bluuebunny/crossref_metadata_2025_split huggingface dataset:
Oxazolidines versus schiff bases
Authors: Srivastava R. M. , Weissman Katherine , Clapp Leallyn B. 
Published: March 2009

AbstractThe formation of oxazolidines from propionaldehyde and aliphatic β‐aminoalcohols is complicated by the appearance of appreciable amounts of unsaturated Schiff bases. The simple Schiff base, often the dominant species when aromatic aldehydes react with amines, could not be detected in the present aliphatic systems. We conclude that in aliphatic systems the order of stability is magnified image and magnified image. The gem‐dimethyl group α to nitrogen stablizes the heterocyclic ring remarkably.
Irreversible enzyme inhibitors. LXXXIX. candidate active‐site‐directed irreversible inhibitors of dihydrofolic reductase. X. derivatives of 2‐amino‐5‐benzamidopropyl‐4‐pyrimidinol
Authors: Baker B. R. , Coward James K. 
Published: March 2009

AbstractSince 2‐amino‐5‐benzamidopropyl‐6‐methyl‐4‐pyrimidinol (VII) was a reasonably good reversible inhibitor of dihydrofolic reductase, the benzamido group was substituted with p‐bromomethyl (XVIIa), m‐bromomethyl (XVIIIa), and p‐bromoacetyl (XIXa) groups; these compounds, and the corresponding 6‐phenylpyrimidines, were synthesized from the proper 2‐amino‐5‐aminopropyl‐4‐pyrimidinol (V) by devising methods that were compatible with the high reactivity of the halogen. Compounds XVII‐XIX showed in‐activation of dihydrofolic reductase; the fact that p‐nitrobenzyl bromide inactivated the enzyme as rapidly as XVII and XVIII and phenacyl bromide inactivated the enzyme as rapidly as XIX indicated that these inactivations proceeded by a random bimolecular mechanism and not the desired active‐site‐directed mechanism.
Synthesis of possible metabolites of chlorpromazine. I. 7‐hydroxy derivatives of chlorpromazine, nor1‐chlorpromazine and nor2‐chlorpromazine
Authors: Nodiff Edward A. , Ina Shuichiro , Oda Noriichi , Hayazaki Takanori , Nishibe Sansei , Kohno Tetsuya , Hausman Martin , Manian Albert A. 
Published: March 2009

AbstractThe title compounds and various derivatives have been prepared as analytical standards for the identification of chlorpromazine metabolites in biological materials. Additional evidence is presented for the existence of a halogen‐induced Smiles rearrangement in the phenothiazine series.
Purine nucleosides XVII. The synthesis and conformation of 6‐amino‐9‐β‐D‐ribopyranosylpurine and related derivatives prepared via the fusion procedure
Authors: Pan Yung Hsin , Robins Roland K. , Townsend Leroy B. 
Published: March 2009

AbstractThe preparation of 2, 6‐dichloro‐9‐(2′,3′,4′‐tri‐O‐acetyl‐β‐D‐ribopyranosyl)purine (I) has been accomplished utilizing the acid catalyzed fusion procedure. The displacement of the 6‐chloro group, or the 2‐ and 6‐chloro group has been studied. Several new 6‐substituted‐9‐(β‐D‐ribopyranosyl)purines have been prepared by catalytic dehalogenation of the corresponding 2‐chloropurine nucleosides. The conformation and configuration of these D‐ribopyranosylpurines has been assigned with the assistance of proton magnetic resonance studies.
5,6‐dihydro‐4H‐1,3,4‐thiadiazines. II. synthesis and use of 1‐(1‐methylhydrazino)‐2‐propanethiol for the preparation of various thiadiazines and a 2‐thiazolidinethione
Authors: Trepanier D. L. , Krieger P. E. 
Published: March 2009

