bluuebunny/crossref_metadata_2025 huggingface dataset:
Medium‐sized heterocycles: Synthesis of a 2,10‐Bis(alkoxycarbonyl)‐substituted 6‐Oxo‐12H‐dibenzo[d,g][1,3,2]dioxaphosphocin
Authors: Pastor Stephen D. , Spivack John D.
Published: March 2009

The synthesis and characterization of a 2,10‐bis(alkoxycarbonyl)‐substituted 6‐oxo‐12H‐dibenzo[d,g][1,3,2]‐dioxaphosphocin, 6, is described. The lack of an observable 5JHP coupling of phosphorus to the downfield C‐12 methylene proton and the observation of a 2JHCH geminal coupling constant of 14 Hz suggest that the conformation of 6 in solution is not solely a boat‐chair conformation, but may involve a rapid equilibrium of the boat‐chair with either a boat or twist‐boat conformation.
Bond‐switch rearrangement of 3‐oxo‐Δ4‐1,2,4‐thiadiazolin‐5‐yl ureas
Authors: L'Abbé Gerrit , Albrecht Ernestine , Toppet Suzanne
Published: March 2009

5‐Amino‐3‐oxo‐Δ4‐1,2,4‐thiadiazolines 5a,b react with isocyanates to yield 1,2,4‐thiadiazolidine derivatives 9a‐d via bond switching of the corresponding isomers 7. The same type of products 9e‐m was obtained by treatment of 5‐amino‐1,2,3,4‐thiatriazoles 6a‐d with two equivalents of isocyanate.
Novel reaction of carbon suboxide. Synthesis of 6‐amino‐4‐hydroxy‐2(1H)‐pyridone derivatives
Authors: Bonsignore Leonardo , Cocco Maria Teresa , Loy Giuseppe , Onnis Valentina
Published: March 2009

The reaction of 2‐cyanoacetamidines 1 with carbon suboxide 2 afforded 6‐amino‐4‐hydroxy‐2(1H)‐pyri‐dones 4. Compounds 4 were also obtained by reaction of amidines 1 and 2,4,6‐trichlorophenylmalonates 3.
Xanthone analogues of milrinone
Authors: Montanari Paola , Chiarini Alberto , Budriesi Roberta , Valenti Piero
Published: March 2009

The xanthone analogues of milrinone have been prepared. The new compounds do not retain the inotropic activity of the parent compound.
Chemistry of coumarins. Thermal reactions of 4‐chloro‐3‐coumarinyl N,N‐dialkyldithiocarbamates and 3‐nitro‐4‐coumarinyl N‐phenyldithiocarbamate
Authors: Tabaković K. , Tabaković I.
Published: March 2009

The thermal reactions of 4‐chloro‐3‐coumarinyl N,N‐dialkyldithiocarbamates 2–4 and 3‐nitro‐4‐coumarinyl N‐phenyldithiocarbamate, 9, afforded the novel heterocyclic systems, e.g. bis‐6H‐1‐benzopyrano[4,3‐b]1,4]dithiin, 7, and bis‐6H‐1‐benzopyrano[4,3‐b][1,4]thiazine, 14. A possible mechanism of the formation of the reaction products is discussed.
Synthesis of 1‐aryl‐5‐arylazo‐3‐phenylsulfonylpyrazol‐4‐ols from 1‐chloro‐3‐phenylsulfonyl‐2‐propanone
Authors: Takahashi Masahiko , Oshida Takeshi
Published: March 2009

Treatment of 1‐chloro‐3‐phenylsulfonyl‐2‐propanone (2) with arenediazonium chlorides gave 1‐arylhydrazono‐3‐chloro‐1‐phenylsulfonyl‐2‐propanones 4, which were cyclized in the presence of sodium acetate to 1‐aryl‐3‐phenylsulfonylpyrazol‐4‐ols 5B. Further treatment of 5B with arenediazonium chlorides yielded 1‐aryl‐5‐arylazo‐3‐phenylsulfonylpyrazol‐4‐ols.
Reduction of 1,3,4,6‐tetrakis(alkylthio)thieno‐[3,4‐c]thiophenes with sodium or sodium anthracenide leading to the cleavage of the alkyl‐sulfur bond
Authors: Tsubouchi Akira , Matsumura Noboru , Inoue Hiroo
Published: March 2009

The reaction of 1,3,4,6‐tetrakis(alkylthio)thieno[3,4‐c]thiophenes 1 with sodium or sodium anthracenide in hexamethylphosphoric triamide (HMPA) gave thieno[3,4‐c]thiophene‐1(3H)‐thiones 2 by the cleavage of the alkyl‐sulfur bond through the intermediary formation of their radical anions.
The synthesis of syn‐ and anti‐2(S)‐phthalimido‐methyl‐2,3,4,4a,7,7a‐hexahydro‐6‐oxo‐5H‐pyrano‐[2,3‐b]pyrroles as rigid β‐bend peptide‐mimetics
Authors: Krstenansky John L. , Del Rosario‐Chow Michelle , Currie Bruce L.
Published: March 2009

The synthesis of the syn‐ 14 and anti‐ 13 isomers of 2(S)‐phthalimidornethyl‐2,3,4,4a,7,7a‐hexahydro‐6‐oxo‐5H‐pyrano[2,3‐b]pyrrole was accomplished starting from sodium 3,4‐dihydro‐2H‐pyran‐2‐carboxylate. The isomers were separated by preparative high performance liquid chromatography. Both isomers can serve as β‐bend mimetics and represent three amino acids plus the amino group of the fourth amino acid of a peptide. The lactam nitrogen was alkylated to provide the equivalent of a leucine as the fourth amino acid residue.
Unusual formation of a novel pyrrolo[1′,2′:1,2]pyrido[3,4‐b]indole
Authors: Giri Venkatachalam S. , Das Sankar K. , Sankar Parasuraman Jai , Shoolery James N. , Keifer Paul
Published: March 2009

Reaction of 1‐methyl‐3,4‐dihydro‐β‐carboline 1 with methyl glycidate 4 gave the novel tetracyclic conjugated γ‐lactam, 2‐methylpyrrolo[1′,2′:1,2]pyrido[3,4–6]indol‐3‐one 5. The same compound 5 was obtained in higher yield when 1 was treated with methyl 2‐methoxyacrylate 7. Sodium borohydride treatment of 5 resulted in the cleavage of lactam to yield the unexpected alcohols 8 and 9.
Tricyclic heteroaromatic systems. 5H‐1,2,4‐triazolo[5,1‐c][1,4]benzodiazepine
Authors: Melani F. , Cecchi L. , Colotta V. , Catarzi D. , Filacchioni G.
Published: March 2009

The synthesis of the new tricyclic heteroaromatic system 5H‐1,2,4‐triazolo[5,1‐c][1,4]benzodiazepine, diazaanalogue of 5H‐pyrrolo[2,1‐c][1,4]benzodiazepine, which is the common feature of some antitumor antibiotics, is reported. The structure of the new tricyclic system and of some of its key intermediates is assigned by means of nuclear magnetic resonance studies.
Synthesis of lipophilic crown ethers with pendant phosphonic acid or phosphonic acid monoethyl ester groups
Authors: Czech Bronislaw P. , Desai Dhimant H. , Koszuk Jacek , Czech Anna , Babb David A. , Robison Thomas W. , Bartsch Richard A.
Published: March 2009

