bluuebunny/crossref_metadata_2025 huggingface dataset:
A simple regioselective synthesis of pyrimido[1,2‐a]benzimidazoles
Authors: Tseng Shin‐Shyong , Epstein Joseph W. , Brabander Herbert J. , Francisco Gerardo
Published: April 2009

2‐Aminobenzimidazoles were reacted with enaminones in acetic acid to give pyrimido[1,2‐a]benzimidazoles. With a substituted enaminone only one regioisomer was obtained. Structural assignments based on nmr and uv spectroscopy are presented. Possible pathways leading to the products are discussed.
Optical resolution of rotenoids
Authors: Abidi S. L.
Published: April 2009

Optical resolution of selected rotenoids containing 1‐3 asymmetric centers in dihydrobenzopyranofuroben‐zopyranone and dihydrobisbenzopyranopyranone series has been achieved on two chiral high‐performance liquid chromatographic (hplc) stationary phases. In most cases, the absolute stereochemistry at the cis‐B/C ring junction of the rotenoidal antipodes can be related to their elution order. Generally, the 6aα,12aα‐enantiomers were more strongly retained by the chiral substrate than their corresponding optical antipodes. The elution‐configuration relationship provides potential utility for predicting the absolute configuration of related rotenoidal compounds. Chiral phase hplc on amino‐acid‐bonded‐silica yielded results explicable in terms of Pirkle's bonding schemes for chiral recognition. Resolution data for 12a‐hydroxy‐, 12a‐methoxy‐, and 12‐hydroxyiminorotenoids further corroborate the mechanistic rationale, and demonstrate that nonpolar π‐π interactions appeared to be important for enantiomeric separation on helic poly‐triphenylmethylacryl‐ate‐silica (CPOT). In the latter system, steric effects and conformational factors in association with the modification of E‐ring structures might play significant roles in the chiral separation process in view of the reversal to the elution order observed for all methoxylated rotenoids and elliptone derivatives including the parent deguelin. The unique separability (α = 1.44) of 12a‐hydroxyelliptone on CPOT was suggestive of structural effects of the 5′‐side chain on the resolution of the rotenoids having a five‐membered‐E‐ring. The results obtained with two different types of chiral phases are complementary and useful for optical resolution of a wide variety of natural and synthetic rotenoidal compounds.
Sulfur‐containing 2‐arylquinolinemethanols as potential antimalarials
Authors: Epling Gary A. , Lin Kuei‐Ying
Published: April 2009

The synthesis and antimalarial activity of six new 2‐arylquinoline‐4‐methanols is described. The compounds bearing a sulfur were prepared to determine if antimalarial activity can be retained while photo‐reactivity and phototoxicity is diminished by such substituents. The observed antimalarial activity of some of the new compounds show this to be possible.
Direct synthesis of pyrrole nucleosides by the stereospecific sodium salt glycosylation procedure
Authors: Ramasamy Kandasamy , Robins Roland K. , Revankar Ganapathi R.
Published: April 2009

A stereospecific high‐yield glycosylation of preformed fully aromatic pyrroles has been accomplished for the first time. Reaction of the sodium salt of pyrrole‐2‐carbonitrile (1a) and pyrrole‐2,4‐dicarbonitrile (1b) with 1‐chloro‐2‐deoxy‐3,5‐di‐O‐p‐toluoyl‐α‐D‐erythro‐pentofuranose (2) gave exclusively the corresponding blocked nucleosides with β‐anomeric configuration 3a and 3b, which on deprotection gave 1‐(2‐deoxy‐β‐D‐erythro‐pentofuranosyl) derivatives of 1a (3c) and 1b (3d). Functional group transformation of 3c and 3d provided a number of 2‐monosubstituted 4a‐c and 2,4‐disubstituted 4d‐f derivatives of 1‐(2‐deoxy‐β‐D‐erythro‐pentofuranosyl)pyrrole. Similar glycosylation of the sodium salt of 1a and 1b with 1‐chloro‐2,3,5‐tri‐O‐benzyl‐α‐D‐arabinofuranose (5) and further functional group transformation of the intermediate blocked nucleosides 6a and 6b provided 1‐β‐D‐arabinofuranosyl derivatives of pyrrole‐2‐carboxamide (7b) and pyrrole‐2,4‐dicarboxamide (7d). The synthetic utility of this glycosylation procedure for the preparation of 1‐β‐D‐ribofuranosylpyrrole‐2‐carbonitrile (12) has also been demonstrated by reacting the sodium salt of 1a with 1‐chloro‐2,3‐O‐isopropylidene‐5‐O‐(t‐butyl)dimethylsilyl‐α‐D‐ribofuranose (10) and subsequent deprotection of the blocked intermediate 11. This study provided a convenient route to the preparation of aromatic pyrrole nucleosides.
Acetylenchemie. 4 mitt. Synthese von haplophyllin und N‐methylflindersin, zwei wege zu N‐funktio‐nalisierten pyrano[3,2‐c]chinolin‐alkaloiden
Authors: Reisch Johannes , Bathe Andreas , Rosenthal Bernd H. W. , Salehi‐Artimani Reza A.
Published: April 2009

