bluuebunny/crossref_metadata_2025 huggingface dataset:
A new one‐step synthesis of 2,3‐dihydro‐5H‐thiazolo[2,3‐b]quinazolin‐5‐one and 3,4‐dihydro‐2h,6h[1,3]thiazino[2,3‐b] quinazolin‐6‐one
Authors: Payne L. G. , Przytycki J. , Patchett A. A. , Wu M. T.
Published: April 2009

2,3‐Dihydro‐5H‐thiazolo[2,3‐b]quinazolin‐5‐one and 3,4‐dihydro‐2H,6H[1,3] thiazino[2,3‐b]‐quinazolin‐6‐one have been synthesized in one step by the reaction of methyl anthranilate with ehloroalkyl isothiocyanates.
Synthèse d'amino‐4 aryl‐3 triazol‐1,2,4 ones‐5
Authors: Milcent René , Redeuilh Catherine
Published: April 2009

La synthèse des arnino‐4 aryl‐3 triazol‐1,2,4 ones‐5 a été réalisée par quatre méthodes: a partir du carbohydrazide par reactions avec les chlorhydrates d'aryliminoéthers, l'orthobenzoate d'éthyle ou le trichlorophénylméthane, et aussi à partir du N‐carbéthoxyhydrazone du benzoate d'éthyle et de ses dérivés par réaction avec l'hydrazine. Les mécanismes de ces reactions sont proposés; ils ont en commun la formation d'un intermédiaire, la monocarbohydrazone du benzoate d'éthyle. Les spectres ir, uv, rmn de ces hétérocycles sont discutés.
A new simple synthesis of 1,4‐benzodiazepines
Authors: Sugasawa T. , Adachi M. , Toyoda T. , Sasakura K.
Published: April 2009

A convenient synthesis of 1,4‐benzodiazepines starting from secondary‐2‐aminobenzhydrols, which are easily obtained from secondary anilines and benzaldehydes, is described. 7‐Nitro‐1‐methyl‐1,4‐benzodiazepine 1d can be formed from 5‐nitro‐2‐methylaminomethylacylaminobenzo‐phenone 10b and c by using ammonium carbonate instead of ammonia, which gives only the Smiles‐rearranged product 11.
Application of photoelectron spectroscopy to biologically active molecules and their constituent parts IV. Methylnitroimidazoles
Authors: Kajfež F. , Klasinc L. , Šunjić V.
Published: April 2009

Photoelectron (PE) spectra of imidazole (1), 1‐methylimidazole (2), 2‐methylimidazole (3), 4(5)‐nitroimidazole (4), 2‐methyl‐4(5)nitroimidazole (5), 1,2‐dimethyl‐5‐nitroimidazole (6), 1‐ethyl‐2‐methyl‐5‐nitroimidazole (7), 1‐bromoethyl‐2‐methyl‐5‐nitroimidazole (8) and 1‐hydroxyethyl‐2‐methyl‐5‐nitroimidazole (9) have been recorded using Hel excitation. The electronic structure of the potent antitrichomonal agent 9 is discussed in comparison with compounds 1–8 allowing for the study of the influence of substituents on the imidazole ring.
The insertion and extrusion of heterosulfur bridges. X. Conversions in the triphenylene‐triphenylo[4,5‐bcd] thiophene system
Authors: Klemm L. H. , Lawrence Ross F.
Published: April 2009

Sulfur bridging of triphenylene (3) to form triphenylo[4,5‐bcd]thiophene (4) is effected in 18% yield by means of hydrogen sulfide and a molybdena catalyst (CMA‐1) at 500°. Compound 4 is purified through its sulfoxide, converted into its sulfone (6), and desulfurized (by means of CMA‐1 plus methanol‐benzene) back to 3. The ultraviolet absorption spectrum of 4 resembles closely that of benzo[e]pyrene. On electron impact 4 shows little skeletal fragmentation, while 6 readily evolves sulfur monoxide and the formyl group.
Synthesis of 4‐aminothieno[2,3‐b] pyridine‐5‐carboxylie acids
Authors: Lalezari Iradj
Published: April 2009

2‐Amino‐3‐cyanothiophenes were reacted with ethyl aminocrotonate in the presence of catalytic amounts of p‐toluensulfonic acid. The intermediates 2‐[N‐(3′‐ethoxycarbonyl‐2′‐propenylamino]‐3‐cyanothiophenes obtained were cyclized with sodium ethoxide to give the desired ethyl 4‐aminothieno[2,3‐b] pyridine‐5‐carboxylate. Hydrolysis of the latter aminoesters afforded 4‐aminothieno[2,3‐b]pyridine‐5‐carboxylic acid. The overall yields were about 80%.
Hydrolysis of amides. Electronic effects on kinetics and mechanism of the basic hydrolysis of TV‐substituted benzoylpyrroles
Authors: Cipiciani A. , Linda P. , Savelli G.
Published: April 2009

The hydroxide ion catalyzed hydrolysis of a series of N‐substituted benzoylpyrroles has been studied in water at 25°. Hammett treatment of data shows that substituents affect in a very similar way the rate of formation and of decomposition of the tetrahedral intermediate.
Hydrolysis of amides. Steric effects on kinetics and mechanism of the basic hydrolysis of N‐acylcarbazoles
Authors: Cipiciani A. , Linda P. , Savelli G.
Published: April 2009

The hydroxide ion catalyzed hydrolysis of a series of N‐acylcarbazoles has been studied in water at 25°. Both the rate constants of formation of the tetrahedral intermediate and of its collapse to products are strongly increased by alkyl group branching in the acyl portion.
1,3‐Dipolar cycloadditions of cyclopentadienones with nitrile TV‐oxides
Authors: Argyropoulos N. G. , Alexandrou N. E.
Published: April 2009

The cycloaddition reactions of nitrile oxides with several substituted cyclopentadienones leads to the formation of condensed mono‐isoxazolines (3α,5‐bis‐substituted‐6,6α‐diphenyl‐3αH,4H,6αH‐cyclopenta[2,3‐d]isoxazol‐4‐ones) and in some cases to bis‐isoxazoline derivatives as minor products. The cycloaddition to mono‐adducts is regioselective and only one regioisomer is formed, which can be predicted after consideration of the frontier molecular orbitals of the reacting species. The spectral data of the isoxazolines 3–7 are examined, whereas their structure was fully characterized by X‐ray analysis.
Heterocyclic compounds. XVI . Chemistry of the 1,4,2,3,5,6‐dithiatetrazine ring system
Authors: Weinstein Boris , Hahn Louis T. , Eng Alvin K.
Published: April 2009

Derivatives of 1,4,2,3,5,6‐dithiatetrazine‐2,3,5,6‐tetracarboxylate 1,4‐dioxide can be made by reacting 1,2‐dialkyl hydrazinodicarboxylates with thionyl chloride.
Oxidation of aminoindole radical cations
Authors: Bruni P. , Cardellini L. , Fava G. , Tosi G.
Published: April 2009

