bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis of 6‐chloro‐1,5‐dimethylbenzimidazole
Authors: Criddle W. J. , Ellis G. P. , Jones R. T.
Published: March 2009

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

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

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

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

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

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

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

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

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

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

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

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

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

13C chemical shifts of nine N‐substituted 2‐amino‐4H‐3,1‐benzoxazin‐4‐ones, the isomeric 3‐substituted 2,4‐(1H,3H)quinazolinediones, and the parent compounds of the two series are reported. Support is provided for the endocyclic position of the C=N bond in the former series of compounds.
Synthesis of 2H‐1,4‐thiazin‐3(4H)‐one 1‐oxide and 2H‐1,4‐thiazin‐3‐(4H)‐one 1,1‐dioxide, structural analogs of uracil
Authors: Bobek M.
Published: March 2009

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

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

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

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

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

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

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

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

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

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

A study has been made of the fragmentation upon electron impact of 3,3‐dimethyl‐2,3,4,5,10,11‐hexahydro‐11‐phenyl‐1H‐dibenzo[b,e][1,4]diazepin‐1‐one and fifteen of its derivatives containing chloro, bromo, methyl, methoxy, hydroxy, nitro, amino, carboxyl and carboxymethyl substituents on ortho and para positions of the 11‐phenyl ring. All the spectra analyzed contain molecular ions and the principal fragmentation routes takes place either from the molecular or from (M+‐1) ion. There are, however, some deviations from the general fragmentation pattern in the case of 1,4‐dibenzodiazepin‐1‐ones with o‐nitro, o‐hydroxy and o‐carboxyl substituents caused by direct interactions of these groups with the benzodiazepine ring.
Synthesis and chemical reactivity of indenoisoxazoles
Authors: Lemke Thomas L. , Sawhney Kailash N. , Lemke B. Kaye
Published: March 2009

Treatment of 2‐pivaloyl‐1,3‐indandione (1) with hydroxylamine under acidic conditions, results in formation of 8‐t‐butylindeno[1,2‐c]isoxazol‐7‐one (2) while treatment of the triketone with hydroxylamine at neutral or basic pH gave 6 which upon cyclization gave the isomeric 3‐t‐butylindeno[1,2‐c]isoxazol‐4‐one (7). Compound 7 was readily reduced to amine 12 by treatment with hydrazine or hydrogen over platinum. The amine, although quite unreactive, was converted to 3‐t‐butylindeno[1,2‐c]pyrazol‐4‐one (13) with hydrazine or reduced to 15 and 16 with sodium in liquid ammonia and alcohol. Surprisingly, the amine 3 obtained from isoxazole 2 gave reduction product 15 from a sodium‐liquid ammonia reduction and not the expected product 18. Spectral evidence for each of the structures is discussed.
On the reactivity of N‐benzylpyrimidinium salts with nitrogen nucleophiles
Authors: Dlugosz A. , van der Plas H. C. , Van Veldhuizen A.
Published: March 2009

Treatment of the l‐benzyl salts of pyrimidine, 4,6‐dimethylpyrimidine, and 4‐t‐butylpyrimidine with liquid ammonia leads to debenzylation. The 1H‐nmr spectroscopic evidence is presented that the initial step in the debenzylation of l‐benzyl‐4,6‐dimethylpyrimidinium bromide is the addition of the ammonia at C‐2, while with l‐benzyl‐4‐t‐butylpyrimidinium bromide the addition takes place at C‐6. It is proved by 15N labelling that the debenzylation occurs according to the ANRORC mechanism. The above‐mentioned l‐benzylpyrimidinium bromides give with hydrazine, pyrazole, 3,5‐dimethylpyrazole and 3‐t‐butylpyrazole, respectively.
Synthesis of pyrido[3,4‐b]pyrano[3,4‐b]indoles
Authors: Freter Kurt , Fuchs Victor
Published: March 2009

The synthesis of some pyrido[3,4‐b]pyrano[3,4‐b]indoles (3) from 3‐hydroxy‐4‐(3‐indolyl)piperidines (6) is reported.
Oxidation of 4‐chromanones with thallium(III) nitrate
Authors: Ciattini Pier Giuseppe , Morera Enrico , Ortar Giorgio
Published: March 2009

Treatment of 4‐chromanones 1a‐g with thallium(III) nitrate in acidic methanol results mainly in dehydrogenation, whereas α‐methoxylation and/or Taylor‐McKillop rearrangement predominate in trimethyl orthoformate. The mechanistic features of these oxidations are briefly discussed.
A comparative study of the rearrangement of some 6‐ and 7‐halo‐substituted 3‐amino‐3,4‐dihydro‐l‐hydroxycarbostyrils in concentrated hydrohalic acids
Authors: Mccord Tommy J. , Crawford Charles P. , Rabon James A. , Gage Larry D. , Winter J. Mark , Davis Alvie L.
Published: March 2009

