bluuebunny/crossref_metadata_2025 huggingface dataset:
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

A 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

The 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

Benzo[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

Rate 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

The 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

A 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

All 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

Benzo[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

The 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

The 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

The 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

A 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

2(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.
A qualitative molecular orbital picture of 2‐substituted carbonyl derivatives of furan and pyrrole
Authors: Capdevila Jaume , Canadell Enric
Published: March 2009

The conformational preferences for some 2‐substituted furans and pyrroles have been studied by MINDO/3 and a qualitative model including solvent effects is proposed.
Synthesis of some 2‐alkyl‐4‐quinolone and 2‐alkyl‐4‐methoxyquinoline alkaloids
Authors: Somanathan Ratnasamy , Smith Kevin M.
Published: March 2009

Acid‐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

The 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

5,6‐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

Reaction 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.
Substituent effects in heterocyclic systems. 1H‐NMR Study of methyl 3,5‐diarylisoxazolium iodides
Authors: Baumstark Alfons L. , Dunams Tambra
Published: March 2009

Methyl 3‐aryl‐5‐phenylisoxazolium iodides (I) and methyl 3‐phenyl‐5‐arylisoxazolium iodides (II) were synthesized from the corresponding isoxazoles in moderate yields. The 1H‐nmr chemical shifts for H‐4, series I and II, and the quaternary methyl group series II were found to correlate with values. The rho value observed for H‐4 series II was 3.3 times that observed in series I. The correlation observed in series I contrasts with the lack of (poor) correlations reported in the corresponding isoxazole and chalcone systems. The rho value observed in the correlation of the quaternary methyl group series II correlates well with an estimate based on methyl pyridinium salt data. The chemical shifts of the quaternary methyl group series I showed little or no variation. Swain‐Lupton and DSP treatments did not show improved correlations over the single parameter results. However, interpretation of these treatments reveals that similar processes are occuring in all three cases. The results for H‐4 series I showed that the reduction of transmission of the substituent effect in series I compared to that in series II was essentially due to equal reduction of both inductive and resonance effects. The mechanism of transmission seems to differ only in degree and not type.
Base‐induced cycloaddition of N‐(tosylmethyl)imino compounds to michael acceptors. Synthesis of 2,3,4‐trisubstituted pyrroles
Authors: Houwing Hendrik A. , Van Leusen Albert M.
Published: March 2009

A series of N‐(tosylmethyl)imino compounds [TosCH2NC(L)A] has been prepared, and applied to a new, base‐induced, one‐operational synthesis of otherwise more difficultly accessible 2,3,4‐trisubstituted pyrroles from electron deficient olefins. This regiospecific process probably is an 1,3‐anionic cycloaddition, combined with the elimination of sulfinic acid and a leaving group L. The group A is retained as the 2‐substituent of the resulting pyrroles.
Monoamine oxidase and succinate dehydrogenase inhibitory properties of substituted mercaptoquinazolones
Authors: Mehrotra Suman , Barthwal J. P. , Saxena A. K. , Bhargava K. P. , Parmar S. S.
Published: March 2009

Twelve 6‐substituted‐2‐(1′‐mercaptoacetyl‐3′‐arylurea)‐3‐phenyl‐4‐quinazolones were synthesized by condensation of 6‐substituted anthranilic acids and aryl isothiocyanates followed by reaction with chloroacetyl arylurea. These compounds were characterized by their sharp melting points and elemental analyses. All compounds were evaluated for their enzyme inhibitory activity. It was found that all substituted quinazolones at a final concentration of 2 × 10−4Minhibitedin vitromonoamine oxidase and succinate dehydrogenase activity of rat brain homogenates and the degree of inhibition ranged from 11–77% and 25–53%, respectively.
Chemistry of the phenoxathiins and isosterically related heterocycles. XVIII. The synthesis, 1H‐ and 13C‐NMR Spectroscopy of benzo[b]‐1,4,9‐triazaphenoxathiin
Authors: Turley James C. , Martin Gary E. , Inners Ruth R.
Published: March 2009

The first synthesis of a triazaphenoxathiin system, benzo[b]‐1,4,9‐triazaphenoxathiin, is reported. Attempts directed toward the total assignment of the 13C‐nmr spectrum of the title compound failed to produce an unequivocal assignment. The carbons of the benzo‐portion of the molecule could not be unequivocally assigned at 25.2 MHz but were subgrouped into permutable pairs of resonances on the basis of relaxation times, a result of the antisotropic reorientation of the molecule. Further attempts to complete the 13C‐nmr assignment at 100 MHz by selective on‐resonance decouplings in the 400 MHz 1H‐nmr spectrum were also unsuccessful because of similarities in the chemical shifts of the benzo‐protons. Complete 1H‐nmr chemical shifts and homo‐nuclear spin‐coupling constants were obtained using the PANIC program.
Heterocycles from N‐benzoylthioamides and dinucleophilic reagents
Authors: Whitfield Lawrence L. , Papadopoulos Eleftherios P.
Published: March 2009

N‐Benzoylthioamides (1) react with hydrazines and hydroxylamine to form 1H‐1,2,4‐triazoles and 1,2,4‐oxadiazoles, respectively. A similar treatment of the S‐methyl derivatives of 1 with amidines leads to 1,3,5‐triazines. Ethyl ZV‐benzoylthiocarbamate undergoes analogous reactions to yield the corresponding ethoxyheterocycles.
Bleomycin analogs. Synthesis and proton nmr spectral assignments of thiazole amides related to bleomycin a2
Authors: Riordan James M. , Sakai Ted T.
Published: March 2009

