bluuebunny/crossref_metadata_2025_split huggingface dataset:
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

AbstractThe 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

AbstractThe 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

AbstractThe 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

AbstractThe 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

AbstractAn 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

Abstract4‐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

Abstract2‐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

AbstractVarious 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

AbstractIn 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

AbstractThe 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

AbstractThe 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

AbstractHalogenation 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

AbstractA 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

AbstractThree 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

AbstractCatalytic 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

AbstractThe 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

AbstractSynthesis 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

AbstractA 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

AbstractLes 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

AbstractPolyphosphoric 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

AbstractThe 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

AbstractPhotolysis 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

AbstractMethyl‐ 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

AbstractThe 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

AbstractEpimeric 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

AbstractThe 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

AbstractA 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

Abstract1,9,10‐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

AbstractThe 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

AbstractThe 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

Abstract6‐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.