The 6‐bromo (16), 6‐fluoro (17), 7‐bromo (14), and 7‐fluoro (15) substituted 3‐amino‐3,4‐dihydro‐l‐hydroxycarbostyrils were treated with concentrated hydrochloric and hydrobromic acids under reflux conditions. The 7‐halogenated N‐hydroxycarbostyrils (14,15) gave the normal rearrangement products, the 6,7‐dihalolactams (18–21). The 6‐halogenated compounds (16,17) yielded the corresponding 6,8‐dihalolactams (22–24) under the same experimental conditions, with the exception of the hydrobromic acid reaction of the 6‐fluoro derivative 17 which yielded a mixture of products. Based on the comparison of the nmr spectrum of the product mixture with those of two authentic compounds, the mixture was identified as consisting of the normal rearrangement product, the 8‐bromo‐6‐fluorolactam (27) and the straightforward reduction product, the 6‐fluorolactam (26) in a ratio of about 2:1. The latter compounds were prepared by an independent method of synthesis in which 2‐amino‐5‐fluorophenylalanine (25) was acidified to yield the corresponding lactam 26, followed by bromination to afford the 8‐bromo‐6‐fluorolactam 27. A mechanism is proposed to interpret the experimental results of nucleophilic substitution with rearrangement and reduction which occur with the 6‐fluoro compound 17 when exposed to bromide ions in strongly acidic solution.
Synthesis of some 5,10,15,20‐tetraalkylchlorin and tetraalkylporphyrin complexes of transition metals
Authors: Ulman Abraham , Fisher Diane , Ibers James A.
Published: March 2009

Metal‐assisted template syntheses of 5,10,15,20‐tetraalkylchlorin and tetraalkylporphyrin complexes of transition metals are described. With Co only the porphyrins are obtained; with Cu only the chlorins; with Ni a mixture of chlorin and porphyrin is obtained depending on alkyl and added anhydride. As opposed to the higher alkyls, (5,10,15,20‐tetramethylporphyrinato)nickel(II) dimerizes in solution, a dimerization constant of 3.9 ± 1.3 M−1 being derived from 1H nmr data.
Heterocycles. Part I. A new route to the synthesis of substituted 2‐aminopyrimidines
Authors: El‐Rayyes N. R.
Published: March 2009

Heterocyclic aldehydes (A) reacted with alkyl aryl ketones (B) to give the corresponding 1,3‐diaryl‐2‐propen‐1‐ones (Ia‐1). Condensation of these chalcones with guanidine produced the corresponding 2‐amino‐4,6‐diarylpyrimidines (IIa‐1). The structure of all products was substantiated by chemical and spectroscopic methods.
Synthése d'héterocycles. XX. Reaction du malononitrile avec quelques cinnamonitriles
Authors: Del Carmen Chacón María , Del Carmen Pardot María , Soto José Luis , Lorente Antonio , Fuentes Luis
Published: March 2009

La reaction de certains cinnamonitriles para‐substitués avec le malononitrile en milieu methanol‐methylate de sodium conduit aux dihydropyridines 5, dont l'aromatisation fournit les pyridines 6. Dans le cas du p‐nitrocinnamonitrile on obtient directement la pyridine 6d.
Synthesis of 3H‐pyrazol‐3‐one derivatives containing a 9H‐thioxanthene ring
Authors: Okabayashi Ichizo
Published: March 2009

2,4‐Dihydro‐5‐methyl‐2‐phenyl‐4‐(9H‐thioxanthen‐9‐yl)‐3H‐pyrazol‐3‐one (3) was prepared by condensing 9H‐thioxanthen‐9‐ol (1) with 2,4‐dihydro‐5‐methyl‐2‐phenyl‐3H‐pyrazol‐3‐one (2), or by cyclizing ethyl α‐acetyl‐9H‐thioxanthene‐9‐acetate (4) with phenylhydrazine. 2,4‐Dihydro‐5‐methyl‐2‐phenyl‐4‐(9H‐thioxan‐ then‐9‐yl)‐3H‐pyrazol‐3‐one 10,10‐dioxide (8) was prepared by cyclizing ethyl α‐acetyl‐9H‐thioxanthene‐9‐acetate 10,10‐dioxide (7) with phenylhydrazine. Compound 8 was also obtained by oxidizing 3 with hydrogen peroxide in acetic acid. 5‐Amino‐2,4‐dihydro‐2‐phenyl‐4(9H‐thioxanthen‐9‐yl)‐3H‐pyrazol‐3‐one (10) was obtained by condensing 1 with 5‐amino‐2,4‐dihydro‐2‐phenyl‐3H‐pyrazol‐3‐one (9).
Synthesis of benzo[1,2]phenaleno[bc]thiophenes
Authors: Pratap Ram , Castle Raymond N. , Lee Milton L.
Published: March 2009