The synthesis of a series of 2‐substituted thiazole‐4‐carboxamides of 3‐aminopropyldimethylsulfonium chloride is described and the proton nmr spectral assignments of these derivatives are made. The compounds, which are fragments and analogs of the DNA‐binding portion of the antitumor antibiotic bleomycin A2, will serve as probes of structure‐activity relationships in this family of drugs.
Condensation of 3‐methylbenzoxazolinone with α,β‐unsaturated acids
Authors: Merdji B. , Lesieur D. , Lespagnol C. , Barbry D. , Couturier D.
Published: March 2009

The reaction between 3‐methylbenzoxazolinone and some unsaturated acids in PPA leads to mixtures of compounds, depending on the acid: 6‐crotonyl‐ (or cinnamoyl)‐3‐methylbenzoxazolinones, 2,3‐dihydro‐2,5‐(or 2,7)dioxo‐3‐methylcyclopenta[f]benzoxazoles and 6‐(3‐oxo‐indanyl)‐3‐methylbenzoxazolinones. The structure of the products was established by 13C and 1H nmr spectroscopy and (or) by independent synthesis. Possible mechanisms of the reaction are discussed; when competition is possible as in the last step of the cyclization, the benzene ring shows a higher reactivity than the aromatic nucleus of the benzoxazolinone; the contrary is observed when the benzene ring is p‐chloro‐substituted.
Formation of pyrrole derivatives through aminolysis of 2‐azetidinone derivatives
Authors: Kano Shinzo , Shibuya Shiroshi , Ebata Tsutomu
Published: March 2009

A mixture of 3‐(α,β‐epoxyisopropyl)‐1‐phenyl‐2‐azetidinone and benzylamine was heated in a sealed tube at 120–130° yielding 4‐anilinomethyl‐1‐benzyl‐3‐hydroxy‐3‐methyl‐2‐pyrrolidinone as a mixture of diastereoisomers. By this method, 4‐anilinomethyl‐3‐hydroxy‐3‐methyl‐1‐phenyl‐2‐pyrrolidinone and 4‐anilinomethyl‐3‐hydroxy‐3‐methyl‐1‐(3,4‐dimethoxyphenethyl)‐2‐pyrrolidinone were obtained by using aniline and 3,4‐dimethoxyphenethylamine, respectively, instead of benzylamine. The reaction of 4‐formyl‐1‐phenyl‐2‐azetidinone with 3,4‐dimethoxyphenethylamine afforded 4‐anilino‐1‐(3,4‐dimethoxyphenethyl)‐2,3‐dihydro‐2‐oxopyrrole. In a similar fashion, the 1‐n‐butyl and 1‐isobutyl analogues were obtained by the use of n‐butylamine and isobutylamine, respectively, instead of 3,4‐dimethoxyphenethylamine.
Studies on furan derivatives. XII. Nucleophilic substitution of methyl 5‐nitro‐2‐furancarboxylate. Preparation of methyl 5‐phenoxy‐2‐furancarboxylates
Authors: Tanaka Akira , Usui Toshinao , Shimadzu Masaji
Published: March 2009

Twenty one methyl 5‐phenoxy‐2‐furancarboxylates prepared from the reaction of methyl 5‐nitro‐2‐furan‐carboxylate with phenoxides via displacement of the nitro group. In the reaction of potassium 2‐nitrophen‐oxide with methyl 5‐nitro‐2‐furancarboxylate at 110°‐120°, 2,2′‐dinitrodiphenyl ether was obtained as a main product.
Photochemical reactions of 6‐alkylamino‐ and 6‐alkylanilino‐5H‐benzo[a]phenothiazin‐5‐ones
Authors: Ueno Yoshio , Koshitani Jinya , Yoshida Takatoshi
Published: March 2009

Photochemical reactions of 6‐alkylamino‐ and 6‐alkylanilino‐5H‐benzo[a]phenothiazin‐5‐ones have been investigated. 6‐Ethylamino‐ and 6‐isopropylamino‐5H‐benzo[a]phenothiazin‐5‐ones and 6‐methylanilino‐ and 6‐ethylanilino‐5H‐benzo[a]phenothiazin‐5‐ones gave 6‐amino‐5H‐benzo[a]phenothiazin‐5‐one and 6‐anilino‐5H‐benzo[a]phenothiazin‐5‐one, respectively, on irradiation.
Preparation of 3‐methyl‐4‐vinyl‐1,2,5‐oxadiazole and 3‐methyl‐4‐vinyl‐1,2,5‐thiadiazole
Authors: Boger Dale L. , Brotherton Christine E.
Published: March 2009

Short and high yielding preparations of 3‐Methyl‐4‐vinyl‐1,2,5‐oxadiazole (6a) and 3‐Methyl‐4‐vinyl‐1,2,5‐thiadiazole (6b) are described.
Synthesis of (±)‐O‐methylcannabichromene and some homologues
Authors: De La Torre M. , García F. , Cruz R.
Published: March 2009

A facile novel synthesis of (±)‐O‐methylcannabichromene (5d) together with (±)‐2‐methyl‐2‐(4‐methyl‐3‐pentenyl)‐5‐methoxy‐2H‐benzopyran (5a) and its 7‐methyl (5b) and 7‐propyl (5c) homologues, using organolithium salts is described.
Improved synthesis of 3‐aralkylidine‐5‐arylthiophen‐2‐(3H)ones
Authors: Miller Gerald A. , Heindel Ned D. , Minatelli John A.
Published: March 2009