AbstractThis paper reports the synthesis of 1‐(1‐methylhydrazino)‐2‐propanethiol and the results of a study of its reactions with benzaldehyde, benzonitrile, benzoyl chloride, triethyl orthoformate, succinonitrile, cyanogen bromide, and cyclopropylcyanide to give a thiadiazine directly or a product which can be converted to a thiadiazine. It also reports the condensation of 1‐(1‐methylhydrazino)‐2‐propanethiol with carbon disulfide to yield a 2‐thiazolidinethione.
The synthesis of some 1‐(β‐diethylaminoethyl)‐2‐(p‐ethoxybenzyl)‐5‐substituted benzimidazoles
Authors: Carroll F. I. , Handy R. W. , Kepler J. A. , Gratz Joan A. 
Published: March 2009

AbstractThe syntheses of several 5‐substituted benzimidazoles structurally related to the highly active analgesic 1‐(β‐diethylaminoethyl)‐2‐(p‐ethoxybenzyl)‐5‐nitrobenzimidazole are presented.
Structural modification studies of 3‐piperonylsydnone I. synthesis of piperonyl‐substituted pyrazoles, isoxazoles, triazoles, oxadiazoles and thiadiazoles
Authors: Boots Sharon G. , Cheng C. C. 
Published: March 2009

AbstractAs a structural modification study of the antimalarial compound 3‐piperonylsydnone, a number of pyrazoles, isoxazoles, 1,2,4‐triazoles, ψ‐1,2,4‐triazoles, 1,3,4‐oxadiazoles, 1,3,4‐thiadiazoles and their intermediates all of which contain the piperonyl moiety have been synthesized. The antimalarial activity of these compounds was found to be less than that of the original sydnone. With the exception of 2,4‐diamino‐5‐piperonylpyrimidine, among the compounds tested, those which showed survival time of eleven days or over all possess a N‐N linkage.
The synthesis of tetrahydroisoquinolines from 1,4‐dihydro‐3 (2H)‐isoquinolones
Authors: Finkelstein Jacob , Brossi Arnold 
Published: March 2009

AbstractExperimental procedures are given for the facile synthesis of various types of 1,4‐dihydroisoquinolones and their reduction to the corresponding 1,2,3,4‐tetrahydroisoquinolines.
Pyrazolo‐N‐hydroxyuracils from the modified lossen rearrangement of vicinal pyrazoledicarbohydroxamates
Authors: Bauer Ludwig , Mahajanshetti C. S. 
Published: March 2009

AbstractThe reaction of 1‐phenyl‐3,4‐ and 4,5‐pyrazoledicarbohydroxamates, II and VIII, with benzene‐ and methanesulfonyl chlorides is reported. Each hydroxamate yielded two isomeric N‐phenyl‐N‐hydroxypyrimidinediones whose structures were established. The NMR spectra of a number of isomeric pyrazole derivatives are discussed.
Novel heterocyclic derivatives of quinuclidine
Authors: Renters William A. , Gibs Gabriel J. , Weiss Martin J. 
Published: March 2009

AbstractTreatment of ethyl 3‐quinuclidinone‐2‐carboxyIate (III) with appropriate reagents gave 2,3‐fused heterocycles including pyrazolol, aminopyrimidinone, and aminopyridazinone types. The thiourea derivative of III could not be cyclized. Triazoline, pyrazoline, and isoxazoline derivatives were prepared by 1,3‐dipolar cycloadditions to the 2‐ and 3‐positions of methyl 2,3‐dehydroquinuclidine‐3‐carboxylate (XIIIa). Such facile formation of cycloaddition products was not possible with 2,3‐dehydroquinuclidine, which reacted only with phenylazide (in poor yield). Structural assignments for the products of cycloaddition were made by analogy, but alternative structures could not be ruled out by the nmr or mass spectra.
4‐thiazohne‐2‐thiones. III. The thermodynamic stability of intermediate, tautomeric thiazolidines and dithiocarbamates
Authors: Lamon R. W. , Humphlett W. J. , Blum W. P. 
Published: March 2009