The synthesis of both isomers of benzo[1,2]phenaleno[bc]thiophene namely, benzo[1,2]phenaleno[3,4‐bc]‐thiophene and benzo[1,2]phenaleno[4,3‐bc]thiophene is described.
Electron impact mass spectrometry of 2,5‐bis(p‐R‐phenyl)thiophenes
Authors: Jiménez R. , Cortés E.
Published: March 2009

The mass spectra of a series of 2,5‐bis(p‐R‐phenyl)thiophenes are reported and discussed. The fragmentation patterns and mechanisms postulated have been confirmed by the determination of the metastable peaks. All the compounds possess the molecular ion as the base peak.
Conformational and configurational studies on 3‐azabicyclo[3.3.1]nonane (3‐abn) derivatives and related systems employing carbon‐13 NMR spectroscopy
Authors: Jeyaraman R. , Jawaharsingh Cooksley Baldwin , Avila S. , Ganapathy K. , Eliel Ernest L. , Manoharan Muthiah , Morris‐Natschke Susan , Kenan W. R.
Published: March 2009

The 13C nmr spectra of 4 cis‐2,4‐diphenyl‐3‐azabicyclo[3.3.1]nonanes, 11 cis‐2,4‐diaryl‐3‐azabicyclo[3.3.1]‐nonan‐9‐ones, 26 cis‐2,4‐diaryl‐3‐azabicyclo[3.3.1]‐nonan‐9‐ols or acetates thereof, 5 cis‐2,4‐diaryl‐3‐azabi‐cyclo[4.3.1]decan‐10‐ones or ‐10‐ols and 5 cis‐2,4‐diphenyl‐3‐aza‐7‐thiabicyclo[3.3.1]nonan‐9‐ones, ‐9‐ols or 9‐yl acetates have been recorded. Except for the 7‐thia compounds, which appear to exist mainly in the configuration and conformation with the nitrogen‐containing ring in the boat form, these compounds seem to exist overwhelmingly in chair‐chair conformations. The configuration of the 9‐ols and their acetates (syn or anti to the nitrogen‐containing ring) has been deduced from the spectra. In a number of cases, the structures assigned differ from those earlier postulated. Broadening of one set of aryl signals (probably those due to the ortho carbons) in the case of N‐methyl (but not N‐H) compounds without ortho substituents is ascribed to restricted phenyl rotation.
Alkylation en catalyse par transfert de phase d'une série d'acridanone‐9 substituées: Compétition entre O‐ et N‐alkylation
Authors: Mahamoud Abdallah , Galy Jean‐Pierre , Vincent Emile‐Jean , Galy Anne‐Marie , Barbe Jacques
Published: March 2009

L'alkylation en catalyse par transfert de phase d'une série d'acridanones diversement substituées conduit a un mélange d'isomeres O‐ et N‐alkyles. Contrairement au substituant, l'agent alkylant a un rǒle essentiel dans l'orientation de la reaction. Celle‐ci peut, d'ailleurs, ětre interprétee a l'aide du principe HSAB.
Photoaddition of carbonyl compounds to five‐membered ring heterocycles
Authors: Rivas C. , Bolivar R. A. , Cucarella M.
Published: March 2009

It has been possible to prepare oxetanes from several carbonyl compounds and derivatives of furan, pyrrole and thiophene. This account summarizes the successful and some of the unsuccessful attempts carried out in this laboratory to extend the Paterno‐Büchi reaction to the common five‐membered heterocyclic systems; the new compounds obtained in this connection are reported and several interesting facts which may help understand the reactivity of heterocycles in the presence of excited carbonyl compounds are commented.
Synthesis of 2‐(5′‐substituted isoxazol‐3′‐yl)‐4‐oxo‐3‐thiazolidinylalkanoic acids
Authors: Baraldi P. G. , Simoni D. , Moroder F. , Manfredini S. , Mucchi L. , Dalla Vecchia F. , Orsolini P.
Published: March 2009

A series of 2‐substituted 4‐oxo‐3‐thiazolidinylalkanoic acids bearing an isoxazole nucleus in the 2‐position have been prepared. None of the compounds synthesised showed antibacterial activity in vitro.
Synthesis of pyrido[1,2‐a]benzimidazoles by cyclizative condensation of 2‐halopyridines and 1,2‐benzenediamines. Scope and mechanism of the reaction
Authors: Sundberg Richard J. , Ellis James E.
Published: March 2009

The scope and mechanism of acid‐catalyzed cyclizative condensation of 2‐halopyridines with 1,2‐benzene‐diamines has been explored. The reaction requires a 2‐halopyridine which is activated toward nucleophilic substitution. Evidence in favor of a mechanism involving pyridine ring opening is presented. Of three substituted 1,2‐benzenediamines which were examined, the 4‐nitro compound gave a single cyclization product whereas 4‐chloro and 4‐methy 1‐derivatives gave isomeric mixtures. The structure of the product from 2‐chloro‐5‐nitropyridine and 4‐nitro‐1,2‐benzenediamine is shown to be 2,8‐dinitropyrido[1,2‐a]benz‐imidazole.
Synthesis of some new bicyclic pyrazoline derivatives
Authors: Khalaf Ali Ali , El‐Shafei Ahmed Kamal , El‐Sayed Ahmed Mahmoud
Published: March 2009