3‐Aralkylidene‐5‐arylthiophen‐2‐(3H)ones can be prepared in two steps from 4‐aryl‐4‐oxobutanoic acids through the intermediacy of butenolides and thiophenones generated by the sequential action of acetic anhydride, sodium hydrosulfide and aromatic aldehydes.
Synthesis of some 2‐amino‐4‐phenyl‐3H‐1,5‐benzodiazepines by reaction of aromatic diamines and acetylenic imidates
Authors: Unangst Paul C.
Published: March 2009

The reaction of several aromatic 1,2‐diamines with conjugated acetylenic imidate salts is described. The use of hexamethylphosphoric triamide (HMPA) as the solvent allows preparation of 2‐amino‐4‐phenyl‐3H‐1,5‐benzodiazepines in a one‐step reaction.
Thiophene systems. 6. An unexpected bromine migration during the synthesis of thieno[3,4‐b][1,5]benzoxazepin‐10‐ones
Authors: Press Jeffery B. , Eudy Nancy H.
Published: March 2009

7‐Bromothieno[3,4‐b][1,5]benzoxazepin‐10‐one (1a) was unexpectedly formed upon acid catalyzed ring closure of 5‐bromo‐4‐ethoxy‐2′‐hydroxy‐3‐thiophenecarboxanilide (2a). Ring closure of the chlorine analogue 2c proceeded normally to give 3‐chlorothieno[3,4‐b][1,5]benzoxazepin‐10‐one (1b).
An easy and efficient synthesis of 4H‐thiazolo[5,4,3‐ij]quinolin‐4‐ones and 5H‐1,4‐thiazino[2,3,4‐i,j]quinolin‐5‐ones
Authors: Babudri Francesco , Di Nunno Leonardo , Florio Saverio
Published: March 2009

The title heterocycles have been synthesized by a Claisen‐type self condensation of acetylbenzothiazolines and acetyldihydrobenzothiazines and subsequent cyclization.
One‐Pot synthesis of substituted pyrrolidines via aminomercuration‐demercuration of 1,4‐ and 1,5‐Hexadiene
Authors: Barluenga J. , Najera C. , Yus M.
Published: March 2009

The aminomercuration‐demercuration of 1,4‐ and 1,5‐hexadiene yield cis‐ and trans‐2,5‐dimethyl‐N‐arylpyrrolidines via one‐pot process. The intermolecular cyclization reaction goes through the corresponding mercurated pyrrolidines; these intermediates were isolated and characterized when the mercuration reaction was completed. The high stereoselectivity observed allows an easy way of synthesis for N‐substituted trans‐2,5‐dimethylpyrrolidines.
Selenium‐sulfur analogs. Mass spectrometric comparison of substituted selenazoles and thiazoles
Authors: Jham G. N. , Vouros Paul , Hanson R. N. , Giese R. W.
Published: March 2009

The electron impact mass spectra of a series of thiazoles and selenazoles were compared. No major differences in the mass spectral behavior between the sulfur and selenium containing compounds were observed. Isotopic labelling with deuterium permitted deconvolution of ion peaks of identical mass and composition, but arising from different fragmentation pathways.
Bromothiophene reactions. I. Friedel‐crafts acylation
Authors: Agua M. J. Del , Alvarez‐Insúa A. S. , Conde S.
Published: March 2009

Friedel‐Crafts acylation of 2,5‐dibromo‐ and 2,3,5‐tribromothiophenes with different acyl chlorides and anhydrous aluminium trichloride has been studied. The reaction afforded a mixture of acyl derivatives and tetrabromothiophene. The results obtained suggest a mechanism which involves the formation of bromine cations in the reaction medium. Several products obtained in this reaction are described.
Herstellung kondensierter 2‐alkylthio‐4‐hydroxypyrimidine
Authors: Haede Werner
Published: March 2009

Aromatische Amine werden mit Alkoxycarbonyl‐senföl in Thioharnstoffe 7 überführt. Diese werden zu S‐Alkylisothioharnstoffen 8 alkyliert, die beim Erwärmen unter Alkoholabspaltung kondensierte 2‐Alkylthio‐4‐hydroxypyrimidine 9 bilden.
Syntheses and spectral properties of 2‐Thiobiotin and biotin derivatives
Authors: Flaster Harry , Kohn Harold
Published: March 2009

A series of methylated derivatives of 2‐thiobiotin (2‐4) have been prepared as potential aids in elucidation of the mechanism of biotin catalysis. The syntheses and mass, infrared, 1H nmr, and 13C nmr spectral properties for these substrates, their 2‐thiobiotin precursors (6, 10‐14) and the corresponding biotin analogs (1, 15, 31‐34) are described. A series of selective proton‐proton and proton‐carbon decoupling experiments were employed to secure a number of the 1H and 13C nmr assignments. Consistent patterns noted throughout the data set proved helpful in structure determination.
Ein neuer zugang zu indeno[1,2‐b]pyridinen
Authors: Kunstmann Rudolf , Lerch Ulrich , Wagner Konrad
Published: March 2009