The varying stabilities of certain aminoindole radical cations toward oxidation with molecular oxygen have been studied. Oxidation leads to different products depending upon the environment around the N‐amino nitrogen. A plausible reaction mechanism is proposed based on electronic and magnetic resonance spectroscopy.
Synthesis and photolysis of doxyl derivatives of 5β‐androstan‐3‐ones
Authors: Smith Douglas L. , Spencer Thomas A.
Published: April 2009

In an unsuccessful attempt to effect remote functionalization at C9, 4,4‐dimethyloxazolidine‐N‐oxyl (doxyl) derivatives at C3 of 5β‐androstan‐3,17‐dione and 5β‐androstan‐17β‐ol‐3‐one were prepared and photolyzed. The former doxyl yielded its C13 stereoisomer; the latter was converted very slowly to intractable material.
Synthesis and stereochemistry of 2‐benzylidene‐4‐carbethoxy‐5‐methyl‐3‐(2H)‐furanones
Authors: Pitta Ivan da Rocha , Lacerda Maria do Socorro , Duc Cuong Luu
Published: April 2009

The title products were obtained by Knoevenagel condensation between 4‐carbethoxy‐5‐methyl‐3‐(2H)furanone and substituted benzaldehydes (or 4‐chloroacetophenone). The configuration of the resulting compounds was investigated by 1H nmr using the lanthanide shift reagent.
A new method for the oxidation of 2‐Keto‐1,2,3,4‐tetrahydro‐quinoxaline, investigations on the complex formed between 2‐hydroxyquinoxaline and cuprous chloride
Authors: Borthakur Naleen , Bhattacharya Alok K. , Prasad Rajendra , Garg Avinash , Rastogi Ramesh C.
Published: April 2009

2‐Keto‐1,2,3,4‐tetrahydroquinoxaline I is rapidly oxidised to 2‐hydroxyquinoxaline II on reaction with cupric chloride. This is an oxidation‐reduction reaction in which the cupric chloride in the process is reduced to cuprous chloride. The latter instantaneously reacts with II forming an insoluble brick red complex. Compound II can be regenerated from the complex by treatment with alkali. The properties of this new complex are discussed.
The synthesis of 1‐cyclohexyl‐2‐phenyl‐3‐nitroaziridine and the stereochemistry of cyclization
Authors: Edasery James P. , Cromwell Norman H.
Published: April 2009

The title compound was synthesized by the cyclization of α,β‐dibromonitrostyrene with three moles of cyclohexylamine. Evidence for the steric course of the cyclization reaction is also reported.
Heterocycles from substituted semicarbazides and thionyl chloride. 1‐oxo‐1, 2,3,5‐thiatriazolidin‐4‐one
Authors: Ziman S. D.
Published: April 2009

Reaction of thionyl chloride and semicarbazides or thiosemicarbazides produces the novel 1‐oxo‐1,2,3,5‐thiatriazolidin‐4‐one or 4‐thione ring system.
A new method for the preparation of 2‐carhoalkoxypyrazolo [5,1 ‐B] quinazolin‐9(1H)ones
Authors: Beam Charles F. , Brown Jane , Dawkins Donna R. , Fives William P. , Fleindel Ned D.
Published: April 2009

Anthranilic acid hydrazides were condensed with acetylene diesters, and the intermediate adduets were identified as aeylhydrazones of oxalacetic diester. These anthranilic hydrazones could be thermally cyclized to 2‐carboalkoxypyrazolo[5,1‐b] quinazolin‐9(1H)ones.
Réduction alkylante de quelques composés hétéroaromatiques polyazotés
Authors: Costnao Jean‐Marie , Collision Noéul , Quéaguiner Gay
Published: April 2009

La réduction alkylante de la quinoxaline, de la phlalazine et de la pyrido[2,3‐b] pyrazine, par le tétrahydruroborate de potassium en présence d'acide carboxylique est décrite. Les acides formique, acétique, chloroacétique et n‐propionique sont utilisés, Généralement la réduction et l'alkylation concernent le cycle diazinique du substrat, conduisant au dérivé tétrahydro‐di‐N‐alkylé correspondant. Avec le couple quinoxaline‐acide formique, la réaction de N‐formylation peut devenir prépondérante. L'utilisation de tétradeutérioborate de sodium a permis d'isoler un dérivé héxadeutérié.
A novel reaction of thionyl chloride with 3‐aryl‐2,1‐benzisoxazoles
Authors: Boruah Romesh Chandra , Sandhu J. S. , Thyagarajan G.
Published: April 2009

Novel reductive chlorination of 3‐aryl‐2,1‐benzisoxazoles with thionyl chloride is described.

The chlorinated aminobenzophenones have been characterised.
Synthesis of some new fluorine‐containing 5‐amino‐1,3‐disubstituted pyrazoles and 1H‐pyrazolo[3,4‐b]pyridines
Authors: Joshi Krishna C. , Pathak Vijai N. , Garg Urmila
Published: April 2009

Nine new fluorine containing 5‐amino‐1,3‐disubstituted pyrazoles have been synthesized and characterized by spectral studies. Condensation reactions of these 5‐amino‐1,3‐disubstituted pyrazoles with fluorinated 1,3‐diketones in the presence of glacial acetic acid have been studied and the structures of the resulting 1H‐pyrazolo[3,4‐b]pyridines have been confirmed by ir, pmr and 19F nmr spectral studies.
The synthesis of di‐ and tetramethyl substituted macrocyclic polyether‐diester ligands
Authors: Bradshaw Jerald S. , Jolley Scott T.
Published: April 2009

Three series of macrocyclic polyether‐diester ligands have been prepared from dimethyl triethylene glycol (20), two dimethyl tetraethylene glycols (21,23), dimethyl pentaethylene glycol (22) and tetramethyl tetraethylene glycol (24) and diglycolyl chloride (products 5–9), thiadiglycolyl chloride (products 10–14) and 2,6‐pyridine dicarbonyl chloride (products 15–19). The eighteen‐membered rings (6 and 16) formed solid potassium thiocyanate complexes. The eighteen‐ and twenty‐one‐membered ring compounds 6–8 and 16–18 complexed with benzylammonium perchlorate in methylene chloride‐d2 as shown by significant chemical shift changes in the 1H nmr spectra.
Condensed pyridazines. Part III. Rearrangement and ring cyclization during the thermolysis of (z)‐methyl 3‐(6‐azido‐3‐chloro‐1‐methyl‐4‐oxo‐1,4‐dihydropyridazin‐5‐yl)‐2‐methylacrylate
Authors: Maeba Isamu , Castle Raymond N.
Published: April 2009

