bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthetic models related to DNA intercalating molecules: Preparation of 9‐aminoacridines linked to the nucleotide bases adenine, guanine and thymine
Authors: Constant J. F. , Carden B. M. , Lhomme J.
Published: April 2009

A series of novel compounds were prepared in which the aromatic ring of the drug quinacrine (2‐methoxy‐6‐chloro‐9‐alkylaminoacridine) is linked to the nucleotide bases adenine, guanine and thymine by penta‐and hexamethylene bridges.
Nature of reissert analogs derived from N,N‐dialkyl and N,N‐diaryl carbamoyl chlorides
Authors: Kant Joydeep , Popp Frank D. , Uff Barrie C.
Published: April 2009

Reissert analogs were prepared from the reaction of isoquinoline and phthalazine with carbamoyl chlorides and cyanide using the methylene chloride‐water method. Alkylation, condensation, Michael addition, and hydrolysis reactions of these Reissert analogs have been studied and found in many cases, to be similar to those of the isoquinoline Reissert compound.
Synthesis and 13C‐NMR study of pyrazolo[4,5‐c] and pyrazolo[4,3‐c benzazepines. III
Authors: Melani Fabrizio , Cecchi Lucia , Palazzino Giovanna , Filacchioni Guido
Published: April 2009

The synthesis of pyrazolo[4,5‐c][1]benzazepin‐10‐ones 10 and 13 and pyrazolo[4,3‐c][1]benzazepin‐10‐ones 11 and 12 is reported. The structure of compounds 10‐13 and that of their parent compounds 2‐5 ensues from a 13C nmr study.
Indane‐1,3‐dione, phthalimidine and phthalide derivatives as alkylating agents
Authors: Barili Pier Luigi , Scartoni Valerio
Published: April 2009

The title compounds gave carbocations in acid media. The electrophilic aromatic substitution of those carbocations was studied.
Synthesis of spiro[cycloalkane‐1,3′‐[3H]indoles] from cycloalkanecarbaldehydes. Acid‐catalyzed rearrangement to cycloalkano[b]indoles
Authors: Rodríguez J. G. , Benito Y. , Temprano F.
Published: April 2009

Spiro[cycloalkane‐1,3′‐[3H]indoles] 2 can be obtained from the cycloalkanecarbaldehydes 1 by the Fischer reaction of their phenylhydrazones. These cyclizations are sensitive to the acid catalyst, solvent and temperature employed. Rearrangement of the 2 to the homologous cycloalkane derivatives 3 can occur by an acid catalyst or by thermal treatment of 2 in ethyleneglycol.
Large scale synthesis of bilirubin‐XIIIα from IXα
Authors: Reisinger M. , Trull F. R. , Lightner D. A.
Published: April 2009

A convenient large‐scale preparation of bilirubin‐XIIIα from IXα via acid‐catalyzed isomerization is described.
The crystal structure of 3′‐methoxy‐5‐phenyl‐5,10‐dihydrophenarsazine, C19H16AsNO
Authors: de Meester Patrice , Chu Shirley S. C. , Jovanovic Misa V. , Biehl Edward R.
Published: April 2009

The crystal structure of 3′‐methoxy‐5‐phenyl‐5,10‐dihydrophenarsazine, C19H16AsNO has been determined by the single crystal x‐ray diffraction method. The crystals are monoclinic with a = 15.305(6), b = 5.809(2), c = 17.595(6)Å, β = 92.92(2)°, V = 1562.3(1.0Å3, space group P2,/n, Z = 4 and dcalc = 1.485g cm−3. An automatic diffractometer with graphite monochromatized MoKα radiation was used to obtain 1480 observed reflection with I > 3σ(I) at 2θ < 50°. Final R = 0.040 and wR = 0.032. The tricyclic ring is folded with the central ring in a flattened boat conformation. The folding angle between the least‐squares planes of the two benzo rings is 164.6(2)°. The 3′‐methoxyphenyl group is in a boat‐axial conformation with respect to the central ring.
Synthèse univoque du nitro‐2 methoxy‐3 benzofuranne et des naphtofurannes correspondants
Authors: Einhorn Jacques , Demerseman Pierre , Royer René
Published: April 2009

Les méthoxy‐3 arénofurannes sont obtenus avec de bons rendements globaux à partir de la coumaronne‐3, des trois naphtofurannones isomères correspondantes et de la méthoxy‐7 naphto[2,1‐b]furannone‐1 par car‐bométhylation suivie de saponification et de décarboxylation. Leur nitration régio‐sélective en position 2 est assurée en les traitant successivement par du t‐butyllithium, du chlorure de triméthyl étain et du tétranitro‐méthane.
Reaction of 5‐(3,4‐dimethoxyphenyl)pyrazine‐2,3‐dicarbonitrile with alkyl radicals
Authors: Tada Masaru , Momose Hiroshi
Published: April 2009

The reaction of 5‐(3,4‐dimethoxyphenyl)pyrazine‐2,3‐dicarbonitrile (Ib) with alkyl radicals gives addition products at the C(6)‐position of the pyrazine ring as the intermediates which collapse into substitution products, 6‐alkyl‐5‐(3,4‐dimethoxyphenylpyrazine‐2,3‐dicarbonitrile (II), under oxidative conditions. Under non‐oxidative conditions the intermediate is converted into dihydropyrazine derivatives, 6‐alkyl‐(3,4‐dimethoxy‐phenyl)‐5,6‐dihydropyrazine‐2,3‐dicarbonitrile (III), and 3,6‐disubstituted pyrazine derivatives, 3,6‐dialkyl‐5‐(3,4‐dimethoxyphenyl)pyrazine‐2‐carbonitrile (IV) and 3‐acyl‐6‐alkyl‐5‐(3,4‐dimethoxyphenyl)pyrazine‐2‐carbonitrile (V).
An NMR study of the decomposition of a 2,2‐disubstituted thiazolidine. Kinetic evidence for a schiff base intermediate
Authors: Pesek Joseph J. , Niyati‐Shirkhodaee Fatemeh , Kashefi Mohammad
Published: April 2009

The pH‐rate profile for the decomposition of 2,2,5,5‐tetramethyl‐4‐thiazolidinecarboxylic acid is used to identify the presence of a Schiff base intermediate. Activation parameters for the reaction are reported at various pH's and in particular the negative values of entropy support the presence of a carbinolamine in the rate‐determining step.
Electroreduction of bicyclic heteroaromatics. Selective product formation
Authors: Kariv‐Miller Essie , Dedolph Douglas F. , Ryan Christopher M. , Mahachi Tendai J.
Published: April 2009

The electroreductions of 1‐methylindole and several benzofurans were investigated and compared with the corresponding alkali‐metal/liquid ammonia reductions. The cathodic reductions were performed using a simple apparatus with aqueous THF as the solvent and were found to be regioselective. Over‐reduction and other side reactions were avoided. The possible mechanism of the electroreductions is discussed.
Improved procedure for the preparation of 3,4‐dihydro‐2,2‐dimethyl‐2H‐1‐benzopyran‐3‐ones
Authors: Camps F. , Colomina O. , Conchillo A. , Messeguer A.
Published: April 2009