2,6‐Diarylidenecyclohexanones react with hydrazine to give the corresponding bicyclic pyrazolines. The synthesis of a series of twenty eight substituted pyrazolines is described. The structure of all products was confirmed by microanalyses, ir and nmr data.
Heterocycles from phosphonium salts: A facile method for modification of the 4(5)‐methyl group of thiazoles
Authors: Lee Webb R. , Lam Bing L. , Lewis Joseph J. , Wellman George R. , Berkoff Charles E.
Published: March 2009

Thiazolyl phosphonium salts, formed from the condensation of acyl vinyl phosphonium salts with thioamides and thiourea, are readily functionaitzed in high yield. The sequence represents a useful general synthesis of multifunctional thiazoles.
Functional derivatives of thiophene. II. Synthesis and 1H‐NMR spectra of 1‐[2′‐(5′‐nitrothienyl)]pyrazoles
Authors: Gálvez C. , García F.
Published: March 2009

The preparation of 5‐methyl‐3,5‐dimethyl‐ and 3,4,5‐trimethyl‐l[2′‐(5′‐nitrothienyl)]pyrazoles from thienylhydrazines are described. The 1H‐nmr spectra of these compounds are discussed.
Synthesis and spectral studies of 2‐mercaptobenzimidazole derivatives. I
Authors: Saxena D. B. , Khajuria R. K. , Suri O. P.
Published: March 2009

The syntheses of some 2‐mercaptobenzimidazole (I) derivatives have been described. While preparing such compounds it has been observed that I reacts predominantly as the thione under anhydrous reaction conditions, and as the thiol in the presence of an alkali. Strutures of all of the nine compounds have been established with the help of spectral methods including 13C nmr spectroscopy of the two compounds (II and III).
Studies on the synthesis of heterocyclic compounds. Part VIII. A facile synthesis of new pyrazolo[3,4‐b]benzazepine‐4,9‐diones
Authors: Daidone Giuseppe , Plescia Salvatore
Published: March 2009

2‐Carbomethoxybenzoyl chloride reacted with some 5‐methylamino‐l‐phenyl‐3‐R‐pyrazoles to yield N‐methyl‐l‐phenyl‐3‐R‐pyrazol‐5‐yl)‐2‐carbomethoxybenzamides. These products were readily transformed into the corresponding acid, which in turn, refluxed in phosphorus oxychloride afforded the tricyclic system, l‐phenyl‐3‐R‐pyrazolo[3,4‐b]benzazepine‐4,9‐dione.
Efficient syntheses of thieno[2,3‐b]quinoxalines
Authors: Ibrahim Yehia A. , Badawy M. A. , El‐Bahaie S.
Published: March 2009

Three simple routes for the synthesis of thieno[2,3‐b]quinoxalines are described.
Nitrile oxide cycloaddition routes to 2‐(isoxazolyl)‐benzoates and 2‐(1,2,4‐oxadiazol‐3‐yl)benzoates
Authors: Howe Robert K. , Schleppnik Frances M.
Published: March 2009

Cycloaddition of aromatic nitrile oxides to methyl o‐vinylbenzoate produced methyl 2‐(3‐aryl‐2‐isoxazolin‐5‐yl)benzoates; the isoxazolines were converted to methyl 2‐(3‐arylisoxazol‐5‐yl)benzoates. Reaction of the nitrile oxide from o‐methoxycarbonylbenzohydroximinoyl chloride (11) with phenylacetylene, styrenes, and aromatic nitriles resulted in methyl 2‐(5‐phenylisoxazol‐3‐yl)benzoate, methyl 2‐(5‐aryl‐2‐isoxazolin‐3‐yl)‐benzoates (15), and methyl 2‐(5‐aryl‐1,2,4‐oxadiazol‐3‐yl)benzoates, respectively. The isoxazolines 15 were converted to the corresponding isoxazoles 16.
Synthesis of 8‐amino‐6‐methoxycinnoline. A precursor for 2‐azaprimaquine
Authors: Coburn Robert A. , Gala Dinesh
Published: March 2009

4‐Methoxy‐2‐nitroaniline was converted in seven steps to 8‐amino‐6‐methoxycinnoline with an overall yield of 33%. Several attempts to introduce a 5‐aminopentan‐2‐yl side‐chain in the amino‐group to give 2‐azaprimaquine were unsuccessful.
Solvent effects on the tautomerism of t‐butyl 2‐picolyl and t‐butyl quinaldyl ketones
Authors: Roussel R. , DeGuerrero M. Oteyza , Spegt P. , Galin J. C.
Published: March 2009