The thermolysis of (Z)‐methyl 3‐(6‐azido‐3‐chloro‐1‐methyl‐4‐oxo‐1,4‐dihydropyridazin‐5‐yl)‐2‐methylacrylate (II) provides a new synthetic route to pyrrolo[2,3‐c‐]pyridazines, specifically, methyl 3‐chloro‐1,6‐dimethyl‐4‐oxo‐1,4‐dihydro‐7H‐pyrrolo[2,3‐c]pyridazine‐5‐carboxylate (III) in 91% yield. Treatment of III with ozone provides an entry into the novel pyridazino[3,4‐d][1,3]oxazine ring system, specifically, 3‐chloro‐1,7‐dimethylpyridazino[3,4‐d][1,3]oxazine‐4,5‐dione (IV) in 73% yield. Compound IV is smoothly hydrolyzed into 6‐acetylamino‐3‐chloro‐1‐methyl‐4‐oxo‐1,4‐dihydropyridazine‐5‐carboxylic acid (V) which is readily recyclized into IV by dehydration with acetic anhydride. Furthermore, IV undergoes a facile reductive ring opening reaction with sodium borohydride to give 3‐chloro‐6‐ethylamino‐1‐methyl‐4‐oxo‐1,4‐dihydropyridazine‐5‐carboxylic acid (VI) in 95% yield.
Ir and pmr spectra of 2‐aryl‐4‐thiazolidinones. III. Stereochemical analysis of 2‐aryl‐3‐(2‐pyridyl)‐4‐thiazolidinones
Authors: Vigorita M. G. , Chimirri A. , Grasso S. , Fenech G.
Published: April 2009

The long‐range coupling through the sulphur atom observed in a number of 2‐aryl‐3‐(2‐pyridyl)‐4‐thiazolidinones suggests that the C2 proton and one of methylene protons are in a cis 1,3 diequatorial relationship. Some additional information concerning the preferred orientations of the substituents in this system are given from Eu(fod)3, [tris(1,1,1,2,2,3,3‐heptafluoro‐7,7‐dimethyloctane‐4,6‐dionato)]europium, induced shift data.
Chemistry of thienopyridines. XXVI. Synthesis of 6‐(γ‐diethylaminopropylamino)thieno[2,3‐b]pyridine
Authors: Klemm L. H. , Bajer Marietta
Published: April 2009

6‐(γ‐Diethylaminopropylamino)thieno[2,3‐b]pyridine (3b) was obtained (58% yield) from copper‐promoted aminodechlorination of 6‐chlorothieno[2,3‐b]pyridine at 168°. A mechanistic rationalization for the reaction and the mass spectral fragmentation pattern for 3b are presented.
Carbon‐13 nuclear magnetic resonance spectra of phenycyclidine analogs
Authors: Brine G. A. , Williams E. E. , Boldt K. G. , Carroll F. I.
Published: April 2009

Natural abundance carbon‐13 chemical shifts are reported for the hydrochloride salts of phencyclidine (1a) and sixteen analogs. The signals are assigned on the basis of chemical shift theory, SFORD multiplicities, signal intensities, and comparisons with model compounds. In addition to its forensic value, the data suggests that the solution conformations of the analogs are similar to that of phencyclidine hydrochloride.
Synthesis of 1,2‐dialkyl‐4‐pyrazolidinols
Authors: Kornet Milton J. , Daniels Ralph
Published: April 2009

Condensation of 1,2‐dialkylhydrazines with epichlorohydrin affords 1,2‐dialkyl‐4‐pyrazolidinols in moderate yield.
Selenium heterocycles. XXVIII . Synthesis of pyrrolo[3,2‐d]selenazole and pyrrolo[3,2‐d|thiazole. Two novel heterocycles
Authors: Shafiee A. , Mazloumi A. , Cohen V. I.
Published: April 2009

Starting from the readily available 2‐substituted‐4‐formylselenazoles and 2‐substituted‐4‐formylthiazoles, a series of substituted‐pyrrolo[3,2‐d]selenazoles and substituted‐pyrrolo[3,2‐d|‐thiazoles were prepared respectively.
An attempt to convert heterocyclic amines into azides by an aza‐transfer reaction under phase‐transfer reaction conditions
Authors: Stanovnik B. , Tišler M. , Gabrijelčič D. , Kunaver M. , Žmitek J.
Published: April 2009

The conversion of heterocyclic amines into the corresponding azides or tetrazoloazines under phase transfer reaction conditions is described. It was found that this transformation is limited ordy to aminopyridine (1a‐d) aminoisoquinoline (1e) and 2‐aminobenzothiazole (1f) derivatives, while other heterocyclic amines (1g‐w) could not be transformed under these conditions.
Rotenoid interconversion. Synthesis of elliptone from rotenone
Authors: Anzeveno Peter B.
Published: April 2009

The preparation of (—)‐elliptone (5) from (—)‐rotenone (1) via (—)rot‐2′‐enonie acid (2) is described.
A simple one‐step synthesis of 3‐amino‐2,4(1H,3H)quinazolinediones
Authors: Lalezari Iraj , Stein C. A.
Published: April 2009

Anthranilic acids and alkyl carbazates in refluxing quinoline give high yields of 3‐arnino‐2,4(1H,3H)‐quinazolinediones.
Acylation reaction of γ,β‐unsaturated β‐keto esters and of ethyl hydrogen malonate. Synthesis of 6‐alkenyl‐5‐ethoxycarbonyl‐2,3‐dihydro‐4H‐pyran‐4‐ones and 4,5‐dioxo‐2,3,7,8‐tetrahydro‐4H,5H‐pyrano[4,3‐b]pyran derivatives
Authors: Chantegrel Bernard , Nadi Abdel‐Ilah , Gelin Suzanne
Published: April 2009

The syntheses of 6‐alkenyl‐5‐ethoxycarbonyl‐2,3‐dihydro‐4H‐pyran‐4‐one derivatives by acylation of γ,β‐unsaturated β‐keto esters or by diacylation of ethyl hydrogen malonate with α,β‐unsaturated acyl chlorides are described. These compounds were converted to 4,5‐dioxo‐2,3,7,8‐tetrahydro‐4H,5H‐pyrano[4,3‐b]pyran derivatives.
The reformatsky reaction of 1‐aryl‐2(1H)pyrimidinones
Authors: Katoh Akira , Omote Yoshimori , Kashima Choji
Published: April 2009

1‐Aryl‐2(1H)pyrimidinones I reacted with α‐haloesters in the presence of zinc to give mainly 3,4‐dihydro‐4‐alkoxycarbonylmethyl‐1‐aryl‐2(1H)pyrimidinones IV in addition to the minor products of 3,6‐dihydro‐6‐alkoxycarbonylmethyl‐1‐aryl‐2(1H)pyrimidinones V. Further, 3,4‐dihydro derivatives IVa‐c were successfully converted into the corresponding exomethylene compounds Vla‐c in high yields.
Selenium‐sulfur analogs. 7. Synthesis and characterization of 4‐aralkyl‐1,3‐selenazoles and ‐1,3‐thiazoles
Authors: Hanson Robert N.
Published: April 2009

The diketones 3 and 7 were brominated to give the bromomethyldiketones 4 and 8 which were condensed with selenourea and thiourea to give the corresponding 2‐amino‐1,3‐selenazoles 5a, 9a and 2‐amino‐1,3‐thiazoles 5b, 9b. Reaction with acetic anhydride and benzoic anhydride yielded the 2‐acylated derivatives. Biologic evaluation of these compounds indicated some activity as adrenocortical enzyme inhibitors, but significantly less than that of metyropone.
Synthesis and structure elucidation of 3‐methoxy‐1‐methyl‐1H‐1,2,4,‐triazol‐5‐amine and 5‐methoxy‐1‐methyl‐1H‐1,2,4,‐triazol‐3‐amine
Authors: Selby T. P. , Lepone G. E.
Published: April 2009