Treatment of 2,2‐dimethyl‐2H‐1‐benzopyrans 5 with a m‐chloroperoxybenzoic acid‐trifluoroacetic acid mixture and subsequent short path bulb to bulb vacuum distillation of the crude 3,4‐hydroxyesters 6 formed afforded title compounds in good yields. Suppression of trifluoroacetic acid was required when using 2,2‐di‐methyl‐2H‐1‐benzopyrans with electron donating substituents such as precocenes, as starting compounds.
1‐Aminohypoxanthine and analogues
Authors: Scheiner Peter , Arwin Sara , Eliacin Manes , Tu James
Published: April 2009

1‐Aminohypoxanthine (1a), a new positional isomer of guanine, has been obtained from 5‐aminoimidazole‐4‐carboxylic acid hydrazide and triethyl orthoformate. Pyrazolo 11 and triazolo 21 analogues of 1 result from similar reactions of the corresponding o‐aminoazole hydrazides. An indirect synthesis involving excess ortho‐ester and hydrolysis of the resulting intermediate 6 was found most effective for 1, but 11 may be prepared directly from 3‐aminopyrazole‐4‐carboxylic acid hydazide and orthoesters. Triazoles proved most resistant to fused pyrimidinone formation. The riboside of 1a (1‐aminoinosine) has been synthesized, indicating the versatility of the method.
P‐N Compounds. 27. Synthesis of a 5‐amino‐4,6‐dioxo‐1,3,5,2‐triazaphosphorine 2‐oxide
Authors: Cates Lindley A. , Li Ven‐Shun
Published: April 2009

Heating N4‐phenylphosphinyl‐bis‐(N1‐dimethyl) semicarbazide in the presence, but not in the absence, of iodomethane gave 2‐phenyl‐5‐dimethylamino‐4,6‐dioxo‐1,3,5,2‐triazaphosphorine 2‐oxide and a mechanism for this reaction is proposed. The compound was also prepared by the addition of 1,1‐dimethylhydrazine to phenylphosphonic diisocyanate. Treatment of the product with excess iodomethane gave a polymeric material and 1,1,1‐trimethylhydrazinium iodides.
Synthesis and photochemical reactivity of 3‐methylisoxazolo[4,5‐d]pyridazines
Authors: Camparini Alfredo , Ponticelli Fabio , Tedeschi Piero
Published: April 2009

A synthetic pathway to 3‐methylisoxazolo[4,5‐d]pyridazine and some of its derivatives is described. Uv irratiation of 4,7‐dimethoxy (XVII) and 7‐chloro‐4‐hydrazino‐3‐methylisoxazolo[4,5‐d]pyridazine (IX) shows that both intramolecular rearrangements and solvent involving reactions can occur.
Acylaminoacetyl derivatives of active methylene compounds. 2. The cyclization of the acetylaminoacetyl derivatives to α‐substituted tetramic acids and the formation of N‐acetyl‐α‐substituted tetramic acids
Authors: Igglessi‐Markopoulou Olga , Sandris Constantine
Published: April 2009

The reaction of aceturic acid p‐nitrophenyl ester with active methylene compounds Y‐CH2‐CO2R has been found to give either the normally expected C‐acylation compounds 2 (Y = ‐CN, ‐CO2R, ‐COCH3) or N‐acetyl‐α‐Y‐substituted tetramic acids 3 (Y = ‐CO2R,‐COCH3), depending on the reaction conditions. Moreover, the intramolecular condensation of the C‐acylation compounds 2 derived from malonic and acetoacetic esters (Y = ‐CO2R, ‐COCH3) to α‐Y‐substituted tetramic acids is shown to proceed through initial cyclization to the corresponding N‐acetyl‐α‐Y‐substituted tetramic acids 3 (Y = ‐CO2R, ‐COCH3).
A facile “one pot” synthesis of 2,9‐disubstituted 8‐azapurin‐6‐ones (3,5‐disubstituted 7‐hydroxy‐3H‐1,2,3‐triazolo[4,5‐d]pyrimidines)
Authors: Barili Pier Luigi , Biagi Giuliana , Livi Oreste , Scartoni Valerio
Published: April 2009

A series of title compounds have been synthesized by utilising benzylazide, cyanoacetamide, ethyl or methyl esters of aliphatic or aromatic carboxylic acids and sodium ethoxide as catalyst.
The rearrangement of 2‐benzyl‐5‐mesitoyl‐3(2H)‐isothiazolone to 2‐phenyl‐6‐mesitoyl‐3,4‐dihydro‐1,3‐thiazin‐4(2H)‐one
Authors: Tsolomitis A. , Sandris C.
Published: April 2009

2‐Benzyl‐5‐mesitoyl‐3(2H)‐isothiazolone (8) has been prepared from 3‐mesitoylpropionic acid (5). Reaction of the isothiazolone 8 with sodium ethoxide in ethanol has been found to yield an isomeric rearranged compound, which was characterized as 2‐phenyl‐6‐mesitoyl‐3,4‐dihydro‐1,3‐thiazin‐4(2H)‐one (9). This unexpected rearrangement is attributed to the abstraction of a benzylic hydrogen atom from the N‐benzyl group, followed by ring enlargement through cleavage of the isothiazolone SN bond.
(Perhalogenmethylthio)heterocyclen. XXI. Reaktionen halogenierter perhalogenmethylthiopyrrole: Salz‐ und radikalbildung, dimerisierung
Authors: Cibura K. , Gerstenberger M. R. C. , Haas A. , Kirste B.
Published: April 2009

Umsetzungen von 2‐Chlor‐3,4,5‐tris(trifluormethylthio)pyrrol (2a), 3‐Chlor‐2,4,5‐tris(trifluormethylthio)‐pyrrol (2b) bzw. 3,4‐Dichlor‐2,5‐bis(trifluormethylthio)pyrrol (2c) mit Silbernitrat/Silberacetat führten in guter Ausbeute zu den N‐Silberverbindungen 3a bis c. Verbindung 2b reagiert mit Kaliumhydroxidlösung zum analogen N‐Kaliumsalz 4. Reaktionen der Silbersalze 3a und b mit Jod lieferten die Dimeren 2,2′‐Di‐chlor‐3,3′,4,4′,5,5′‐hexakis(trifluormethylthio)‐2,2′‐bi‐2H‐pyrrolyl (5a) bzw. 3,3′‐Dichlor‐2,2′,4,4′,5,5′‐hexakis‐(trifluormethylthio)‐2,2′‐bi‐2H‐pyrrolyl (5b). Die Dimeren zerfallen in Lösung in Pyrrolyl‐Radikale; 3‐Chlor‐2,4,5‐Tris(trifluormethylthio)pyrrolyl wurde ESR‐ und ENDOR‐spektroskopisch vermessen, Kopplungskonstanten werden angegeben. Für die neu dargestellten Verbindungen werden Schmelzpunkte, 19F‐NMR‐ und IR‐Spektren angegeben.
Synthesis of 5‐Oxo and 7‐Oxopyrido[2,3‐d]pyrimidines
Authors: Anderson Gary L. , Richardson Stephen G.
Published: April 2009