The tautomeric equilibria (constant Kτ) of tbutyl 2‐picolyl ketone (ketone ⇋ enol) and of tbutyl quinaldyl ketone (ketone ⇋ enamine) in semi‐dilute solution (0.3 mole.l−1) were studied by 1H‐nmr and uv spectroscopy as a function of solvent polarity, for a set of twenty‐five different solvents including apolar, dipolar aprotic as well as amphiprotic ones. The contribution of electrostatic field effects (π*), of solute‐solvent hydrogen bonding interactions (α) and of solvent cavitation effects (δh) were estimated separately and critically discussed, using multiparametric regression analysis and empirical polarity parameters, according to the “Solvatochromic Comparison Method” developed by Taft, et al. For both heterocyclic ketones, the hydrogen bond donor power of the solvent (α) is the major factor of the Kτ variations, as a result of preferential solvation of the ketonic tautomer.
Preparation of 7‐aminoquinolines as candidate antiparasitic agents
Authors: Markovac Anica , Wu Geng‐Shuen , Lamontagne Maurice P. , Blumbergs Peter , Meng‐Sheng Ao
Published: March 2009

A series of ten 7‐quinolinediamines were prepared and evaluated for potential antiparasitic activity against P. berghei, P. cynomolgi, L. donovani and T. rhodesiense. Compounds 1d and 8 showed activity being slightly effective against L. donovani in hamsters.
Syntheses of fluorescent dyes. XIV. Standards for fluorescence measurements in the near neutral pH‐range
Authors: Wolfbeis Otto S. , Urbano Edmund
Published: March 2009

Highly fluorescent cationic indicators have been obtained by reaction of heterocyclic nitrogen bases with 1,3‐propane sultone. Unlike the bases themselves, the fluorescence intensity of the cationic salts is practically pH‐independent in the neutral pH‐range, which makes them useful reference substances in measuring fluorescence intensities in physiological studies. Furthermore, they are sufficiently water soluble, the fluorescence maxima covering the wavelength range from 440 to 530 nm. 2‐(3‐Sulfonatopropyl)harmanium, (5) appears to be the most useful compound for intra‐ and extracellular liquids, since its fluorescence is not quenched by chloride ion.
Chemistry of the phenoxathiins and isosterically related heterocycles. XXII. 6,7,9‐trimethyl‐4‐azaphenoxathiin: First reported synthesis of an analog of the 4‐azaphenoxathiin ring system
Authors: Puig‐Torres Salvador , Martin Gary E. , Smith Keith , Cacioli Paul , Reiss James A.
Published: March 2009

The reaction of 2‐chloro‐3‐thiocyanatopyridine with a substituted spiroepoxycyclohexadienone, which served as a masked phenol with reversed polarity, led to the first reported synthesis of an analog of the 4‐azaphenoxathiin ring system. Confirmation of the structure was obtained from the assignment of the 13C‐nmr spectrum.
Skeletal rearrangement of 3‐methoxy‐N‐chloromorphinan
Authors: Mohacsi E. , Hayes T.
Published: March 2009

3‐Methoxymorphinan (1) was converted to the corresponding N‐chloro derivative 2 by treatment with aqueous sodium hypochlorite. Upon exposure to methanolic silver nitrate, 2 was rearranged to the carbinolamine ether 3. In addition, considerable amounts of the dechlorinated morphinan 1 were formed. The structure of 3 was secured by spectral analysis and its degradation to the hexahydroindoline derivative 4. The observed skeletal rearrangement of 2 which requires the migration of an alkyl group is discussed in terms of a nitrenium ion.
Synthesis of thieno[2,3‐e]‐1,2,4‐triazines
Authors: Ibrahim Yehia A. , Abdel‐Hady S. A. L. , Badawy M. A. , Ghazala M. A. H.
Published: March 2009

3‐Methylmercapto‐5‐oxo‐6‐vinyl‐ and 2‐methyl‐3‐mercapto‐5‐oxo‐6‐vinyl‐2,5‐dihydro‐1,2,4‐triazines were readily converted into the corresponding thieno[2,3‐e]‐1,2,4‐triazine in one step by the action of phosphorus pentasulfide in pyridine. 4‐Methyl‐3‐mercapto‐5‐oxo‐4,5‐dihydro‐1,2,4‐triazine is only converted into the 5‐thioxo analog and no thiophene ring product was obtained under the same conditions. Thieno[2,3‐e]‐1,2,4‐triazines were also more efficiently obtained by the action of phosphorus petnasulfide in pyridine on the appropriate 6‐acylmethyl‐3‐mercapto‐5‐oxo‐2,5‐dihydro‐1,2,4‐triazine.
Synthesis of julolidines from anilines
Authors: Katayama Hajime , Abe Eiichi , Kaneko Kimiyoshi
Published: March 2009

Substituted Julolidines were prepared by a single step of reactions from substituted anilines.
Structure of the bromination product of 2‐ethyl‐1,4‐benzothiazin‐3(4H)‐one
Authors: Bates Robert B. , Duguay Laurent M. , Klenck Robert E. , Kriek George R. , Tempesta Michael S. , Brewer Arthur D.
Published: March 2009