Previously it was shown that condensation of dimethyl N‐cyanodithioimidocarbonate (1a) with methylhydrazine gave predominantly 1‐methyl‐5‐methylthio‐1H‐,2,4‐triazol‐3‐amine (2), which was initially identified erroneously as the regioisomer l‐methyl‐3‐methylthio‐1H‐1,2,4‐triazol‐5‐amine (3). We have found that reaction of dimethyl N‐cyanoimidocarbonate (1b) with methyl hydrazine affords a high yield of 3‐methoxy‐1‐methyl‐1H‐1,2,4‐triazol‐5‐amine (4) rather than the regioisomer 5‐methoxy‐1‐methyl‐1H‐1,2,4‐triazol‐3‐amine (5). The structure assignment of 4 was confirmed by X‐ray crystallographic analysis of the benzenesulfonyl isocyanate adduct 7. Triazole 5 was obtained after reacting dimethyl N‐cyanothioimidocarbonate (1c) with methylhydrazine.
Dihydropyrimidines and related structures. I. N2‐substituted 2‐pyrimidinamines and dihydro‐2‐pyrimidinamines by reaction of phenylbutenones and monosubstituted guanidines
Authors: Wendelin Winfried , Schermanz Karl
Published: April 2009

The reactions of monosubstituted guanidines 2 with phenylbutenones 7 and 10 exclusively yield N2‐substituted 2‐pyrimidinamines 8 and 9. The structure of the reaction products is proved and their differing stability is discussed. Action of methyl‐ and benzylguanidine respectively (2b, c) on 4‐phenyl‐3‐buten‐2‐one (7) and of 2c on l‐phenyl‐2‐buten‐1‐one (10) under atmospheric oxygen affords aromatic N2‐substituted 2‐pyrimidinamines 9b and c. The dihydropyrimidines 8b and c, probable intermediates of the reactions, could not be isolated. In contrast, heating of arylguanidines 2d, e with 7 leads to stable dihydropyrimidinarnines 8d and e, which can be isolated as bases. Addition of methanol to 8d yields 6‐methoxy‐2‐pyrimidinamine 11d, boiling of 8d in DMF affords 9d. Under nitrogen, guanidine adds to 7 to yield aminopyrimidinol 13a, which is transformed by heating in benzene into pyrimidine 9a. The low stability of 8a‐c is attributed to their strong basicity, the greater stability of 8d and e to their lower basicity. The structural formulae of 8d, e and 9b‐d and their salts respectively were established partly (8e) by nmr and partly (9b‐d) by comparison of the corresponding picrates with authentic samples [17].
The reactivity of 4‐hydroxy‐6‐methyl‐2‐pyrone towards aliphatic saturated and α,β‐unsaturated aldehydes
Authors: de March P. , Moreno‐Mañas M. , Casado J. , Pleixats R. , Roca J. L. , Trius A.
Published: April 2009

4‐Hydroxy‐6‐methyl‐2‐pyrone (triacetic acid lactone) reacts at C‐3 with 2‐butenal and similar aldehydes by Michael addition. The nonisolated intermediates can undergo transformations in at least five different ways. On the contrary, reaction of the title pyrone with cinnamaldehyde occurs at the carbonyl group of the aldehyde.
The oxidation of 1‐alkyl(aryl)quinolinium chlorides with rabbit liver aldehyde oxidase
Authors: Angelino S. A. G. F. , Van Valkengoed B. H. , Buurman D. J. , Van Der Plas H. C. , Müller F.
Published: April 2009

1‐Alkyl(aryl)quinolinium chlorides are oxidized by rabbit liver aldehyde oxidase at positions C‐2 and C‐4. The site and the maximum rate of oxidation are dependent on the size and the steric conformation of the N‐1 substituent. The presence of a 3‐carboxamido group directs the oxidation completely to position C‐4, irrespective of the size of the N‐substituent. Application of covalent amination in liquid ammonia as an “enzyme model” for the oxidation of these compounds shows little resemblance.
A versatile approach to analogues of the cannabinoid‐like anti‐emetic nonabine (BRL 4664)
Authors: Gardner Derek V. , Miller David
Published: April 2009

Analogues of the cannabinoid‐like anti‐emetic nonabine (BRL 4664), in which the 4‐pyridinyl and 1,2‐dimethylheptyl groups have been replaced by other aryl and alky groups respectively, have been synthesised from the appropriate resorcinol by a novel procedure. The route has been shown to be of general applicability, although in the case of nonabine itself the procedure does not represent a viable alternative to that previously published.
Synthesis and antibacterial activity of 2‐phenyl‐4H‐benzo[b]thiopyran‐4‐ones (Thioflavones) and related compounds
Authors: Nakazumi Hiroyuki , Ueyama Tamio , Kitao And Teijiro
Published: April 2009

A number of 2‐phenyl‐4H‐benzo[b]thiopyran‐4‐ones (thioflavones) and related compounds have been prepared to test their antibacterial activity. The flavone derivatives were also prepared to compare with their antibacterial activity. It was found that hydroxythioflavones were easily prepared by demethylation of methoxythioflavones with aluminium chloride. In the test of antimicrobial activity, methoxy‐ or hydroxythioflavones were found to be inactive. It is suggested that the sulfone or sulfoxide of thioflavone is required for antimicrobial activities against yeast funguses and molds. These thioflavone derivatives exhibit low acute toxicity.
Voies d'accès aux bisaminopyrimidines pontées par une chaine polyméthylenique
Authors: Menichi Gabriel , Hubert‐Habart Michel
Published: April 2009

Seules parmi les produits isomères possibles les N(2),N'(2′) α,ω alcanediylbis(amino‐2 pyrimidines) sont formées lorsque des polyméthylènebisguanidines sont condensées avec l'éthoxyméthylènemalonate d'éthyle, la méthyl‐3 chromone, la flavone, l'acétylacétaldéhyde diméthylacétal, et l'acétyl‐3 éthyl‐2 benzofuranne.
13C NMR spectra and carbon‐proton coupling constants of various methylangelicins
Authors: Rodighiero P. , Manzini P. , Pastorini G. , Guiotto A.
Published: April 2009

The 13C‐nmr spectra of various methyl derivatives of angelicin are reported. The assignment of chemical shifts for all the C atoms has been achieved by using carbon‐proton coupling constants, nuclear Overhauser effect consideration and shift effects caused by the introduction of methyl groups on various positions of the angelicin nucleus. Substituent effects on 13C chemical shifts and carbon‐proton coupling constants are discussed.
A convenient and efficient conversion of diethyl [[[2‐(3‐ or 4‐pyridinyl)‐4‐pyrimidinyl]amino]methylene]propanedioates to higher homologs by base‐catalysed transesterification
Authors: Singh Baldev
Published: April 2009