The synthesis of 4‐amino‐2‐methylthio‐5‐oxopyrido[2,3‐d]pyrimidine 4 and its isomer, 4‐amino‐2‐methyl‐thio‐7‐oxopyrido[2,3‐d]pyrimidine 6 is described. The regiochemistry of the reaction of 4,6‐diamino‐2‐methyl‐thiopyrimidine 9 and diethyl ethoxymethylene malonate 12 is discussed.
The condensation products of 2,3,6‐trisubstituted‐1,4‐naphthoquinones with 2‐aminothiophenol
Authors: Kang W. B. , Nan'Ya Seiko , Yamaguchi Yasushi , Maekawa EturǑ , Ueno Yoshio
Published: April 2009

The 2,6‐disubstituted‐, 3,6‐disubstituted‐5H‐benzo[a]phenothiazin‐5‐one derivatives and 7‐substituted‐benzo[a] [1,4]benzothiazino[3,2‐a]phenothiazine derivatives were prepared by the condensation of 2,3,6‐trisubstituted‐1,4‐naphthoquinones with 2‐aminothiophenol. The resulting compounds were subjected to reduction, dehalogenation and condensation with aniline. Some of the condensation intermediates were isolated and the reaction mechanism was also investigated.
Synthesis, spectroscopic studies and the mechanism of formation of 4,5‐dihydro‐1,2,4‐oxadiazoles
Authors: Srivastava Rajendra M. , Freire Maria V. S. , Chaves AngeloS. S. C. , Beltrão Thereza M. , Carpenter Gene B.
Published: April 2009

Nine 4,5‐dihydro‐1,2,4‐oxadiazoles, 2a‐i, were synthesized by the reaction of benzamidoximes, 1a‐i, with aliphatic and aromatic aldehydes. None of these compounds were encountered in the literature. The ultraviolet, infrared and proton magnetic resonance spectral studies supported the cyclic structure. Structure determination of a chloral‐benzamidoxime adduct, 15, by X‐ray crystallography helped us to suggest the mechanism of formation of 4,5‐dihydro‐1,2,4‐oxadiazole from benzamidoxime and an aldehyde. Substances 2a,b,d,e,g,h, showed some activity against fungus Neurospora crassa. Compound 2e also presented growth inhibition in Mycobacterium smegmatis.
Synthesis of some substituted tetrahydropyrimido[4,5‐b][1,6]naphthyridines as potential antitumor agents
Authors: Gangjee Aleem , Ohemeng Kwasi A.
Published: April 2009

Cyclocondensation of two disubstituted 6‐aminopyrimidines 11 and 12 with 1‐benzyl‐3‐hydroxymethylene‐4‐piperidone afforded new tricyclic, linear disubstituted 6,7,8,9‐tetrahydropyrimido[4,5‐b][1,6]naphthyridines 4 and 5 respectively. Similar cyclocondensation of 11 with 1‐benzoyl‐1,2,3,6‐tetrahydropyridine‐5‐carboxalde‐hyde gave the corresponding benzoylated tetrahydropyrimido[4,5‐b][1,6]naphthyridine 6. Debenzoylation of 6 afforded 7. 1‐Benzyl‐3‐aminomethylene‐4‐piperidone when cyclocondensed with 11 also afforded 4. The linear structures were established by 1H nmr and 13C nmr. The growth of leukemia L1210 cells in culture was inhibited about 50% by 4,5,6 and 7 at 100 μM.
On Triazoles. VI. The acylation of 5‐amino‐1,2,4‐triazoles
Authors: Reiter József , Pongó László , Dvortsák Péter
Published: April 2009

The isomeric and tautomeric structure of I and II type monoacylated 5‐amino‐1,2,4‐triazole derivatives was studied with the help of their ir, uv, pmr and cmr spectra as well as model compounds prepared for this purpose. It was stated that the structure of the I type ring‐acylated derivatives is 2o and those of their II type isomers is 5a.
An efficient synthesis of 6‐fluoronalidixic acid and its conversion to enoxacin
Authors: Sanchez Joseph P. , Rogowski John W.
Published: April 2009

1‐Ethyl‐6‐fluoro‐1,4‐dihydro‐7‐methyl‐4‐oxo‐1,8‐naphthyridine‐3‐carboxylic acid (8) has been prepared in large quantities by a highly efficient process. It has in turn been degraded to give 7‐chloro‐1‐ethyl‐6‐fluoro‐1,4‐dihydro‐4‐oxo‐1,8‐naphthyridine‐3‐carboxylic acid (11). This intermediate has been reacted with piperazine to give the known antibacterial agent, enoxacin (12).
Preparation of 3‐azetidinols with non‐bulky 1‐alkyl substituents
Authors: Higgins Robert H. , Eaton Quentin L. , Worth Leroy , Peterson Myra V.
Published: April 2009

Cyclization of either the tetrahydropyranyl or trimethylsilyl ether of 1‐(alkylamino)‐3‐chloro‐2‐propanols 1 followed by cleavage of the azetidinyl ether provides a general method for the preparation of 1‐alkyl‐3‐azetidinols. Unhindered amines provide a more facile preparation of derivatives of 1, or its ethers, than do hindered amines, while hindered derivatives of 1 undergo more facile ring closure.
Synthesis of 3,3′‐biisoxazoles from cyanogen N,N′‐dioxide and trimethylsilyl enol ethers via the corresponding 5,5′‐bis(trimethylsilyloxy)‐3,3′‐Δ2‐biisoxazolines
Authors: Papadopoulou M. V. , Litinas K. E. , Nicolaides D. N.
Published: April 2009

Regioselective 1,3‐dipolar cycloaddition of Cyanogen N,N′‐dioxide (2) to trimethylsilyl enol ethers 3a‐d, 6 and 7 gave the corresponding 5,5′‐bis(trimethylsilyloxy)‐3,3′‐Δ2‐biisoxazolines which upon short heating with 10% hydrochloric acid afforded 3,3′‐biisoxazoles 5a‐d, 8 and 9. Only the intermediate 5,5′‐bis(trimethylsilyloxy)‐derivative 4a was isolated and studied. Reaction of 2 with vinyl methyl ketone (10) gave biisoxazoline 11 which by oxidation with γ‐manganese dioxide gave biisoxazole 12.
Pyrrolothienopyrazines. IV. Synthese de derives de 1′amino‐5 pyrrolo[1,2‐a]thieno[2,3‐e]pyrazine
Authors: Effi Yamien , Rault Sylvain , Lancelot Jean‐Charles , Robba Max
Published: April 2009

Les amino‐5 pyrrolo[1,2‐a]thiéno[2,3‐e]pyrazines sont obtenues par cyclisation intramoléculaire des dérivés de la N‐(pyrrolyl‐1)‐3 thiényl‐2 urée. La synthèse de ces dérivés a été mise au point à partir de l'azoture de (pyrrolyl‐1)‐2 thénoyle‐3. Les spectres de rmn sont étudiés.
Synthesis of metabolites of 3‐O‐t‐butylmorphine
Authors: Mohacsi E.
Published: April 2009

The synthesis of 2‐hydroxymethyl‐2‐propylmorphine (5) and 2‐hydroxymethyl‐2‐propylnormorphine (7), the major rat urinary metabolites of 3‐O‐t‐butylmorphine (3) are described.
The preparation of N‐carboalkoxypyrazoles and N‐phenylpyrazoles from C(α)‐dianions of carboalkoxyhydrazones and phenylhydrazones
Authors: Duncan Dean C. , Trumbo Todd A. , Almquist Catharine D. , Lentz Teresa A. , Beam Charles F.
Published: April 2009