Es wird über eine neue Synthese von 5H‐Indeno[1,2‐b]pyridinen aus 5‐Oxo‐5‐phenylvaleronitrilen I bzw. Deren Cyclisierungsprodukten, den 6‐Phenyl‐3,4‐dihydropyridin‐2‐onen II, berichtet. Die in Polyphosphorsäure durchgeführte Kondensation von I bzw. II mit aromatischen oder heteroaromatischen Aldehyden III liefert in 5‐Stellung substituierte 1,2,3,4‐Tetrahydro‐5H‐indeno[1,2‐b]pyridin‐2‐one IV. Aus diesen kb̈nnen u.a. die bisher nur schwer zugänglichen 2,3,4,4a,5,9b‐Hexahydro‐1H‐indeno[1,2‐b]pyridine X, XI leicht hergestellt werden.
Synthèse de l'amino‐4 formyl‐3 méthyl‐6 pyridazine
Authors: Turck Alain , Brument Jean‐François , Quéguiner Guy
Published: March 2009

Nous avons préparé par deux méthodes différentes un nouveau réactif de synthèse dans la série de la pyridazine: l'amino‐4 formyl‐3 méthyl‐6 pyridazine. Ceci nous a conduit à synthétiser plusieurs composes orthodifonctionnels nouveaux de la pyridazine.
Synthesis of macrocyclic‐acyclic polyether‐ester compounds with isoxazole units
Authors: Auricchio S. , Ricca A. , De Pava O. Vajna
Published: March 2009

A series of macrocyclic‐acyclic ether‐ester compounds containing the isoxazole ring has been prepared by treating various dihydroxy compounds with 3,5‐isoxazoledicarbonyl chloride.
The action of bentonitic earth on natural product epoxides
Authors: Salmón Manuel , Penieres Guillermo , Miranda Rene , Alvarez Cecilia
Published: March 2009

The ring opening of the epoxide group in the epoxiguaianolides by commercially available bentonitic earth produces specifically the trans diol in good yield under mild conditions.
Polynitroalkyltetrazoles
Authors: Grakauskas Vytautas , Albert Anthony H.
Published: March 2009

5‐(Fluorodinitromethyl)‐and 5‐(trinitromethyl)tetrazoles were synthesized in the reactions of fluorodinitroacetonitrile with sodium azide, and trinitroacetonitrile with trimethylsilyl azide, respectively, and characterized as their ammonium salts.
Photochemistry of 4‐Pyrones in water. Formation of dihydroxycyclopentenones and furan derivatives
Authors: Pavllk James W. , Snead Thomas E. , Tata James R.
Published: March 2009

Irradiation of aqueous solutions of aikyl substituted 4‐pyrones leads to the formation of dihydroxycyclopentenones. These primary products are also photolabile and in certain cases are photochemically converted to furan derivatives.
Steroidal thiazoles, isothiazoles, thiazolines and thiazolidines
Authors: Catsoulacos Panayotis , Camoutsis C. H.
Published: March 2009

In order to discover new useful steroids in which the cyclopentanoperhydrophenanthrene system is condensed with various heterocyclic rings, many new compounds are continually being synthesized and tested for physiological action. The thiazole, isothiazole, thiazoline and thiazolidine ring condensed on several positions of the steroidal skeleton, has shown great interest due to the physiological properties. Literature coverage for this review includes publications which appear from 1946 to the 1980′s.
The synthesis of substituted pyrazino[2,3‐d]‐1,2,4‐triazolo[4,3‐b]pyridazines
Authors: Thompson Robert Douglas , Castle Raymond N.
Published: March 2009

The synthesis of 1,2,4‐triazolo[4,3‐b]pyridazines and the unknown ring system, pyrazino[2,3‐d]‐1,2,4‐triazolo[4,3‐b]pyridazine, has been achieved. The preparation of the new tricyclic 1,2,4‐triazole was accomplished first by ring closure of the triazole ring followed by formation of the pyrazine ring. Substitution of the pyrazino[2,3‐d]‐1,2,4‐triazolo[4,3‐b]pyridazine ring system was carried out in order to provide information of its reactivity and to provide a variety of interesting compounds for biological testing.
Synthesis of some new derivatives of 4‐hydrazino‐5H‐pyridazino[4,5‐b]indole
Authors: Monge‐Vega A. , Aldana I. , Ferández‐Alvarez E.
Published: March 2009

This paper describes the synthesis of 1‐chloro‐4‐hydrazino‐5H‐pyridazino[4,5‐b]indole (4) and some of the triazoles (6–8), tetrazoles (10–11), triazolotetrazoles (9) and bis‐tetrazoles (12) derived from it. All of these were previously unknown compounds.

Treating 1,4‐dioxo‐1,2,3,4‐tetrahydro‐5H‐pyridazino[4,5‐b]indole (1) with phosphorus oxychloride gave 1,4‐dichloro‐5H‐pyridazino[4,5‐b]indole (2), which reacts regioselectively with hydrazine to give compound 4. The reactions of 4 with formic and acetic acids gave 6‐chloro‐11 H‐1,2,4‐triazolo[4,3‐b]pyridazino[4,5‐b]indoles (6a‐6b), respectively. Reaction of compound 6a with hydrazine gave 6‐hydrazino‐11H‐1,2,4‐triazolo[4,3–6]‐pyridazino[4,5,‐b]indole (8). This with nitrous acid gave 6‐azido‐11H‐1,2,4‐triazolo[4,3‐b]pyridazino[4,5‐b]‐indole (9). Compound 4 reacted with nitrous acid to give 6‐chloro‐11H‐tetrazolo[4,5‐b]pyridazino[4,5‐b]‐indole (10), which gave 1,4‐diazydo‐5H‐pyridazino[4,5‐b]indole (12), through successive reactions with hydrazine and nitrous acid. All compounds were characterized by elemental analysis, ir and 1H‐nmr spectra.
The reaction of 1‐hydrazinophthalazine with phthalaldehydic acid. Occurrence of ring‐chain tautomers
Authors: Amer Adel , Zimmer Hans
Published: March 2009