Base‐catalysed transesterification of diethyl [[[2‐(3‐ or 4‐pyridinyl)‐4‐pyrimidinyl]amino]methylene]propanedioates gave higher homolog esters in high yields.
Stereospecific synthesis of new 5‐substituted 6‐methyl‐4,5‐dihydro‐2H‐pyridazin‐3‐ones. X‐ray assignment study
Authors: Taoufik J. , Couquelet J. D. , Couquelet J. M. , Carpy A.
Published: April 2009

Reaction of hydrazine hydrate with 4,5‐dihydro‐3H‐4‐acetyl furan‐2‐ones I led to ring opening and rearrangement into 6‐methyl‐4,5‐dihydro‐2H‐pyridazin‐3‐ones II (1–20), the structure of which was determined by spectroscopic methods (ir, 1H and 13C nmr). An X‐ray crystal structure study of compound 2 supports the assignment of configuration erythro (5RS, 7SR) for pyridazinones II. Stereochemical courses of this new synthetic route are discussed.
2,1‐benzisothiazoles. XIII. Intermediates and products in the sulfur extrusion reaction of 2,1‐benzisothiazolin‐3(1H)‐one. A new synthesis of 11H‐pyrido[2,1‐b]quinazolin‐11‐one (“pyracridone”)
Authors: Davis Michael , Hook Robert J. , Wu Wen Yang
Published: April 2009

Triethyl phosphite abstracts sulfur from 2,1‐benzisothiazolin‐3(1H)‐one (1); a reaction intermediate is the spirocyclic compound 11, and products include the benzoxazine 6 and polyanthraniloyl compounds. In the presence of pyridine, pyracridone (13) is formed. The ketene‐imine 9 is probably not an intermediate in these reactions. The reactions of other nucleophiles with 1 and with its N‐methyl derivative 15, have been examined.
Synthesis of isomeric β‐haloethylthienopyrroles
Authors: Gálvez C. , García F.
Published: April 2009

The preparation of ethyl 4‐(2‐bromoethyl)thieno[2,3‐b]pyrrole‐5‐carboxylate and ethyl 6‐(2‐bromoethyl)thieno[3,2‐b]pyrrole‐5‐carboxylate by reaction of t‐butyl 2‐(2‐thienyl)carbazate and t‐butyl 2‐(3‐thienyl)carbazate with ethyl‐5‐bromo‐2‐oxopentanoate are described.
Reactivity of 1H‐pyrrolo[2,3‐b]pyridine. II. Synthesis of 3‐(β‐haloethyl)‐7‐azaindole
Authors: Gálvez C. , Viladoms P.
Published: April 2009

The preparation of 3‐(2‐chloroethyl)‐7‐azaindole and 3‐(2‐bromoethyl)‐7‐azaindole are described.
Reissert compound studies. XLV. The phenanthridine reissert compound
Authors: Kant Joydeep , Popp Frank D.
Published: April 2009

A series of phenanthridine Reissert compounds and Reissert analogs have been prepared using the trimethylsilyl cyanide method. The reactions of the conjugate base and fluoroborate salt have been studied and found, generally, to be similar to those of the isoquinoline Reissert compounds.
Fused‐s‐triazino heterocycles. XI. Displacement reactions of 7,9‐dichloro‐2,5‐bis(trichloromethyl)‐1,3,4,6,9b‐pentaazaphenalene
Authors: Shaw John T. , Rapple Rodney S. , Hicks John C. , Vossers John T.
Published: April 2009

The preparation of 7,9‐dichloro‐2,5‐bis(trichloromethyl)‐1,3,4,6,9b‐pentaazaphenalene (1e) by the chlorination of 2‐trichloromethyl‐5‐methyl‐1,3,4,6,9b‐pentaazaphenalene (1a) using molecular chlorine is described. Displacement of one or both trichloromethyl groups of 1e by a variety of nucleophiles led to the corresponding 7,9‐dichloro‐2,5‐bis‐substituted or 7,9‐dichloro mixed 2,5‐disubstituted derivatives. The reaction of 1a with N‐chlorosuccinimide proved not to be a useful route to 1e but instead led primarily to substitution of positions 7 and/or 9 by chlorine.
Hétérocycles dioxinniques. Nouvelle méthode de synthèse des benzo (4H) dioxinnes‐1,3
Authors: Denis Alain , Delmas Michel , Gaset Antoine
Published: April 2009

La condensation de phénols diversement substitués avec le paraformaldéhyde est étudiée. l'utilisation d'échangeurs d'ions comme catalyseurs associée à un contrôle précis de l'hydratation du milieu réactionnel permet l'obtention hautement sélective des benzo (4H) dioxinnes‐1,3 correspondants.
Reaction of schiff bases with acryl esters. Synthesis of 2‐oxo‐ and 4‐oxotetrahydropyridines
Authors: Barluenga José , Muñiz Laudina , López Fernando , Palacios Francisco , Gotor Vicente
Published: April 2009

Ketimines react with acryl esters in the presence of aluminium chloride to afford 2‐oxo‐ and 4‐oxotetrahydropyridines. The heterocycles obtained are isolated depending on the structure of the ester and the polarity of the solvent.
Mass spectrometric synthesis. II. The reaction of catechol with acetone in a protic medium
Authors: Podda Gianni , Maccioni Antonio , Daolio Sergio , Traldi Pietro
Published: April 2009

The reaction of catechol with acetone, carried out in the chemical ionization chamber of a VG ZAB 2F mass spectrometer and in the presence of a protic medium (CH5+), leads to 2,2‐dimethyl‐1,3‐benzodioxole. This has been proved by exact measurements and collisionally activated dissociation mass analyzed ion kinetic energy spectra.
Pyrrolo‐ and pyrido[1,2‐a]indoles via an intramolecular wittig reaction
Authors: Crenshaw Michael D. , Zimmer Hans
Published: April 2009

Several pyrrolo‐ and pyrido[1,2‐a]indoles were prepared via an intramolecular Wittig reaction in good yields. This reaction sequence represents a facile entry into the mitosene ring system.
Substituted 5‐(D,L‐erythro‐1′,2′‐dihydroxypropyl)pyrazines. Potential precursors for the synthesis of biopterin derivatives
Authors: Pastor Stephen D. , Nelson Aaron L.
Published: April 2009

A convenient synthesis of substituted 5‐(D,L)‐erythro‐1′,2′‐dihydroxypropyl)pyrazines from crotonic acid 4 is described. The anomalous behavior during decarboxylation of functionalized 2‐oximino‐3‐oxoesters 8a,b is noted. The structures of prepared compounds were determined by spectroscopic methods.
Indole esters as heterocyclic synthons. III. Preparation and reactions of furo[3,2‐b]indoles
Authors: Unangst Paul C. , Carethers Mary E.
Published: April 2009

The preparation of furo[3,2‐b]indoles via Dieckmann cyclization is described. The precursor diesters were obtained from 3‐hydroxy‐1H‐indole‐2‐carboxylic acid esters and methyl or ethyl bromoacetate. Reactions of the furo[3,2‐b]indole enolic esters prepared are discussed.
Determination of rotational barriers of carboncarbon bonds in 2‐arylpiperidines
Authors: Giralt Ernest , Feliz Miguel , Rubiralta Mario , Bosch Joan
Published: April 2009

