bluuebunny/crossref_metadata_2025_split huggingface dataset:
3‐Amino‐1‐[2‐(2‐ethoxyethoxy)ethoxy ] benzo[∫]quinazoline
Authors: Sengupta Sisir K. , Protopapa Heljo Kangur , Modest Edward J. , Das Bhupesh C. 
Published: March 2009

AbstractThe structure of an anomalous product, isolated as a companion substance during the catalytic dehydrogenation of 1,3‐diamino‐5,6‐dihydrobenzo[ƒ] quinazoline, has been elucidated with the aid of chemical and spectral evidence, including mass spectrometric data. The mass spectrometric fragmentation pattern of the compound is in good agreement with the assigned structure.
Reaction of 2‐aminobenzimidazole with bifunetional carboxylie acid derivatives. Formation of pyrimido[1,2‐a] benzimidazolones
Authors: Chow A. W. , Jakas D. R. , Trotter B. P. , Hall N. M. , Hoover J. R. E. 
Published: March 2009

Abstract2‐Aminobenzimidazole reacts with α,β‐unsaturated carboxylic acid chlorides or esters to give only pyrimido [1,2‐a] benzimidazol‐2‐(1H) ones. β‐Ethoxymethylenemalonie acid derivatives or β‐ketocarboxylic acid derivatives give only pyrimido [1,2‐a] benzimidazol‐4‐(1H)ones. Structural assignments based on nmr and chemical manipulations are discussed.
Synthesis of a potential camptothecin intermediate
Authors: Kametani Tetsuji , Takeda Hiromitsu , Satoh Fumio , Takano Seiichi 
Published: March 2009

AbstractCondensation of dimethyl 1,2‐dihydro‐2‐oxopyridine‐4,6‐dicarboxylate (IIIb) with methyl acrylate yielded 1,2,3,5‐tetrahydro‐2,7‐dimethoxycarbonyl‐1,5‐dioxoindolizine (IV), which on hydrolysis and decarboxylation gave 1,2,3,5‐tetrahydro‐1,5‐dioxoindolizine‐7‐carboxylic acid (VI). Friedländer condensation of VI with 2‐aminobenzaldehyde, followed by esterification of the resulting oxoindolizino[1,2‐b]quinoline‐7‐carboxylic acid (VIIa), yielded a potential camptothecin intermediate 9,10‐dihydro‐7‐methoxycarbonyl‐9‐oxoindolizino[1,2‐b]quinoline (VIIb).
A study of some quinolizone derivatives
Authors: Al‐Jallo Hikmat N. , Al‐Azawi Fatin W. 
Published: March 2009

AbstractThe condensation of methyl 2‐pyridylacetate and ethyl phenylpropiolate has been found to be a simple and convenient method for the preparation of 4‐quinolizone derivatives. Upon hydrolysis and decarboxylation, the initial condensation product, l‐carbethoxy‐2‐phenyl‐4H‐quinolizin‐4‐one (V) was converted to 2‐phenyl‐4H‐quinolizin‐4‐one (VII). Nitration and bromination of these quinolizones were affected under mild conditions. Nitration of V displaced the carbethoxy group, while bromination did not and 1,3‐dinitro‐4H‐quinolizin‐4‐one and 1‐carbeth‐oxy‐2‐phenyl‐3‐bromo‐4H‐quinolizin‐4‐one were obtained, respectively.
Nitration of trans‐2‐styrylthiophene
Authors: Arcoria Antonino , Maccarone Emanuele , Tomaselli Gaetano A. 
Published: March 2009

AbstractThe nitration of trans‐2‐styrylthiophene in carbon tetrachloride, nitroethane and acetic anhydride has been investigated.The nitration products were: β‐nitro‐2‐styrylthiophene as the main product with 3‐nitro‐2‐styrylthiophene and the 5‐nitro isomer in smaller amounts. They were identified by the chromato‐graphic and spectroscopic (uv and nmr) comparison with the reference compounds.The isomer percentages, determined by glc, were unchanged under different nitration conditions (time, temperature and molar ratio), but were dependent on the solvent used.
Selective ring opening reactions of 3,7‐diarylsulfonyl‐1,3,5,7‐tetrazabicyclo[3.3.1] nonaries
Authors: Yoshida H. , Sen C. , Thyagarajan B. S. 
Published: March 2009

