐2,1‐benzisoxazole (VII) exclusively gives 4‐nitro‐5‐chloro‐2,1‐benzisoxazole (XII). However, 5‐chloro‐3‐phenyl‐2,1‐benzisoxazole (VIII) gives dinitrated products XIII, one nitro group entering at position C7 instead of C4 of the carbocyclic ring and the other at the 4′ position of the 3‐aryl ring. When 6‐nitro‐3‐carbalkoxy‐2,1‐benzisoxazoles (X and XI) are nitrated, 4‐nitroisomers XV and XVI are obtained exclusively. The substituents already present in the carbocyclic ring exert decisive directing influence. While the parent 2,1‐benzisoxazole (Ia) fails to react with dimethyl acetylenedicarboxylate, 6‐nitro‐2,1‐benzisoxazole (XVII) and 5‐chloro‐2,1‐benzisoxazole (VII) react to give 1,4‐cycloadducts XIX and XX, respectively. These results suggest that 2,1‐benzisoxazoles possess benzenoid as well as ortho‐quinonoid character.
Pyrimidine derivatives and related compounds. 38. Synthesis of 1,3‐oxazine‐2,4‐diones and their reaction with nucleophiles. Ring transformation of 1,3‐oxazines to pyrimidines
Authors: Yogo Motoi , Hirota Kosaku , Senda Shigeo 
Published: March 2009

Abstract5,6‐Unsubstituted 1,3‐oxazine‐2,4‐diones (3) and 6‐unsubstituted 5‐methyl‐1,3‐oxazine‐2,4‐diones (4) were prepared by reduction of the corresponding 6‐chloro derivatives (1 and 2). Treatment of 6‐chloro‐3‐methyl‐1,3‐oxazine‐2,4‐dione (1a) with sodium azide, sodium cyanide, secondary amines and aniline gave the corresponding 6‐substituted compounds (7, 9, 10 and 11) while the reaction of 1a and 2a,b with primary aliphatic amines such as methylamine and ethylamine caused a ring transformation to pyrimidine ring system giving barbituric acids (13a‐d).
Reaction of 3‐methoxy‐17‐methylmorphinan‐6‐one with formaldehyde
Authors: Leland David L. 
Published: March 2009

AbstractReaction of 3‐methoxy‐17‐methylmorphinan‐6‐one (1) and formaldehyde with the presence of calcium hydroxide in aqueous dioxane gave 7,7‐bis(hydroxymethyl)‐3‐methoxy‐17‐methyl‐5‐methylenemorphinan‐6β‐ol (2a). Catalytic reduction of 2a yielded the 5α‐methyl compound, 2b. Tosylation of 2a,b followed by lithium triethylborohydride reduction gave either 7α‐methyl‐6β,7β‐oxetanes 4a,b or 7,7‐dimethyl‐6β‐ols 5a,b, depending on reaction conditions. The C‐6 ketones 6a,b were prepared by oxidation of 5a,b. One compound in this series, 6a, had antinociceptive activity.