Synthetic routes to fifteen lipophilic crown ether phosphonic acid monoethyl esters and nine lipophilic crown ether phosphonic acids are described. For both classes of crown ethers which have pendant, protonionizable groups, the crown ether ring sizes are systematically varied from 12‐crown‐4 and 24‐crown‐8.
Synthesis and antibacterial activity of new 5‐substituted 1‐cyclopropyl‐6‐fluoro‐7‐piperazinyl‐1,4‐dihydro‐4‐oxo‐1,8‐naphthyridine‐3‐carboxylic acids
Authors: Remuzon Philippe , Bouzard Daniel , Di Cesare Pierre , Dussy Christian , Jacquet Jean‐Pierre , Jaegly Alexandre
Published: March 2009

The 5‐hydroxymethyl and the 5‐formyl‐1‐cyclopropyl‐6‐fluoro‐7‐piperazinyl‐1,4‐dihydro‐4‐oxo‐1,8‐naphthyridine‐3‐carboxylic acids have been prepared via a 5‐trimethylsilyl group and were tested in vitro as potential antibacterials.
Synthesis of substituted 1H‐pyrrolo[3,2‐c]quinolines
Authors: Park Kwanghee Koh , Rapoport Henry
Published: March 2009

1H‐2‐Phenylpyrrolo[3,2‐c]quinoline (1a) is made by thermal cyclization of quinol‐4‐yl hydrazone. Subsequent substitution of the C‐3 hydrogen atom of the pyrrole ring of 1a with chlorine and a formyl group is easily achieved by reacting 1a with trichloroacetyl chloride and phosphorus oxychloride in DMF, respectively.
K‐region oxides and imines of benzo[b]phenanthro[2,3‐d]thiophene and benzo[b]phenanthro[3,2‐d]thiophene
Authors: Blum Jochanan , Shalom Yosef , Harvey Ronald G.
Published: March 2009

The syntheses of the K‐oxides and K‐imine derivatives of benzo[b]phenanthro[2,3‐d]thiophene and benzo‐[b]phenanthro[3,2‐d]thiophene are described. The parent hydrocarbons 1 and 2 were oxidized with osmium tetroxide and sodium metaperiodate, and the dialdehydes 12 and 18 so formed, cyclized to the corresponding epoxides 1a,12b‐dihydrobenz[b]oxireno[9,10]phenanthro[2,3‐d]thiophene (7) and 1a,12b‐dihydrobenz‐[b]oxireno[9,10]phenanthro[3,2‐d]thiophene (13). Reaction of the oxiranes with sodium azide gave mixtures of azido‐alcohols that, in turn, were transformed to the thiaarene imines 1a,12b‐dihydro‐1H‐benz[b]azirino‐[9,10]phenanthro[2,3‐d]thiophene (8) and 1a,12b‐dihydro‐1H‐benz[b]azirino[9,10]phenanthro[3,2‐d]thiophene (14), respectively, with the aid of tri‐n‐butylphosphine.
N,N‐Coupled heterobicycles from cyclic hydrazine derivatives. Part 6. Electron ionization mass spectrometry of some substituted 1‐thiocarbamoyl and 1‐carbamoylpyrazolidines
Authors: Vainiotalo P. , Morgenstern O. , Richter P. H.
Published: March 2009

The electron ionization mass spectra of six substituted 1‐thiocarbamoyl and four substituted 1‐carbamoyl‐pyrazolidines were measured and carefully analyzed. The fragmentation pathways were elucidated by metastable ion analysis and exact mass measurement. The principal fragmentations were the same for all the compounds studied. The related importance of different decomposition channels, however, varied according to the structure of the compounds. Some substituents also prompted fragmentations unique to them. The most important reaction was the loss of the thiocarbamoyl or carbamoyl substituent with simultaneous hydrogen atom migration from the (thio)carbamoyl nitrogen to the ring nitrogen giving rise to ionized pyrazolidine at m/z 72. In this process for 1‐(N‐arylthiocarbamoyl)pyrazolidines the charge tended to remain with the substituent part of the molecule. Moreover for all the compounds studied [M‐2H]+. ion peaks formed by dehydrogenization of the original compounds were observed.
Acetylene chemistry. Part 29. A convenient synthesis of 9‐(n‐alkynyl)acridinamines via a nucleophilic displacement reaction between 9‐chloroacridine and N‐alkynyl amines
Authors: Reisch Johannes , Kamal G. M. , Gunaherath B.
Published: March 2009

Three new 9‐(N‐alkynyl)acridinamines 5, 6 and 7 have been synthesized from 9‐chloroacridine using a simple aromatic nucleophilic substitution reaction.
An efficient synthesis of 6‐formyl‐1,2‐dihydro‐2‐oxo‐3‐pyridinecarboxylic acid and some carbonyl derivatives of it and its 6‐acetyl homologue
Authors: Sanchez Joseph P. , Mich Thomas F. , Huang Gin G.
Published: March 2009

Starting with 1,1‐dimethoxy‐2‐propanone (1), 6‐formyl‐1,2‐dihydro‐2‐oxo‐3‐pyridinecarboxylic acid (5a) has been prepared in large quantities by a highly efficient, 4‐step synthesis. This compound, along with its one carbon homologue, 6‐acetyl‐1,2‐dihydro‐2‐oxo‐3‐pyridinecarboxylic acid (5b) has been reacted with several carbonyl derivative forming reagents to provide a series of side chains for β‐lactams. Among these carbonyl derivatives are styrylamides which were prepared from Wittig and Horner‐Emmons reagents. The preparation of the phosphonium salts and phosphonate esters is also described.
Formation of an 6α, 14‐epoxy‐bridged isomorphinan, an unusual product from a substituted 6α,14‐dihydroxymorphinan
Authors: Davis Ronda D. , Nelson Timothy D. , Nelson Wendel L.
Published: March 2009

During alkylation of 3‐O‐benzyl‐6α‐naltrexol (1) with large aralkyl halides like 2‐bromomethylnaphthalene and 9‐chloromethylanthracene under phase transfer catalysis conditions (potassium hydroxide, tetrabutylammonium bromide, methylene chloride), formation of a new 6α,14‐epoxide‐bridged isomorphinan (4) was noted. Chemical and spectral evidence, including nmr and mass spectral data, are presented to prove its structure. Its formation results from 6α‐oxygen displacement of a 14‐O‐aralkyl ether intermediate under the phase transfer catalysis alkylation conditions.
Condensation reactions of aryl acyloins with ureas in ethylene glycol
Authors: Kim Yong Boon , Kim Chung Soo , Lee Chang Kiu
Published: March 2009

4,5‐Diaryl‐4‐imidazolin‐2‐ones were prepared in good yield by heating aryl acyloins with ureas in eth‐ylene glycol for 0.5‐2 hours. 4,4′‐Dimethoxybenzoin and 2,2′‐pyridoin gave 4‐oxazolin‐2‐one derivatives in addition to 4‐imidazolin‐2‐ones.
On the two isomeric tris(perchlorothienyl)methyl radicals
Authors: Gronowitz Salo , Temciuc Marcel , Eberson Lennart
Published: March 2009

The two isomeric tris(trichlorothienyl)carbinols have been synthesized. Upon treatment with acid the tris(trichlorothienyl)carbenium ions were formed, which upon reduction with iodide gave the tris(trichlorothienyl)methyl radicals, which were studied by epr‐spectroscopy. The β‐isomer, the tris(2,4,5‐trichloro‐3‐thienyl)methyl radical, was much more stable than the α‐isomer and showed great similarity to the perchlorotrityl radical.
He I and He II spectra of 2‐halopyridines
Authors: Caine Gavin R. , Dunne Simon J. , Von Nagy‐Felsobuki Ellak I.
Published: March 2009