Carbon‐carbon sp3‐sp2rotational barriers of 3,3‐dimethyl‐2‐(3,4,5‐trimethoxyphenyl)‐4‐piperidones and their ethylene ketals have been evaluated using nmr techniques. The conformation of1hydrochloride has been studied by NOE determinations. Values found for the hydrochlorides of the title compounds are discussed in terms of equilibria with free bases and nitrogen inversion.
The synthesis of benzofuroquinolines. III. Two dihydroxybenzofuroquinolinones
Authors: Yamaguchi Seiji , Yoshimoto Yoshiteru , Murai Rikuko , Masuda Fumihiko , Yamada Minora , Kawase Yoshiyuki
Published: April 2009

Two dihydroxybenzofuroquinolinones, 3,9‐dihydroxy‐5H‐benzofuro[3,2‐c]quinolin‐6‐one (V) and 3,8‐dihydroxy‐6H‐benzofuro[2,3‐b]quinolin‐11‐one (VI), were obtained by the demethyl‐cyclization of 3‐(2,4‐dimethoxyphenyl)‐4‐hydroxy‐7‐methoxy‐1H‐quinolin‐2‐one (IV). By the methylation with diazomethane, V gave a dimethylated compound (VII), while VI gave a trimethylated compound (VIII).
Synthesis of precocenes with ionoforic groups
Authors: Camps F. , Coll J. , Ricart S.
Published: April 2009

Preparation of potential insect antijuvenile hormone agents with polyoxyethyl and glycosyl groups at C‐8 position of the 2‐H‐chromene ring of precocenes is described.
On the oxidation of N‐methyl and N‐benzylpyrimidin‐2‐ and ‐4‐ones by rabbit liver aldehyde oxidase
Authors: Angelino S. A. G. F. , Buurman D. J. , van der Plas H. C. , Müller F.
Published: April 2009

The presence of a methyl or benzyl group at N‐1 or N‐3 of 2‐ and 4‐pyrimidone does not affect the site of oxidation by rabbit liver aldehyde oxidase. From all substrates studies only one product viz. the corresponding N‐1 or N‐3 substituted uracil has been obtained. The maximum rates of oxidation by free enzyme show an optimum in the pH range 6.5–7.8, which is little influenced by the site and the size of the N‐substituent. Application of immobilized enzyme in small scale synthesis gives 1‐ or 3‐R‐uracils (R = methyl, benzyl) in 43–78% yield.
Ambident reactivity of a thiazolo[3,2‐a]pyridinium salt with nucleophiles
Authors: Hajós Gy , Messmer A.
Published: April 2009

Reaction of thiazolo[3,2‐a]pyridinium salt 1 with secondary amines, depending on the reaction condition, may result in both stable pseudo bases 2 as addition products and thiazolyl‐dieneamines 4 as products of ring opening. The ambident reactivity of the title system is interpreted by frontier orbital theory.
Correlation of resonances of strongly coupled spin systems via responses due to strong coupling in homonuclear two‐dimensional j‐resolved spectra: Total assignment of the 1H‐NMR spectrum of 2‐(2′‐pyridyl)‐1,8‐naphthyridine
Authors: Ezell Edward L. , Thummel Randolph P. , Martin Gary E.
Published: April 2009

Homonuclear two‐dimensional J‐resolved (2DJ) spectra of molecules containing strongly coupled spin systems contain additional responses and thus additional information, the responses arising from the mixing effects of the 180° pulse employed to create the spin echo upon which the experiment is based. Although additional responses due to strong coupling are generally considered to be an undesirable complication inherent to the experiment, it is shown that they can serve a useful correlation function. Total assignment of the 1H‐nmr spectrum of 2‐(2′‐pyridyl)‐1,8‐naphthyridine at 100 MHz is reported, and members of the three strongly coupled spin systems of the molecule are identified via the additional responses due to strong coupling.
Quinone chemistry. Synthesis and tautomerism of 4,7‐indazolequinones
Authors: Agarwal Nand L. , Bohnstengel Hans , Schäfer Wolfram
Published: April 2009

The reaction of 1 with hydrazines provided hydrazinium‐4,7‐dioxo‐4,7‐dihydroindazol‐3‐olates 2a‐e and 4,7‐indazolequinones 3f,g depending upon the nature of the substituent present in the reactants. Compounds 3a‐g were obtained by treatment of 2a‐e with sodium hydroxide. Fixed tautomers 4a‐b and 5c‐f were synthesized by methylation of the corresponding 3a‐f or 2a‐2e with diazomethane. Migration of a methyl group of 5c‐f from the oxygen at C3 to N1 on heating afforded 6c‐f. The tautomerism of 2a‐e and 3a‐g has been studied by comparing ir, uv, 1H nmr and 13C nmr spectra with those of the fixed tautomers.
Studies on quinones. XIII. Synthesis and reactivity in acid medium of cyclic O,N‐ketals derived from acylbenzoquinones and enamines
Authors: Cassis RaÚL , Tapia Ricardo , Valderrama Jaime A.
Published: April 2009

A series of cyclic O,N‐ketals 14–20 derived from benzo[b]furan has been synthesized by reaction of acylbenzoquinones and enamines. Compounds 14–20, in warm aqueous sulfuric acid, react to give elimination or rearrangement products depending on the structure of the substrate. The behavior of heterocycles 14–20 in acid conditions is interpreted on the basis of the arrangement of the carbon substituents on the furan ring.
Synthesis and reduction of 5,5‐dimethyl‐2,4‐bis(3,4‐dimethoxyphenyl)‐2‐chloro‐2,5‐dihydrofuran
Authors: Biftu Tesfaye
Published: April 2009

A new, stable 5‐membered ring heterocyclic cation was prepared and reduced into the corresponding dihydrofuran, tetrahydrofuran and pentanol derivatives.
Studies on phenothiazines. Part 11. Synthesis and spectral studies of substituted 1‐chloro/methyl/nitrophenothiazines
Authors: Gupta R. R. , Kalwania G. S. , Kumar M.
Published: April 2009

Synthesis of the title compounds by the Smiles rearrangement has been reported. 1‐Nitrophenothiazines have been prepared by the reaction of 2‐amino‐3‐chloro/methyl/methoxythiophenol with substituted o‐halonitrobenzenes in ethanolic sodium hydroxide, in which Smiles rearrangement occurs in situ. 1‐chloro/methyl‐7‐substituted phenothiazines have been prepared by Smiles rearrangement of 3‐chloro/methyl‐2‐formamido‐2′‐nitro‐4′‐substituted diphenyl sulphides. The latter were prepared by the formylation of the diphenyl sulphides obtained by the condensation of 2‐amino‐3‐chloro/methylthiophenols with substituted o‐halogenonitrobenzenes in ethanolic sodium acetate. Spectral studies are also included.
Reactions of substituted phenacyl bromides with various bases. o‐ and p‐nitrophenacyl bromide. I
Authors: Scott James H. , Smith Thomas A. , Hutchinson James H.
Published: April 2009