2‐Ethyl‐1,4‐benzothiazin‐3(4H)‐one and bromine react smoothly to give Z‐2‐(1‐bromoethylidine)‐2(H)‐1,4‐benzothiazin‐3(4H)‐one, which results from a complex bromination‐oxidation sequence. The structure of this product was determined by an X‐ray study.
Synthesis of some 10‐alkyl‐5‐deazaflavins and their use in the oxidation of benzyl alcohol and benzylamine
Authors: Kuroda Kazunori , Nagamatus Tomohisa , Sakuma Yoshiharu , Yoneda Fumio
Published: March 2009

A series of 3‐methyl‐ and 3‐phenyl‐10‐alkyl‐5‐deazaflavins were synthesized in order to examine whether the length of 10‐alkyl‐substituents influences the oxidizing power.
The chemistry of carbazoles. X. Structure of a pentamethylcarbazole isolated from a kuwait mineral oil. An application of the UV spectral additivity
Authors: Tsunashima Yutaka , Sugimoto Tokunori , Kuroki Masatane
Published: March 2009

The structure of Carruthers' pentamethylcarbazole isolated from Kuwait mineral oil was determined. From the reported spectral data, we deduced methyl‐substitutions at the 1‐, 2‐, 4‐, 6‐ and 8‐positions and this was confirmed by synthesis. This is a good example demonstrating the usefulness of uv spectral additivity.
Note sur le mécanisme réactionnel de la transposition de Dimroth. Une étudeab initio
Authors: Nguyen Mint Tho , Leroy Georges , Sana Michel , Elguero José
Published: March 2009

Une étudeab initiode la transposition de Dimroth de l'amino‐5 tétrazole‐1,2,3,4 conduit è la conclusion qu'en phase vapeur l'étape déterminante de la vitesse n'est pas l'isomérie cycle‐chaîne, mais soit l'isomérie Z‐E de la double liaison CN, soit la migration sigmatropique‐1,3 du proton.
Synthesis of some 8‐substituted 5‐deazaflavins
Authors: Yoneda Fumio , Mori Kenya , Sakuma Yoshiharu , Koshiro Akira
Published: March 2009

Treatment of 8‐fluoro‐3,10‐dimethyl‐5‐deazaflavin (Ia) with ethyl cyanoacetate in ethanol in the presence of potassium carbonate gave the corresponding 8‐(1‐cyano‐1‐ethoxycarbonylmethyl)‐5‐deazaflavin, which was converted into 3,8,10‐trimethyl‐5‐deazaflavin by refluxing in aqueous dimethylformamide. Treatment of Ia with sodium azide in ethanol yielded 8‐azido‐3,10‐dimethyl‐5‐deazaflavin (V). Compound V was converted into the corresponding 8‐amino‐, 8‐acetamido‐, and 8‐benzamido‐5‐deazaflavins by heating in high boiling alcohols, acetic anhydride, and benzoic anhydride, respectively. Fusion of compound V with dimethyl acetylenedicarboxylate yielded 4,5‐bis(methoxycarbonyl)‐1‐(3,10‐dimethyl‐5‐deazaflavin‐8‐yl)‐1,2,3‐triazole.
Imino‐bridged heterocycles. I. A derivative of benzo[5,6]cyclohepta[1,2‐b]pyridin‐5,11‐imine
Authors: Halczenko W. , Shepard K. L.
Published: March 2009

The current interest in structures that contain a tricyclic framework with a nitrogen bridged central ring has prompted us to examine the synthesis of imino‐bridged benzocycloheptapyridines. Treatment of 5,6‐trans‐dibromobenzo[5,6]cyclohepta[1,2‐b]pyridin‐11‐one with anhydrous methyl amine in THF produced 6‐β‐bromo‐5,6‐dihydro‐11α‐hydroxy‐12‐methyl‐11H‐benzo[5,6]cyclohepta[1,2‐b]pyridin‐5,11‐imine, the first example of the desired bridged derivatives.
Synthèse deN‐2 alkyl (aryl) dioxo‐3,5 oxadiazolidine‐1,2,4
Authors: Kraus Jean‐Louis , Dugenet Philippe , Yaouanc Jean‐Jacques
Published: March 2009

La synthèse de nouveaux dérivésN‐2 alkyl (aryl) dioxo‐3,5 oxadiazolidine‐1,2,4 bioisostères de composés biologiquement actifs a été étudiée. La méthode de synthèse décrite, qui utilise des dérivés nitrés comme produit de départ et une base non‐aqueuse lors de l'étape de cyclisation, permet d'obtenir avec de bons rendements les composés alkylés ou arylés en positionN‐2.
Preparation of 3‐Amino‐1,2,4‐benzothiadiazine 1‐Oxides
Authors: Ross Donn D. , Lednicer Daniel
Published: March 2009

