bluuebunny/crossref_metadata_2025 huggingface dataset:
Nucleoside analogs. I. A synthesis of 1,3‐dihydroxy‐2‐(6‐substituted‐9‐purinyl)cyclohexane
Authors: Suami Tetsuo , Sato Yutaka , Fukai Yasushi , Sakota Yukio
Published: March 2009

Biologically active 1,3‐dihydroxy‐2‐(6‐substituted‐9‐purinyl)cyclohexanes (VI‐X) were prepared by a reaction between trans‐2‐amino‐1,3‐cyclohexanediol (I) and 4,6‐dichloro‐5‐amino‐pyrimidine (II), followed by cyclization and nucleophilic substitution.

Compounds VI and VII showed a weak inhibitory effect against Xanthomonas oryzae, a pathogenic bacteria of leaf blight of rice plant.
Synthesis and interconversion of 6‐aroyl‐4‐oxohexanoie acids and 5‐aryl‐2‐furanpropionic acids. Antiinflammatory agents
Authors: Short Franklin W. , Rockwood Gail M.
Published: March 2009

A series of 6‐aroyl‐4‐oxohexanoic acids (2) was prepared for intermediate use by acid‐catalyzed solvolysis of substituted 3‐(2‐furyl)acrylophenones (1). This reaction occasionally gave 5‐aryl‐2‐furanpropionic acids (3) instead of, or in addition to, the desired diketones (2). Equilibrium between 2 and 3 was observed in the case where Ar is m‐nitrophenyl. A rationalization for the formation of 3 is offered, and published reports with which our results differ are discussed. Diketones (2) were cyclized to furans (3) and antiinflammatory screening data are reported for the latter.
Aminolysis of 1,2,3‐benzotriazin‐4(3H)‐thione
Authors: Gilbert Everett E. , Veldhuis B.
Published: March 2009

A series of 4‐N‐substituted 1,2,3‐benzotriazin‐4(3H)‐imines was prepared by aminolysis of 1,2,3‐benzotriazine‐4(3H)‐thione and its 6‐chloro derivative with primary aliphatic amines. The reaction was shown to be sensitive to amine structure and to reaction conditions. Frequently observed tar formation is attributed to instability resulting from the cryptodiazonium character of the triazine ring. Spectral data substantiate the thiono and imino structures of the starting compounds and products, respectively, in the solid state.
Mass spectral study on thiazolo[3,2‐a]benzimidazoles. Studies on heterocyclic compounds. IV
Authors: Ogura H. , Itoh T. , Kikuchi K.
Published: March 2009

Condensation of α‐halocarbonyl compounds and 2‐mercaptobenzimidazole gives thiazolo‐[3,2‐a]benzimidazoles. This condensation occurred at the mercapto group of the benzimidazole followed by cyclization to form the thiazole ring. This was confirmed by the examination of the mass spectra of 2‐ and 3‐methylthiazolo[3,2‐a]benzimidazoles, 2‐ and 3‐phenylthiazolo[3,2‐a]‐benzimidazoles, and their derivatives.
Chloro‐ and dichloro‐3‐alkyl‐1,2,3‐benzotriazin‐4(3H)ones
Authors: Gilmore W. Franklin , Clark Robert N.
Published: March 2009

Several chloro‐ and dichloro‐3‐alkyl‐1,2,3‐benzotriazin‐4(3H)ones have been prepared by diazotization of methyl anthranilates. A brief study was made of factors affecting the formation of 3‐allyl‐1,2,3‐benzotriazin‐4(3H)one from methyl anthranilate. Good nmr evidence was obtained to substantiate the previously proposed methyl 2‐(3‐allyltriazeno)benzoate (VIc) intermediate.
Friedel‐crafts cyclisations. II. Further studies of polyphosphoric acid‐catalysed cyclisations of N‐cinnamoyl derivatives of aromatic amines
Authors: Johnston K. M.
Published: March 2009

Further studies of the effects of substituents in the N‐phenyl nucleus on the polyphosphoric acid‐catalysed cyclisation of cinnamanilide to 4‐phenyl‐3,4‐dihydrocarbostyril have confirmed that the isomerisation is prevented by a nitro group and retarded by other substituents in the ortho position to the NH‐ group. Although a methyl group ortho to the only position at which cyclisation can occur was also shown to retard the reaction, N‐cinnamoyl‐2,4,5‐trichloroaniline was cyclised in moderate yield after prolonged heating, but the 2,4‐dibromo and 2,5‐dimethoxy analogues were not isomerised.

Isomerisation of 2‐cinnamamidobiphenyl to 4,8‐diphenyl‐3,4‐dihydrocarbostyril was accompanied by cyclodehydration to 6‐styrylphenanthridine. Five new derivatives of cinnamanilide and eight new derivatives of 4‐phenyl‐3,4‐dihydrocarbostyril are described.
Crystal and molecular structure of 3‐hydroxy‐5‐phenylisoxazole (α form)
Authors: Biagini S. , Cannas M. , Marongiu G.
Published: March 2009

The crystal structure of the α form of 3‐hydroxy‐5‐phenylisoxazole has been determined from three‐dimensional X‐ray data. The crystals are monoclinic, space group P21/n with four molecules in the unit cell. The cell dimensions are: a = 10.41(2); b = 3.89(1); c = 19.14(4) Å; β = 96.1° (3). The structure was refined by the block‐diagonal least‐squares method to a final R value of 0.080 for 1111 observed reflections. The molecular dimensions are in good overall agreement with those in β form, while the packing is markedly different. Conjugation and planarity in the molecule are discussed.
Synthesis of 1H‐naphth[2,3‐d]imidazole‐4,9‐diones by acid catalyzed cyclization of 2‐Acylamino‐3‐amino‐1,4‐naphthoquinones
Authors: Carroll F. I. , Blackwell J. T.
Published: March 2009

The conversion of 2‐acylamino‐3‐amino‐1,4‐naphthoquinones (II) to the corresponding 2‐substituted 1H‐naphth[2,3‐d]imidazole‐4,9‐diones (I) under both alkaline and acid catalyzed conditions has been effected and the results compared. Treatment of 3‐(4′‐chlorobutanonyl‐amino)‐3‐amino‐1,4‐naphthoquinone (He) with aqueous ethanolic sodium hydroxide solution gives 1,2‐butanonaphth[2,3‐d]imidazole‐4,9‐dione (V); whereas, treatment of lie with refluxing formic acid gave 2‐(4′‐chlorobutyl)‐1H‐naphth[2,3‐d]imidazole‐4,9‐dione. Treatment of 2‐substi‐tuted 1H‐naphth[2,3‐d]imidazole‐4,5‐diones in DMF with alkyl halides in the presence of potassium carbonate affords the expected 1,2‐disubstituted naphth[2,3‐d]imidazole‐4,9‐diones (VI). The spectral properties of I, II, V and VI as well as those of some 2‐acylamino‐3‐chloro‐1,4‐naphthoquinones IV are discussed.
Insertion of chloral into linear and cyclic acetals
Authors: Dietrich H. J. , Karabinos J. V. , Raes M. C.
Published: March 2009