A reaction involving 1‐hydrazinophthalazine (hydralazine, 1)designed to give a condensed heterocyclic system in which an eight membered ring is fused to phthalazine was investigated. With phthalaldehydic acid (2) the expected system was obtained. However, it occurs as an easily convertible mixture of ring‐chain tautomers. It was found that the course of the reaction depends on the solvent. Thus, 6,7‐dihydro‐7‐hydroxy‐12H‐phthalazino[2,1‐b][2,4]benzodiazocin‐12‐one (5) and 2‐(2‐formylbenzoyl)‐1‐hydrazono‐1,2‐dihydrophthalazine (6) were the products of the reaction of 1 with 2 in aqueous medium. Upon prolonged standing this mixture converts into 3‐(2‐carboxyphenyl)‐s‐triazolo[3,4‐a]phthalazine (8). In contrast, the isomeric ring‐chain tautomers 2‐(1‐aminophthalazino)‐3‐hydroxy‐1‐oxoisoindole (12) and 1‐[2‐(2‐formylbenzoyl)hydrazino]phthalazine (13) were formed when the reaction was run in ethanol as solvent.
Hydantoin formation from alaninamide derivatives. Reactions with 5‐amino‐5‐methylhydantoin
Authors: Zanotti Giancarlo , Pinnen Francesco
Published: March 2009

The influence of the α‐substitution on hydantoin formation from urethan protected alaninamide derivatives is investigated. Several 5‐methyl‐5‐substituted hydantoins, obtained from 5‐amino‐5‐methylhydantoin, are described.
Acyclic analogues of purine and imidazole nucleosides
Authors: Parkin Ann , Harnden Michael R.
Published: March 2009

Hydroxyl‐protected derivatives of 1‐ and 3‐(2‐hydroxyethoxymethyl)imidazoles (4,5,7‐10) have been prepared from 5‐amino‐4‐carbamoylimidazoles (2). The protected derivatives were converted to acyclic analogues of imidazole nucleosides (6) or subjected to various cyclisation reactions leading to 9‐(2‐hydroxy‐ethoxymethyl)‐substituted 2‐methyl‐, 2‐phenyl‐ and 2‐azahypoxanthines (18,13and20, respectively) and 1‐methylguanine (28). For assignment of structures to isomeric imidazole and purine derivatives,13C chemical shifts have been used.
Stereospecific synthesis of N‐(1‐phenylethyl)‐2,4,5‐triphenyloxazolidines
Authors: Alcaide Benito , Lopez‐Mardomingo Carmen , Perez‐Ossorio Rafael , Plumet Joaquin
Published: March 2009

Treatment of the diastereoisomeric N‐(1‐phenylethyl)‐1,2‐diphenyl‐2‐aminoethanols with benzaldehyde yields stereospecifically N‐(1‐phenylethyl)‐2,4,5‐triphenyloxazolidines with four chiral centers. The configurations of these oxazolidines are established through their ring‐opening reactions with methylmagnesium iodide and subsequent oxidation with lead tetracetate.
Diazo‐, azo‐, and azidoazoles. VII. Imidazo[1,2‐b]‐ versus imidazo[2,1‐c]benzo‐as‐triazines
Authors: Castillón Sergio , Meléndez Enrique , Vilarrasa Jaume
Published: March 2009

Treatment of 3‐aminobenzo‐as‐triazines with bromoacetaldehyde ethylene acetal give linear tricyclic imidazobenzo‐as‐triazines, where 3‐amino‐7‐methylbenzo‐as‐triazine 1‐oxide yields the angular isomer. The structures of these compounds have been established by comparing their nmr spectra to those of pyrazolo [5,1‐c]‐ and s‐triazolo[5,1‐c]benzo‐as‐triazines obtained form the appropriate azo derivatives by intramolecular cyclization.
Configuration and conformation of substituted azetidines
Authors: Kingsbury C. A. , Soriano D. S. , Podraza K. F. , Cromwell N. H.
Published: March 2009

Studies of compounds such as 1‐cyclohexyl‐2‐carbomethoxy‐4‐methylazetidine by H‐1 nmr coupling constants, nuclear Overhauser effects, C‐13 steric shifts, and N‐15 nmr support the revised assignment of configuration for cis/trans isomers in a series of N‐alkyl substituted azetidines. The trans isomer displayed spectral characteristics consistent with a planar or nearly planar ring. The cis isomer favors a puckered ring, with major substituents at C‐2 and C‐4 equatorial. Compounds lacking the C‐4 methyl are also puckered. Puckering angles are estimated. In contrast, trans‐1‐cyclohexyl‐2‐carboxy‐4‐methylazetidine (a zwitterion) prefers a puckered ring, possibly implicating the time averaged effect of nitrogen inversion on ring shape. The N‐15 spectra show a large difference in chemical shift between cis and trans isomers of the azetidines, although analogous aziridines show an even larger difference.
Tetracyclic phenothiazines. VI. Attempted pummerer cyclization of 10‐(2‐Keto‐3‐methylsulfinylpropyl)phenothiazine
Authors: Vishwakarma L. C. , Martin A. R.
Published: March 2009