A series of 3‐amino‐1,2,4‐benzothiadiazine 1‐oxides were obtained from the corresponding 3‐thiomethyl ethers by displacement with a series of amines; examples of the last included variously substituted piperazines and piperidines.
Halogenated ketenes. 37. The synthesis of pyranones utilizing the (4 + 2) cycloaddition of ketenes and siloxy dienes
Authors: Brady William T. , Agho Michael O.
Published: March 2009

The reaction of diphenyl‐, dichloro‐, and chloroketenes with several siloxy dienes results in (4 + 2) and/or (2 + 2) cycloaddition products depending primarily on Substitution in the diene. The (4 + 2) cycloaddition products are easily hydrolyzed to pyranones. These results are discussed in terms of a dipolar intermediate.
Synthesis of 6H‐pyrazolo[2,3‐a][1,3,5]benzotriazepines
Authors: Peet Norton P. , Sunder Shyam , Barbuch Robert J.
Published: March 2009

Treatment of 5‐amino‐1‐(2‐aminophenyl)‐1H‐pyrazole‐4‐carbonitrile (15) with triethyl orthoformate produces 6H‐pyrazolo[2,3‐a][1,3,5]benzotriazepine‐3‐carbonitrile (16). Other members of this novel ring system result from treating 15 with triethyl orthoacetate and triethyl orthopropionate. These latter reactions, which yield homologs 17 and 19, respectively, of 16, also produce acyclic Schiff bases. These Schiff bases are useful in determining the position of the triazepine double bond in pyrazolobenzotriazepines 16,17 and 19, using 13C nmr spectroscopy.
1,3‐Dipolar cycloaddition of nitrones with α,β‐unsaturated sulfones
Authors: Dalla Croce Piero , La Rosa Concetta , Stradi Riccardo , Ballabio Marzia
Published: March 2009

C,N‐Diphenyl nitrones react with substituted α,β‐unsaturated phenylsulfones yielding isoxazolidinic cycloadducts whose structure and stereochemistry were assigned on the basis of 1H and 13C nmr data. The ycloaddition regioselectivity is discussed in accordance with frontier orbital considerations.
Selenium‐Sulfur analogs. 6. Selenoisosteres of levamisole
Authors: Jones Gerald S. , Hanson Robert N. , Davis Michael A.
Published: March 2009

A series of three new isosteres of levamisole was prepared by the substitution of the phenyl ring by the thienyl and selenienyl moieties and of the thiazole group by selenazole. The physiochemical properties and infrared spectra of the sulfur‐ and selenium‐containing analogs were very similar. Differentiation was mostapparent in the nuclear magnetic resonance spectra where the α‐ and β‐protons of the selenienyl compounds were shifted downfield relative to those of the corresponding thienyl compounds. With deuterated thiofluoroacetic acid as the solvent, a more rapid exchange was observed for the α‐proton of the selenienyl ring of compounds 17 and 18 compared to that observed for compound 16.
Reaction of ketenes with N,N‐disubstituted α‐aminomethyleneketones. XIII. Synthesis of 2H‐pyrano[3,2‐d]‐1‐benzoxepin derivatives
Authors: Menozzi Giulia , Mosti Luisa , Schenone Pietro
Published: March 2009

Cycloaddition of dichloroketone to N,N‐disubstituted (E)‐4‐aminomethylene‐3,4‐dihydro‐1‐benzoxepin‐5(2H)‐ones gave N,N‐disubstituted 4‐amino‐3,3‐dichloro‐3,4,5,6‐tetrahydro‐2H‐pyrano[3,2‐d]‐1‐benzoxepin‐2‐ones II, which are derivatives of the new heterocyclic system 2H‐pyrano[3,2‐d]‐1‐benzoxepin. Dehydrochlorination with triethylamine of II afforded N,N‐disubstituted 4‐amino‐3‐chloro‐5,6‐dihydro‐2H‐pyrano‐[3,2‐d]‐1‐benzoxepin‐2‐ones III in good to moderate yields. In the triethylamine treatment of IIh (NR2 = diphenylamino), 3‐chloro‐5,6‐dihydro‐2H‐pyrano[3,2‐d]‐1‐benzoxepin‐2‐one was isolated in low yield near to IIIh, whereas IIc (NR2 = diisopropylamino) gave in low yield 4‐diisopropylamino‐5,6‐dihydro‐2H‐pyrano(3,2‐d)‐1‐benzoxepin‐2‐one.
Synthesis of some 5,6,7,8‐tetrahydro‐4‐cinnolone derivatives and 1‐methyl‐3‐arylacetyl‐4,5,6,7‐tetrahydroindazoles
Authors: Gelin Suzanne , Dolmazon René
Published: March 2009