Contrary to the known difficulties of synthesizing dialkyl‐acetals of chloral, it was found that the latter can be quantitatively inserted into the COC bonds of cyclic, linear, substituted, or unsubstituted acetals at low temperatures in substantially anhydrous, acidic media, providing a variety of novel co‐acetals, including a 1,3,5,8‐tetraoxecane. The reaction was not applicable to ketals, where an aldol condensation was observed, nor to aldehydes other than chloral. A mechanism which avoids unstable chloral carbonium ion intermediates is discussed. In cases of substituted cyclic acetals or when two chloral units were added, often pure structural isomers were isolated, selectively formed by different Lewis acid catalysts.
Studies on the syntheses of heterocyclic compounds. Part CCCXXIX. Syntheses of i‐spiroisoquinoline derivatives by phenolic cyclization
Authors: Kametani T. , Kigasawa K. , Hiiragi M. , Ishimaru H.
Published: March 2009

Phenolic cyclization of 2‐(3‐hydroxyphenyl)‐2‐methylethylamine (XIIIa) and 2‐(3‐hydroxyphenyl)phenethylamine (XIIIb) with various carbonyl compounds afforded eight types of corresponding 1‐spirocycloalkano‐ and 1‐spiroheterocycloalkano‐1,2,3,4‐tetrahydroisoquinoline derivatives (1‐VIII) and 1,1‐disubstituted‐1, 2,3,4‐tetrahydroisoquinoline derivative (IX). The acetyl derivatives of VI and IX and the benzoyl derivatives of III and V were also prepared. In addition, a synthetic method for obtaining the starting phenethylamines was examined.
Synthesis of 10‐deazariboflavin and related 2,4‐Dioxopyrimido[4,5‐b]quinolines
Authors: O'Brien Darrcll E. , Weinslock Louis T. , Cheng C. C.
Published: March 2009

Condensation of substituted anthranilaldehydes with barbituric acid results in the formation of 2,4‐dioxopyrimido[4,5‐b]quinolines. Using this general synthetic approach, 7,8‐dimethyl‐2,4‐dioxo‐10‐ribityl‐2,3,4,10‐tetrahydropyrimido[4,5‐b]quinoline (10‐deazariboflavin) was prepared by the condensation of barbituric acid with 4,5‐dimethyl‐N‐ribitylanthranilaldehyde. The latter was obtainedin situby the treatment of 1‐[4,5‐dimethyl‐N‐(ribityl)anthraniloyl]‐2‐(p‐toluenesulfonyl)hydrazine, prepared from 4,5‐dimethylanthranilic acid with anhydrous sodium carbonate.
1,4‐Cycloaddition reactions. II. Preparation of p‐dioxino[2,3‐g]furo[3,2‐c] quinolines, p‐dioxino[2,3‐f] furo[3,2‐c] quinolines, and [1,3] dioxolo[4,5‐g] furo[3,2‐c] quinolines from 2,3‐dihydro‐5‐methylfuran and schiff bases
Authors: Perricone S. C. , Elslager Edward F. , Worth Donald F.
Published: March 2009

The boron trifluoride catalyzed 1,4‐addition of 2,3‐dihydro‐5‐methylfuran to N‐(p‐methoxy‐benzylidene)‐1,4‐benzodioxan‐6‐amine (II) gave 2 pairs of epimers, 2,3,3a,4,5,8,9,11b‐octahydro‐4‐(p‐methoxyphenyl)‐11b‐methyl‐p‐dioxino[2,3‐g]furo[3,2‐c]quinoline (IIIa and b) and 2,3,7,8,8a,9.10,1la‐octahydro‐8‐(p‐methoxyphenyl)‐11a‐methyl‐p‐dioxino[2,3‐f]furo[3,2‐c]quinoline (IVa and b). When N‐(p‐methoxybenzylidene)‐3,4‐methylenedioxyaniline (V) was condensed with 2,3‐dihydro‐5‐methylfuran in an analogous manner, a mixture of 2 epimers of 2,3,3a,4,5,10b‐hexahydro‐4‐(p‐methoxyphenyl)‐10b‐methyl[1,3]dioxolo[4,5‐g]furo[3,2‐c]quinoline (VIa and b) was isolated. Treatment of this mixture with sulfur afforded 6‐(p‐methoxyphenyl)‐8‐methyl‐1,3‐dioxolo[4,5‐g]quinoline‐7‐ethanol (VIII). Structural assignments for all of the products were made from NMR spectra. None of the compounds possessed appreciable biological activity.
Polarographic reduction of azines in acetonitrile
Authors: Millefiori Salvatore
Published: March 2009

The polarographic reduction potentials of some mono and diaza compounds were measured in acetonitrile solution and the reduction mechanism investigated by oscillopolarography and the Kouleckys analysis of the waves. Distinct regression lines were obtained for the two classes of compounds between the cathodic half‐wave potentials and the energy of the lowest unoccupied Hüekel π‐molecular orbital.
Benzimidazolediones. 1,4‐addition reactions of 4,7‐benzimidazoledione
Authors: March Louis C. , Joullié Madeleine M.
Published: March 2009

A number of 1,4‐addition reactions of 4,7‐benzimidazoledione with hydrogen halides, thiols and amines are described.
Synthesis of isoacronycine and its pyranone analog
Authors: Oh Chan Soo , Greco Claude V.
Published: March 2009

The Pechmann condensation of malic acid with 1,3‐dihydroxy‐10‐methyl‐9‐acridanone (6), performed during the search for a synthetic approach to 5‐methoxy‐2,2,11‐trimethyl‐2H‐pyrano[2,3‐b]acridan‐6‐one (isoacronycine, 11a), afforded 5‐hydroxy‐11‐methyl‐2H‐pyrano[2,3‐b)acridan‐2,6‐dione (7). This is the first example of a new heterocyclic ring system in which an acridanone and a pyranone ring have been fused. Compound 7 served as the intermediate for the preparation of 11a and was readily converted into the pyranone analog 9 of isoacronycine by known procedures. Spectral and chemical evidence distinguishing 11a from acronycine (12a) is presented.
Porphyrinogens and porphodimethenes, intermediates in the synthesis of meso‐tetraphenylporphins from pyrroles and benzaldehyde
Authors: Dolphin D.
Published: March 2009

The reaction between pyrroles and benzaldehyde in refluxing acetic acid gives meso‐tetraphenylporphins and chlorins. The initial condensations give a porphyrinogen which undergoes an acid catalyzed autoxidation to porphyrin via a porphodimethene. The chlorin is shown to be derived from the reduction of porphyrin.
Synthesis of 5‐lodo‐ and 5‐nitro‐3‐indolyl phosphates as cytochemical substrates for acid phosphatase
Authors: Rabiger Dorothy J. , Chang Mildred Y. , Matsukawa S. , Tsou K. C.
Published: March 2009