AbstractThe intermediate products isolated from preparations of 3‐substituted 4‐thiazoline‐2‐thiones by the reaction of primary amines, carbon disulfide, and α‐haloketones may be either 4‐hydroxy‐thiazolidine‐2‐thiones or dithiocarbamates. Tautomeric equilibrium of the two types of intermediates in solution is demonstrated, and the more thermodynamically stable form is determined. Steric and electronic effects of substitution on stability are described.
The reaction of methyl propiolate with 2‐aminopyridines
Authors: Wilson J. G. , Bottomley W. 
Published: March 2009

AbstractThe structure (III) reported by Lappin (2) for the diadducts formed by the reaction of methyl propiolate with 2‐aminopyridines has been found to be incorrect. The correct structure (IV) has been proven by spectral studies and cyclisation to compound VII. In two cases new compounds having structures of the type (III) have been isolated. N.M.R. data are reported for all products.
New synthesis routes to 2‐halopyridines. I. 2‐chloropyridine
Authors: Boudakian Max M. , Frulla F. F. , Gavin David F. , Zaslowsky Joel A. 
Published: March 2009

AbstractIn contrast to the wide variety of products previously reported from the non‐photolytic liquid or vapor phase chlorination of pyridine (I), it has been demonstrated that the corresponding photochemical chlorination of I in carbon tetrachloride under reflux conditions gave 2‐chloropyridine (IV) in 62–78 percent yield.
Benzo[b]thiophene derivatives I. 6‐methoxybenzo[b]thiophene analogs of plant growth regulators
Authors: Schuetz Robert D. , Titus Richard L. 
Published: March 2009

AbstractThe acid catalyzed ring closure of an appropriately substituted phenyl ketoester sulfide served as the initial reaction in the synthesis of several 3,4‐ and 3,6‐disubstituted benzo[b]thiophenes. One of these compounds, 4‐methoxybenzo[b]thienyl‐3‐acetic acid, showed marked plant growth enhancement.
1‐(2‐pyridyl)‐3,4‐dihydro‐6,7‐dimethoxyisoquinoline and some of its hydrogenated and N‐substituted derivatives
Authors: Wenner Wilhelm , Stefaniw Mychajlo 
Published: March 2009

AbstractThe preparation of 1‐(2‐pyridyl)‐ and 1‐(2‐piperidyl)‐substituted, partly hydrogenated derivatives of 6,7‐dimethoxyisoquinoline is described.
1,4‐disubstituted pyridazino[4,5‐d] pyridazines
Authors: Dorman Linneaus C. 
Published: March 2009

Abstract1,4‐Bis(methyIthio)pyridazino[4,5‐d]pyridazine (IV) was synthesized from 4,5‐pyridazinedi‐carboxylic acid in three steps. By employing IV as an intermediate, various 1,4‐disubstituted pyridazino[4,5‐d]pyridazine derivatives of classes 1,4‐N,S; 1,4‐N,O; 1,4‐O,S; and 1,4‐O,O were prepared by one‐step or two‐step nucleophilic substitution reactions. Steric, polar and resonance effects were observed in some of these reactions and are discussed.
The crystal molecular structure of cis‐13,13‐dimethyl‐13‐azoniabicyclo [10.1.0] tridecane iodide
Authors: Trefonas L. M. , Towns R. , Majeste R. 
Published: March 2009

AbstractThe crystal and molecular structure of cis‐13,13‐dimethyl‐13‐azoniabicyclo[10.1.0]tridecane iodide has been determined by a three‐dimensional, single‐crystal, x‐ray diffraction study. The compound crystallizes in the orthorhombic space group Pnam with cell dimensions aQ = 21.36 ± .01, bO = 9.07, cO = 8.29 Å. The aziridine ring is fused to the cyclododecane ring with fusion angles of 123.5°. The molecule is bisected by a mirror plane with the cyclododecane portion distorted from its anticipated square conformation. Transannular hydrogen interactions are estimated on the basis of geometric considerations. A final value of R = 0.112 was obtained for the 557 non‐equivalent reflections which were observed.
3‐H‐isoxazolin‐5‐ones
Authors: De Sarlo Francesco , Dini Giuliano 
Published: March 2009