The He I and He II ultraviolet photoelectron spectra of 2‐fluoro‐, 2‐chloro‐, 2‐bromo‐, and 2‐iodopyridine have been recorded and interpreted in terms of a composite‐molecule model. The sequence of the four lowest ionization energies for 2‐fluoro‐ and 2‐chloropyridine is: π3 (1a2) > nN (11a1) > π2 (2b1) > πpyr (7b2), whereas for 2‐bromo‐ and 2‐iodopyridine the assignment is: π3 (1a2) ‐ πX > nN (11a1) > πX > π2 (2b1), where X represents a bromine and iodine lone‐pair. Comparison of the He I and He II band intensities confirmed this assignment. However, ab initio calculations at the STO‐3G*/STO‐3G* and 6–31G**/STO‐3G* levels did not agree with the sequence predicted by either the composite‐molecule model, simple correlations and the He I/He II cross‐section ratios. For the 2‐fluoropyridine, a comparison using the HAM/3 model was found to be in agreement with this assignment.
New organic nitrates. II. Synthesis of 2H‐pyrido[2,3‐e]‐1,3‐oxazine‐2,4(3H)‐diones, 2H‐pyrido[4,3‐e]‐1,3‐oxazine‐2,4(3H)‐diones, 2H‐pyrido[4,3‐e]‐1,3‐oxazin‐4(3H)‐ones, 2H‐thieno[2,3‐e]‐1,3‐oxazin‐4(3H)‐ones and 2H‐thieno[3,4‐e]‐1,3‐oxazin‐2,4(3H)‐diones
Authors: Benedini Francesca , Bertolini Giorgio , Ferrario Francesco , Motti Angelo , Sala Alberto , Somenzi Flavio
Published: March 2009

The preparation and the physico‐chemical characterization of 2H‐pyrido[2,3‐e]‐1,3‐oxazine‐2,4(3H)‐diones, 2H‐pyrido[4,3‐e]‐1,3‐oxazine‐2,4(3H)‐diones, 2H‐pyrido[4,3‐e]‐1,3‐oxazin‐4(3H)‐ones, 2H‐thieno[2,3‐e]‐1,3‐oxazin‐4(3H)‐ones and 2H‐thieno[3,4‐e]‐1,3‐oxazine‐2,4(3H)‐diones are reported.
Synthesis of new 1,2,4‐triazolines and 1,3,4‐thiadiazolines from bithioureas
Authors: Ernst Steffen , Richter Christian , Hobert Annette , Mariam Getachew G. , Schulze Klaus
Published: March 2009

2,4‐Disubstituted thiosemicarbazides 1 react with acyl isothiocyanates to give bithioureas 2, which by the action of sodium ethanolate cyclize to 1,2,4‐triazoline‐3‐thiones 3 and 5, respectively. Treatment of 2 with methyl iodide yields 1,3,4‐thiadiazoline‐2‐imines 8 isomeric with 3. Compound 8d undergoes a thermal induced DIMROTH rearrangement to give 3d in good yield.
Reactivity of 7‐(2‐dimethylaminovinyl)pyrazolo[1,5‐a]pyrimidines: Synthesis of pyrazolo[1,5‐a]pyrido[3,4‐e]pyrimidine derivatives as potential benzodiazepine receptor ligands. 2
Authors: Bruni Fabrizio , Selleri Silvia , Costanzo Annarella , Guerrini Gabriella , Casilli Maria Lucia , Giusti Laura
Published: March 2009

A series of pyrazolo[1,5‐a]pyrido[3,4‐e]pyrimidin‐6‐ones was obtained by reaction of ammonium acetate with ethyl 7‐dimethylaminovinylpyrazolo[1,5‐a]pyrimidine‐6‐carboxylates and these had been prepared from ethyl 7‐methylpyrazolo[1,5‐a]pyrimidine‐6‐carboxylates by reaction with dimethylformamide dimethylacetal. Under these conditions the compounds bearing a 2‐hydroxy group were also O‐alkylated. During the preparation of the ethyl 2‐hydroxy‐7‐methyl‐3‐phenylpyrazolo[1,5‐a]pyrimidine‐6‐carboxylate the corresponding 5‐methyl isomer was isolated and identified.
Photoreaction of pyrido[2,3‐c]furoxan
Authors: Miyazawa Tomoyuki , Takabatake Tohru , Hasegawa Minoru
Published: March 2009

When pyrido[2,3‐c]furoxan 4 was irradiated in acetonitrile containing a little water with a low pressure mercury lamp, 3‐nitro‐2‐pyridone 5 was obtained. When compound 4 was irradiated in the presence of morpholine with a low pressure mercury lamp in an argon atmosphere, 6‐morpholinopyridine 2,3‐dioxime 6, 6‐morpholinopyrido[2,3‐c]furazan 7, 3‐amino‐6‐morpholino‐2‐nitropyridine 8, and 3‐amino‐4,6‐dimorpholino‐2‐nitropyridine 9 was produced. The results of photoreaction study indicated the only photo‐product to be compound 6. The main difference between these two reactions may be considered due to the behavior of nitrogen in the pyridine ring.
Reaction of N1, N2‐diarylamidines with chloranil and 2,3‐dichloro‐1,4‐naphthoquinone
Authors: Döpp Dietrich , Gomaa Mohsen Abdel‐Motaal , Henkel Gerald , El‐Din Ahmed Mokhtar Nour
Published: March 2009

Nucleophilic attack by N2 of N1 N2‐diarylformamides 1a‐c on C‐2 of chloranil (2) and subsequently by N1 on C‐1 of 2 initiates the formation of benzimidazolinones 8a‐c. In contrast, when 1b‐e is reacted with 2,3‐dichloro‐1,4‐naphthoquinone (9), both chlorine atoms are successively substituted by the two nitrogen atoms and 2‐(arylamino)‐3‐(N‐formylarylamino)‐1,4‐naphthoquinones 13b‐e result, which (probably via their cyclic tautomers 12b‐e) may be cyclodehydrogenated to form N1,N3‐diarylnaphtho[2,3‐d] imidazoline‐2,4,9‐triones (as 14b,c). On the other hand, N1,N2diarylacetamidines 15a‐d attack 2 and 9 at C‐2 with N2 but subsequently exert nucleophilic character at the acetamidine α‐carbon attacking C‐1 of 2 and 9, respectively, thus forming 1‐aryl‐2‐(arylimino)‐3a‐hydroxy‐2,3,3a,6‐tetrahydro‐1N‐indol‐6‐ones 18a‐d and 3‐aryl‐2‐(arylimino)‐9b‐hydroxy‐2,3,5,9b‐tetrahydro‐1‐H‐benz[e]indol‐5‐ones 19b,c, respectively. The latter may be thermally dehydrated to the fully conjugated 2,5‐dihydro‐3H‐benz[e]indol‐5‐ones 20b,c. Unambiguous structural assignments for 18b and 20c are made on the basis of X‐ray crystal structure analyses.
Furopyridines. xvi. Photo[2+2]cycloaddition of furo‐[3,2‐c]pyridin‐4(5H)‐one with acrylonitrile
Authors: Shiotani Shunsaku , Tsukamoto Youichi
Published: March 2009