The synthesis of 5‐iodo‐3‐indolyl and 5‐nitro‐3‐indolyl phosphate for cytochemical demonstration of acid phosphatase is reported. Enzymatic hydrolysis of these compounds liberates the corresponding indoxyl which is oxidized to the substituted indigo at an acid pH. In contrast, the 5‐bromo and the unsubstituted indoxyl are not oxidized readily at an acid pH. Comparison of the UV and visible, spectra of the disubstituted indigo has offered a partial explanation for this difference. E.S.R. measurements showed that 5,5′‐diiodoindigo, unlike 5,5′‐dibromoindigo, gives a detectable radical ion at an acid pH.
Reactions of vinyl azides and β‐haloalkyl azides with active methylene compounds. Synthesis of 1‐vinyl‐1,2,3‐triazoles
Authors: L'abbé G. , Hassner Alfred
Published: March 2009

A general synthetic approach to the yet unknown class of 1‐vinyl‐1,2,3‐triazoles is the condensation of active methylene compounds with vinyl azides or their precursors, the β‐haloalkyl azides, in the presence of an alkoxide. Triazole‐4‐carboxylic acids prepared in this manner are decarboxylated smoothly on heating above their melting point. The use of NMR spectra in the structure assignment of some of the triazoles is discussed.
Purine nucleosides XXVIII. The synthesis of 7‐(2′‐deoxy‐α‐ and β‐d‐ribofuranosyl)purines from 2′‐deoxyribofuranosylimidazoles. Preparation of the 2′‐deoxy derivative of the nucleoside from pseudovitamin B12 factor G
Authors: Rousseau Robert J. , Robins Roland K. , Townsend Leroy B.
Published: March 2009

The synthesis of 1‐(2′‐deoxyribofuranosyl)imidazoles have been achieved for the first time via the fusion method of glycosidation. 4‐Amino‐5‐carboxamido‐1‐(2′‐deoxy‐α‐D‐ribofuranosyl)‐imidazole (8) and 4‐amino‐5‐carboxamido‐1‐(2′‐deoxy‐β‐D‐ribofuranosyl)imidazole (10) have been obtained and their structures established by spectroscopic methods. The first examples of 7‐(2′‐deoxyglycosyl)purines [7‐(2′‐deoxy‐α‐D‐ribofuranosyl)hypoxanthine (6) and 7‐(2′‐deoxy‐β‐D‐ribofuranosyl)hypoxanthine (11)] have been obtained from the requisite 2′‐deoxyribofuranosylimidazoles. The preparation of 6 has furnished the 2′‐deoxy derivative (α‐configuration) of the nucleoside from pseudovitamin B12 Factor G, which constitutes the first 2′‐deoxy derivative of any nucleoside isolated from the various naturally occurring pseudovitamin B12 factors.
Structure and chemistry of 4‐hydroxy‐6‐methyl‐2‐pyridone
Authors: Wang Chun‐Shan
Published: March 2009

The structure of 4‐hydroxy‐6‐methyl‐2‐pyridone formed by the reaction of 6‐methyl‐2H‐pyran‐2,4(3H)‐dione and ammonia is characterized. A method is discussed for the structure determination of pyridone type compounds. Reaction of 4‐hydroxy‐6‐methyl‐2‐pyridone with an equivalent amount of benzenesulfonyl chloride gives 4‐benzenesulfonyloxy‐6‐methyl‐2‐pyridone. With two equivalent amounts of benzenesulfonyl chloride, 2,4‐dibenzenesulfonyloxy‐6‐picoline is formed. 4‐Hydroxy‐6‐methyl‐2‐pyridone is preferentially attacked by electrophiles at the 3 position.
1,5‐naphthyridines. Synthesis of 7‐chloro‐4‐(4‐diethylamino‐1‐methylbutylamino)‐2‐methoxy‐1,5‐naphthyridine and related compounds
Authors: Mccaustland Daniel J. , Cheng C. C.
Published: March 2009

The synthesis of 7‐chloro‐4‐(4‐diethylamino‐1‐methylbutylamino)‐2‐methoxy‐1,5‐naphthyridine, a compound which incorporates the structure of both chloroquine (a schizontocidal drug) and pamaquine (a gametocytocidal drug), has been carried out. In addition, two structurally related derivatives, the, “5‐azachloroquine” and the “5‐azapamaquine,” have also been obtained by multi‐step syntheses. “5‐Azachloroquine” possesses good antimalarial activity against Plasmodium berghei. The compound was also found to be less toxic than the known 4‐aminoquinoline and 8‐aminoquinoline antimalarial drugs.
Quinazolines and 1,4‐benzodiazepines. XLVI. Photochemistry of nitrones and oxaziridines
Authors: Ning Robert Y. , Field George F. , Sternbach Leo H.
Published: March 2009

The cyclic nitrones 7‐chloro‐1,3‐dihydro‐5‐phenyl‐2H‐1,4‐benzodiazepin‐2‐one 4‐oxide (5a) and 1,3‐dihydro‐7‐methylthio‐5‐phenyl‐2H‐1,4‐benzodiazepin‐2‐one 4‐oxide (5b) are photoisomerized to readily isolable oxaziridines, 7‐chloro‐4,5‐epoxy‐5‐phenyl‐1,3,4–5‐tetrahydro‐2H‐1,4‐benzodiazepin‐2‐one (6a) and 4,5‐epoxy‐5‐phenyl‐1,3,4,5‐tetrahydro‐7‐methylthio‐2H‐1,4‐benzo‐diazepin‐2‐one (6b). Oxaziridine 6b upon further irradiation gave ring expansion and ring contraction products, 4,6‐dihydro‐2‐phenyl‐9‐methylthio‐5H‐1,3,6‐benzoxadiazocin‐5‐one (7b) and 4‐benzoyl‐3,4‐dihydro‐6‐methylthioquinoxalin‐2(1H)‐one (8b) respectively. The ring contraction product, 4‐benzoyl‐6‐chloro‐3,4‐dihydroquinoxalin‐2(1H)‐one (8a), was obtained from irradiation of oxaziridine 6a.
The structure of the cations from 2– and 4‐pyridones and related pyridines
Authors: Shoffner James P. , Bauer Ludwig , Bell Charles L.
Published: March 2009

An infrared spectral investigation of 2– and 4‐pyridone hexachloroantimonates and hexachlorostannates is reported. Protonation of these pyridones occurs on oxygen to form the 2‐ and 4‐hydroxypyridinium ions, as witnessed by the presence of both OH and NH stretching bands. Aromatic ring and skeletal frequencies in these cations correlated very well with those found in other 2– and 4‐substituted pyridinium hexachloroantimonates included in this study.
Reactions of some 4‐methylene‐4H‐pyran derivatives with primary and secondary amines
Authors: Vanallan J. A. , Reynolds G. A. , Petropoulos C. C. , Maier D. P.
Published: March 2009

4‐Dicyanomethylene‐4H‐pyrans react with secondary amines to give 2‐aminopyridine and 2‐pyridone derivatives which, in turn, have been used to prepare copyrine derivatives. These pyrans and primary amines gave copyrine and iminopyridone derivatives in addition to the dicyanomethylene‐1,4‐dihydropyridines, which had been reported previously. Reaction of cyanocarbamoylmethylene‐4H‐pyrans with secondary amines gave 2‐pyrones, and with primary amines, gave copyrines and 1,4‐dihydropyridine derivatives.
Derivatives Of ditraizinylamine and tritriazinylamine
Authors: Nohara N. , Sekiguchi S. , Matsui K.
Published: March 2009

2‐Arylamino‐4,6‐dichloro‐s‐triazine reacts with cyanuric chloride in the presence of alkali to yield N,N‐bis(4,6‐dichloro‐s‐triazin‐2‐yl)‐arylamine. In like manner, 2‐substituted o‐chloro‐, p‐chloro‐, o‐nitro‐ and p‐carbomethoxyphenylamino‐4,6‐dimethoxy‐s‐triazines react with cyanuric chloride to yield the corresponding 4,6‐dichloro‐s‐triazin‐2‐yl‐4′,6′‐dimethoxy‐s‐triazin‐2′‐ylaryl‐amine, while anilino‐, p‐toluidino, o‐ and p‐methoxyphenylamino and o‐carbomethoxyphenylamino derivatives did not.