The title compound (3), a β‐ketosulfoxide prepared by a Claisen‐type condensation of ethyl 2‐(10‐phenothiazino)acetate (4) with dimsyl carbanion, was subjected to a variety of catalysts in attempts to achieve a Pummerer cyclization to 1,2‐dihydro‐3‐methylthio‐2‐oxo‐3H‐pyrido[3,2,1‐kl]phenothiazine (2). Although the Pummerer rearrangement product, 10‐(2‐oxo‐3‐hydroxy‐3‐methylthiopropyl)phenothiazine (5), could be obtained in excellent yield under mild conditions, neither it nor the β‐ketosulfoxide could be successfully cyclized under any of the conditions attempted. Instead, phenothiazine, 2‐hyroxy‐3‐(10‐phenothiazinyl)‐2‐propen‐1‐al (7), 3‐(10‐phenothiazinyl)‐1,1‐di(methylthio)propan‐2‐one (8), 3‐(10‐phenothiazinyl)‐1‐methylthiopropan‐2‐one (9) and 10‐phenothiazinylformamide (10) were variously obtained.
Effect of p‐substitution on the spectroscopic properties of 1,2‐dihydro‐4H‐2‐phenyl‐3,1‐benzoxazines
Authors: Saeed Ali A. H.
Published: March 2009

A series of 1,2‐dihydro‐4H‐2‐phenyl‐3,1‐benzoxazines (I) were obtained by condensation of o‐aminobenzyl alcohol and substituted benzaldehyde. The effect of p‐substitution on their spectroscopic properties was investigated by uv and mass spectroscopy.
Synthesis of 3‐(1‐hydroxyalkyl)‐4,5,6,7‐tetrahydroindazole derivatives. Structure determination of N‐alkyl isomers
Authors: Dolmazon René , Gelin Suzanne
Published: March 2009

A novel series of 3‐(1‐hydroxyalkyl)‐4,5,6,7‐tetrahydroindazoles and their 1 and 2‐alkyl‐3‐(1‐hydroxyalkyl)‐or‐3‐(1‐acetoxyalkyl) derivatives were synthesized via condensation between 3‐oxo‐2,3,4,5,6,7‐hexahydrobenzo[b]furans or 2‐(2‐acetoxyacyl)cyclohexanones and hydrazines. Structure assignment are based on 1H and 13C nmr spectra.
An anomalous reaction of 10‐chloro‐5H‐benzoxazolo[3,2‐a]quinolin‐5‐one with sodium diethyl malonate to form 9‐chloro‐8‐ethoxy‐12‐hydroxy‐5H‐dibenz[c,f]quinolizin‐5‐one
Authors: Kim Dong Han
Published: March 2009

Treatment of 10‐chloro‐5H‐benzoxazole[3,2‐a]quinolin‐5‐one (I) with an excess of sodium diethyl malonate at 190° for 3 hours in hexamethylphosphoramide gave, in 38% yield, 9‐chloro‐8‐ethoxy‐12‐hydroxy‐5H‐dibenz[c,f]quinolizin‐5‐one (IV) which, on heating with acetic anhydride, afforded monoacetylated product, V. A possible reaction mechanism for the novel ring expansion reaction is suggested.
Studies on v‐triazoles. Part III. On the nitration of 9‐oxo‐1H,9H‐benzopyrano[2,3‐d]‐v‐triazole
Authors: Buckle Derek R.
Published: March 2009

The nitration of 9‐oxo‐1H,9H‐benzopyrano[2,3‐d]‐v‐triazole (1) leads not to the expected benzenoid substitution product 2 but to initial attack on the triazole moiety resulting in fission to 3‐diazo‐2‐nitrimino‐2H‐[1]benzopyran‐4‐yl oxide (3). Mild hydrolysis of 3 results in cleavage of the nitrimine to give 3‐diazo‐2‐oxo‐2H‐[1]benzopyran‐4‐yl oxide (4). Further nitration of 3 under more forcing conditions leads to the 6‐nitro derivative of 3 which also undergoes facile hydrolysis to a diazocoumarin.
Mass spectra of synthetic mitosenes
Authors: Hodges John , Schram Karl H. , Baker Peter F. , Remers William A.
Published: March 2009

The mass spectral fragmentation of a series of 10 mitosene analogs is described. Major pathways arise through decomposition of the substituents in the 1 and 10 positions and are unaffected by the substituent in the 7 position. The base peak in the spectrum, in most cases, is represented by the basic mitosene ring. The patterns are general for this series of compounds and may have application in elucidating the structure of the DNA alkylation sites involved in reactions with mitosenes or natural mitomycins.
N‐ethoxycarbonylamidines as starting materials and intermediates in the synthesis of heterocyclic compounds
Authors: Dean W. D. , Papadopoulos E. P.
Published: March 2009

Treatment of N‐ethoxycarbonylthioamides (1) with primary aromatic amines yields N‐aryl‐N′‐ethoxy‐carbonylamidines (2), which thermally cyclize to 2‐aryl‐4(3H)‐quinazolinones (6). Analogous reactions of 1 with ethyl 3‐aminocrotonate and with 2‐amino‐2‐thiazoline lead respectively to ethyl 2‐aryl‐3,4‐dihydro‐6‐methyl‐4‐oxo‐5‐pyrimidinecarboxylates (10) and to 2‐aryl‐6,7‐dihydro‐4H‐thiazolo[3,2‐a]‐1,3,5‐triazin‐4‐ones (14), presumably through the corresponding N‐ethoxycarbonylamidines.
Synthesis of 2‐alkoxy‐6‐aryl‐5‐cyano‐4(3H)‐pyrimidinones
Authors: Pérez Miguel A. , Soto José L.
Published: March 2009