AbstractThe selective formation of 1,3,5,7‐tetrazacyelooctanes from the title compounds is described. Exclusive cleavage of the IN‐CH2‐N bonds at the bridge methylene is shown to be a facile process, thus providing a convenient route to tetrazacyclooctane derivatives.
1,2,4‐Triazines X: Dimerizations of 1,2,4‐triazmes
Authors: Krass Dennis K. , Chen Teh‐Kuei , Paudler William W. 
Published: March 2009

Abstract5,5′‐Bi‐1,2,4‐triazinyl compounds are obtained by the treatment of 5‐unsubstiluted 1,2,4‐triazines with either sodium methoxide or with aqueous potassium cyanide.5,5′‐Bi‐1,2,4‐triazinyl is also obtained by the reaction of 1,2,4‐triazine with potassium cyanide.It is proposed that the sodium methoxide catalyzed dimerizations occur via a carbanionic intermediate; the aqueous potassium cyanide catalyzed reactions via a cyanide addition product and the potassium in liquid ammonia reaction via a free radical dimerization process.
The synthesis and ultraviolet spectra of some N‐aryl‐2,3‐dihydro‐3‐oxo‐4H‐1,4‐oxazine derivatives
Authors: Abdulla Riaz F. 
Published: March 2009

AbstractTwo new derivatives of the 1,4‐oxazine ring system (3a and 3b) derived from p‐aminobenz‐amides have been synthesized. The uv absorption spectra of sixteen representative 1,4‐oxazines all show two high intensity bands (ϵ ∼ 105) between 220‐400 ran. The positions and intensities of the absorption maxima have been correlated with the steric and electronic effects of the oxazine ring substituents.
The preparation of substituted 1,2,4‐triazolines and substituted picolinic acid methylene hydrazides by the action of certain carboxamide hydrazones with ketones
Authors: Case Francis H. 
Published: March 2009

AbstractThe action of certain ketones with carboxamide hydrazones, yielding, depending on conditions, 1,2,4‐triazolines or substituted picolinic acid methylene hydrazides, has been investigated. Also the preparation of 3‐subsliluted‐5‐phenyl‐1,2,4‐triazines from the action of phenyl glyoxal and certain carboxamide hydrazones is described.
Synthesis of 4(5)‐substituted 2‐amino‐5(4)‐hydroxyimino‐5(4)H‐imidazoles and their transformation into the corresponding 3‐substituted 5‐amino‐1,2,4‐oxadiazoles
Authors: Cavalleri Bruno , Bellani Piero , Lancini Giancarlo 
Published: March 2009

AbstractTreatment of 4(5)‐phenyl(or alkyl)‐2‐aminoimidazoles with isoamyl nitrite in acetic acid afforded the corresponding 4(5)‐substituted 2‐amino‐5(4)‐hydroxyimino‐5(4)H‐imidazoles which by heating in water were transformed into 3‐benzoyl(or acyl)‐5‐amino‐1,2,4‐oxadiazoles.
Synthesis and antimalarial effects of 5,6‐dichloro‐2‐[(4‐||4‐(diethylamino)‐i‐methylbutyl] amino||‐6‐methyl‐2‐pyrirnidinyl)amino] benzimidazole and related benzimidazoles and lH‐imidazo[4,5‐b] pyridines
Authors: Werbel Leslie M. , Curry Ann , Elslager Edward F. , Hess Carolyn 
Published: March 2009