The reaction of cyanuric chloride with 2,4‐dichloro‐6‐ethylamino‐s‐triazine in the presence of alkali yields the condensation product of the ditriazinylamine type and the reaction of cyanuric chloride with ammonia yields N,N‐bis(4,6‐dichloro‐s‐triazin‐2‐yl)‐ or tris(4,6‐dichloro‐s‐triazin‐2‐yl)amine.
Antifilarial and antimalarial agents. Basically substituted 10‐aminobenzo[b] [1,5] naphthyridines, 10‐Aminobenzo[b] [1,5] naphthyridine N‐Oxides, and 8‐Amino‐1,5‐naphthyridines
Authors: Elslager Edward F. , Perricone S. C. , Worth Donald F.
Published: March 2009

Various 2‐alkoxy 7‐chloro‐10‐[[[(dialkylamino)alkyl]amino]]benzo[b][1,5]naphthyridines (XI) and N‐oxides (XV, XVII, XVIII, XXII), 4‐[(2‐alkoxy‐7‐chlorobenzo[b][1,5]naphthyridin‐10‐yl)‐amino]‐α‐(diethylamino)‐o‐cresol derivatives (XII‐XIV, XXI) and N‐oxides (XIX, XX, XXV), 2‐butoxy‐8‐[[[(dialkylamino)alkyl]amino]]‐1,5‐naphthyridines (XXVIa and b), and 2‐butoxy‐8–[[3‐[(diethylamino)methyl]‐p‐anisidino]]‐1,5‐naphthyridine (XXVII) were synthesized for antifilarial and antimalarial evaluation. The compounds were obtained in 13–91% yield by the condensation of 2‐alkoxy‐7,10‐dichlorobenzo[b][1,5]naphthyridines, 2‐alkoxy‐7,10‐dichlorobenzo[b][1,5]naphthyridine 5‐oxides, and 2‐butoxy‐8‐chloro‐1,5‐naphthyridine with the appropriate diamine in phenol, or by perbenzoic acid oxidation of the parent 10‐amino‐7‐chlorobenzo‐[b][1,5] naphthyridines in chloroform. Among them, eight compounds killed adult Litomosoides carinii in gerbils when administered in daily gavage doses of 25–400 mg./kg. for 5 days. Azacrine 5‐oxide (XVII), the most active compound, was equipotent with amodiaquine (1a), azacrine (IX), and quinacrine 10‐oxide (VI). Twelve substances were active orally against Plasmodium berghei in mice at doses ranging from 3.8–155 mg./kg./day for 6 days. 7‐Chloro‐10‐[[‐3‐[(diethylamino)‐methyl]‐p‐anisidino]]‐2‐methoxybenzo[b][1,5]naphthyridine 5‐oxide dihydrochloride (XX) was approximately 12 times as potent as quinine against P. berghei, but was highly cross‐resistant with chloroquine (IV). Structure‐activity relationships are discussed.
Acid‐base equilibria of dipyridylethylenes studied by absorption and fluorescence spectrometry
Authors: Beggiato G. , Favaro G. , Mazzucato U.
Published: March 2009

In connection with photochemical and fluorimetric studies and with previous pK measurements on styrylpyridines, the acid‐base equilibria of the trans‐1,2‐dipyridylethylenes have been studied by absorption and fluorescence spectrometry. The results obtained by the two methods are compared and the pK's of first and second protonation discussed in dependence with the nitrogen positional isomerism.

The measurements of the dissociation constant of the trans‐3‐styrylpyridinium ion is also reported as a particularly convenient application of fluorescence spectrometry.
A new synthesis of substituted pyrazoles from 1,4‐dianions of phenylhydrazones having an α‐hydrogen
Authors: Foote Robert S. , Beam Charles F. , Hauser Charles R.
Published: March 2009

The 1,4‐dianions of acetophenone, para‐substituted acetophenones, deoxybenzoin and dibenzyl ketone phenylhydrazone were prepared by treatment of the respective phenylhydrazone with two molecular equivalents of n‐butyllithium in tetrahydrofuran‐hexane at 0° and condensed with a variety of aromatic esters, followed by acid cyclization to give the substituted pyrazole in good yield. The synthesis procedure appears to be a convenient and unequivocal method for preparing a particular pyrazole isomer without interfering side reactions. The 1,4‐dianion of N,N‐diphenylsemicarbazone was also prepared, and the condensation‐cyclization gave the pyrazole in somewhat lower yield.
Synthesis of 2– and 4‐amino‐1,5‐naphthyridines
Authors: Brown Ellis V. , Plasz Andrew C.
Published: March 2009

The structure of the product obtained from the reaction of potassium amide in liquid ammonia on 1,5‐naphthyridine has been identified as 4‐amino‐1,5‐naphthyridine by comparison with a known sample. The 2‐amino isomer was not detected in the mixture. The NMR spectra for 2‐and 4‐amino‐1,5‐naphthyridine along with the corresponding chloroisomers are described.
6(5H)‐phenanthridinones. III. halo‐6(5H)phenanthridinones
Authors: Pan Hsi‐Lung , Fletcher T. Lloyd
Published: March 2009

Halogenation of 6(5H)‐phenanthridinone or its 3,8‐dihalo derivatives with N‐bromo or N‐chlorosuccinimide in dimethylformamide gives the corresponding 2‐halophenanthridinones (I,V,XI‐XIV). Further halogenation of 2‐halo‐6(5H)‐phenanthridinone with the appropriate N‐halosuccinimide, in the same medium, gives the corresponding 2,4‐dihalo derivatives (II,VI). NXS/DMF is found to be a very convenient halogenating system in these preparations. 1,3,8‐Trihalo‐6(5H)‐phenanthridinones (XIX,XX) are prepared from the 1‐nitro derivatives which are obtained by a Schmidt rearrangement of 2,7‐dihalo‐4‐nitro‐9‐oxofluorenes. Similarly, rearrangement and further reaction of 2‐nitro‐5‐chloro‐9‐oxofluorene (XXI) leads to 3,10‐dichloro‐6(5H)‐phenanthridinone (XXIV). UV absorptions as well as selected IR absorptions of these 6(5H)‐phenanthridinones are described.
Synthesis of potential antimalarials
Authors: Schaefer John P. , Kulkarni K. S. , Costin R. , Higgins J. , Honig Linda M.
Published: March 2009