The products obtained from the reaction of o‐ and p‐nitrophenacyl bromide with various bases is described.
The behavior of 6‐p‐chlorostyryl‐3‐thioxo‐1,2,4‐triazin‐5‐one toward phenylmagnesium bromide
Authors: Zaher H. A. , Mohammady R. , Ibrahim Yehia A.
Published: April 2009

The action of phenylmagnesium bromide on 6‐p‐chlorostyryl‐3‐thioxo‐1,2,4‐triazin‐5‐one (1) was studied whereby a mixture of seven products was obtained. These were separated and characterised, and a reasonable mechanism for their formation is presented and discussed.
The regioselective alkylation of 4,6‐dimethyl‐1‐phenyl‐2(1H)‐pyrimidinone
Authors: Katoh Akira , Omote Yoshimori , Kashima Choji
Published: April 2009

4,6‐Dimethyl‐1‐phenyl‐2(1H)‐pyrimidinone (I) was treated with alkyl halides in the presence of sodium hydride at low temperature to afford only C‐6 alkylated products III and IV in good yields. Further, the mono‐, IIIa‐d, and di‐alkylated 2(1H)‐pyrimidinones IVa‐d were selectively obtained by changing the amount of alkyl halides.
Synthesis and mass spectrum of 3,3′‐thiobispyridine and polarographic reduction of 1,1′‐dimethyl‐3,3′‐thiobispyridinediium diiodide
Authors: Summers Lindsay A. , Trotman Sylvia
Published: April 2009

3,3′‐Thiobispyridine is prepared by reaction of pyridine‐3‐thiol with 3‐bromopyridine. The base peak in the mass spectrum of 3,3′‐thiobispyridine is due to the molecular ion which fragments by loss of H, HCN and CS as well as by central bond rupture. The 1,1′‐dimethyl diquaternary salt of 3,3′‐thiobispyridine is reduced polarographically by a one electron transfer not involving hydrogen to an unstable radical cation at a potential (Eo) of −0.72 V in the pH range 7.4–11.2.
Two‐dimensional relayed coherence transfer experiments as a means of subgrouping protonated carbon resonances of complex polynuclear heteroaromatics on the basis of vicinal proton‐proton connectivities
Authors: Musmar M. J. , Martin Gary E. , Tedjamulia Marvin L. , Kudo Hirotaka , Castle Raymond N. , Lee Milton L.
Published: April 2009

Application of autocorrelated homonuclear (COSY) and proton‐carbon chemical shift correlation two‐dimensional nmr experiments to the problem of assigning the 1H‐ and 13C‐nmr spectra of phenanthro[4,3‐a]dibenzothiophene fails despite their considerable utility in the assignment of the spectra of the smaller phenanthro[b]thiophenes. The failure of these techniques in the case of phenanthro[4,3‐a]dibenzothiophene is predominantly due to the inability of the COSY spectrum to provide the means of subgrouping the proton resonances into their component spin subsystems. Two‐dimensional relayed coherence transfer nmr experiments which first established coherence between vicinally coupled protons which is then transferred to the carbon spins which are ultimately observed circumvent these problems. The application of two‐dimensional relayed coherence transfer to phenanthro[4,3‐a]dibenzothiophene is described, the technique leading to the sub‐grouping of all five of the proton spin subsystems and thus providing a means of beginning the total assignment.
Synthesis and reactivity of 1‐methyl‐3‐phenyl‐4‐diazo‐5‐benzoylamidopyrazole. A potential antitumor agent
Authors: Cecchi Lucia , De Sio Francesco , Melani Fabrizio
Published: April 2009

The title compound 2 was prepared in excellent yield by diazotation of the parent amino derivative. Compound 2 was found to react with a variety of acyclic and cyclic active methylene compounds to yield the corresponding pyrazolo‐4‐ylhydrazones.
The synthesis of isoindolin‐3‐ones, Phthalazin‐4(3H)‐ones and related systems
Authors: Dunn A. D.
Published: April 2009

The reaction between methyl 2‐cyanobenzoate and its pyridine analogues gave isoindolin‐3‐ones, phthalazin‐4(3H)‐ones and their corresponding aza analogues. Some reactions of 1‐benzylaminoiminoisoindolin‐3‐one 5b were investigated.
The synthesis of pyrrolopyridines and pyridopyridazines
Authors: Dunn A. D.
Published: April 2009

The synthesis of the aza analogues 3a‐d of 1‐iminoisoindolin‐3‐one 1 and their use in the preparation of pyrrolopyridines and pyridopyridazines is described. The synthesis of derivatives of these imines is also reported.
Sulfur derivatives of 1‐methylpyrrole
Authors: Gronowitz Salo , Kada Rudolf
Published: April 2009

Metalation of 1‐methylpyrrole using n‐butyllithium and tetramethylethylenediamine (TMEDA) in ether furnished 1‐methyl‐2‐pyrrolyllithium, which in turn was converted to 1‐methyl‐2‐methylthiopyrrole upon treatment with dimethyldisulfide. Further formylation with dimethylformamide, phosphorus oxychloride in dichloroethane led to the corresponding pyrrole‐2‐carboxaldehyde, which was then condensed with malononitrile and methylcyanoacetate under Knoevenagel reaction conditions to give 2‐cyano‐3‐(1‐methyl‐5‐methylthio‐2‐pyrrolyl)acrylonitrile and 2‐cyano‐3‐(1‐methyl‐5‐methylthio‐2‐pyrrolyl)acrylic acid methyl ester, respectively. Their oxidation by hydrogen peroxide furnished the corresponding sulfones. Analogously, 5‐phenylthio derivatives were prepared.
Studies on 8‐aminoquinoline 1‐oxide antimalarial agents
Authors: Johnson Judith L. , Worth Donald F. , Colbry Normal L. , Werbel Leslie M.
Published: April 2009

The synthesis of N‐oxides of 8‐aminoquinolines related to primaquine has been explored in an effort to obtain a less toxic, curative, antimalarial drug. Several side chain N‐oxide analogs (2b, 3b) were prepared as well as the ring N‐oxide of primaquine with both amines trifluoroacetylated (13). All attempts to deblock this material failed. Trifluoroacetylation of primaquine also yielded the novel acyl analog 12 which had curative activity versus P. cynomolgi in the monkey about equal to that of primaquine.
Ring nitrogen functionalization of 2‐aminothiazol‐4‐acetic acid derivatives. I. Synthesis and properties of novel 2‐aminothiazole N‐oxides
Authors: Perrone Ettore , Alpegiani Marco , Giudici Franco , Bedeschi Angelo , Pellizzato Renato , Nannini Giuliano
Published: April 2009