Abstract4‐Alkyl and 4‐phenyl isoxazolin‐5‐ones were prepared. The 4‐alkyl compounds were found to isomerize easily to α‐cyano carboxylic acids. The acidity and the tautomeric composition of the compounds prepared arc surveyed and compared to the results of the previous literature.
Synthesis and properties of fluorine‐containing heterocyclic compounds. V. Trifluoromethyl‐1,8‐ and 1,10‐phenanthrolines
Authors: Nyquist Edwin B. , Joullié Madeleine M. 
Published: March 2009

AbstractThe condensation of ethyl trifluoroacetoacetate with various heterocyclic amines yielded 2‐(trifluoromethyl)phenanthrolin‐4‐ones. The structures of these compounds were established from a study of their infrared and ultraviolet spectra. Substituted phenanthrolines were prepared by nucleophilic attack on a chlorophenanthroline. The oxidation of 5‐methoxy‐2‐trifluoromethyl‐1,10‐phenanthroline yielded an o‐quinone which was treated with typical quinone reagents. A molecular orbital calculation was carried out in an attempt to explain the ease of reduction of the 1,10‐phenanthroline system and the colors of the reduced compounds.
Naphthyridine chemistry. VIII. The mass spectra of the 1,X‐naphthyridines and some of their methyl derivatives
Authors: Paudler William W. , Kress Thomas J. 
Published: March 2009

AbstractThe mass spectra of the four parent 1,X‐naphthyridines, the 2,3 and 4‐monomethyl‐1,5‐,1,6‐. and 1,8‐ naphthyridincs, seven dimethyl‐1,8‐naphthyridines, and one trimethyl‐1,8‐naphthyridine are reported. Evidence for an azatropylium ion intermediate in the fragmentation of the methyl compounds is presented. The fragmentation modes of the naphthyridines are similar to those for the quinolines in addition to several new processes
as‐Triazine chemistry. V.The oxidative ring‐opening of 5,6‐diphenyl‐as‐triazine‐3(2H)‐ones with Organic Peracids
Authors: Sasaki Tadashi , Minamoto Katsumaro 
Published: March 2009

AbstractThe structures of the oxidation products of 5,6‐diphenyl‐as‐triazine‐3(2H)‐ones (Ia‐b) with organic peracids were chemically and spectroscopically reinvestigated and it was concluded that the products were 1,4‐dibenzoyl semicarbazide (IIa) and the 2‐methyl analogue (IIb).
A new synthesis of thiazolo[3,2‐a] pyrimidinones
Authors: Andrew H. F. , Bradsher C. K. 
Published: March 2009

Abstract5H‐Thiazolo[3,2‐a]pyrimidin‐5‐ones (V) have been prepared by S‐alkylation of 6‐methyl‐2‐thiouracil (Ib) with bromoacetone or bromoacetophenone followed by cyclization in sulfuric acid. By the same series of reactions, 2‐thiouracil (Ia) gave rise to 7H‐thiazolo[3,2‐a]pyrimidin‐7‐ones (VI). The properties and structures of the intermediates and products are discussed.
PMR spectra and conformation of some four‐membered rings containing one nitrogen atom. 2‐Azetidinones, 2‐azetidinethiones and 1‐azetines
Authors: Vigevani Aristide , Gallo Gian Gualberto 
Published: March 2009

AbstractBy PMR studies at different temperatures a planar conformation is proposed for the 2‐azetidinone, 2‐azetidinethione and 1‐azetine rings. The chemical shifts and the vicinal and geminal coupling constants of the ring methylene protons are reported and discussed. The application of the relationship between the Jgem value and the angle between the methylene group and the adjacent 7r‐bond is considered.
Synthesis and reactions of 3,9‐diisocyanates and diisothiocyanates in the 2,4,8,10‐tetraoxa‐3,9‐diphosphaspiro[5.5] undecane series
Authors: Pivawer Philip M. , Bliss Arthur D. , Ratz Rudi 
Published: March 2009