The 1,4‐dianions of C(α),N‐carboalkoxyhydrazones and C(α),N‐phenylhydrazones were prepared in an excess of lithium diisopropylamide (LDA). These dilithiated intermediates resulted from metalation of substituted hydrazones of several all‐aliphatic cyclic ketones, aliphatic‐aromatic cyclic ketones phenylacetaldehyde, and several substituted propiophenones or acetophenones. The esters utilized for Claisen‐type condensations of these dianion intermediates included methyl salicylate, methyl p‐hydroxybenzoate, methyl nicotinate and related materials. The condensations were followed by acid‐cyclizations to give a variety of N‐phenylpyrazoles and N‐carboalkoxypyrazoles, most of which are new.
Hétérocycles à fonction quinone. 10. Synthèse et activité cytotoxique de la (diamino‐2,4 pyrimidinyl‐5)‐6 méthoxy‐2 naphtalènedione‐1,4
Authors: Delacotte Jean‐Michel , Parrot‐Lopez Hélène , Renault Jean , Cros Suzanne
Published: April 2009

Le cycle pyrimidinique de la (diamino‐2,4 pyrimidinyl‐5)‐6 méthoxy‐2 naphtalènedione‐1,4 (14) est obtenu par cycloaddition de la guanidine sur un α‐cyanocéténedithioacétal. La fonction quinone résulte de l'oxydation de l'amine primaire correspondante par le nitrosodisulfonate de potassium (réactif de Frémy). La cytotoxicité de cette quinone 14 est prometteuse.
Synthesis of di‐ and tetraalkyl‐3‐piperazinoisoquinolines and related compounds as potential antidepressant agents
Authors: Bartmann Wilhelm , Konz Elmar , Rüger Wolfgang
Published: April 2009

A series of di‐ and tetraalkyl‐3‐piperazinoisoquinolines and related compounds was synthesized via di‐ and tetraalkylated 1‐indanones as intermediates.
Aroylnitrile oxide cyclizations. 1. Synthesis of (3‐aroyl‐1,2,4‐oxadiazol‐5‐yl)acetic acids
Authors: Tegeler John J. , Diamond Craig J.
Published: April 2009

Intrermolecular cyclization of 1,3‐dipolar aroylnitrile oxides to malononitrile provided a viable approach to a variety of novel (3‐aroyl‐1,2,4‐oxadiazol‐5‐yl)acetic acid derivatives.
Thermal dealkylations of quaternized methoxyquinolinium and methoxyisoquinolinium iodides in the mass spectrometer
Authors: Peet Norton P. , Karrick Gregory L. , Barbuch Robert J.
Published: April 2009

Dealkylations of N‐alkyl 6‐ and 7‐methoxy quinolinium and isoquinolinium iodides in the mass spectrometer proceeded to give predominantly O‐demethylation when resonance stabilized ions were produced. When O‐demethylation did not provide a resonance stabilized ion, N‐dealkylation predominated.
Tetracyclic benzodiazepines. 3. Synthesis of the 2,3‐dihydro‐1h‐quino[1,8‐ab][1,5]benzodiazepine ring system, and derivatives of potential biological interest
Authors: Glamkowski Edward J. , Chiang Yulin
Published: April 2009

The synthesis of the 2,3‐dihydro‐1H‐quino[1,8‐ab][1,5]benzodiazepine ring system is described. The key step involves a Bischler‐Napieralski type cyclization of the formamide 3. This was achieved by refluxing in phosphorus oxychloride to effect a cyclodehydration to form the seven‐membered central ring. A subgroup of 1H‐quinobenzodiazepines bearing a pendant N‐methylpiperazine substituent was synthesized by a similar cyclization of ureas of type 6. These derivatives 7 are structurally related to the antipsychotic drug clozapine.
The demethylation chemistry of 3‐substituted 2‐methoxypyridines
Authors: Balko T. W. , Brinkmeyer R. S.
Published: April 2009

Upon acylation of 3‐amino‐2‐methoxypyridines, two side products were discovered, a pyridone, 5,6, and 8, and a pyridyloxazine, 4 and 9. The ratios of these products can be affected by changes in the reaction parameters. When oxalyl chloride was the acylating agent a pyridone 13 was isolated.
Isolement de nouveaux complexes de zinc de dipyrrométhènes formés au cours de la synthèse de la méso‐tétramésitylporphyrine par la réaction de Rothemund
Authors: Marchon J.‐C. , Ramasseul R. , Ulrich J.
Published: April 2009

Trois nouveaux complexes de zinc bis‐dipyrrométhèniques ont été isolés dans la préparation de la méso‐tétramésitylporphyrine par la méthode de Rothemund utilisant comme gabarit de condensation l'acétate de zinc.
Synthesis and reactions of pyrrolo[1,2‐a][3,1,6]benzothiadiazocines
Authors: Cheeseman G. W. H. , Varvounis G.
Published: April 2009

A new synthesis of the thiadiazocine ring is reported together with an investigation of the diverse chemical reactions of pyrrolo[1,2‐a][3,1,6]benzothiadiazocines.
Polycondensed nitrogen heterocycles. Part 17. Isoxazolo[4,3‐d]pyrazolo[3,4‐f][1,2,3]triazepine. A new ring system
Authors: Almerico Anna Maria , Dattolo Gaetano , Cirrincione Girolamo , Presti Giuseppe , Aiello Enrico
Published: April 2009

The title compounds were prepared by nitration of compounds 2, reduction of the dinitro derivatives 4 and diazotization of the diamino derivatives 6 followed by an intramolecular coupling reaction. Compound 4a showed good activity against Salmonella cholerasuis and Clostridium perfringens bacteria.
The structure of the diazonium coupling products of phenacyl thiocyanate and phenacyl selenocyanate with diazotized 3‐phenyl‐5‐aminopyrazole
Authors: Farag Ahmad M. , Fahmi Abdelgawad A. , Abdelhamid Abdou O. , Shawali Ahmad S. , Algharib Mohamed S.
Published: April 2009

The reaction of diazotized 3‐phenyl‐5‐aminopyrazole with phenacyl thiocyanate 1a and phenacyl selenocyanate 1b afforded directly 2‐imino‐3‐(3‐phenyl‐5‐pyrazolyl)‐5‐benzoyl‐2,3‐dihydro‐1,3,4‐thiadiazole monohydrate 9a and 2‐imino‐3‐(3‐phenyl‐5‐pyrazolyl)‐5‐benzoyl‐2,3‐dihydro‐1,3,4‐selenadiazole monohydrate 9b, respectively. The products 9a and 9b were also obtained from the reaction of C‐benzoyl‐N‐(3‐phenyl‐5‐pyrazolyl)formohydrazidoyl bromide 10 with potassium thiocyanate and potassium selenocyanate, respectively. Acetylation, benzoylation, and nitrosation of 9 afforded the corresponding diacetyl, dibenzoyl, and nitroso derivatives 11‐13, respectively. Cyclization of C‐benzoyl‐N‐(3‐phenyl‐5‐pyrazolyl)‐nitrilimine 6 was shown to give the pyrazolo [5,1‐d]triazole 8 and not the pyrazolo[5,1‐c]‐as‐triazine derivative 7, as previously reported.
The reaction of N‐carboalkoxy reissert analogs with carboxylic acids
Authors: Popp Frank D. , Duarte Frederick F. , Uff Barrie C.
Published: April 2009