Cyclization of thiocyanomethylketone oximes with hydroxylamine hydrochloride and oxidation of 2‐aminothiazole derivatives with peracids are shown to afford the same products, which can be formulated either as 2‐imino‐3‐hydroxy‐2,3‐dihydrothiazolines or 2‐aminothiazole N‐oxides. Compounds of this type bearing at position 4 an acetic or α‐oxyiminoacetic residue are useful synthons for highly active β‐lactam antibiotics; the problems connected with their preparation in a suitably protected form are examined. Scope and limitations of this previously unreported oxidation of the thiazole nucleus are discussed. All the products show limited stability in alkaline media: the 4‐acetic derivatives, in addition, undergo a transposition to afford 4‐methylidenethiazolidines. Possible types of isomerism and tautomerism are discussed in the light of the acquired spectral data. The uv and ir spectra of the compounds synthesized lend support to their formulation as 2‐aminothiazole N‐oxides.
Pyrimidines. 7. A study of the chlorination of pyrimidines with phosphorus oxychloride in the presence of N,N‐dimethylaniline
Authors: Gershon Herman , Grefig Anthony T.
Published: April 2009

The chlorination of 6‐trifluoromethyluracils by phosphorus oxychloride in the presence of N,N‐dimethylaniline was studied and compared with results obtained with 6‐methyluracils. 6‐Trifluoromethyluracil and its 5‐chloro analog afforded moderate yields of the di‐ and trichloropyrimidines, accompanied by good yields of the 2‐N‐methylanilino by‐products, after a 3‐hour reaction time. After 24 hours, the 2‐N‐methylanilinopyrimidines were the primary or sole products. A small yield of 2,4‐bis(N‐methylanilino)‐6‐trifluoromethylpyrimidine was also obtained. The 6‐methyluracils afforded high yields of the di‐ and trichloropyrimidines, after 3 and 24 hours, along with minor amounts of the 2‐N‐methylanilino by‐products. After 48 hours, the proportion of 2,4‐dichloro‐6‐methylpyrimidine decreased, and the 2‐N‐methylanilino product increased. 2‐Chloro‐4‐methylanilino‐6‐methylpyrimidine and bis(2‐N‐methylanilino)‐6‐methylpyrimidine were also formed in small amounts. The chlorination products from 5‐chloro‐6‐methyluracil remained constant over 188 hours of reaction time.

It appears that the π electron distribution around the ring, as influenced by the substituents, controls the course of the chlorination and by‐product formation. Since the amination by a tertiary amine is a type of Hofmann reaction, the presence of the chlorine in the 5 position of the ring adds steric hindrance and thus enhances the regiospecificity of the formation of by‐products.
Non‐steroidal antiinflammatory agents. 1. Synthesis of 4‐hydroxy‐2‐oxo‐1,2‐dihydroquinolin‐3‐yl alkanoic acids by the wittig reaction of quinisatines
Authors: Faber Kurt , StÚckler Hubert , Kappe Thomas
Published: April 2009

The Wittig reaction of quinisatines (1a,b) with 1‐ethoxycarbonylethyliden‐ (2a) and ethoxycarbonylmeth‐ylenetriphenylphosphorane (2b) has been investigated. In both cases unusual reaction products (3a,b and 12a,b respectively) were isolated in high yields and converted to potential antiinflammatory acids 6, 8, 15 and lactones 4, 7.
Synthesis of 2‐aroylpiperazinyl‐4‐alkoxyquinazolines by phase‐transfer‐catalysed heteroaromatic nucleophilic substitution
Authors: GÓmez‐Gil M. C. , GÓmez‐Parra V. , SÁnchez F. , Torres T.
Published: April 2009

A series of quinazolines, with cardiovascular activity, having 2,3‐dihydroxypropoxy or 2‐hydroxy‐3‐t‐ butylaminopropoxy groups substituted at the 4‐position and chlorine or 2‐aroylpiperazinyl groups at the 2‐position have been synthesized. The introduction of the alkoxy substituent at C‐4 was carried out under phase‐transfer catalysis conditions.
Quenching of the fluorescence of quinoline derivatives by exciplex formation with heteroatom‐containing compounds
Authors: Epling Gary A. , Lin Kuei‐Ying
Published: April 2009

The efficient fluorescence of 2‐phenylquinoline compounds is readily quenched by heteroatom‐containing compounds such as amines and sulfides. The mechanism of quenching involves the formation of an exciplex between the quencher and the quinoline; in a few cases a new, red‐shifted emission from the exciplex was observed. The efficiency of quenching depends on the ionization potential of the quencher ‐ the compounds having low ionization potentials quench the fluorescence at a diffusion‐controlled rate.
Studies in organic mass spectrometry. IV. Electron impact induced fragmentation of 2‐substituted 3‐(5‐isoxazolyl)‐4(3H)‐quinazolinones of pharmaceutical interest
Authors: Ceraulo̊ Leopoldo , Plescia Salvatore , Daidone Giuseppe , Bajardi Maria Luisa
Published: April 2009

The fragmentation under electron impact of thirteen 2‐substituted‐3‐(5‐isoxazolyl)‐4(3H)‐quinazolinones has been investigated with the aid of metastable ion detection and high resolution measurements. Molecular ions are always abundant and the main primary fragmentation route involves acetonitrile elimination through isoxazole ring opening. The other common processes, particularly those leading to the abundant [R‐C8H4N2]+ ion (b or b'), as well as those due to the nature of the 2‐substituent are reported and discussed.
The synthesis of naphtho[1,2‐b]thiophene and all of the eight isomers of monomethylnaphtho[1,2‐b]thiophene
Authors: Tedjamulia Marvin L. , Stuart John G. , Tominaga Yoshinori , Castle Raymond N. , Lee Milton L.
Published: April 2009

The synthesis of naphtho[1,2‐b]thiophene and all of the eight monomethylnaphtho[1,2‐b]thiophene isomers is described.
Synthesis of 8‐methyl‐2‐azainosine and related nucleosides
Authors: Andrés J. Ignacio , Herranz Rosario , López M. Teresa García
Published: April 2009

The synthesis of 6‐methyl‐7‐(β‐D‐ribofuranosyl)imidazo[4,5‐d]‐v‐triazin‐4‐one (8‐methyl‐2‐azainosine (2)) and 6‐methyl‐7‐(β‐D‐glucopyranosyl)imidazo[4,5‐d]‐v‐triazin‐4‐one (5) by diazotization of 5‐amino‐1‐(β‐D‐ribofuranosyl)‐2‐methylimidazole‐4‐carboxamide (1) and diazotization of 5‐amino‐1‐(2,3,4,6‐tetra‐O‐acetyl‐β‐D‐glucopyranosyl)‐2‐methylimidazole‐4‐carboxamide (3), followed by deacetylation of the resulting compound 4, is described. The preparation of 6‐methyl‐5‐(β‐D‐ribofuranosyl)imidazo[4,5‐d]‐v‐triazin‐4‐one (10) and 6‐methyl‐5‐(β‐D‐glucopyranosyl)imidazo[4,5‐d]‐v‐triazin‐4‐one (11) by glycosylation of 6‐methylimidazo[4,5‐d]‐v‐triazin‐4‐one (8‐methyl‐2‐azahypoxanthine, (7)) is also described. Structural assignments were made on basis of analytical and 1H‐nmr and uv spectral data.