AbstractThe synthesis of several novel phosphorus‐containing isocyanates and isothiocyanates is reported. These compounds are spiranes with two six‐membered dioxaphosphorinane rings in their respective molecule. The phosphorus‐bonded isocyanato and isothiocyanato groups are capable of undergoing addition reactions with active hydrogen atom‐containing compounds.
1‐Azetines
Authors: Pifferi Giorgio , Consonni Pietro , Pelizza Giuseppina , Testa Emilio 
Published: March 2009

AbstractThe synthesis, characteristics and chemical behaviour of some 3,3‐disubstituted‐2‐ethoxy‐ and 2‐ethy lthio‐1‐azetines, the first examples of a new class of heterocyclic compounds, are described.
NMR spectra of 2‐pyrone and 2‐pyrone derivatives
Authors: Pirkle W. H. , Dines Martin 
Published: March 2009

AbstractAn analysis of the complex NMR spectrum of 2‐pyrone is presented and the spectra of a series of variously substituted 2‐pyrones and 5,6‐dihydro‐2‐pyrones are discussed. It is demonstrated that NMR spectroscopy affords a convenient and reliable method of assigning the position of substituents on the 2‐pyrone nucleus.
Preparation of 4‐pyrimidinetliiones from acyl lsothiocyanate‐enamine adducts
Authors: Lamon Robert W. 
Published: March 2009

AbstractAdducts formed from benzoyl isothiocyanate and l‐morpholinocyclopentene or β‐(N,N‐diethylamino)styrene and that prepared from acetyl isothiocyanate and l‐pyrrolidinoeyclopen‐tene gave 4‐pyrimidinethiones when treated with primary amines or ammonia. In some cases intermediates, the products of amine exchange, were isolated. These intermediates were readily cyclized to 4‐pyrimidinethiones with dilute alkali.
Studies on the syntheses of heterocyclic compounds. part CCLXXIX . Synthesis of O‐isobutylcularidine
Authors: Kametani T. , Iida H. , Kibayashi C. 
Published: March 2009

AbstractAlthough various methods of oxepine formation from phenoxybenzene dicarboxylic acids was attempted, only 11‐hydroxy‐4‐isobutoxy‐7,8‐dimethoxydibenz[b,f]oxepin‐l‐ylaeetic acid lactone (XXX) was synthesized successfully. Compound XXX gave O‐isobutylcularidine (XXXVlIb) in a few steps. Our synthetic O‐isobutylcularidine was identical with that prepared from natural cularidine proving the structure for cularidine proposed by Manske. However, dealkylation of synthetic O‐isobutylcularidine was unsuccessful.
Synthesis of substituted dihydroisocarbostyrils from 5‐hydroxyamides obtained from dilithio‐N‐substituted o‐toluamides
Authors: Mao Chung‐Ling , Burnish I. T. , Hauser Charles R. 
Published: March 2009

Abstractδ‐Hydroxyamides, prepared by condensation of ketones or aldehydes at the 2‐methyl group of Nsubstituted o‐toluamides by means of n‐butyllithium, were cyclodehydrated with sulfuric acid to form 2,3‐disubstituted and 2,3,3‐trisubstituted 3,4‐dihydroisocarbostyriIs. Also, δ‐hydroxyamides obtained from condensation of ketones at the 2‐benzyl group of N‐methyl‐o‐benzylbenzamide, were cyclodehydrated to give 2,3,3,4‐tetrasubstituted 3,4‐dihydroisocarbo‐styrils. All of the products appeared to be new. This new method, which involves an unusual acid catalyzed cyclodehydration, is convenient and apparently quite general.
Benzothiazoline derivatives. II. Preparation of N‐substituted derivatives of 2‐benzothiazolinethione by thiation of the 2‐oxo analogs
Authors: Sohar Paul , Denny George H. , Babson Robert D. 
Published: March 2009