The reaction of methyl 3‐aryl‐2‐cyano‐3‐methoxypropenoates 1 with cyanamide and sodium methoxide in methanol afforded after acid hydrolysis the methyl 3‐[(aminocarbonyl)amino]‐3‐aryl‐2‐cyanopropenoates 4. By performing the reaction in higher boiling alcohols the 2‐alkoxy‐6‐aryl‐5‐cyano‐4(3H)‐pyrimidinones 2 were obtained in good yields.
Synthése de nouvelles amidines bicycliques. 1. Dérivés de l'imidazole, du triazole‐1,3,4 et du tétrazole
Authors: Langlois Michel , Guillonneau Claude , Vovan Tri , Meingan Jean‐Pierre , Maillard Jacques
Published: March 2009

Les auteurs décrivent la synthèse de pyrrolo[1,2‐a]imidazoles, pyrrolo[1,2‐c]triazoles et pyrrolo[1,2‐a]tétrazole et quelques homologues contenant un cycle pyridine ou azépine à la place du pyrrole. Ces composés sont obtenus à partir d'amidines cycliques, au moyen de réactions décrites pour d'autres hétérocycles.
Reaction of tetramethyl‐1,2‐dioxetane with triphenylphosphine: Activation parameters for the formation of 2,2‐dihydro‐4,4,5,5‐tetramethyl‐2,2,2‐triphenyl‐1,3,2‐dioxaphospholane
Authors: Baumstark Alfons L. , Barrett Morgan , Kral Kathleen M.
Published: March 2009

The reaction of tetramethyl‐1,2‐dioxetane (1) and triphenylphosphine (2) in benzene‐d6 produced 2,2‐dihydro‐4,4,5,5‐tetramethyl‐2,2,2‐triphenyl‐1,3,2‐dioxaphospholane (3) in ˜90% yield over the temperature range of 6–60°. Pinacolone and triphenylphosphine oxide (4) were the major side products [additionally acetone (from thermolysis of 1) and tetramethyloxirane (5) were noted at the higher temperatures]. Thermal decomposition of 3 produced only 4 and 5. Kinetic studies were carried out by the chemiluminescence method. The rate of phosphorane was found to be first order with respect to each reagent. The activation parameters for the reaction of 1 and 2 were: Ea ≅ 9.8 ± 0.6 kcal/mole; ΔS≠ = −28 eu; k30° = 1.8 m−1sec−1 (range = 10–60°). Preliminary results for the reaction of 1 and tris (p‐chlorophenyl)phosphine were: Ea ˜ 11 kcal/mole, ΔS≠ = −24 eu, k30° = 1.3 M−1sec−1 while those for the reaction of 1 and tris(p‐anisyl)phosphine were: Ea ˜ 8.6 kcal/mole, ΔS≠ = −29 eu, k30° = 4.9 M−1 sec−1.
Radical anions from N,N′‐dimethylisoindigo and its methoxyderivatives
Authors: Bruni P. , Cardellini L. , Cardillo B. , Tosi G.
Published: March 2009

N,N′‐Dimethylisoindigo and four methoxy derivatives have been synthesized and reduced to the corresponding radical anions by t‐BuOK‐DMSO. The epr spectra are reported and discussed.
The preparation of 5‐phenacylisoxazoles and 5‐hydroxyphenyl‐isoxazoles and ‐pyrazoles by the condensation of C(a)‐dianions with ethyl benzoylacetate and methyl salicylate
Authors: Livingston Melanie J. , Chick Marlisa F. , Shealy Ernest O. , Beam Charles F.
Published: March 2009

C(α), O‐Dilithiooximes and C(α), N‐Dilithiophenylhydrazones were prepared in an excess of lithium diisopropylamide (LDA). The former was condensed with ethyl benzoylacetate and methyl salicylate, and the latter condensed with methyl salicylate. The resulting precyclization intermediates were then treated with aqueous acid, which was followed by cyclodehydration to give phenacylisoxazoles and hydroxyphenyl‐isoxazoles and ‐pyrazoles.
Synthesis of benzo[b]phenanthro[d]thiophenes
Authors: Pratap Ram , Lee Milton L. , Castle Raymond N.
Published: March 2009

The synthesis of benzo[b]phenanthro[1,2‐d]thiphene (1), benzo[b]phenanthro[4,3‐d]thiophene (2), benzo‐[b]phenanthro[2,1‐d]thiophene (3) and benzo[b]phenanthro[3,4‐d]thiophene (4) from appropriately substituted olefines by photochemical cyclodehydrogenation is described. The photolysis of olefin 9 gave a mixture of 4 and anthra[1,2‐b]benzo[d]thiophene (5).
Studies on new routes for the synthesis of 4‐ and 5‐aminoimidazole nucleoside derivatives
Authors: García‐Lopez M. Teresa , Herranz Rosario
Published: March 2009

The synthesis of urethane protected 4‐ and 5‐aminoimidazole nucleoside derivatives 4 and 9 by two different routes is described. These routes are transformation of the carboxylate substituted imidazole nucleoside 1 via a Curtius rearrangement to give 4 and direct ribosylation of the imidazole base 6 to give a mixture of positional isomers 7 and 8, which by deacetylation afford 4 and 9, respectively. The convenience of each route depended on the positional isomer to be synthesized.
Chemistry of the phenoxathiins and isosterically related heterocycles. XX. Assignment of the 13C‐NMR spectra of phenarsazine‐10‐chloride and several substituted analogs. The effect of substitution on the anisotropic reorientation of the phenarsazine system
Authors: Jay Michael , Martin Gary E.
Published: March 2009