AbstractA group of fifty‐five 2‐[(4‐11[(dialkylamino)alkyI]amino11‐6‐methyl‐2‐pyrimidinyl)amino]‐benzimidazoles (VII) was synthesized in 3‐88% yield by the condensation of the requisite 2‐[(2‐benzimidazolyl)amino]‐4‐chloro‐6‐methylpyrimidine (VI) with the appropriate polyamine in ethanol‐hydrochloric acid or neat with excess amine containing potassium iodide. The 2‐[(2‐benzimidazolyl)amino]‐6‐methyl‐4‐pyrirnidinol precursors (V), obtained in 11‐51% yield by cyclization of 2‐(cyanoamino)‐4‐hydroxy‐6‐methylpyrimidine with a suitably substituted o‐phenylenediamine, were chlorinated with phosphorus oxychloride to give the intermediate 2‐[(2‐benzimidazolyl)amino]‐4‐chloro‐6‐rnethylpyrimidines (VI) (27‐99%). Oxidation of 5,6‐dichloro‐2‐[(4‐11[4‐(diethylamino)‐l‐methylbutyl] amino 11‐6‐methyl‐2‐pyrimidinyl) amino ]benzimidazole (29) with m‐chloroperbenzoic acid gave the distal N4'‐oxide (31) (19%). Fusion of 2,3‐uiaminopyridine with 2‐(cyanoamino)‐4‐hydroxy‐6‐methylpyrimidine provided 2‐[(4‐hydroxy‐6‐tnethyl‐2‐pyrimidinyl)amino]‐lH‐imitlazo[4,5‐b]pyrimidine (VIII) (30%), which upon chlori‐nation with phosphorus oxychloride (63%) followed by amination with i N, N‐diethylethylene‐diamine afforded 2‐(4‐11[2‐(diethylamino)ethyl] amino 11‐6‐methyl‐2‐pyrimidinyl)‐lH‐imidazo [4,5‐b]pyridine (X) (8%). Thirty‐eight of the novel 2‐[(4‐amino‐6‐methyl‐2‐pyrimidinyl)amino]‐benzimidazoles possessed “curative” activity against Plasmodium berghei at single subcutaneous doses ranging from 20.640 mg./kg. Orally, thirty‐one compounds exhibited suppressive activity against P. berghei comparable with or superior to the reference drugs 1‐(p‐chlorophenyl)‐3‐(4‐11[2‐(diethylarnino)ethyl]amino 11‐6‐methyl‐2‐pyrimidinyl)guanidine (I) and quinine hydrochloride, while twelve of them were 5 to 28 times as potent as I and quinine hydrochloride. Eight compounds also displayed strong suppressive activity against P. gallinaceum in chicks. 5,6‐Dichloro‐2‐[(4‐112‐(diethylamino)ethyl]amino11‐6‐methyl‐2‐pyrimidinyl] benzimidazole (18) showed marked activity against a cycloguanil‐resistant line of P. berghei, and the most promising member of the series, namely 5,6‐dichloro‐2‐[(4‐11[4‐(diethylamino)‐l‐methylbutyl]amino11‐6‐methyl‐2‐pyrimidinyl)amino]benzimidazole (29) (Q = 28), was designated for preclinical toxico‐logical studies and clinical trial. Structure‐activity relationships are discussed.
The formation of a stable o‐semidine rearrangement intermediate
Authors: Paudler William W. , Zeiler Andrew C. , Goodman Mark M. 
Published: March 2009

AbstractTreatment of 5,6,11,12‐tetrahydrodibenzo‐[b, f][1,2] diazocine with dilute acids affords a spiro‐1,2,3,4‐tetrahydroquinoline derivative which represents the first isolated stable o‐semidine rearrangement intermediate.
The schmidt reaction with oxa‐ and azabenzocycloalkenones
Authors: Misiti D. , Rimatori V. , Gatta F. 
Published: March 2009

AbstractFive, seven and eight membered ring oxa‐ and azabenzocycloalkenones were submitted to the Schmidt reaction and the ratio of the respective isomeric rearrangement products have been determined and compared with that of six membered ring oxa‐ and azabenzocycloalkenones.
Heterocyclic derivatives of naphthalene‐1,8‐dicarboxylic anhydride. Part II. Colour and dyeing properties on synthetic fibres of some substituted 7H‐benzimidazo[2,1‐a]benz[de]isoquinolin‐7‐ones
Authors: Grayshan P. H. , Peters Arnold T. 
Published: March 2009

AbstractThe effect on colour resulting from substitution in the phenyl and naphthyl rings of 7H‐benzimidazo [2,1‐a]benz[de]isoquinolin‐7‐one (I) is discussed; dycing and fastness properties of these dyes on synthetic fibres are described and the synthesis of some new 1,8‐naphthalimides and derivatives of I recorded.
The crystal and molecular structure of phenothiazine‐10‐propionitrile. The effect of crystal packing on the dihedral angle of phenothiazine heterocycles
Authors: Malmstrom Mary Carl , Cordes A. W. 
Published: March 2009