The reaction of N‐carboalkoxy Reissert analogs in the presence of carboxylic acids yields the corresponding ester and heterocyclic base. Use of methoxy substituted benzoic acids yields, instead of the ester, the respective anhydride. Amides can also be prepared in a similar fashion.
Synthesis and hydrolysis of substituted imidazolinium salts. Behaviour of the degradation products on varying pH
Authors: Fernández Beatriz M. , Reverdito Ana M. , Paolucci Guillermo A. , Perillo Isabel A.
Published: April 2009

Reaction of l‐alkyl‐2,3‐diarylimidazolinium iodides 1a‐i with alkaline solutions afforded N'‐alkyl‐N‐aroyl‐N‐arylethylenediamines 2a‐i. Compounds 2 are stable under acid conditions but in neutral or alkaline media rearrange giving N‐alkyl‐N‐aroyl‐N‐arylethylenediamines 3a‐i. Treating compounds 3 with concentrated acids reverse reaction 3 → 2 takes place.

Kinetic studies were performed on this intramolecular N → N' aroyl transfer over the Ho‐pH range −0.9 to 2.30. Compounds 3 undergo acyl transfer to give 2 by a mechanism which involves a change in the rate determining step from formation to catalysed decomposition of a heterocyclic intermediate I2+ on going from Ho to pH values. The existence of maxima in the pH rate profile allowed to determine apparent pKa values of the imidazolidine intermediates which gave good correlation with Hammett sigma values. Stability of these heterocycles was also predicted by determination of thermodynamic parameters.
Nouvelle méthode de synthèse de thiazolopyridines
Authors: Couture Axel , Grandclaudon Pierre , Huguerre Eric
Published: April 2009

Il est démontré que la condensation de thioesters aromatiques et aliphatiques avec l'anion d'orthoaminochloropyridines diversement préparé constitue la meilleure stratégie d'accès vers des systèmes polyhétérocycliques condensés tels que les thiazolopyridines. La formation éventuelle de thioamides intermédiaires peut être complétée par une conversion chimique ou photochimique en produits de condensation désirés.
Kinetic study on the anelation of heterocycles. 1. Quinoxalinone derivatives synthesized by hinsberg reaction
Authors: Abasolo María I. , Gaozza Carlos H. , Fernández Beatriz M.
Published: April 2009

Kinetic studies on the Hinsberg condensation were performed trying to improve yields and achieve regio‐selectivity in the attainment of benzene‐substituted 3‐methylquinoxalin‐2(1H)‐ones. The course of the reactions between o‐phenylenediamine (o‐PDA) and substituted o‐PDA with pyruvic acid (2a) or ethyl pyruvate (2b) were followed by uv spectrophotometry at different pH values. The formation of 3‐methylquinoxalin‐2(1H)‐one (6a) was improved using sulphuric acid‐water mixtures, in which the reaction proceeded by a different mechanism. 3‐Methyl‐7‐methoxyquinoxalin‐2(1H)‐one (7b) was regioselectively synthesized independently of the pH of the reaction media. Reaction of 2‐amino‐4‐methylamine (1c) with 2a or 2b led to a mixture of 6 and 7‐quinoxalinone isomers, 6c and 7c, while 2‐amino‐4‐nitroaniline (1d) and 2,4‐diaminoaniline (1e) with 2a or 2b did not afford the heterocycle. In every case reactions with 2a were 100–1000 times faster than those with 2b. Mechanisms are proposed trying to account for the experimental results.
A 6‐bromocoumarin analog of chloramphenicol
Authors: Joshi Ramachandra V. , Badiger Virupax V.
Published: April 2009

dl‐threo‐2‐Dichloroacetamidol‐1‐[3‐(6‐bromocoumarinyl)]propane‐1,3‐diol (7) was synthesized according to Sorm's method. The fragmentation of dichloroacetamidomethyl 3‐(6‐bromocoumarinyl)ketone (4) under electron impact is reported. The results of in vitro antibacterial screening of the newly synthesized compounds have been presented.
Synthesis of 4,7‐dihydro‐4‐oxoisoxazolo[5,4‐b]pyridine‐5‐carboxylic acid derivatives as potential antimicrobial agents
Authors: Chiarino D. , Napoletano M. , Sala A.
Published: April 2009

Synthetic approaches to 3‐substituted‐7‐ethyl‐4,7‐dihydro‐4‐oxoisoxazolo[5,4‐b]pyridine‐5‐carboxylic acid derivatives from 3‐substituted‐5‐aminoisoxazoles are reported.
Flavonoids. 41. Stereospecific synthesis of 2,3‐dihydro‐c‐3‐substituted‐t‐3‐methyl‐r‐2‐phenyl‐4H‐1‐benzopyran‐4‐ones
Authors: Patonay Tamás , Patonay‐Péli Erzsébet , Litkei György , Szilágyi László , Batta Gyula , Dinya Zoltán
Published: April 2009

The synthesis of 2,3‐dihydro‐t‐3‐mesyloxy‐c‐3‐methyl‐r‐2‐phenyl‐4H‐1‐benzopyran‐4‐one (1) is described. The reaction of mesylate 1 with various nucleophiles, first of all O‐ and N‐nucleophiles, yields the corresponding 2,3‐dihydro‐c‐3‐substituted‐t‐3‐methyl‐r‐2‐phenyl‐4H‐1‐benzopyran‐4‐ones 2b, 7b, 9, 10, 12, 14 and 18. Azide 14 is a useful intermediate for the synthesis of flavonoids 15–17.
Correlation of the rates of solvolysis of the S‐Ethyldibenzothiophenium Ion
Authors: Kevill Dennis N. , Anderson Steven W.
Published: April 2009

The specific rates of solvolysis of S‐ethyldibenzothiophenium trifluoromethanesulfonate have been found to give a good linear correlation with the previously determined specific rates of solvolysis of the triethyloxonium ion, and hence with the solvent nucleophilicity scale established from the triethyloxonium ion study. A value for the sensitivity to changes in solvent nucleophilicity (1) of greater than unity (1.15) is in accord with reactivity‐selectivity considerations.
Aktive malonester als synthons für heterocyclen: Eine methode zur herstellung von 4‐hydroxy‐2(1H)‐pyridonen
Authors: Kappe Thomas , Ajili Samir , Stadlbauer Wolfgang
Published: April 2009

4‐Hydroxy‐2(1H)‐pyridone 3 können in ausgezeichneten Ausbeuten aus den Azomethinen 1 mit Trichlorphenyl‐malonaten 2 hergestellt werden, wobei die Variation der Substituenten in 1‐, 3‐, 5‐ und 6‐Stellung in einem weiten Rahmen möglich ist. Auf diese Weise werden auch in 5,6‐Stellung überbrückte Pyridone 5, 7 synthetisiert. Weiters wird die Herstellung 1‐unsubstituierter Pyridone über die Entbenzylierung der 1‐Benzylpyridone 3a,b sowie die Halogenierung zu isomeren 2‐ bzw. 4‐Chlorpyridonen 8, 9 und dem Dichlorpyridin 10 beschrieben.
The synthesis of a series of (α‐amino)indol‐3‐yl ketones
Authors: Sanchez Joseph P. , Parcell Robert F.
Published: April 2009