A series of quinoline derivatives containing a 2‐thienyl ring in the 2‐position and CO2H, CH2OH, CHO, CH(OH)CN, CH(OH)CO2H, CO2C2H5, COCH[N(C2H5)2]CO2C2H5, COCH2N(C2H5)2, COCH3,magnified imagesubstituents in the 4‐position was synthesized. Both intermediate and target compounds were tested for antimalarial activity. A second series with a 5‐bromo‐2‐thienyl group in the 2‐position and CHOHCH2N(C2H5)2, CHOHCH2N(CH2)6, and CHOHCH2N(CH2C6H5)2substituents in the 4‐position was also prepared, it was found that, although these quinoline methanols were moderately active antimalarials, they exhibited a high degree of phototoxicity. A third series of compounds with 2‐alkyl substituents (methyl,t‐butyl) was also synthesized, and these were found to combine a modest degree of antimalarial activity with low phototoxicity. Several novel synthetic routes to the above compounds were developed and are detailed.
Cyclic acylimines and cyclic carbinolamides II. isoquinolones
Authors: Ben‐Ishai D. , Inbal Z. , Warshawsky A.
Published: March 2009

Three cyclic acylimines (X, XI, XXX) and six methoxyamides (VII, VIII, IX, XXIII, XXIX, XXXV) were synthesized and their chemical properties studied. The isoquinolone acylimines added readily, across the carbon‐nitrogen double bond, weak nucleophiles such as alcohols and amides to give addition products. The methoxyamides can substitute, in the presence of an acid catalyst, the unsaturated compound in the various reactions. Diels‐Alder type products were obtained with dienes and amidoalkylation derivatives with acetone and dimedone.
Alkaloid studies. VI. lithium aluminum hydride reduction of apoyohimbine and the synthesis of 3,4,5,6‐tetradehydroyohimbane‐16‐methanols
Authors: Albright J. Donald , Mitscher Lester A. , Goldman Leon
Published: March 2009

Catalytic reduction of apoyohimbine (1), prepared from yohimbine and thionyl chloride in pyridine, gives methyl yohimbane‐16α‐carboxylate (2) after equilibration with methoxide. LAH reduction of 2 or β‐yohimbine O‐tosylate (3) gives yohimbane‐16α‐methanol (4a). LAH reduction of 1 affords yohimbane‐16α‐carboxaldehyde (5), yohimb‐16‐ene‐16‐methanol (6a) and yohimbane‐16β‐methanol (7a). Structural assignments 6a and 7a are confirmed by mass spectral measurements. Pmr spectra of 4a, 6a and 7a and their O‐acetates 4b, 6b and 7b are discussed. LAH reduction of apo‐α‐yohimbine (8) affords alloyohimb‐16‐ene‐16‐methanol (9). Dehydrogenation of 4a with palladium black and maleic acid gives 3,5,4,5,6‐tetradehydroyohimbane‐16α‐methanol (10) iodide, and 7a gives 3,4,5,6‐tetradehydroyohimbane‐16β‐methanol (11) iodide and picrate. Properties of 10 and 11 differ from those of melinonine E.
New evidence supporting the formation of a diaziridinium cation in the hydrolytic fission of diaziridines
Authors: Swanson J. S. , Stucky G. D.
Published: March 2009

The isolation and characterization of the bisulfate salt of the 3,3‐dimethyldiaziridinium monocation is described. Elemental analysis, infrared, mass spectral, and conductivity data are presented along with results of chemical investigations to support the proposed structure. The only diaziridinium salts isolated previously were formulated as dications, hence the scope of diaziridine salt formation has been greatly expanded and new evidence has been provided which supports the formation of diaziridinium cations in acid hydrolysis and reductive fission.
Synthesis of some substituted pyridylsydnones
Authors: Greco Claude V. , Hunsberger I. Moyer
Published: March 2009

Synthesis of the I‐oxide (2) of the photochromic N‐(3‐pyridyl) sydnone (1), of N‐(5‐bromo‐3‐pyridyl) sydnone (3), and the I‐oxide (4) of 3 were undertaken in order to study the effect on photochromism exerted by substituents on the pyridine ring. Compounds 2 and 3 were prepared via the corresponding aminopyridines and N‐pyridylglycines by the general procedure used earlier to prepare 1. The required amines, 3‐aminopyridine I‐oxide and 3‐amino‐5‐bromopyridine, were obtained by Hofmann rearrangement of the corresponding amides. An excellent preparation of 5‐bromonicotinamide was developed involving bromination in thionyl chloride followed by reaction of the bromoacid chloride with ammonia in chloroform. Proof of structure for 2 and 3 was accomplished by acid hydrolysis to the corresponding hydrazines, which were isolated, respectively, as acetophenone 3‐pyridylhydrazone I‐oxide and as 5‐bromo‐3‐pyridylhydrazine hydrochloride. These products were identical with samples prepared by reduction of the respective diazotized amines. Sydnone 4 eluded preparation by this general procedure. 3‐Amino‐5‐bromopyridine I‐oxide was prepared conveniently from 5‐bromonicotinamide but attempts to prepare the corresponding glycine by catalytic hydrogenation of a mixture of the amine and butyl glyoxylate afforded, in acid solution, N‐(3‐pyridyl)glycine and, in neutral or alkaline solution, the I‐oxide of N‐(3‐pyridyl)glycine. Both products resulted from the reductive cleavage of the bromine atom. Neither 2 nor 3 was photochromic.
1,2,4‐triazines. III. A convenient synthesis of 1,2,4‐triazines and their covalent hydration
Authors: Paudler William W. , Chen Teh‐Kuei
Published: March 2009

A general synthesis of 1,2,4‐triazines, from 3‐methylthiotriazines is described. It has been shown that 1,2,4‐triazines undergo covalent hydration across the N4‐C5 bond.
Nouveaux oxagermacycloalcanes et oxagermacycloalcenes. Methodes de synthese
Authors: Massol M. , Barrau J. , Satgé J.
Published: March 2009

Les réactions de transalcoxylation des méthoxydiorganogermanes R2(H)GeOMe, avec des alcools éthyléniques et acétyléniques conduisent à des alcénoxy ou alcynoxygermanes du type magnified image. Ces dérivés à liaison germanium‐hydrogène subissent à la température ordinaire ou sous effet thermique, en présence ou non de catalyseurs platinés une cyclisation intramoléculaire prépondérante par addition du groupement Ge‐H sur l'insaturation carbone‐carbone. La structure des oxagermacycloalcanes de type furannique et pyrannique ainsi obtenus est confirmée par divers autres modes de synthèse. Les premiers oxagermacycloalcènes à double liaison carbone‐carbone en α du Ge sont décrits.
Synthesis of 1,2‐diaryl‐2‐imidazolines
Authors: Perillo Isabel , Lamdan Samuel
Published: March 2009