The total assignment of the 13C‐nmr spectra of phenarsazine‐10‐chloride and several substituted analogs is reported. Spin‐lattice (T1) relaxation measurements have shown these systems to reorient anisotropically. In the case of the parent system and the 3‐chloro substituted system, the axis of anisotropic reorientation has been shown to pass approximately through the center of the molecule. In the case of benzo[c]phenarsazine‐7‐chloride, the axis of anisotropic reorientation, which has been accurately defined, is shifted 23° from that in the previous cases, the shift occurring in the direction of the benzo‐moiety.
Les systèmes biphasiques. 3. Alkylation des purines en catalyse par transfert de phase
Authors: Hedayatullah Mir
Published: March 2009

La méthylation de l'adénine en catalyse par transfert de phase fournit sélectivement la méthyl‐9 adénine (98%), tandis que sa benzylation conduit à la benzyl‐9 adénine comme produit majoritaire à cǒté de très faibles quantités de benzyl‐3 adénine. L'alkylation de la xanthine, de la théobromine et de la théophylline par la měme technique donne naissance aussi aux dérives N‐alkylés correspondants avec de hauts rendements à l'exclusion de tout autre régioisomere O‐alkylé. Cette technique d'alkylation constitue, tant par sa simplicité que par sa sélectivityé, une amélioration considerable des méthodes conventionnelles.
Synthèse de triazolo‐1,2,3 nucléosides par cycloaddition entre azotures de glycosyle et acétyléniques ativés
Authors: Chrétien Francoise , Gross Bernard
Published: March 2009

Cette note traite d'une nouvelle méthode de préparation d'azotures de glycosyle sur lesquels la cycloaddition de composés acétyléniques activés pour donner des triazolo‐1,2,3 nucléosides a été améliorée. Ceci a été réalisé en séries allo‐, ribo‐ et arabinofurannoses et mannopyrannose avec le propiolate de méthyle et l'acetylene dicarboxylate d'éthyle.
Sur l'orientation et les anomalies de l'acetylation des Bz‐méthoxy nitro‐2 benzofurannes
Authors: Clavel Jean‐Marc , Guillaumel Jean , Demerseman Pierre , Royer Rene
Published: March 2009

Alors que le nitro‐2 benzofuranne lui‐měme n'a pu ětre acétylé selon Friedel et Crafts, ses derives meth‐oxyles en 4, en 5 ou en 7 sont susceptibles de l'ětre, dans des conditions expérimentals adaptees a chaque cas. Ils donnent ainsi, respectivement, les acétyl‐7 méthoxy‐4 nitro‐2 benzofuranne acetyl‐4 méthoxy‐5 nitro‐2 benzofuranne et acétyl‐4 méthoxy‐7 nitro‐2 benzofuranne.

Il se forme en měme temps de la dihydro‐2,3 méthoxy‐4 (méthoxy‐4′ nitro‐2′ benzofuryl‐7′)‐3 benzofurannone‐2 a partir du méthoxy‐4 nitro‐2 benzofuranne et de la chloro‐3 dihydro‐2,3 méthoxy‐5 benzofurannone‐2 à partir du méthoxy‐5 nitro‐2 benzofuranne. Celui‐ci subit en outre une chloration tout à fait singuliére en position 4.

Quant au méthoxy‐6 nitro‐2 benzofuranne, il ne peut ětre acétyle sans decomposition dans les měmes con‐ditions que ses isoméres méthoxylés en 4, en 5 ou en 7.
Preparation of some 4H‐1,3,2‐benzothioxaborine and 1H,4H‐1,3,2‐benzazoxaborine
Authors: Bernard Angela Maria , Cocco Maria Teresa , Plumitallo Antonio , Secci Mario
Published: March 2009

The preparation of some 2‐substituted‐4H‐1,3,2‐benzothioxaborine and 2‐substituted‐1H,4H‐1,3,2‐benzazoxaborine is described.
Natural benzofurans: Synthesis of isopterofuran
Authors: Scannell Ralph T. , Stevenson Robert
Published: March 2009

A synthesis of the fungistatic phytoalexin, isopterofuran is described. In the key step, the benzofuran heterocycle is constructed by reaction of an o‐iodophenol with a cuprous arylacetylide.
Synthesis of 2‐S‐dioxo isosteres of purine and pyrimidine nucleosides. II
Authors: Fernández‐Resa Piedad , Stud Manfred
Published: March 2009

The preparation of glucosyl and ribosyl derivatives of 3,4,5‐triamino‐2H‐1,2,6‐thiadiazine 1,1‐dioxide (2), 7‐amino‐4H‐furazano[3,4‐c]‐ and 7‐amino‐1H, 4H‐imidazo[2,3‐c][1,2,6]thiadiazine 5,5‐dioxide (3 and 4 respectively) is described. Different synthetic approaches have been used.
Synthesis of 6‐(2‐nitrobenzyl)‐3,5‐dioxo‐2,3,4,5‐tetrahydro‐as‐triazine and some derivatives
Authors: Hajpál István , Berenyi Edit
Published: March 2009

6‐(2‐Nitrobenzyl)‐3,5‐dioxo‐2,3,4,5‐tetrahydro‐as‐triazines were prepared as intermediates for investigations aimed at the synthesis of as‐triazino[5,6‐b]quinolines. The substances were obtained by new methods based on the elucidation of stereochemical conditions.