A series of [(α‐amino)indol‐3‐yl]‐2‐methyl‐1‐propanones and [(α‐amino)indol‐3‐yl]cyclopentylmethanones has been synthesized by a variety of reductive reactions performed on the corresponding series of (α‐azido)‐indol‐3‐yl ketones. One of the more interesting reductive procedures involved the palladium‐catalyzed decomposition of formic acid with the formation of hydrogen in situ. The (α‐azido)ketones were prepared in excellent yield by the displacement of the tertiary bromine atom from the (α‐bromo)ketones using sodium azide in N,N‐dimethylformamide. Bromination was accomplished by using either cupric bromide in ethyl acetate/chloroform or phenyltrimethylammonium tribromide in tetrahydrofuran.
An intramolecular cyclization of 7‐substituted 6‐fluoro‐ 1,8‐naphthyridine and ‐quinoline derivatives
Authors: Nishimura Yoshiro , Minamida Akira , Matsumoto Jun‐Ichi
Published: April 2009

A synthesis of 1,4‐oxazine and pyrazine ring systems by an intramolecular cyclization of 7‐substituted 1‐ethyl‐6‐fluoro‐1,4‐dihydro‐4‐oxo‐1,8‐naphthyridine and ‐quinoline derivatives having a nitrogen or oxygen nucleophilic site in the C‐7 appendage was studied. The in vitro antibacterial activities of compounds prepared by this method were tested.
Synthesis of 3,4‐Dihydro‐2‐methyl‐3‐oxo‐N‐aryl‐2H‐[1]benzothieno[3,2‐e1,2‐thiazine‐4‐carboxamide 1,1‐Dioxides
Authors: Marfat A. , Chambers R. J.
Published: April 2009

A novel synthesis of the title compounds, representing a new heterocyclic ring system, is described. Chlorosulphonation of 3‐methylbenzo[b]thiophene followed by reaction with methylamine gave sulfonamide, 4. Lithiation of 4, followed by quenching with carbon dioxide yielded acetic acid, 5. Cyclodehydration of 5 to benzothienothiazine 6 followed by reaction with aryl isocyanates afforded the desired benzothieno[3,2‐e]‐1,2‐thiazine‐4‐carboxamides 1a‐f.
Sur le mécanisme de la réaction de meth‐cohn‐tarnowski de préparation des thiocoumarines
Authors: El‐Ahmad Youssef , Reynaud Pierre
Published: April 2009

La mise en oeuvre du t‐butylthio‐2 benzaldéhyde et la cyclisation par chauffage dans l'acide polyphosphorique des (t‐butylthio‐2 phényl)‐3 cyano‐2 acrylamides conduit intermédiairement aux carboxamido‐3 imino‐2 2H‐(benzo[b]thiopyranne‐1), hydrolysables en thiocoumarines. Les auteurs suggèrent la formation intermédiaire d'un ion thiophénate prenant naissance par un mécanisme électronique à six centres.
Synthesis of 1,4,5‐trisubstituted imidazoles as juvenile hormone analogues
Authors: Bernasconi Silvana , Jommi Giancarlo , Pagliarin Roberto , Tavecchia Paolo
Published: April 2009

Eight compounds containing N‐ or N′‐alkylated imidazole rings have been synthesized and their structures have been chemically and spectroscopically demonstrated. These molecules, submitted to biological tests in order to evaluate their activity as juvenile hormones, provoke morphological changes in the pupae of Tenebrio Molitor.
Macrocyclic polyether‐diester compounds as phase‐transfer catalysts
Authors: Anchisi Carlo , Corda Luciana , Fadda Anna Maria , Maccioni Anna Maria , Podda Gianni
Published: April 2009

Three new macrocyclic polyether‐diester have been prepared. The catalytic activity of these compounds has been tested in the Br/I exchange reactions of octyl bromide with different ionic diameter cations.
Synthesis and physicochemical studies on 1,2‐bisazolylethanes
Authors: Torres J. , Lavandera J. L. , Cabildo P. , Claramunt R. M. , Elguero J.
Published: April 2009

Twenty symmetrical and asymmetrical 1,2‐bisazolylethanes have been obtained from azoles and 1,2‐dibromoethane or 1‐chloro‐2‐(pyrazol‐1‐yl)ethane by phase transfer catalysis (PTC). The 1H and 13C nmr properties are reported and the chemical shifts of the ethylene carbon atoms discussed using an additive model.
A facile synthesis of [1,2,4]triazino[3,2‐f]purines and [1,2,4]triazepino[3,2‐f]purines
Authors: Ueda Taisei , Adachi Tsuneyasu , Nagai Shin‐Ichi , Sakakibara Jinsaku , Murata Mitsuo
Published: April 2009

[1,2,4]Triazino[3,2‐f]purines 3a‐e and [1,2,4]triazepino[3,2‐f]purine 5 were synthesized by the reaction of 7,8‐diamino‐1,3‐dimethylxanthine 1 with diketones such as glyoxal, diacetyl, dibenzoyl, pyruvic aldehyde dimethyl acetal, phenylglyoxal or acetylacetone in acetic acid in the presence of boric acid or polyphosphoric acid.
Reactions of 1,3‐thiazine‐2,6‐dithiones. Part 7. Formation reactions of 3‐thioureidocinnamthioamides, 3‐[bis(alkylthio)methyleneamino]‐ and 3‐[bis(alkoxy)methyleneamino]‐dithiocinnamic acid esters by the thiazine ring opening reactions with primary amines, thiols, and alcohols. Recyclizing reactions of the acyclic thioamides and the alkyl dithiocinnamates and some related compounds
Authors: Yamamoto Tatsuo , Muraoka Motomu
Published: April 2009

2‐Alkylamino‐ and 2‐arylamino‐1,3‐thiazine‐6‐thiones 3 were synthesized by the reactions of 1,3‐thiazine‐2,6‐dithiones 1 or 2‐methylthio‐1,3‐thiazine‐6‐thiones 2 with aliphatic or aromatic primary amines. 3‐(3‐Alkyl‐thioureido)cinnamthioamides 4 were formed on treatment of compounds 3 with primary amines. The same compounds 4 formed pyrimidine‐2,4‐dithiones 5 and primary amines by acid‐catalyzed intramolecular cyclization and the primary amines and compounds 5 gave compounds 4 quantitatively (vice versa). Further, treatment of compounds 4 (R3 = butyl, pentyl, hexyl) with hydrochloric acid or thermolysis of 4 gave rise to 2‐alkylimino‐6‐amino‐1,3‐thiazine‐5‐(N‐alkyl)carbothioamides 6 accompanied by compounds 5. Compounds 3, when allowed to react with the amines in aqueous ethanol gave 3‐alkyl‐2‐alkylaminopyrimidine‐6‐thiones 8 in addition to compounds 4 by two types of reactions occuring simultaneously.