Polyphosphoric acid and N‐aryl‐N′‐benzoylethylenediamines in a type of Bischler‐Napieralski reaction afforded 1,2‐diaryl‐2‐imidazolines in good yields, rather than the 2,3‐dihydro‐1H‐[1,4]‐benzodiazepines. Blocking of the amino nitrogen by a methyl or ethyl group, to avoid imidazoline formation, gave starting material rather than the expected dihydrobenzodiazepine. When p‐tosyl was the blocking group, imidazoline was again the only product isolated. Analytical and spectroscopic data of several unreported 1,2‐diaryl‐2‐imidazolines are presented.
Studies on the syntheses of azole derivatives. Part I. Formation of 1‐substituted‐3‐hydroxy‐1H‐indazole and I‐substituted benzimidazolin‐2‐one derivatives by thermal reaction of N‐substituted‐N‐arylcarbamoyl azides.
Authors: Kametani Tetsuji , Sota Kaoru , Shio Masahisa
Published: March 2009

The formation of 1‐substituted‐3‐hydroxy‐1H‐indazole and 1‐substituted‐benzimidazolin‐2‐one derivatives by thermal reaction of N‐substituted‐N‐arylcarbamoyl azides was examined.
Studies on the syntheses of azole derivatives. Part IV. Novel Syntheses of 1‐Benzylbenzimidazolines by Photolysis of N‐Aryl‐N‐benzylcarbamoyl Azides [Studies on the Syntheses of Heterocyclic Compounds. Part CCCLXXVIII
Authors: Kametani Tetsuji , Shio Masahisa
Published: March 2009

Photolysis of N‐benzyl‐N‐(4‐substituted‐phenyl)carbamoyl azides (Ia and Ib) afforded N‐benzylidene‐N′‐benzylhydrazines (XIIa and XIIb) and the debenzylated benzimidazolines (XIIIa and XIIIb).
Reactions of 2‐acyl‐1,3‐indandiones with monosubstituted hydrazines and hydrazides
Authors: Mosher William A. , Bechara Ibrahim S.
Published: March 2009

Methyl‐ and phenylhydrazines react with 2‐(diphenylacetyl)‐1,3‐indandione (1) to yield respectively the 1‐(methylhydrazone) and the 1‐(phenylhydrazone) of 2‐(diphenylacetyl)‐1,3‐indandione (2a and 2b). In comparison, acetic and benzoic acid hydrazides react with 1 to give respectively the α‐(acetylhydrazone) and the α‐(benzoylhydrazone) of 2‐(diphenylacetyl)‐1,3‐indandione (3a and 3b). Cyclization of 2a and 2b gives 2,3‐disubstituted indeno[1,2‐c]pyrazol‐4(2H)‐ones (7a and 7b). Cyclization of 3a and 3b, followed by methylation, gives 1‐methyl‐ and 2‐methyl‐3‐(diphenylmethyl)indeno[1,2‐c]pyrazol‐4(1 and 2H)‐ones (9a and 9b). 2‐Isovaleryl‐1,3‐indandione reacts with phenylhydrazine to give directly 3‐isobutyl‐1‐phenylindeno[1,2‐c]‐pyrazol‐4(1H)‐one (10).
1‐Arylquinolizidines
Authors: Temple Davis L. , Sam Joseph
Published: March 2009

The reaction of arylmagnesium bromides with 1‐ketoquinolizidine provided predominantly 1(e)‐aryl‐1(a)‐hydroxyquinolizidines. Dehydration of the latter and subsequent hydrogenation yielded 1‐arylquinolizidines.
Epimeric 1‐hydroxy‐1‐substituted indolizidines
Authors: Hibbett Eugene P. , Sam Joseph
Published: March 2009

Epimeric mixtures of 1‐hydroxy‐1‐phenylindolizidines and 1‐hydroxy‐1‐methylindolizidines were obtained from the reaction of 1‐ketoindolizidine with the appropriate Grignard reagent. The resulting alcohols were separated by chromatographic and distillation techniques. Infrared data and physical constants were utilized for the elucidation of the structures. Structural assignments of the indolizidinium iodides were made on the basis of nmr data.
Derivatives of the new ring system pyrazolo[4,3‐d]‐v‐triazine and the synthesis of 5,7‐disubstituted 3‐methylpyrazolo[4,3‐d] pyrimidines and 5,7‐disubstituted 3‐methylpyrazolo[4,3‐d]pyrimidine 6‐uxides which are structurally related to the nucleoside antibiotics formycin and formycin B
Authors: Long Robert A. , Gerster John F. , Townsend Leroy B.
Published: March 2009

The synthesis of 7‐methylpyrazolo[4,3‐d]‐v‐triazin‐4‐one (6), a derivative of the new ring system, pyrazolo[4,3‐d]‐v‐triazine, has been accomplished by a diazotization reaction. Ring closure of the appropriate pyrazole derivative and oxidation of the preformed bicyclic heterocycle withm‐chloroperoxybenzoic acid has furnished 7‐substituted 3‐methylpyrazolo[4,3‐d]pyrimidine 6‐oxides. Ring closures to yield various 5,7‐disubstituted 3‐methylpyrazolo[4,3‐d]pyrimidines are also discussed.
A synthesis of isothiazoles and pyrimidines via a vilsmeier‐haack reaction
Authors: Crenshaw R. R. , Partyka R. A.
Published: March 2009

A new synthesis of isothiazoles is reported which involves the reaction of Vilsmeier salts of N,N‐dimethylamides with enamino nitriles, and treatment of the intermediates successively with sodium hydrosulfide and iodine. 4‐Isothiazolecarbonitriles prepared were: 3‐phenyl; 3,5‐dimethyl; 3,5‐diphenyl; 3‐methyl‐5‐phenyl; and 3‐phenyl‐5‐methyl. The 5‐phenylisothiazoles were obtained in low yields due to a side reaction involving the formation of pyrimidines. Pyrimidines encountered were 6‐chloro‐2,4‐diphenyl and 6‐chloro‐4‐methyl‐2‐phenylpyrimidines.
Synthesis of 1,9,10‐anthyridine
Authors: Carboni S. , Da Settimo A. , Tonetti I.
Published: March 2009

1,9,10‐Anthyridine (VIII) was synthesized by oxidation of 5,10‐dihydro‐1,9,10‐anthyridine (VII) with chromic acid. The structures of VII and VIII were determined by UV and NMR analyses.
The synthesis of ribonucleotide‐5′‐(5‐Iodoindol‐3‐ol) and (4‐methylcoumarin‐7‐ol) esters for the histochemical demonstration of nucleases
Authors: March Louis C. , Tsou K. C.
Published: March 2009

The syntheses of ribonucleotide‐5′ monoesters with 5‐iodoindol‐3‐ol and 5′‐uridylic acid and 5′‐adenylic acid monoesters with 4‐methylcoumarin‐7‐ol has been accomplished by the reaction of phosphorodichloridates with various 2′,3′‐O‐isopropylidene ribonucleosides, followed by hydrolysis and anion exchange chromatography.
Studies on the preparation and exchange reactions of 5‐deuterated uracils
Authors: Santi Daniel V. , Brewer Curtis F. , Farber Debora
Published: March 2009