The photocycloaddition of furo[3,2‐c]pyridin‐4(5H)‐one (1) and its N‐methyl derivative (1‐Me) to acrylonitrile has been studied. The structures of the photoadducts isolated by column chromatography were determined on the basis of the nuclear magnetic resonance spectroscopy. The cycloaddition of 1 afforded an adduct 2 at the carbonyl oxygen and four possible isomers 3a, 3b, 3c and 3d of cyclobutane‐fused adduct at the 6‐ and 7‐position of 1, and the addition of 1‐Me the N‐methyl derivatives 3a‐Me, 3b‐Me, 3c‐Me and 3d‐Me.
New syntheses of diaza‐crown ethers using boc protecting groups
Authors: Krakowiak Krzysztof E. , Bradshaw Jerald S.
Published: March 2009

BOC‐protected m‐xylylenediamine was treated with tetraethyleneglycol ditosylate to form BOC‐protected diazabenzo‐18‐crown 5 (5) in a good yield. BOC‐protected diazabenzo‐21‐crown‐6 (6) was prepared in the same manner from BOC‐protected m‐xylylenediamine and pentaethylene glycol ditosylate. Bis‐BOC‐protected diaza‐17‐crown‐5 (12) was prepared by treating BOC‐protected 1,4‐diaminobutane with 1,11‐diiodo‐3,6,9‐trioxaundecane. The BOC‐protecting groups were removed in methanolic 2 N hydrogen chloride to form the corresponding diaza‐crown ethers 7, 8 and 13.
Synthesis and nitration of some thieno‐fused analogues of the benzo[a]quinolizinium cation
Authors: Sato Kiyoshi , Arai Sadao , Yamagishi Takamichi
Published: March 2009

Three thieno‐fused analogues of benzo[a]quinolizinium (1), thieno[3,2‐a]‐ and thieno[2,3‐a]quinolizinium 4 and 5 and thiazolo[2,3‐a]isoquinolinium (6), were synthesized by photocyclization of 1‐(2‐thienylvinyl)pyridinium salts 9a and 9b and 3‐styrylthiazolium salt 9c, respectively. The nitration of the compounds 4, 5, and 6 occurred predominantly at positions 2, 3, and 7, respectively, while the nitro group was introduced into the 8‐ and 10‐positions of 1 in the ratio of 68:32. The nmr and uv spectral properties and reduction potentials of 4–6 were also compared with those of the parent compound 1.
Synthesis of 3‐(2‐guanidinoethyl) and 3‐[2‐(S‐methylisothioureidoethyl)] analogs of 5‐isopropyl 2,6‐dimethyl‐1,4‐dihydro‐4‐(2,3‐dichlorophenyl)pyridine‐3,5‐dicarboxylate as a respective releaser of nitric oxide and inhibitor of nitric oxide synthase
Authors: Iqbal Nadeem , Knaus Edward E.
Published: March 2009

The Hantzsch condensation of 2‐azidoethyl acetoacetate with 2,3‐dichlorobenzaldehyde and isopropyl 3‐aminocrotonate afforded 3‐(2‐azidoethyl) 5‐isopropyl 2,6‐dimethyl‐1,4‐dihydro‐4‐(2,3‐dichlorophenyl)pyridine‐3,5‐dicarboxylate (7). Reduction of the 3‐(2‐azidoethyl) moiety of 7 using 5% palladium‐on‐calcium carbonate and hydrogen gas gave the 3‐(2‐aminoethyl) derivative 8, which was subjected to guanylation using 1H‐pyrazole‐1‐carboxamidine hydrochloride to yield the target 3‐(2‐guanidinoethyl) analog 9. The 3‐(2‐aminoethyl) product 8 was elaborated to the title compound 3‐[2‐(S‐methylisothioureidoethyl)] 5‐isopropyl 2,6‐dimethyl‐1,4‐dihydro‐4‐(2,3‐dichlorophenyl)pyridine‐3,5‐dicarboxylate hydrochloride (12) via the intermediate 3‐(2‐thioureidoethyl) compound 10. The 3‐(2‐guanidinoethyl 9 and 3‐[2‐(S‐methylisothioureidoethyl)] 12 compounds were about 116‐ and 23‐fold less potent calcium channel antagonists, respectively relative to the reference drug nifedipine.
Synthesis and total 1H‐NMR assignment of naphtho[1′,2′:4,5]thieno[2,3‐c][1,10]phenanthroline and naphtho[2′,1′:4,5]‐thieno[2,3‐c] [1,10]phenanthroline
Authors: Halverson Aileen Pfleider , Castle Lyle W. , Castle Raymond N.
Published: March 2009

Naphtho[1′,2′:4,5]thieno[2,3‐c][1,10]phenanthroline and naphtho[2′,1′:4,5]thieno[2,3‐c][1,10]phenanthroline, two novel polycyclic heterocyclic ring systems, have been synthesized in four steps from known starting materials. The total 1H nmr spectral assignments were made using a COSY experiment to identify the spin systems.
Synthesis and spectroscopic characterisation of 4,5‐dihydro‐[1,2,3]triazolo[5,1‐f][1,2,4]triazines. A novel condensed heterocyclic ring system
Authors: Laskos Efstathios , Lianis Pygmalion S. , Rodios Nestor A.
Published: March 2009

The reaction of the 5‐bromomethyl‐1‐dibenzoylamino‐1,2,3‐triazole (5) with aromatic amines gave the corresponding 5‐arylaminomethyl‐1‐benzoylamino‐1,2,3‐triazoles 9, which on treatment with phosphorus pentachloride gave the [1,2,3]triazolo[5,1‐f][1,2,4]triazine derivatives 10. Hydrolysis of the amide bond in 9 gave the 1‐aminotriazoles 11, which with ethyl orthoformate gave the [1,2,3]triazolo[5,1‐f][1,2,4]triazines 12, whereas with phosgene the triazolotriazinones 13 were obtained. The spectroscopic characteristics of all the new compounds are also given.
The nitration of some 1‐aryl(or benzyl)pyrroles
Authors: Korakas D. , Varvounis G.
Published: March 2009

Nitration of 1‐arylpyrroles 1a‐c with acetyl nitrate, and 1‐arylpyrroles, 1a‐e and 1‐(2‐ethoxycarbonylbenzyl)pyrrole 4 with trifluoroacetyl nitrate gave the corresponding 2‐nitro isomers 2a‐e and 5, and 3‐nitro isomers 3a‐e and 6. 3‐Nitropyrroles 3d and 3e were further nitrated with a mixture of nitric and sulfuric acids to give compounds 10, 11 and 12, respectively. Under the same conditions 1‐(2‐ethoxycarbonylbenzyl)‐3‐nitropyrrole 6 gave derivative 13.
The synthesis of 5‐acyl‐4‐aryl(alkyl)‐2‐aryl‐1,2,3‐triazole 1‐oxides by lead tetraacetate oxidation of mono‐ and bisarylhydrazones of α‐hydroxyimino‐β‐diketones
Authors: Hadjiantoniou‐Maroulis Constantina P. , Ikonomou Vassiliki , Parisopoulou Evi
Published: March 2009

The synthesis and lead tetraacetate oxidation of the title mono‐ and bis‐arylhydrazones to the corresponding 5‐acyl‐4‐aryl(alkyl)‐2‐aryl‐1,2,3‐triazole 1‐oxides is described.
NMR spectroscopic investigations with isatin guanylhydrazones
Authors: Holzer Wolfgang , Györgydeák Zoltan
Published: March 2009