On the other hand, compounds 2, when treated with thiols and alcohols instead of primary amines in the presence of alkyl iodide, yielded alkyl 3‐[bis(alkylthio)methyleneamino]dithiocinnamates 11 and alkyl 3‐[bis(methoxy)methyleneamino]dithiocinnamates 14 respectively.

The mechanisms of the formation of these cyclic and acyclic compounds here obtained are also discussed in some detail.
Reaction between o‐diamino‐1,2,6‐thiadiazine 1,1‐dioxides and aldehydes to give fused imidazo and pyrazino derivatives
Authors: Herrero Angela , Ochoa Carmen
Published: April 2009

Reaction between 3,4,5‐triamino‐1,2,6‐thiadiazine 1,1‐dioxides and aldehydes, in acetic acid or DMF, under anhydrous conditions, leads to a mixture of imidazo[4,5‐c]‐ and pyrazino[2,3‐c]‐1,2,6‐thiadiazine derivatives. The ratio of both compounds depends on the nature of the aldehydes used. The same reaction, in the absence of solvent, affords, only pyrazinothiadiazine derivatives. The uv, 1H‐ and 13C‐nmr data of the new compounds are reported.
Reactions of electron‐rich heterocycles with orthocarboxylic acid derivatives. 11. Reactions of carbazole and 4‐methoxycarbazole with triethyl orthoformate: Regiospecific functionalization of the carbazole nucleus
Authors: Witzel H. , Pindur U.
Published: April 2009

Carbazole (1a) and 4‐methoxycarbazole (1b) can be regioselectively functionalized by reaction with triethyl orthoformate. Whereas the reaction of 1a with the ortho ester furnishes the amide acetal 2, the new carbazole derivatives 4–10 are formed, depending on the reaction conditions, in the electrophilic substitution of 1b. The products of this reaction sequence provide a contribution to studies on the mechanism of the transformation of 1b to tris‐carbazolylmethane 5. Compound 5 represents a new, three‐bladed propeller in the triheteroarylmethane series.
Organic sonochemistry. Synthesis and use of reissert compounds under PTC‐ultrasound
Authors: Ezquerra Jesus , Alvarez‐Builla Julio
Published: April 2009

Use of phase transfer catalysis and ultrasound stirring improved the synthesis, alkylation and hydrolysis of several Reissert derivatives.
Heterocyclic photorearrangements. Photochemical behaviour of some 3,5‐disubstituted 1,2,4‐oxadiazoles in methanol at 254 nm
Authors: Buscemi Silvestre , Cicero Maria G. , Vivona Nicolò , Caronna Tullio
Published: April 2009

Photochemical behaviour of some 3,5‐disubstituted 1,2,4‐oxadiazoles in methanol at 254 nm has been investigated. Ring photoisomerization to the 1,3,4‐oxadiazole heterocycle or formation of open chain compounds involving the nucleophilic solvent was shown to depend on the nature and the position of the substituent. Photoinduced ring closure into the benzimidazole system, involving a 3‐N‐phenylamino side chain sequence and a photolytic intermediate of the oxadiazole heterocycle, is also reported.
A new synthesis of 1‐aryl‐5‐cyano‐1H‐pyrazole‐4‐carboxylic acid, ethyl esters
Authors: Beck James R. , Ackmann Stephen A. , Staszak Michael A. , Wright Fred L.
Published: April 2009

A novel conversion of 5‐amino‐1‐aryl‐1H‐pyrazole‐4‐carboxylic acid, ethyl esters to the corresponding 5‐cyano esters is described. The process involves nonaqueous diazotization of the amine to form the methyl thioether, which is oxidized to the methyl sulfone, which, in turn, is displaced by cyanide ion. The cyano esters are precursors to chemical hybridizing agents in wheat and barley.
Photochemistry of ommochromes and related compounds
Authors: Bolognese A. , Liberatore R. , Scherillo G.
Published: April 2009

The photochemistry of some synthetic ommochromes, the 1‐methoxy‐11‐(β‐aspartoyl‐acetyl‐methyl ester)‐5H‐pyrido[3,2‐a]phenoxazin‐5‐one (2), the 1‐methyl‐1‐(1′‐[1′[11‐(β‐aspartoyl‐methyl ester‐imino)]ethenyl)‐ketal‐1 H,5H‐pyrido[3,2‐a]phenoxazin‐5‐one (3) and the 1,5‐dimethoxy‐11‐(β‐aspartoyl‐N‐acetyl‐methyl ester)‐pyrido[3,2‐a]phenoxazine (4), obtained from the oxidation of the 3‐hydroxykynurenine (1), has been examined. In an acidic methanol solution of 2, a reversible solvent photoaddition was observed, associated with a yellow‐red bathochromic shift. The mixture, stored in the dark, quantitatively records the starting absorption spectrum. In an acidic enviroment, 3 and 4, affording 2, show the same photochemical behaviour. A plausible mechanism, for explanation of the process is suggested.
Products from furans. V Synthesis of oxygen containing isosteres of sympathomimetic amines via 6‐hydroxy‐2H‐pyran‐3(6H)‐ones and their cis‐platinum(II) complexes
Authors: Georgiadis Minas P. , Haroutounian Serkos A. , Bailar John C.
Published: April 2009

Novel amino analogues of sympathomimetic amines, which contain the pyran ring as a consequence of their common route of preparation, were synthesized. A modified Strecker reaction on tetrahydro‐2H‐pyran‐3‐one derivatives yielded α‐benzylamino nitriles, which upon subsequent hydrogenation and hydrogenolysis gave the target 1,2‐diamines. The prepared diamines were indeed sympathomimetic on the basis of molecular mechanics studies, since they have been found to fulfill earlier considerations on the minimal structural requirements, necessary to attain high affinity to dopamine (DA) receptors. Furthermore the prepared 1,2‐diamino compounds were used as ligands for the synthesis of cis‐Platinum(II) complexes.
Synthesis of amino derivatives of 5‐aralkylidene‐3‐pyrrolin‐2‐ones
Authors: Adembri G. , Anselmi C. , Camparini A. , Rossetti M. G. , Scotton M.
Published: April 2009

Preparation of some derivatives of 5‐aralkylidene‐3‐pyrrolin‐2‐ones is reported. Compounds with an amino group on the phenyl ring at the 3‐position of the pyrrolinone ring showed suitable properties as potential UV‐A filters. Some of the compounds were quaternarized to enhance their solubility in aqueous solvents.
A convenient synthesis of amino‐substituted 1,3,5‐oxadiazinium salts
Authors: Al‐Talib Mahmoud , Tashtoush Hasan
Published: April 2009

Diacyl chlorides react with dialkylcyanamide in the presence of a Lewis acid to give amino‐substituted bis‐1,3,5‐oxadiazinium salts in excellent yields. A mechanism leads to the formation of the product has been postulated. All new compounds have been characterized by 1H‐nmr, 13C‐nmr, ir‐spectroscopy and elemental analysis.
A novel urocanic acid derivative from skin tissue extracts; (E)‐3‐[1‐(1,1‐dimethyl‐3‐oxobutyl)imidazol‐4‐yl]propenoic acid
Authors: Ienaga Kazuharu , Yamamoto Atsushi , Yamada Toshio , Joh Yoshinori
Published: April 2009