The mechanism of base catalyzed proton exchange at the 5‐position of uracil and its N‐methylated derivatives has been studied. These reactions proceed by addition — elimination across the 5,6‐double bond when the 1‐nitrogen is substituted with a methyl group, or with anchimeric assistance of the N‐1 anion if the 1‐position is unsubstituted. The base catalyzed hydrolyses of 1,3‐dimethyluracil and 3‐methyluracil also appear to proceed through hydrated intermediates. A facile method for an acid catalyzed preparation of 5‐deuterated uracils is described as well as a simple and accurate method for analysis of deuterium content.
Cyclic acylimines and cyclic carbinolamides III. Piperidone and isoindolone
Authors: Warshawsky A. , Ben‐Ishai D.
Published: March 2009

6‐Phenyl‐2,3,4,5‐tetrahydro‐3,3,5,5‐tetramethyl‐2‐pyridone (6), 1‐phenyl‐3‐isoindolone, and their methanol (5) and butanol (19) addition products, as well as 6‐methoxy‐3,3,5,5‐tetramethyl‐2‐piperidone (4) and 1‐methoxy‐3‐isoindolinone (11) were prepared and their chemical properties studied. The cyclic acylimines and their methanol addition products were found to react with weak nucleophiles (amides, alcohols), active methylene compounds (acetone, dimedone) or dienes (1,2,3,4‐tetramethyl and 2,3‐dimethylbutadiene) to give addition products.
A new class of heterocyclic betaines: 1,1‐dimethyl‐3‐phenylpyrazolium‐5‐oxide
Authors: Henery‐Logan Kenneth R. , Keiter Ellen A.
Published: March 2009

1,1‐Dimethyl‐3‐phenylpyrazolium‐5‐oxide (1) was isolated as a minor product (3%) in the reaction of ethyl benzoylacetate with 1,1‐dimethylhydrazine and also was obtained as the major product (58%) from the reaction of methyl p‐toluenesulfonate with ethyl benzoylacetate dimethylhydrazone. The structural assignment was made on the basis of chemical reactions and spectral data and the formula is represented by a resonance structure for which there are two principal canonical forms. Reaction of 1 with methanol at room temperature afforded methyl benzoylacetate dimethylhydrazone. Ethyl benzoylacetate dimethylhydrazone was shown to exist as a tautomeric mixture containing 65% of the imine form at room temperature.
The mass spectra of pseudo‐azulenes containing both nitrogen‐ and sulfur‐heteroatoms
Authors: Buu‐Hoï N. P. , Croisy A. , Jacquignon P. , Martani A. , Ricci A.
Published: March 2009

The fragmentation under electron impact of [1]benzothiopyrano[4,3‐b]indoles and their thiophene analogs has been investigated. These pseudo‐azulenes behaved in accordance with their aromatic structure and their fragmentation followed simple patterns, leading to hitherto unreported ions.
Benzothiazinones by addition of o‐Mercaptobenzamides to acetylene esters
Authors: Heindel Ned D. , Ko C. C. Ho
Published: March 2009

The condensation of o‐mercaptobenzamides with methyl acetylenedicarboxylate or methyl propiolate occurs with trans addition of the SH to the alkyne linkage. The resulting vinyl sulfide adducts can be ring closed to 1,3‐benzothiazin‐4‐ones in excellent yield.
Reaction of 4,5‐diaminopyrimidine and ethyl acetoacetate: Synthesis and chemistry of isomeric dihydropyrimido[4,5‐b][1,4] diazepinones
Authors: Israel Mervyn , Tinter S. Karin , Trites Dorothy H. , Modest Edward J.
Published: March 2009

Depending upon reaction conditions, 4,5‐diaminopyrimidine and acetoacetic ester gave a variety of condensation products, including the two isomeric dihydropyrimido[4,5‐b][1,4]‐diazepinones. Under conditions leading to bicyclic products, the formation of 1,5‐dihydro‐4‐methyl‐2H‐pyrimido[4,5‐b][1,4]diazepin‐2‐one (2) was strongly favored. The isomeric 3,5‐dihydro‐2‐methyl‐4H‐4‐one compound (4) was best obtained by cyclization of ethyl 3‐(4‐amino‐5‐pyrimidylamino)crotonate (3) under base catalysis. Thermal rearrangement of 2 and 4 proceeded, in each instance, with loss of the isopropenyl moiety and gave 8‐purinone. Compound 4 underwent ring contraction under the influence of alkoxide to yield a product which was shown to be the 7‐isopropenyl‐8‐purinone (6).
Fluorinated aminooxazolines. Synthesis and properties
Authors: Middleton W. J. , Metzger Diana , Cunningham Karen B. , Krespan C. G.
Published: March 2009

4‐Amino‐2,2,5,5‐tetrakis(trifluoromethyl)‐3‐oxazoline (3a) was prepared from the reaction of sodium cyanide with hexafluoroacetone and hexafluoroacetone imine, and from the reaction of hexafluoroacetone cyanohydrin with the imine. Several other oxazolines were also prepared by related reactions of other fluoroketones and imines. The proton nmr spectrum of an 15N‐labeled sample of 3a shows that it exists in solution primarily as the amino tautomer and not as the imino tautomer 3b. Comparison of 3a with the closely related, pharmacologically active 4‐amino‐2,2,5,5‐tetrakis(trifluoromethyl)‐3‐imidazoline (2) has shown large differences in ΔH of complex formation and reactivity with electrophilic reagents.
The reaction ofN‐Acylpyridinium salts with indole
Authors: Bergman Jan
Published: March 2009

Depending on the solvent used and the ratio of the reactants,N‐acylpyridinium salts condense with indole to give 3‐(N‐acyl‐1,4‐dihydro‐4‐pyridyl)indole (1) or 4‐(N‐acyl‐3‐indolyl)pyridinium chloride (3). Compound 1 is an intermediate in the formation of compound3. The reaction mechanism has been studied, and a hydrogen transfer reaction is suggested as a key step. Alkaline hydrolysis,e.g., of 4‐(N‐acetyl‐3‐indolyl)pyridinium chloride (3a), gave 3‐(4‐pyridyl)indole (2a).