The synthesis of some novel (substituted) guanylhydrazones of isatin, 5‐methylisatin and 1‐methylisatin is decribed. Moreover, detailed nmr‐spectroscopic studies (1H‐nmr, 13C‐nmr) with these compounds and previously known congeners are presented.
A simple and general method for the synthesis of novel hetarenonaphthyridones
Authors: Nemazany Alexei , Haider Norbert
Published: March 2009

Reaction of hetarylacetonitriles 1 with ethyl esters of chloro‐ or bromo‐substituted pyridinecarboxylic acids in the presence of a base affords a series of novel heterocycle‐annelated [1,6]‐, [2,6]‐, and [2,7]naphthyridones with a bridgehead nitrogen atom.
1‐Phenyl‐4(1H)‐quinazolinones and 2,3‐dihydro‐1‐phenyl‐4(1H)‐quinazolinones as potential cholecystokinin receptor ligands
Authors: Pentassuglia Giorgio , Bertani Barbara , Donati Daniele , Ursini Antonella
Published: March 2009

A series of new l‐phenyl‐4(1H)‐quinazolinones and 2,3‐dihydro‐1‐phenyl‐4(1H)‐quinazolinones were synthesized and tested as cholecystokinin receptor ligands. All the compounds showed moderate affinity and 1‐phenyl‐4(1H)‐quinazolinones resulted more effective towards the cholecystokinin‐B receptor, meanwhile the dihydro derivatives were generally more effective towards the cholecystokinin‐A receptor.
Unexpected rearrangement products from animations of 5‐bromo‐2‐nitrothiazole
Authors: Lee Ho H. , Palmer Brian D. , Boyd Maruta , Denny William A.
Published: March 2009

While reaction of 2‐bromo‐5‐nitrothiazole (2) with weakly basic secondary aliphatic amines gives the expected 2‐amino products from nucleophilic displacement of the bromine, reaction of the isomeric 5‐bromo‐2‐nitrothiazole (3) with such amines gives mixtures of the expected 5‐amino products together with 2‐aminated 5‐nitrothiazole rearrangement products. The identity of the latter were detemined by alternative synthesis, and by X‐ray crystallographic determination of a derivative. The mechanism proposed is a slow thermal isomerization of 5‐bromo‐2‐nitrothiazole (3) to the much more reactive 2‐bromo‐5‐nitro isomer 2 which competes, in the case of relatively weak amine nucleophiles, with the direct (but slow) nucleophilic displacement of the 5‐bromo group to form the normal displacement products.
Conformational analysis of 4‐(2′‐furyl)‐2‐(methylamino)pyrimidine
Authors: Mokrosz Jerzy L. , Bojarski Andrzej J. , Harden Donald B. , Strekowski Lucjan
Published: March 2009

Conformational transformations of the title compound 1 were studied using high‐resolution 1H‐nmr techniques, semi‐empirical PM3 calculations and molecular dynamics. The unfused furan‐pyrimidine ring system of 1 predominantly exists in an s‐trans conformation in solution and the considerable sp2 character of the C2amino bond results in the hindered rotation which is observed on the nmr time scale.
New process for the synthesis of UP 269‐6, a 1,2,4‐triazolo[1,5‐c]pyrimidine derivative as a potent orally active angiotensin ii antagonist
Authors: Boyer T. , Fournel L. , Nicolaï E. , Teulon J. M.
Published: March 2009

A new synthetic route to prepare the 2‐hydroxy‐5‐methyl‐7‐n‐propyl‐8‐[[2′‐(1H‐tetrazol‐5‐yl)biphenyl‐4‐yl]methyl]‐[1,2,4]triazolo[1,5‐c]pyrimidine (UP 269‐6, Ripisartan) is described. UP 269‐6 is a non‐peptide angiotensin II antagonist currently in phase II clinical trials for the treatment of hypertension and chronic heart failure. Its development needed a suitable process for industrial production. The laboratory scale synthesis was optimized and particularly two key steps: 4‐hydrazinopyrimidine formation without isolation of the 4‐chloro intermediate and its cyclization into triazolo[1,5‐c]pyrimidine derivative without isolation of the triazolo[4,3‐c]pyrimidine isomer using urea in N‐methylpyrrolidone at 160°C. This cyclization process affords a new and efficient way to prepare directly 2‐hydroxytriazolo[1,5‐c]pyrimidine without isolation of the corresponding triazolo[43‐c]pyrimidine.
The unusual formation of methyl α‐(5,6‐dimethoxycarbonyl‐2,3‐dimethoxyazepin‐7‐ylidene)‐α‐[5‐methoxycarbonyl‐2,3‐dimethoxypyrid‐6‐yl)acetate during the pyrolysis of “Azido‐meta‐hemipinate”: First example of a reaction involving a concomitant ring expansion and ring extrusion
Authors: Eswaran S. V. , Neela H. Y. , Ramakumar S. , Viswamitra M. A.
Published: March 2009

The ortho methoxycarbonyl substituent constitutes a sole exception in the ring closure reactions of ortho substituted aryl azides, as it provides no rate acceleration to this reaction. Pyrolysis of “azido‐meta‐hemipinate”, an aryl azide containing such a substituent, led us to the title compound, a new azepinylidene‐pyridylacetic ester, whose structure has been established unambiguously by a single crystal X‐ray diffraction study. This is the first report of a reaction involving both a ring expansion to an azaheptafulvalene and a ring extrusion to a pyridyl ring residue.
1,3‐cyclohexanedione as the precursor of C4X‐C6‐C4Y systems. Synthesis of pyrrolo[2,3‐e]indoles and thieno[2,3‐e]indoles
Authors: Martínez Roberto , Oloarte Juan Sandoval , Avila Gustavo
Published: March 2009

A novel synthesis of substituted pyrrolo[2,3‐e]indoles and thieno[2,3‐e]indoles is described. This new approach uses 1,3‐cyclohexanedione as the starting material. Diketone intermediates are obtained in four steps from the aforementioned ketone. Using these intermediates, the title compounds are synthesized efficiently.
Dehalogenation of 1‐methyl‐5‐halo‐4‐substituted‐pyridazin‐6‐ones
Authors: Kweon Deok‐Heon , Kang Young‐Jin , Chung Hyun‐A , Yoon Yong‐Jin
Published: March 2009

In order to confirm the regiochemistry for the functionalization of 1‐(1,1‐dibromo‐2‐oxopropyl)‐4,5‐dihalopyridazin‐6‐ones, the dehalogenation of 1‐methyl‐5‐halo‐4‐substituted‐pyridazin‐6‐ones using Pd/C and hydrogen was carried out. The results of the title reaction are reported.
Synthesis and application of 2‐arylazo‐5‐[styryl‐4‐(β‐cyano/‐carbethoxy‐β‐cyanoethenyl)]‐1,3,4‐thiadiazoles
Authors: Rangnekar D. W. , Kanetkar V. R. , Shankarling G. S. , Malanker J. V.
Published: March 2009