AbstractPhenothiazine‐10‐propionitrile, C12H8SNC2H4CN, crystallizes in the centrosymmetric monoclinic space group P21/n, with a = 5.785(1)Å, b = 15.427(3)Å, c = 14.497(4)Å, β = 92.50(1)°, Z = 4, Dmeas = 1.29(1) g cm3 and Dcalc = 1.28 g cm3 at 23°. Three dimensional X‐ray data were collected with a manual diffractometer using MoKα (λ 0.71069Å) radiation and by multiple film Weissenberg techniques using CuKα (λ 1.5418Å) radiation. The structure was determined by Patterson and Fourier methods and refined with 519 observed reflections by full matrix least‐squares methods to an R of 0.077. The dihedral angle between the two planes of the o‐phenylene rings is 135.4(3)°. In the folded heterocyclic ring the C‐S‐C angle is 97.8(7)° and the average CS bond is 1.76(1)Å. A comparison of this structure to that of phenothiazine‐10‐propionic acid shows the two chemically similar molecules have the same dihedral angles in spite of completely different solid state packing patterns.
Spirans XX. Synthesis of 8,8‐dialkylazaspiro[4.5] decanes and 9,9‐dialkylazaspiro[5.5]undecanes
Authors: Rice Leonard M. , Sheth Bhagvandas S. , Wheeler James W. 
Published: March 2009

AbstractN‐(2‐Dimethylaminopropyl)‐8,8‐dimethyl‐2‐azaspiro[4.5]decane (1), N‐(2‐dimethylaminopropyl)‐8,8‐diethyl‐2‐azaspiro[4.5]decane (2), N‐(3‐dimethylaminopropyl)‐9,9‐dimethyl‐3‐azaspiro[5.5]undecane (3), and N‐(3‐dimethylaminopropyl)‐9,9‐diethyl‐3‐azaspiro[5.5]undecane (4) have been synthesized from 4,4‐dimethylcyclohexanone (5) and 4,4‐diethylcyclohexanone (6). Biological evaluation of these amines showed significant inhibition of cancer cell growth in human cancer cells grown in tissue culture.
Spirans XXI. Synthesis of silaazaspiro[4.5]decanes and silaazaspiro[5.5]undecanes
Authors: Rice Leonard M. , Sheth Bhagvandas S. , Wheeler James W. 
Published: March 2009

AbstractN‐(2‐Dimethylaminopropyl)‐8,8‐dimethyl‐8‐sila‐2‐azaspiro[4.5]decane (1) and N‐(3‐dimethyl‐aminopropyl)‐9,9‐dimethyl‐9‐sila‐3‐azaspiro[5.5]undecane (2) have been synthesized from 4,4‐dimethyl‐4‐silacyclohexanone (5). Biological evaluation of 1 and 2 indicated cytotoxic action against human cancer cells grown in tissue culture.
Nitro derivatives of 1‐picrylbenzotriazole
Authors: Coburn Michael D. 
Published: March 2009

AbstractThe synthesis of the isomeric 4,6‐, 5,6‐, and 5,7‐dinitro‐1‐picrylbenzotriazoles has been accomplished. The nmr spectra of these compounds and the mononitro derivatives of 1‐picrylbenzotriazole were determined and the substituent effects of the nitro and picryl groups on the chemical shifts of the various benzotriazole protons are discussed.
Pyridine nucleosides related to 5‐fluorouracil
Authors: Nesnow Stephen , Heidelberger Charles 
Published: March 2009