A novel derivative of urocanic acid (1) had been isolated from acetone extracts of rabbit skin tissue. It proved to be (E)‐3‐[1‐(1,1‐dimethyl‐3‐oxobutyl)imidazol‐4‐yl]propenoic acid (3c), potentially a much better ultraviolet screening agent than urocanic acid. Sterical effect of dimethyl groups in the side chain adjacent to the imidazole ring of 3c on its solubility is also discussed.
Dibromotriphenylphosphorane promoted synthesis of condensed heterocyclic systems from aromatic diamines
Authors: Al‐Khathlan Hamad , Zimmer Hans
Published: April 2009

A new and rather widely applicable method for the synthesis of a number of tri, tetra‐, and pentacyclic compounds from ortho‐aminodiacylarylimides and dibromotriphenylphosphorane via an intramolecular cyclization is reported. A mechanism for this cyclization is proposed.
Benzimidazole condensed ring systems. 1. Syntheses and biological investigations of some substituted pyrido[1,2‐a]benzimidazoles
Authors: Rida Samia M. , Soliman Farid S. G. , Badawey El‐Sayed A. M. , El‐Ghazzawi E. , Kader O. , Kappe Thomas
Published: April 2009

The synthesis of some substituted 3‐hydroxy‐1‐oxo‐1H,5H‐pyrido[1,2‐a]benzimidazole‐4‐carbonitriles and 4‐ethyl carboxylates 3 and their 0‐ and N‐dialkyl derivatives 5,6 is described. 3‐Ethoxy‐5‐ethyl‐2‐phenyl‐1H,5H‐pyrido[1,2‐a]benzimidazol‐1‐one 7 was obtained during the course of ethylating the parent ester 3t with triethyl phosphate. Chlorination of 3 with phosphorus oxychloride afforded the corresponding 1,3‐dichloropyrido[1,2‐a]benzimidazoles 8 which were converted to a variety of azido, amino, morpholino and methoxy derivatives of the system. The synthesis of the indolopyridobenzimidazole 15 is also described. Two compounds exhibited in vitro antibacterial activity. Many compounds were screened for antileukemic, antimicrobial, herbicidal and plant antifungal potencies but were inactive.
Studies on the chemistry of O,N‐ and S,N‐containing heterocycles. 3. Synthesis of 1,5‐benzothiazepines with potential CNS activity
Authors: Bartsch Herbert , Erker Thomas
Published: April 2009

The synthesis of a series of novel triazolo[3,4‐d][1,5]benzothiazepines 6 and 7, obtained from the activated 1,5‐benzothiazepine derivatives 3 and carbohydrazides 4, is described. Under mild reaction conditions some intermediates 5 can be isolated.
Direct synthesis of 2,4‐diaminoquinazolines from 2‐fluorobenzonitriles
Authors: Hynes John B. , Pathak Alpana , Panes Constantina H. , Okeke Claudia C.
Published: April 2009

In a search for new methods for preparing 2,4‐diaminoquinazolines having a diversity of substituents in the benzenoid ring, it was found that the reaction of 2,6‐difluorobenzonitrile with guanidine carbonate gave 2,4‐diamino‐5‐fluoroquinazoline in excellent yield. Extension of this approach to other 2‐fluorobenzonitriles, some of which were elaborated for the first time, showed that this reaction possesses considerable generality. The cyclization was successful even when electron donating groups were present at position six. Only in two cases where a primary or secondary amino group was also present ortho to the cyano group was this transformation unsuccessful.
Reaction of pyrazine‐2,3‐dicarbonitrile and 1,3‐dimethyllumazine with the phthalimidoalkyl radical
Authors: Tada Masaru , Totoki Shintaro
Published: April 2009

A phthalimidoalkyl radical reacts with pyrazine‐2,3‐dicarbonitrile (1) to give mono‐ and diphthalimido‐alkylpyrazine‐2,3‐dicarbonitriles 4 and 5. A similar reaction with 1,3‐dimethyllumazine (2) gave only monophthalimidoalkyl‐1,3‐dimethyllumazines 6 or 7. Hydrazine degradation of 7‐(3′‐phthalimido)propyl‐1,3‐dimethyllumazine (6c) gave a 7‐(3′‐amino)propyl derivative 8 but 7‐phthalimidomethyl‐1,3‐dimethyllumazine (6a) gave only 1,3‐dimethyllumazine (2). Thus the phthalimidomethyl group can be used as a protection group of the pteridine nucleus.
Synthesis of 2,3‐diaryl‐1,4‐diazolyl‐2,3‐epoxybutanes
Authors: Moreno‐Mañas M. , Teixidó M.
Published: April 2009

2,3‐Diaryl‐1,4‐diazolyl‐2,3‐epoxybutanes have been prepared from dimethylstilbenes. An efficient although neglected synthesis of the required olefins has been recovered from the literature. The target compounds show moderate antifungal activity.
Pyrimidines, Part XXXI. Synthesis, reactions and properties of 6‐acyl‐1,3‐dimethylpyrrolo[2,3‐d]pyrimidine‐2,4‐diones
Authors: Salih Zuhair S. , Stegmüller Peter , Pfleiderer Wolfgang
Published: April 2009

Acylations of 1,3‐dimethyl‐ (1) and 1,3,7‐trimethylpyrrolo[2,3‐d]pyrimidine‐2,4‐dione (2) with anhydrides in the presence of trifluoroacetic acid proceed well to give in good yields the corresponding 7‐acyl derivatives 3–11. The 6‐trichloroacetyl derivatives 5 and 6 are sensitive towards nucleophiles, which displace the trichloromethyl group easily by formation of the corresponding 6‐carboxylic acid derivatives 12–23. The newly synthesized compounds have been characterized by elemental analysis, uv and 1H nmr spectra and pKa, determinations.
Synthesis of ethyl 2‐[(1‐aryl‐1H‐1,2,4‐triazol‐3‐yl)oxy]propionates and related derivatives
Authors: Beck James R. , Babbitt George E. , Lynch Michael P.
Published: April 2009

Alkylation of 1‐aryl‐1H‐1,2,4‐triazol‐3‐ols with ethyl 2‐bromopropionate under basic conditions resulted in the formation of 2‐[(1‐aryl‐1H‐1,2,4‐triazol‐3‐yl)oxy]propionic acid, ethyl esters. No N‐alkylated products were detected. Similar alkylation of 2‐oxo‐5‐phenyl‐1,3,4‐thiazole and the corresponding 1,3,4‐oxadiazole gave only N‐alkylated derivatives. With 4‐hydroxy‐6‐phenylpyrimidine and 2‐oxo‐4‐phenylthiazole, both O‐ and N‐alkylation occurred. Structure assignments were based on ir and 13C nmr spectral data.
Indole derivatives as agrochemicals
Authors: Andreani Aldo , Rambaldi Mirella
Published: April 2009

The synthesis of indole derivatives prepared as potential agrochemicals is reported. The 1‐carbamoyl‐2‐indolinones 5 showed moderate nematicidal activity while the acylureas 8 were weak insecticides. The 2,4‐dinitrophenyl oxime 11c proved to be a potent herbicide with a narrow spectrum of activity.