A novel efficient synthesis of 2‐arylazo‐5‐[styryl‐4‐(β‐cyano/carbethoxy‐β‐cyanoethenyl)]‐1,3,4‐thiadiazoles was achieved by the condensation of 2‐arylazo‐5‐methyl‐1,3,4‐thiadiazoles with 4‐(β‐cyano‐β‐carbethoxyethenyl)benzaldehyde or 4‐(β,β‐biscyanoethenyl)benzaldehyde in the presence of acetic anhydride.
The synthesis of novel polycyclic heterocyclic ring systems via photocyclization. 22 Dibenzo[f,h]benzothieno[2,3‐c]quinoline, dibenzo[f,h]benzothieno[2,3‐c][1,2,4]triazolo[4,3‐a]quinoline and dibenzo[f,h]naphtho[2′,1′:4,5]thieno[2,3‐c]quinoline
Authors: Luo Jiann‐Kuan , Cabal Maria P. , Federspiel Ronald F. , Castle Raymond N.
Published: March 2009

Photocyclization of 3‐chloro‐N‐(9‐phenanthryl)benzo[b]‐thiophene‐2‐carboxamide (3) and 3‐chloro‐N‐(9‐phenanthryl)‐naphtho[1,2‐b]thiophene‐2‐carboxamide (10) yielded dibenzo[f,h]benzothieno[2,3‐c]‐quinolin‐10(9H)‐one (4) and dibenzo[f,h]naphtho[2′,1′:4,5]thieno[2,3‐c]quinolin‐10(9H)‐one (11), respectively. Further elaboration of the lactams provided three novel unsubstituted new ring systems.
Quinoxalines X. a new and convenient synthesis of 1H‐Pyrazolo [3,4‐b] quinoxalines (Flavazoles)
Authors: Sarodnick Gerhard , Linker Torsten
Published: March 2009

Dedicated to Professor Gerhard Kempter on the occasion of his 70th birthday Quinoxaline‐2‐aldoximes and ‐ketoximes (6) react with hydrazine, alkylhydrazines or arylhydrazines under acidic conditions to afford lH‐pyrazolo[3,4‐b]quinoxalines (flavazoles) (1). Since the oximes (6) are easily available from phenylenediamine, the herein described methodology provides a convenient two step entry to various functionalized flavazoles. Furthermore, acylation and alkylation of the 1‐unsubstituted lH‐pyrazolo[3,4‐b]quinoxalines 7 proceeds smoothly and in good yield to afford 31 different flavazoles 11 and 12.
Two‐step synthesis of new 1,2,4,5‐tetrahydrospiro‐[3H‐2‐benzazepine‐3,4′‐piperidines] from 4‐iminopiperidines
Authors: Alirio Palma R. , Salas Sandra , Kouznetsov Vladimir , Stashenko Elena , Gisela Montenegro N. , Angel Fontela G.
Published: March 2009

New spiro[3H‐2‐benzazepine‐3,4′‐piperidines] and their precursors, N‐substituted 4‐allyl‐4‐N‐benzyl‐aminopiperidines, have been prepared as potential psychotic agents from readily available 4‐iminopiperidines, by a sequence of reactions that included nucleophilic addition of Grignard reagents and Bronsted acid‐mediated intramolecular cyclisation. Some of the compounds prepared have been tested in albine mice for spontaneous motor activity. All compounds prepared were characterized by ir and 1H nmr spectroscopies and cg‐ms spectrometry.
Reactivity of 4‐chlorobenzo[c][2,7]naphthyridines towards Pd(0) catalyzed coupling reactions and nucleophilic substitutions. aroylation by nucleophilic substitution with analogues of acyl anions
Authors: Duvey G. , Nivoliers F. , Rocca P. , Godard A. , Marsais F. , Quéguiner G.
Published: March 2009

Various 4‐substituted benzo[c][2,7]naphthyridines were prepared from the corresponding 4‐chloro derivative by Pd(0) coupling reaction or nucleophilic substitution. More particularly, 4‐aroyl‐benzo[e][2,7]naph‐thyridines were synthesized by aroylation with arenecarbaldehydes in the presence of 1,3‐dimethylimida‐zolium iodide.
Absorption and fluorescence properties of acridinones, thioacridinones, aminoacridines and related crown ethers
Authors: Patellis Anne‐Marie , Galy Jean‐Pierre , Kister Jacky , Chicheportiche Robert , Elguero José
Published: March 2009

We report a study on the absorptive and emissive properties of 9‐acridinones, 9‐thioacridinones and 9‐aminoacridines including six crown ether derivatives. The effect of solvents and of the addition of cations (Na+, K+, Ca2+ and Mg2+) on these properties has been studied. The absorption of the crown ether derivative of 9‐thioacridinone is sensitive to solvents while the fluorescence of crown ethers derived from 9‐aminoacridines shows some specificity towards cations. Empirical modeling was used to discuss the emission characteristics of these compounds.
Imidazo[2,1‐b]thiazoles, imidazo[2,1‐b]imidazoles and Pyrrolo[1,2‐c]imidazoles. synthesis, structure and evaluation of benzodiazepine receptor binding
Authors: Kieć‐Kononowicz K. , Handzlik J. , Lazewska D. , Pȩkala E. , Müller C. E. , Karolak‐Wojciechowska J.
Published: March 2009

As a continuation of our studies on bicyclic heterocycles with benzodiazepine receptor affinity, derivatives with a 5:5 bicyclic skeleton, namely imidazo[2,1‐b]thiazoles, imidazo[2,1‐b]imidazoles and pyrrolo[1,2‐c]imidazoles were prepared. The compounds possessed an aromatic substituent with different spatial arrangement and distance to the bicyclic skeleton. X‐ray structure analysis was performed for Z‐2‐(4‐chlorobenzylidene)‐5,5‐diphenyl‐2,3,5,6‐tetrahydroimidazo[2,1‐b]imidazoline‐3,6‐dione (6a) and 5‐amino‐6‐cyano‐7‐phenyl‐1‐oxo‐3‐thioxo‐2,3‐dihydro‐1H‐pyrrolo[1,2‐c]imidazole (20a). In contrast to the previously described arylideneimidazo[2,1‐b]thiazepinones the smaller heterocyclic ring systems investigated in this study were devoid of meaningful benzodiazepine receptor affinity as well as anti‐convulsant activity.
Synthesis and reactions of 2‐amino‐6‐(3‐methyl‐5‐oxo‐1‐phenyl‐2‐pyrazolin‐4‐yl)‐4‐phenylpyridine‐3‐carbonitrile
Authors: Ahmed R. A. , Kandeel M. M. , Abbady M. S. , Youssef M. S. K.
Published: March 2009

2‐Amino‐6‐(3‐methyl‐5‐oxo‐1‐phenyl‐2‐pyrazolin‐4‐yl)‐4‐phenylpyridine‐3‐carbonitrile (1) obtained by the reaction of 4‐(1‐iminoethyl)‐3‐methyl‐1‐phenyl‐2‐pyrazolin‐5‐one with benzylidenemalononitrile, was reacted with triethyl orthoformate followed by hydrazine hydrate, acetic anhydride, acetyl chloride, alkyl halides, benzoyl chloride, sulphuric acid followed by formamide, phenyl isothiocyanate, carbon disulphide followed by ethyl iodide, formamide, trichloroacetonitrile, nitrous acid, giving new oxopyrazolinylpyridines (2,3,5,6,8,9,10) and related pyridopyrimidines (11‐17) and pyridotriazine (18).
Synthesis and reactions of 10,10‐dimethyl‐10H‐pyrido[1,2‐a]indol‐6‐ones
Authors: Kappe Thomas , Frühwirth Franz , Roschger Peter , Jocham Brigitte , Kremsner Jenny , Stadlbauer Wolfgang
Published: March 2009