Abstract5‐Fluoro‐2‐methoxypyridine (3) synthesized from 5‐amino‐2‐methoxypyridine was converted to 4‐benzyloxy‐5‐fluoro‐2‐methoxypyridine (12) and 2,4‐dimethoxy‐5‐fluoropyridine (13) by a four step procedure employing the intermediate 5‐fluoro‐2‐methoxy‐4‐nitropyridine N‐oxide (7). Condensation of 3, 12, and 13 with 2,3,5‐tri‐O‐benzoyl‐D‐ribofuranosyl bromide gave, after removal of the protecting groups, 4‐deoxy‐5‐fluoro‐3‐deazauridine (20), 5‐fluoro‐3‐deazauridine (23) and 5‐fluoro‐4‐methoxy‐3‐deazauridine (25). Several alkylated and dealkylated derivatives of 3 and 12 were also prepared. Structure proof and anomeric configuration were determined from the uv, nmr, and CD data.
Azetidine‐2‐carboxylic acid derivatives
Authors: Phillips Barry A. , Cromwell Norman H. 
Published: March 2009

AbstractAn improved method for the preparation of DL‐azetidine‐2‐carboxylic acid is reported. The reaction of thionyl chloride with azetidine‐2‐carboxylic acid in methanol gave rise to 2‐carbomethoxyazetidine hydrochloride, which upon treatment with triethylamine yielded 2‐carbomethoxyazetidine. 2‐Carbomethoxyazetidine proved to be unstable and upon standing formed azetidine‐2‐carboxylic acid anhydride. The nmr and ir spectra of 2‐carbomethoxyazetidine are discussed in terms of its conformation. The conversion of azetidine‐2‐carboxylic acid to azetidine‐2‐carboxamide is also described.
Pyrrolopyridazines. II. Synthesis of the novel pyrrolo[3,2‐c]pyridazine ring system
Authors: Dan Cook P. , Castle Raymond N. 
Published: March 2009

AbstractThe first derivatives of the pyrrolo[3,2‐c]pyridazine ring system, ethyl pyrrolo[3,2‐c]pyridazine‐6‐carboxylate 2‐oxide (5) and ethyl 3‐chloro‐6‐methylpyrrolo[3,2‐c]pyridazine‐7‐glyoxalate 1‐oxide (12), were obtained in good yields from the cyclization of 4‐ethoxymethyl‐eneamino‐3‐methylpyridazine 1‐oxide (3) and 3‐chloro‐5‐(α‐ethoxyethylideneamino)‐6‐methylpyridazine 1‐oxide (14, R  Cl, R1  OMe), respectively, with diethyl oxalate and potassium ethoxide in ether.
Bridgehead nitrogen heterocycles. VI. The reaction of 1‐amino‐ and 1,2‐diaminopyridinium salts with β‐dicarbonyl compounds
Authors: Potts K. T. , Dugas R. , Surapaneni C. R. 
Published: March 2009

Abstract1,2‐Diaminopyridinium iodide underwent reaction with ethyl acetoacetate to form 1,4‐dihydro‐2‐methyl‐4‐oxopyrido[1,2‐a]pyrimidin‐1‐ium iodide, and with acetyl acetone it gave 2,4‐dimethylpyrido[1,2‐a]pyrimidin‐5‐ium iodide. Though 2‐acetylcyclohexanone gave the corresponding 5‐methyl‐1,2,3,4‐tetrahydropyrido[1,2‐a]quinazolin‐11‐ium iodide, no reaction was observed with 2,6‐dimethyl‐3,5‐heptanedione, 1‐benzoylacetone, 1,3‐diphenyl‐1,3‐propanedione and its p‐methoxyphenyl derivative. However, 1‐aminopyridinium iodide and acetyl acetone in the presence of base gave 3‐acetyl‐2‐methylpyrazolo[1,5‐a]pyridine and 1‐amino‐2‐methylpyridinium iodide yielded the corresponding 3‐acetyl‐2,7‐dimethylpyrazolo[1,5‐a]pyridine. With ethyl acetoacetate, the latter salt formed 3‐ethoxycarbonyl‐2,7‐dimethylpyrazolo[1,5‐a]pyridine but with 2,6‐dimethyl substituents in the pyridine ring no condensation occurred. Reaction of 1‐amino‐2‐methylpyridinium iodide with benzaldehyde gave N‐benzalimino‐2‐methylpyridinium iodide which, on treatment with base, resulted in the formation of 2‐picoline and benzonitrile, providing a convenient method of deamination.
Mass spectral analysis of substituted pteridines and their reduced analogs
Authors: Williams V. P. , Ayling J. E. 
Published: March 2009