AbstractThuiation of the benzoate and acetate esters of 3‐(2‐hydroxyethyl)‐2‐benzothiazolinone (Ig) gave the corresponding thiones. The benzoate was then deblocked to yield 3‐(2‐hydroxyethyl)‐2‐benzothiazolinethione (Ik), a compound not accessible by direct addition or substitution. Attempts to introduce a chlorine (or bromine) atom in place of the hydroxy 1 group in the latter compound or its S‐isomer, 2‐(2‐hydroxyethylthio)benzothiazole (11a), gave 2,3‐dihydrothiazolo‐[2,3‐b ] benzothiazolium chloride (or bromide) (IIIa or b). The latter compound undergoes dihydrothiazolo ring opening when treated with sodium hydroxide or sodium sulfide to give bis[2‐(2‐benzolhiazolinon‐,3‐yl)ethyl]disulfide (IVc) or bis[2‐(2‐benzothiazolinethion‐3‐yl)ethyl] disulfide (lVb),respectively. 2‐Benzothiazolinethione reacted with ethylenimine and with N‐phenylethylenimine to give S‐substituted derivatives. Addition to vinyl n‐butyl ether gave the expected N‐substituted derivative, which was found to undergo removal of the butyoxyethyl group when subjected to conventional conditions for ether cleavage.
Alkylidenebis‐1‐methyl‐2‐alkylidenehydrazines as intermediates in the reaction of methylhydrazine with aliphatic aldehydes
Authors: Rabjohn Norman , Sloan K. B. 
Published: March 2009

AbstractIt has been shown that heptylidenebis‐1‐methyl‐2‐heptylidenehydrazine (Va) is an intermediate in the reaction of methylhydrazine with heptanal. The bis‐compound (Va) reacts with methylhydrazine to give heptanal methylhydrazone (IIa), or with heptanal, in the presence of acid, to afford 5‐hexyl‐1‐methyl‐4‐pentyl‐2‐pyrazoline (Ia). The latter also results from the treatment of IIa with acid.
Pyrrolopyrimidine nucleosides. IV. The synthesis of certain 4,5‐disubstituted‐7‐(β‐d‐ribofuranosyl)pyrrolo[2,3‐d]pyrimidines related to the pyrrolo[2,3‐d]pyrimidine nucleoside antibiotics
Authors: Hinshaw Barbara C. , Gerster John F. , Robins Roland K. , Townsend Leroy B. 
Published: March 2009

AbstractThe treatment of 4‐chloro‐7‐(2′,3′,5′‐tri‐O‐acetyl‐β‐D‐ribofuranosyl)pyrrolo[2,3‐d]pyrimidine (4) with N‐bromoacetamide in methylene chloride has furnished the 5‐bromo derivative of 4 which on subsequent deacetylation provided a good yield of 5‐bromo‐4‐chloro‐7‐(β‐D‐ribo‐furanosyl)pyrrolo[2,3‐d] pyrimidine (6). Assignment of the halogen substituent to position 5 was made on the basis of pmr studies. Treatment of 6 with methanolic ammonia afforded 4‐amino‐5‐bromo‐7‐(β‐D‐ribofuranosyl)pyrrolo[2,3‐d ]pyrimidine (8, 5‐bromotubercidin) and a subsequent study has revealed that the 4‐chloro group of 6 was replaced preferentially in a series of nucleophilic displacement reactions. The analogous synthesis of 4,5‐dichloro‐7‐(β‐D‐ribo‐furanosyl)pyrrolo[2,3‐d]pyrimidine (13b) and 4‐chloro‐5‐iodo‐7‐(β‐D‐ribofuranosyl)pyrrolo[2,3‐d]pyrimidine (13a) from 4 furnished 5‐chlorotubercidin (15) and 5‐iodotubercidin (14), respectively, on treatment of 13b and 13a with methanolic ammonia. The possible biochemical significance of these tubercidin derivatives is discussed.
Fluorinated nitrogen heterocycles via cyclization. III. 3‐trifluoromethyl‐1‐(4‐trifluoromethyl‐2‐pyridyl)‐pyrazoles from fluorinated 1,3‐diketones and 4‐trifluoromethyl‐2‐hydrazinopyridines
Authors: Pitman‐Dunn Seymour Portnoy 
Published: March 2009