Cyclocondensation of 2,3,3‐trimefhyl‐3H‐indoles 2 with malonates 3 gives 8‐hydroxy‐10,10‐dimefhyl‐10H‐pyrido[1,2‐a]indol‐6‐ones 4, which were halogenated in position 7, 8 and 9 with sulfuryl chloride, bromine or phosphoroxychloride to give the corresponding halo‐10,10‐dimethyl‐10H‐pyrido[1,2‐a]indoles 5, 6, 7 and 8. Amination affords the 8‐amino‐10,10‐dimethyl‐10H‐pyrido[1,2‐a]indol‐6‐one 9. Nitration gives either the 10,10‐dimethyl‐7‐nitro‐10H‐pyrido[1,2‐a]indoles 10 or 10,10‐dimethyl‐7‐hydroxy‐10H‐pyrido[1,2‐a]indoles 11, depending on the conditions.
Synthesis of some benzimidazole‐, benzothiazole‐ and pyridine‐derived chelating agents
Authors: Gilbert Jayakumar G. , Addison Anthony W. , Palaniandavar Mallayan , Butcher Raymond J.
Published: March 2009

Procedures are given for the preparation of new linear bidentate, tetradentate and tripodal heptadentate ligands incorporating benzimidazole, benzothiazole and pyridyl groups. The compounds were characterized by their nmr, uv and mass spectra. The crystal and molecular structure is reported for a chiral benzothiazole derived from camphoric acid.
Synthesis of Aldehydo Sugar (4‐oxoquinazolin‐2‐yl)hydrazones and their transformation into 1‐(alditol‐1‐yl)‐1,2,4‐triazolo‐[4,3‐a]quinazolin‐5(4H)‐ones
Authors: Saleh Mohamed A. , Abdel‐Megeed Mohamed F. , Abdo Mohamed A. , Shkor Abdel‐Basset M.
Published: March 2009

A series of the aldehydo‐sugar hydrazones 4a‐d and 5a‐d were prepared by the reaction of 2‐hydrazino‐quinazolin‐4(3H)‐one (1) and 3‐ethyl‐2‐hydrazinoquinazolin‐4(3H)‐one (2) with aldoses 3a‐d. Treatment of hydrazones 4a‐d and 5a‐d with acetic anhydride in pyridine gave hydrazone acetates 6a‐d and 7a‐d. Compounds 7a‐d were also prepared by ethylation of 6a‐d. Reaction of compounds 4a‐d and 5a‐d with hot ethanolic ferric chloride led to oxidative cyclization to angular ring systems 8a‐d and 9a‐d rather than to the linear system 10. Acetylation of 8a‐d afforded the per‐O, N‐acetyl derivatives 11a‐d, which were converted into the corresponding ethyl derivatives 12a‐d. Compounds 12a‐d were identical with the acetylation products derived from 9a‐d.
Chemical transformations of 3‐amino‐2‐quinolones
Authors: Asías Silvia E. , Bruno Ana M. , Dominici Diego A. , Bollini Mariela , Gaozza Carlos H.
Published: March 2009

In order to find new antimalarial drugs, an exploration about the chemical properties of the starting compounds 3‐amino‐6‐chloro‐4‐phenyl‐1H‐quinolin‐2‐one (1) and 3‐amino‐4‐methyl‐1H‐quinolin‐2‐one (2) was developed. Acylation with acyl chloride, sulfonyl chloride and acetic anhydride were carried out. Despite a previous report [2], when acetyl chloride or acetic anhydride were assayed on 1, only the diacetyl derivative 7 was obtained. When this compound was heated at reflux temperature in a mixture of acetic acid and acetic anhydride, it was transformed in the oxazoloquinoline 8. Further reactions of the acyl derivatives with diazomethane afforded 1‐methylated compounds. Compound 2 gave the imine 16 by condensation with 4‐nitrobenzaldehyde.
Synthesis of new arylidencycloalkylpyrazoles of potential biological interest
Authors: Cardia M. C. , Maccioni E. , Bonsignore L.
Published: March 2009

Indazoles and pyrazoles are known to be pharmaceutically relevant molecules. In particular their application as both analgesic and antitumoral drugs has been reported. In order to investigate the properties of compounds belonging to these families, we have synthesised new cycloalkylpyrazoles bearing an arylidene group on the cycloalkyl ring, with the aim of modifying the biological profile of these molecules.
Natural product synthesis with unnatural results: Characterization of a novel fused imidazolidinone tetrahydropyrroloindole ring system by long‐range 1H‐15N 2D‐NMR
Authors: Hadden Chad E. , Richard David J. , Joullié Madeleine M. , Martin Gary E.
Published: March 2009

Synthetic efforts towards the indole alkaloid natural product roquefortine C resulted in the formation of an unknown intermediate. Elucidation of the structure of this molecule relied on the use of long‐range 1H‐15N 2D‐NMR. Computational predictions were used to facilitate the location of weak responses in long‐range 1H‐13C HMBC spectra. These methods provided conclusive evidence that this compound possessed a novel tetracycle. The complete 12H, 13C, and 15N chemical shift assignments of this unique fused imidazolidinone tetrahydropyrroloindole derivative are reported.
Epoxidation of homoisoflavones
Authors: Lévai Albert
Published: March 2009

A comparative study of the epoxidation of homoisoflavones (3‐benzyl‐4‐chromones) 1–4 has been performed by various oxidizing agents, víz. Epoxidation with isolated dimethyldioxirane (Method A), with alkaline hydrogen peroxide (Method B), and with sodium hypochlorite (Method C) to obtain the epoxides 4–8. Compounds 2 and 3 have also been oxidized with a combination of dimethyldioxirane and Jacobsen's Mn(III)salen catalysts (R,R)‐11 and (S,S)‐11 to afford 3‐benzoyl‐4‐chromones 9 and 10. Structures of all new compounds have been elucidated by microanalyses, ir and nmr spectroscopic measurements.
Syntheses and NMR, MS and X‐ray investigations of homoadamantane‐fused pyridopyrimidinones
Authors: Gyarmati Zsuzsanna Cs. , Csomós Péter , Bernáth Gábor , Valtamo Pauliina , Kivelä Henri , Klika Karel D. , Pihlaja Kalevi , Argay Gyula , Kálmán Alajos
Published: March 2009

The reactions of ethyl 5‐oxotricyclo[4.3.1.13,8]undecane‐4‐carboxylate (2) with methyl‐substituted 2‐aminopyridines in polyphosphoric acid (PPA) gave two products, linearly‐condensed pyridopyrimidinones 4a‐c and 2‐pyridylcarboxamides 5a‐c, whereas the reactions with amino, hydroxy and nitro derivatives of 2‐aminopyridine furnished only linearly‐condensed pyridopyrimidinones (4g‐j). Use of a mixture of PPA and phosphorus oxychloride as solvent afforded both linearly‐ (4a‐c,e,f) and angularly‐condensed (6a–c,e,f) pyridopyrimidinones. In toluene, with p‐toluenesulfonic acid as catalyst, 2‐pyridylcarboxamides 5a‐f were obtained. In a mixture of PPA and phosphorus oxychloride at 80–120 °C, 5a‐f yielded angularly‐condensed pyridopyrimidinones 6a‐f. All the products exhibited characteristic features, as determined by NMR and electron ionization mass spectrometry and X‐ray crystallography.
Synthesis and crystal structures of novel calix[4]azacrowns
Authors: No K. , Lee Hyun J. , Park Ki M. , Lee Shim S. , Noh Kwan H. , Kim Sung K. , Lee Ji Y. , Kim Jong S.
Published: March 2009