AbstractThe reduced forms of substituted pteridines exhibit cofactor and inhibitory properties with the enzyme, phenylalanine hydroxylase (Ayling, et al., Biochemistry, 12, 2045 (1973)). Mass spectrometry has been used as a method for structure confirmation and to determine the state of purity and the extent of reduction. The structural analysis was facilitated by the use of several homologous classes of compounds. Reduced pteridines have not previously been analyzed by mass spectrometry and only a limited amount of data, much of which was from trimethylsilyl or acetyl derivatives, has been published on the mass spectral analysis of the non‐reduced compounds. Detailed mass spectral fragmentation modes are presented for the reduced and non‐reduced forms of the following compounds: 4‐aminopteridine, 4(3H)pteridinone, 6,7‐dimethyl‐4(3H)pteridinone, 2,4‐diamino‐6,7‐dimethylpteridine, 6,7‐dimethyl‐2,4(1H,3H)pteridinedione, 2‐amino‐4(3H)pteridinone, 2‐amino‐6,7‐dimethyl‐4(3H)pteridinone, 2‐amino‐6‐(L‐erythro‐1,2‐dihydroxypropyl)‐4(3H)pteridinone, 2‐amino‐4,6(3H,5H)pteridinedione, 2‐amino‐7‐methyl‐4,6(3H,5H)pteridinedione, 2‐amino‐4,7(3H,8H)pteridinedione, 2‐amino‐6‐methyl‐4,7(3H,8H)pteridinedione.
Reactions of diazo derivatives of 5‐membered heterocycles with hydrazines
Authors: Shealy Y. Fulmer , O'Dell C. Allen 
Published: March 2009

AbstractInteraction of hydrazine or dimethylhydrazine with 5‐diazoimidazole‐4‐carboxamide produced, presumably via tetrazenes, high yields of 5‐azidoimidazole‐4‐carboxamide. In contrast, when semicarbazide reacted with either the diazoimidazole or the analogous diazo‐1,2,3‐triazole, the yield of the azidoheterocycle was low, and the yield of biurea, and presumably the aminoheterocycle, was high. 3‐Azidopyrazole‐4‐carboxamide was obtained from a reaction of hydrazine with the diazopyrazole. Both azido and amino derivatives were formed from reactions of diazo‐imidazole esters with hydrazine or thiosemicarbazide.
Mass spectra of C‐nucleosides II. An unusual fragmentation reaction of the heterocyclic moiety of pyrazomycin and some closely related compounds
Authors: Crain P. F. , McCloskey James A. , Lewis Arthur F. , Schram Karl H. , Townsend Leroy B. 
Published: March 2009

AbstractThe mass spectrum of pyrazomycin has been obtained and reveals a fragmentation pattern with several important peaks which are not normally found in the mass spectra of C‐nucleosides. It has now been established, using model compounds, that these unusual fragment ions are a direct result of the juxtaposition of the exocyclic hydroxy and carboxamido groups of the aglycon. It appears that a facile elimination of ammonia and ethanol from o‐hydroxycarboxamides and o‐hydroxyethylesters, respectively, may be a general fragmentation reaction for aromatic heterocycles. A mass spectrum of the TMS derivative of pyrazomycin has also been obtained and factors which may result in exceptions to the empirical B+30 (M‐103) rule for C‐nucleosides are discussed.
Synthesis and PMR spectra of 7‐hydroxyalkylguanosinium acetates
Authors: Roe Robert , Paul J. S. , Montgomery P. O'B. 
Published: March 2009