AbstractFluorinated 1,3‐diketone compounds having the general structure CF3COCH2COR1 underwent cyclization with 4‐trifluoromethyl‐2‐hydrazinopyridines (IV) to give a series of 3‐trifluoro‐methyl‐1‐(4‐trifluoromethyl‐2‐pyridyl)‐pyrazoles (V). The hydrazinopyridine intermediates (IV) were prepared by conversion of 4‐trifluoromethyl‐2‐pyridones (II) to the chloropyridines (III) followed by treatment of the latter with hydrazine hydrate.
Analogues non glycosidiques des nucléaosides. III. (Méthylène téatrahydro‐2′ furyl)‐1 uracile, thymine et cytosine. (méathylégne téatrahydro‐2′‐r furyl)‐1 uracile
Authors: Defaye J. , Naumberg M. , Reyners T. 
Published: March 2009

AbstractDans le cadre de travaux ayant pour objectif la modification de la réactivité de la liaison base‐sucre des nucléosides et analogues, les dérivés substitués de l'uracile, de la thymine et de la cytosine par les radicaux méthylène tétrahydro‐2 furyle et tétrahydro‐2‐R furyle ont été préparés. Dans ce but, différentes méthodes d'alkylation des pyrimidines ont été étudiées. La préparation de l'énantiomère de configuration absolue R de I'alcool tétrahydro‐2 furfurylique est décrite.
Acylation of nitrogen heterocycles under the conditions of the schotten‐baumann reaction. III. Imidazoles
Authors: Babad E. , Ben‐Ishai D. 
Published: March 2009

AbstractImidazole and five N‐monoalkylimidazoles were tested for their ability to undergo ring fission on carbobenzoxylation. Reaction occurred only with imidazoles substituted with strong electron withdrawing groups such as nitrophenyl, dinitrophenyl and monocarbobenzoxy.
New microbial phenazines
Authors: Gerber Nancy N. 
Published: March 2009

AbstractEleven phenazines were identified as fermentation products of a bacterium. They included the previously unknown 2,9‐dihydroxyphenazine‐1‐carboxyIic acid (4), 1,8‐phenazinediol‐1()‐oxide (5) and 8‐amino‐1‐phenazinol (6) as well as phenazine‐1,6‐dicarboxylic acid (1),9‐hydroxyphena‐zine‐1‐carboxylic acid (2) and 1,8‐phenazinediol (3) not isolated before from natural sources.
On the nitration of 2‐pyrone
Authors: Pirkle W. H. , Dines M. 
Published: March 2009

AbstractA 1:1 adducl of 2‐pyrone and nitronium fluoroborate has been delected by nmr and is a possible precursor of 5‐nitro‐2‐pyrone, a subsequently formed product. From comparison of the nmr spectra of the 1:1 adduct and 2‐methoxypyrylium fluoroborate, the adduct is believed to be the pyrylium fluoroborate derived from nitration of the carbonyl oxygen of 2‐pyrone.
Thiocarbonyls. X. The Isomeric 2,4,6‐Tris(halophenyl)‐1,3,5‐thianes
Authors: Campaigne E. , Georgiadis M. P. 
Published: March 2009

AbstractNine pairs of isomeric 2,4,6‐tris(halophenyl)‐1,3,5‐trithianes have been assayed in the crude state by n.m.r. techniques, and separated and purified by chromatography. Contrary to previous reports, the α‐(cis, trans)‐isomers are the major products in most cases. These compounds are shown to exist as puckered chair trithiane structures, even in the more hindered α‐(cis, trans)‐o‐halophenyl cases, by the clear resolution of axial and equatorial trithiane ring protons in a ratio of 2:1. Ano‐halogen on an axial phenyl group in the α‐isomers causes the aromatic group to exert an anisotropic deshielding effect on adjacent axial protons, so as to cause the axial and equatorial proton peaks to appear as a singlet in some solvents. Melting point differences, in several cases quite large, from those previously reported have been observed for six of the eighteen triaryltrithianes reported.