bluuebunny/crossref_metadata_2025_split huggingface dataset:
Basicity of azoles. VII. Basicity of C‐aminopyrazoles in relation to tautomeric and protonation studies
Authors: Catalán Javier , Menéndez Margarita , Laynez José , Claramunt Rosa María , Bruix Marta , De Mendoza Javier , Elguero José 
Published: April 2009

AbstractThe pKa values of five aminopyrazoles [3(5)‐amino, 1‐methyl‐3‐amino, 1‐methyl‐5‐amino, 4‐amino and 1‐methyl‐4‐amino] were determined. The aqueous basicities are discussed in terms of tautomerism (72% of 3‐amino tautomer), protonation site (only 4‐aminopyrazoles protonate on the amino group) and amino substituent effects. The results of theoretical calculations, carried out at the semiempirical INDO level, indicate that in the gas phase 3‐ and 5‐aminopyrazoles protonate on the pyrazolic nitrogen atom, whereas 4‐aminopyrazoles possess similar proton affinities for both nitrogen atoms (pyrazolic and amino).
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

AbstractA 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

AbstractReissert 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

AbstractThe 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.
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

AbstractSpiro[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.
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

AbstractThe 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

AbstractLes 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

AbstractThe 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

AbstractThe 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

AbstractThe 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

AbstractTreatment 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

Abstract1‐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

AbstractHeating 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

AbstractA 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

AbstractThe 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

AbstractA 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

Abstract2‐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

AbstractUmsetzungen 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

AbstractThe 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

AbstractThe 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

AbstractNine 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

AbstractCyclocondensation 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

AbstractThe 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

Abstract1‐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

AbstractCyclization 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

AbstractRegioselective 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

AbstractLes 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

AbstractThe 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

AbstractThe 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

AbstractLe 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

AbstractA 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

AbstractIntrermolecular 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

AbstractDealkylations 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

AbstractThe 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

AbstractUpon 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

AbstractTrois 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

AbstractA 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

AbstractThe 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

AbstractThe 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.