AbstractGuanosine and 9‐methylguanine treated with epoxides in glacial acetic acid are hydroxyalkylated stereoselectively at the N7 position of the guanine moiety. Previously unreported 7‐(hydroxyalkyl)guanosinium acetates from the reactions of six epoxides with guanosine and 7‐(hydroxyalkyl)‐9‐methylguaninium acetates from the reactions of two epoxides with 9‐methyl guanine in glacial acetic acid have been prepared and characterized by their pmr spectra. By using an excess of epoxide, quantitative conversion of guanosine or 9‐methylguanine to the corresponding 7‐hydroxyalkylguanosinium or 7‐hydroxyalkyl‐9‐methylguaninium acetate was achieved. Comparisons of the pmr spectra of the 7‐(hydroxyalkyl)guanosinium acetates in DMSO‐d6 to the spectrum of guanosine reveal that the H8 and amino group proton absorptions common to guanosine are shifted to a lower field, the absorptions of the H1 proton is absent, and the coupling constant of the H′1‐H′2 protons of the ribosyl group is decreased from about 5.7 ± 0.1 Hz in guanosine to about 3.5 ± 0.1 Hz in the products. The use of the pmr spectral features of 7‐(hydroxyalkyl)‐9‐methylguaninium compounds in characterizing 7‐hydroxyalkylguanosinium compounds is discussed. Evidence is presented which suggests that extensive delocalization of positive charge exists in both the pyrimidine and imidazole rings of N7‐hydroxyalkylated guanosine and N7‐hydroxyalkylated‐9‐methylguanine. The possible effects of charge delocalization upon the hydrogen bonding potential of 7‐hydroxyalkylated guanine moieties in DNA is discussed.
S‐and Se‐dimethylarsino derivatives of thio‐ and selonopyrimidines and purines
Authors: Sarquis Arlyne M. , Zingaro Ralph A. 
Published: March 2009

AbstractThe synthesis of dimethylarsinothio‐and dimethylarsinoselonopyrimidines and ‐purines which utilizes diethylaminodimethylarsine is described. A series of these derivatives, with different substituents on the heterocyclic ring, has been investigated by infrared, nmr, and mass spectroscopic methods. Attempts to prepare O‐or N‐ arsinous acid derivatives from oxy‐ and aminopyrimidines were unsuccessful.
Chemical studies of potential relevance to penicillin hypersensitivity. The synthesis ofdl‐2‐phenoxymethylpenicillenic acid and ofdl‐2‐(2,6‐dimethoxyphenyl)penicillenic acid
Authors: Dudley Kenneth H. , Bius Daniel L. , Johnson Dorothy 
Published: March 2009

AbstractCrystalline samples of DL‐2‐phenoxy melhylpenicillenic acid (14) and ofDL‐2‐(2, 6‐dimethoxyphenyl)penicillenic acid (21) have been synthesized by the reaction ofDL‐penicillamine with 2 phenoxymethyl‐4‐(methoxymethylene)oxazol‐5‐one and 2‐(2, 6‐dimethoxyphenyl)‐4‐(ethoxymethylene)oxazol‐5‐one, respectively. These key oxazol‐5‐one intermediates were synthesized by azlactonization of the appropriately substituted penaldic acid dialkyl acetals. The reaction of mercury(II) chloride with D‐phenoxymethylpenicillin was studied and found to be inapplicable to the synthesis ofD‐14. A comparison of crystallineDL‐ and of amorphous D‐2‐(2,6‐dimethoxyphenyl)penicillenic acid (21), which were prepared by the “oxazolone” and “mercury(11) chloride” methods, respectively, suggests a marked improvement in the purity of theDL‐material.
Fluoroalkyl‐s‐triazines
Authors: Croft Thomas S. , Snyder Carl F. 
Published: March 2009

AbstractA series of symmetrically and asymmetrically substituted s‐triazines was synthesized by condensation of fluorocarbon nitriles (Scheme II, compounds 1a‐c) and by cyclodehydration of a fluorocarbon imidoylamidine utilizing a fluorocarbon anhydride (Scheme III, compounds 2a‐e). Among the new nitriles prepared for incorporation in these reaction paths were 11‐H‐4,9‐dioxahexadecylfluoroundecanenitrile (3) and 6‐chloro‐6‐H‐4‐oxaheptafluorohexanenitrile (4), prepared by Scheme 1.
Selenium heterocycles XII. Heat induced transformation of 1,2,3‐Selenadiazoles to disubstituted selenophenes
Authors: Lalezari I. , Shafiee A. , Rabet F. , Yalpani M. 
Published: March 2009

Abstract4‐Aryl‐1, 2, 3‐selenadiazoles when subjected to heat afforded 2, 5‐diarylselenophenes and small quantities of 2,4‐diarylseneophenes. Monoarylacetylenes and selenium behaved similarly. Phenylacetylene and sulfur gave 2,4‐diphenylthiophene. Mechanistic aspects of these reactions are discussed.