The reaction of α‐chlorosubstituted acyl halides with indole, in the presence of pyridine constitutes a convenient synthesis of 3‐chloroacylindoles.
Circular dichroism spectra of 1,2,3,4,5,6‐Hexahydro‐2,6‐methano‐3‐benzazocines
Authors: Karliner J. , Yee E.
Published: March 2009

Circular dichroism curves of levorotatory 1,2,3,4,5,6‐hexahydro‐2,6‐methano‐3‐benzazocin‐8‐ol derivatives have been determined and correlated with stereochemical features. Compounds with the rectus configuration at C‐6 were found to exhibit negative extrema for the long wavelength phenolic π → π* transition. The remaining Cotton effects have been ascribed to specific aromatic π → π* transitions.
Photostable o‐Hydroxyphenylquinazolines
Authors: Pater Richard
Published: March 2009

The correlation between intrinsic photostability (ϕ−1R) and structure of several intramolecularly hydrogen‐bonded heterocycles containing suitable o‐hydroxyphenyl groups is briefly discussed in terms of the changes in resonance energy resulting in such compounds from a reversible keto‐enol rearrangement in the lowest excited singlet state. The influence of intramolecular hydrogen bonding, resonance and steric effects on photostability in o‐hydroxyphenylquinazolines as elucidated with the aid of spectroscopic methods is discussed in detail.
7‐Amino‐5‐imino‐8(5H)‐quinolones, 6‐Amino‐8‐imino‐5(8H)‐quinolones and 7‐Alkyl‐4,6‐dihydroxy‐5,8‐quinolinediones as potential antiprotozoal agents
Authors: Bullock F. J. , Tweedie J. F.
Published: March 2009

Oxidation of 7‐amino‐8‐hydroxyquinoline‐5‐sulfonic acid with silver oxide in dimethylformamide and in the presence of arylamines provided a series of 7‐amino‐5‐arylimino‐8(5H)‐quinolones (VIIIb). Reaction of 8‐dialkylamino‐5,6‐quinolinediones with triethyloxonium tetrafluoborate gave a series of unstable but synthetically useful enol ethers. These reacted with amines to give 6‐amino‐8‐imino‐5(8H)‐quinolones, isolated and characterized as tetrafluoborate salts (XIa). Proton magnetic resonance studies showed these to be vinylogous amidinium salts, analogous to those previously obtained with 2‐amino‐1,4‐naphthoquinone imines. 4,6‐Dihydroxy‐5,8‐quinolinedione underwent free radical alkylation to give a 7‐alkyl‐4,6‐dihydroxy‐5,8‐quinolinedione. Evaluation of the new compounds against various Plasmodium species in rodents, birds and mosquitoes revealed no significant antimalarial activity.
Synthesis of pyridyl‐ and quinolyl‐substituted 2‐aminothiazoles
Authors: Taurins Alfred , Blaga Aurel
Published: March 2009

Five 2‐amino‐4‐(x‐pyridyl)‐ and 2‐amino‐4‐(x‐quinolyl)thiazoles have been synthesized by the condensation of thiourea with bromoacetylpyridines and ‐quinolines. The reaction of pyridyl pyridylmethyl ketones with thiourea and halogens produced four 2‐aminothiazoles possessing pyridyl substituents in 4‐ and 5‐positions on the thiazole ring. Treatment of N‐(3‐pyridyl)‐ and N‐(3‐quinoiyl)thiourea with α‐bromoketones gave seven new 2‐(3‐pyridyl)amino‐ and 2‐(3‐quinolyl)aminothiazoles. The ultraviolet spectra of the pyridyl‐ and quinolyl‐ substituted 2‐aminothiazoles were recorded.
Oxidative coupling of 2H‐1,4‐Thiazine derivatives
Authors: Sica D. , Santacroce C. , Prota G.
Published: March 2009

When treated with oxidizing agents, 3,5‐disubstituted 2H‐1,4‐thiazines undergo oxidative coupling at the 2‐position yielding 2,2′‐bithiazines. Under similar conditions 3‐substituted 2H‐1,4‐benzothiazines behave similarly to give the corresponding 2,2′‐dehydrodimers.

Evidence is presented that the oxidative coupling of all compounds examined proceeds preferentially to give the meso‐isomers.
The synthesis and chemical reactivity of thieno[2,3‐c]‐ and thieno[3,2‐c] pyridines
Authors: Dressler Mitchell L. , Joullié Madeleine M.
Published: March 2009

The syntheses and reactions of various thieno[2,3‐c]‐ and thieno[3,2‐c] pyridines are described. Molecular orbital calculations were performed on thieno[2,3‐c]pyridine (1) in order to determine the most susceptible sites to electrophilic and nucleophilic attack. Superdelocalizability values, Sr‐ are reported for each position in this molecule to give relative orders of reactivity towards the two types of reactions. Electrophilic attack was found to occur experimentally at C‐3 in all the thienopyridines studied. Peracid oxidation of thieno[2,3‐c]‐ and thieno[3,2‐c]pyridines produced only the N‐oxide. The lack of reactivity of certain thienopyridines under Vilsmeier formylation and Friedel‐Crafts acetylation conditions was related to their basicities. The dissociation constants of various thienopyridinium salts are reported.
The synthesis of alkyl substituted 2‐pyrazolines by the reaction of acids with hydrazine derivatives
Authors: Sloan K. H. , Rabjohn Norman
Published: March 2009

A convenient synthesis of alkyl substituted 2‐pyrazolines (III) has been developed from the reaction of acids with hydrazones (I) and azines (IV). An alkylidenebis‐1‐methyl‐2‐alkylidene‐hydrazine (V) was isolated as an intermediate, in the preparation of 5‐isopropyl‐1,4,4‐ trimethyl‐2‐pyrazoline (IIId), and protonated vinylhydrazones (II) are proposed as common intermediates in the formation of III, IV and V. The 4,5‐dialkyl‐2‐pyrazolines (IIIk‐m) that were prepared were shown to be free of isomers by nmr. The thermal isomerization of IIIk‐m to 3,4‐dialkyl‐2‐pyrazolines (IIIn‐o) was found to be incomplete at the temperatures studied. The reaction of IIIn‐o with acetone afforded 3,4‐dialkyl‐1‐[2‐(2‐methyl‐4‐oxopentyl)]‐2‐pyrazolines (IIIp‐q). The nmr and mass spectral data of III are discussed.
The reaction of aziridine with perhalogenated nitriles
Authors: Lautenschlaeger F.
Published: March 2009

Reaction of one or two molecules of aziridine with the cyano groups of trichloroacetonitrile and trifluoroacetonitrile was observed. The resulting aziridinyl amino derivatives represent novel functional groups. Intramolecular cyclization of a bis‐aziridinyl structure involving one aziridinyl group was observed. New synthetic routes to imidazolines and imidazolidines are a result of these rearrangments.
Synthesis of imidazo[1,2‐c] quinazoline and some of its methyl derivatives
Authors: Franchetti Palmarisa , Grifantini Mario
Published: March 2009

The synthesis of imidazo [1,2‐c] quinazoline was effected by manganese dioxide oxidation of the 5,6‐dihydroimidazo [1,2‐c] quinazoline which was prepared by treatment of 2‐(o‐nitro‐phenyl)‐1‐hydroxyimidazole‐3‐oxide with zinc powder and formic acid. The synthesis of some methyl derivatives of this ring system are also described. Structural assignments for all of the products were made from spectral data.
The synthesis of o‐Amino‐N‐substituted benzamides and 3‐substituted 2,4 (1H,3H)‐quinazolinediones from isatoic anhydride
Authors: Jacobs Richard L.
Published: March 2009

The reaction of isatoic anhydride with sterically hindered amines in DMF or DMSO, and subsequent treatment of the o‐amino‐N‐substituted benzamides thus produced with phosgene, gives high yields of 2,4(1H,3H)‐quinazolinediones with branched alkyl groups in the 3‐position.