2‐Arylidene‐3‐oxo‐2,3,4,5,6,7‐hexahydrobenzo[b]furans 2 react with hydrazine hydrate to afford 5,6,7,8‐tetrahydro‐4‐cinnolones. By methylation, these compounds gave the corresponding N‐1 and N‐2 methyl derivatives. The mesoionic compounds are obtained, accompanied by 3‐arylacetyl‐4,5,6,7‐tetrahydroindazoles upon reaction of 2 with methylhydrazine.
Structural resolution of the stereochemistry of a spirooxirane derived from an α‐arylidene heterocyclic carbonyl. The crystal and molecular structure of 2‐(p‐chlorophenyl)‐5‐phenyl‐7‐methyl‐1‐oxa‐5,6‐diazaspiro[2.4]hept‐6‐en‐4‐one
Authors: Baker Ronald J. , Lankin David C. , Umrigar Pesi P. , Griffin Gary W. , Ege Seyhan N. , Ragone Katherine S. , Trefonas Louis M.
Published: March 2009

The stereochemical assignment of molecular geometry for α‐arylidene carbonyl compounds and spirooxirane derived from them have continued to be a challenging problem for which the most satisfactory solution continues to be an x‐ray diffraction structure determination. In that regard, the title compound (a spirooxirane) has been found to crystallize in the monoclinic space group P21/c with cell dimensions of a = 5.989(1)Å, b = 27.625(4)Å, c = 9.374(2)Å, β = 99.06(1)°. The structure of the compound has been determined, with the refinement to R = 0.059. The previous, tentative assignment of structure has been confirmed substantiating our prediction that the oxidation of the enone system proceeds with rotation of the phenyl group on the β‐carbon away from the carbonyl group, minimizing adverse steric interactions and allowing orbitals of the carbonyl group to overlap with those of the carbanionic center during the closure of the oxirane ring. The agreement between predictions based on nmr data and the x‐ray diffraction determination will support a stronger reliance on the nmr data predictions in subsequent studies.
Synthèse et transformations de pyridopyrimidopyrimidines
Authors: Kokel Bruno , Guillaumel Jean , Royer René
Published: March 2009

Plusieurs pyridopyrimidopyrimidines et une pyrimidopyrimidoisoquinoléine sont élaborées par action de pyridines diversement substitutés ou de l'isoquinoléine sur le produit de condensation de l'amino‐4 diméthyl‐1,3 uracile et du chlorure de N‐diméthyl phosgèneiminium. Ces composés se prětent aisément à de nombreuses transformations.
Synthesis of some pyrrolobenzothiazepines via N‐aryl‐2‐thiocyanatopyrroles
Authors: Cheeseman G. W. H. , Hawi A. A.
Published: March 2009

Pyrrolo[1,2‐a[3,1]benzothiazepines were successfully synthesized from alkylthiopyrroles. The latter compounds were prepared from the appropriate N‐aryl‐2‐thiocyanopyrroles. 2,3‐Dihydro‐3‐oxo‐4‐phenylthieno[3,2‐b]pyrrole (29) was obtained from acid treatment of the 2‐pyrrolylthioacetic acid 28.
Reaction of 4‐methylene‐5(4H)‐oxazolones with diazomethane
Authors: Arenal I. , Bernabé M. , Alvarez E. Fernández , Izquierdo M. L. , Penadés S.
Published: March 2009

The reaction of diazomethane with some (E) and (Z)‐2‐substituted‐4‐methylene‐5(4)‐oxazolones (1a‐c) under two different conditions, has been studied. (E) and (Z)‐1,2‐disubstituted‐7‐oxo‐6‐oxa‐4‐azaspiro[2.4]‐hept‐4‐enes (3a‐c, 4a‐c) were mainly obtained, together with multiple addition compounds. The reaction showed to be stereoselective only when the substituents were aromatic. Acid hydrolysis of compounds 3a and 4a produced a mixture of (E) and (Z)‐3,5‐disubstituted‐tetrahydrofuran‐2‐ones (8a, 9a). Smooth methanolysis of the ring led to (E) and (Z)‐1‐benzamido‐cyclopropanecarboxylic esters (10a‐c, 11a‐c), which, on acid hydrolysis, gave (E) and (Z)‐1‐amino‐2‐phenylcyclopropanecarboxylic acids 12a and 13a. The pmr spectra have been analyzed by an iterative computer method, and the computed best values obtained have been used to deduce the stereochemistry of the spiroderivatives.
Stereochemistry and 13C NMR investigation of 9‐halotetrahydro‐4H‐pyrido[1,2‐a]pyrimidin‐4‐ones
Authors: Tóth Gábor , Hermecz István , Breining Tibor , Mészáros Zoltán , Bitter István
Published: March 2009

It was shown that the halogen atom occupies the quasi‐axial position in the predominant conformer of the 9‐halo derivatives of tetrahydro‐4H‐pyrido[1,2‐a]pyrimidin‐4‐ones. When R3 = Me, the conformational equilibrium is determined by the latter substituent which is always quasi‐axial. The effects of the methyl group and the halogen atoms on the 13C chemical shifts (SCS values) were used for the identification of cis and trans isomers. Interesting non additivity of substituent effects was found in derivatives bearing quasi‐axial substituents at C‐6 and C‐9: and this was caused by the ring flattening.