A series of novel 1,3‐altemate calix[4]arene azacrowns having mono and bis crown ethers on the lower rim of the calix[4]arene framework were synthesized. Solid‐state structures confirmed the three dimensional conformation of compounds 1–3.
Synthesis of dialkyl 1,4‐dihydro‐2,6‐dimethylpyridine‐3,5‐dicarboxylates and alkyl 1,4‐dihydro‐2,6‐dimethyl‐3‐nitropyridine‐5‐carboxylates possessing a c‐4 2,4‐dioxo‐1,2,3,4‐tetrahydropyrimidin‐5‐yl (uracil) substituent to determine calcium channel modulation structure‐activity relationships
Authors: Fassihi Afshin , Velazquez Carlos , Knaus Edward E.
Published: March 2009

The Hantzsch condensation of 5‐formyluracil (1) with methyl, isopropyl or isobutyl acetoacetate (2a‐c) in the presence of ammonium hydroxide afforded the respective dialkyl 1,4‐dihydro‐2,6‐dimethyl‐4‐(2,4‐dloxo‐1,2,3,4,‐tetrahydropyrimidin‐5‐yl)pyridine‐3,5‐dicarboxylate (3a‐c). A group of alkyl 1,4‐dihydro‐2,6‐dimethyl‐3‐nitro‐4‐(2,4‐dioxo‐1,2,3,4‐tetrahydropyrimidin‐5‐yl)pyridine‐5‐carboxylates (6a‐c) were also prepared using a modified Hantzsch reaction that involved the condensation of 5‐formyluracil with nitroacetone and either methyl, isopropyl or isobutyl 3‐aminocrotonate (5a‐c). A C‐4 2,4‐dioxo‐1,2,3,4‐tetrahydropyrimidin‐5‐yl substituent is not a suitable bioisostere for the traditional C‐4 aryl or heteroaryl substituents present in 1,4‐dihydropyridine calcium channel modulators since diisopropyl 1,4‐dihydro‐2,6‐dimemyl‐4‐(2,4‐dioxo‐1,2,3,4‐tetrahydropyrimidin‐5‐yl)pyridine‐3,5‐dicarboxylate (3b) and isobutyl 1,4‐dihydro‐2,6‐dimethyl‐3‐nitro‐4‐(2,4‐dloxo‐1,2,3,4‐tetrahydropyrimidin‐5‐yl)pyridine‐5‐carboxylate (6c) did not exhibit any in vitro calcium channel antagonist activity using a guinea pig smooth muscle calcium channel antagonist assay, or a guinea pig left atrium calcium channel agonist (positive inotropic) assay.
Facile synthesis of 1, 2‐benzisothiazole‐3‐one‐1,1 ‐dioxide methylsulfonyl derivatives
Authors: Xu Liang , Trudell Mark L.
Published: March 2009

An improved and general synthesis of saccharin methylthio and methylsulfone derivatives from chlorosubstituted saccharins is presented. A large‐scale procedure for preparation of chloro‐substituted saccharins was developed. Treatment of the saccharin chlorides with sodium thiomethoxide and t‐BuOK in DMF gave the saccharin methyl sulfides, which upon chromium(VI) oxide catalyzed oxidation with periodic acid afforded the corresponding saccharin methylsulfones in high yields.
Nucleophilic aromatic substitution of methyl 3‐nitropyridine‐4‐carboxylate
Authors: Holt Jarle , Tjosås Freddy , Bakke Jan M. , Fiksdahl Anne
Published: March 2009

The nitro group of methyl 3‐nitropyridine‐4‐carboxylate (1) has successfully been replaced by nitrogen, oxygen and sulphur nucleophiles by nucleophilic aromatic substitution to give the 3‐azido, 3‐methoxy, 3‐phenoxy and 3‐thiophenoxypyridine‐4‐carboxylates (2a — d).
Kinetics of synthesis of bis‐(benzoxazolyl‐2‐methyl) sulfide under phase‐transfer catalysis conditions
Authors: Zeng Zuo‐Xiang , Xue Wei‐Lan , Huo Wen‐Long , Gao Xue‐Chao , Cai Li‐Ya
Published: March 2009

Kinetics of synthesis of bis‐(benzoxazolyl‐2‐methyl) sulfide (BBMS) is investigated under phase‐transfer catalysis conditions. Thus, the reaction of 2‐chloromethylbenzoxazole and sodium sulfide is carried out in a two‐phase (organic/water) medium, and quaternary ammonium salt and quaternary phosphonium salt are used as phase‐transfer catalyst (PTC) in the reaction. The conversion of 2‐chloromethylbenzoxazole is dramatically enhanced by adding a small quantity of PTC and is also greatly affected by the reaction conditions. The effects of various reaction variables on the kinetics are investigated, including the amount of catalyst, the temperature, the kinds of catalysts, the kinds of solvents, and the agitation speed. An interfacial reaction mechanism is proposed to explain the characteristics of the reaction. A pseudo‐first‐order rate model is established to describe the relationship between the fractional conversion and the reaction time. The kinetics data demonstrate that the model is suitable to the reaction of synthesis of BBMS. © 2009 Wiley Periodicals, Inc. Int J Chem Kinet 41: 296–302, 2009
Solubilization and Adsolubilization of Polar and Nonpolar Organic Solutes by Linker Molecules and Extended Surfactants
Authors: Charoensaeng Ampira , Sabatini David A. , Khaodhiar Sutha
Published: March 2009

Adsolubilization reaches its maximum when a surfactant adsorbed onto the solid–liquid interface achieves complete bilayer or maximum adsorption. The attempt to enhance the adsolubilization of organic solute is accomplished by increasing interaction between the hydrophobic core of adsorbed admicelles and the organic solute. Solubilization and adsolubilization were studied with linker‐based and extended‐surfactant‐based systems. Extended surfactants have propylene oxide (PO) groups of intermediate polarity inserted between hydrophobic and lipophilic moieties in the surfactant molecule. This study evaluated the adsolubilization of polar (phenylethanol) and nonpolar (ethylcyclohexane) solutes into conventional linker‐based and extended‐surfactant‐based admicelles. The results demonstrated that the extended‐surfactant‐based systems showed higher solubilization capacity than the conventional sodium dodecyl sulfate alone or with linker. For the polar solute, the presence of PO group has a greater effect than the number of PO groups or the tail length, while for the nonpolar solute as the number of POs groups and the tail length increased, the adsolubilization capacity also increased. Preliminary explanations for these observations are provided.
The Production of an Experimental Table Margarine Enriched with Conjugated Linoleic Acid (CLA): Physical Properties
Authors: Goli Sayed Amir Hossein , Sahri Miskandar Mat , Kadivar Mahdi , Keramat Javad
Published: March 2009

Even though conjugated linoleic acid (CLA) is known to have some beneficial effects on the human body, its consumption has decreased over the past 20 years due to the replacement of animal fats by vegetable oils. In this study, using the structured lipid (SL) containing CLA, an experimental table margarine enriched with CLA was produced and stored for 3 months at two temperatures prior to performing the relevant analyses. The GC results showed that the margarine fat had 10.6% CLA. The solid fat content was the highest in week 0 in all samples, which then decreased during storage but the hardness increased. An increment in dropping point was also observed in the samples. In week 0, all the samples had the β′ crystal as the predominant crystal form but a crystal transformation from β′ to β was observed during storage.