Pyrano[3,2‐c]chinolin‐Alkaloide (3), geeignete Vorstufen für photobiomimetische Dimerisierungen, sind durch PTC‐Reaktion eines 4‐Hydroxychinolin‐2‐ons (1) mit 3‐Chlor‐3‐methylbut‐1‐in zugänglich, wobei als Nebenprodukt die Furo[3,2‐c]chinolin‐2‐on‐isomere (5) anfallen. Bei der Synthese von Flindersin (3a) wurde zusätzlich das Oxazolo[3,2‐a]chinolin‐5‐on (4) gewonnen; bei der vom N‐Methylflindersin (3b) das Bis‐(N‐methyl‐4′‐hydroxychinolin‐2′‐on‐3′‐yl)‐isopenten (7). Alkaloiddimere, deren Bildung aus Intermediaten formulierbar ist, traten nicht auf. Die Entstehung von 7 bestätigt bislang diskutierte Reaktionsabläufe. Halplophyllin (3c) wurde durch N‐Alkylierung von 3a mit 3‐Methylcrotonsäurechlormethylester erstmalig synthetisch dargestellt.
Photochemical intramolecular nitrene insertion of 6‐azidouridine derivatives
Authors: Miyasaka Tadashi , Tanaka Hiromichi , Satoh Kazue , Imahashi Mie , Yamaguchi Kentaro , Iitaka Yoichi
Published: April 2009

A highly efficient intramolecular nitrene insertion was observed upon irradiation of 6‐azidouridine derivatives. The N6,2′‐cyclo structure of the product was determined unequivocally by X‐ray crystallography.
An improved synthesis of [1H]‐isoindolin‐1‐one‐3‐carboxylic acid
Authors: Lowe John A. , Ewing Frank E.
Published: April 2009

Preparation of the title compound in one operation from commercially available phthalaldehydic acid in 34% yield is described.
Establishing vicinal proton‐proton connectivities using two‐dimensional proton zero quantum coherence NMR
Authors: Zektzer Andrew S. , Martin Gary E. , Castle Raymond N.
Published: April 2009

Phenanthro[3,4:3′,4′]phenanthro[2,1‐b]thiophene (1) served as the model system to evaluate two‐dimensional proton zero quantum coherence nmr in order to establish the vicinal proton‐proton connectivities. The utility of the two‐dimensional proton zero quantum nmr experiment has been compared with the utility of the traditional autocorrelated proton‐proton (COSY) experiment. In the case of a molecule such as 1, where the proton chemical shifts are so highly congested, the zero quantum coherence experiment provides data not obtainable from the COSY experiment.
A convenient and one‐pot synthesis of 9‐substituted carbazoles from primary amine hydrochlorides and 2,5‐dimethoxytetrahydrofuran
Authors: Kashima Choji , Hibi Shigeki , Maruyama Tatsuya , Harada Kazuo , Omote Yoshimori
Published: April 2009

Carbazoles are the very important compounds in material science, nevertheless conventional syntheses required severe and complicated reaction conditions. In the process of preparation of pyrrole derivatives, we found that a primary amine hydrochloride 1 and 2,5‐dimethoxytetrahydrofuran 2 were refluxed in a benzenewater (100:4 (v/v)) mixture to be obtained 9‐substituted carbazole 5 in a high yield. This method is the one‐pot synthesis of 9‐substituted carbazoles 5 under mild and convenient conditions.
Synthesis and structure of dithioester stabilised pyridinium ylides
Authors: Alvarez‐Builla J. , Gálvez E. , Cuadro A. M. , Florencio F. , Blanco S. Garcia
Published: April 2009

An improved procedure to prepare dithioester stabilised pyridinium ylides is described. The structure of the products is discussed.
On triazoles. VII Synthesis of novel tri‐ and tetracyclic ring systems
Authors: Reiter József , Pongó László , Krajcsi Péter , Esses‐Reiter Klára , Sohár Pál , Molnár Hilda , Dvortsák Péter
Published: April 2009

The ring‐closure of the 5‐amino‐1‐(2‐aminophenyl)‐3‐methylthio‐1H‐1,2,4‐triazole derivatives 3 and 4 with different simple and cyclic C1 components lead to the formation of 1,2,4‐triazolo[1,5‐α]‐1,3,5‐benzotriazepines 5–6, their 4,5‐dihydro‐ 7, different 5‐spiro‐homocyclic‐ 8–13, and 5‐spiro‐heterocyclic‐ 14‐15 analogues. The structure of the compounds obtained was proved with the use of their ir, uv, 1H‐nmr and 13C‐nmr spectra.
Methylation of 3‐methyl‐ and 3‐phenyl‐4‐arylhydrazonoisoxazol‐5‐ones with diazomethane
Authors: Singh Shyam K. , Summers Lindsay A.
Published: April 2009

3‐Methyl(or phenyl)‐4‐arylhydrazonoisoxazol‐5‐ones on methylation with diazomethane afford 3‐methyl(or phenyl)‐4‐(N‐methylarylhydrazono)isoxazol‐5‐ones and 3‐methyl(or phenyl)‐5‐methoxy‐4‐arylazoisoxazoles. The latter compounds readily rearrange to 4‐methoxycarbonyl‐5‐methyl(or phenyl)‐2‐aryl‐2H‐1,2,3‐triazoles.
Synthesis of N‐(chloromethyl)‐2,6‐diethylcarbaniloyl chloride (1) and derivatives
Authors: D'amico John J. , Bollinger Frederic G. , Tung Ching C. , Dahl William E.
Published: April 2009

The reaction of N‐methylene‐2,6‐diethylbenzenamine with phosgene furnished the titled compound 1. The reaction of 1 with the potassium salts of various thiazolethiols in an acetone medium afforded the expected N‐substituted 2,6‐diethylthiolcarbanilates 2–6. Substituting the above thiazolethiols with the potassium salt of 2‐mercaptobenzimidazole furnished a novel heterocyclic compound 7 in 98% yield. The rection of 1 with the triethylamine salt of disubstituted‐dithiocarbamic acids afforded an alternate method for the synthesis of bis(N‐substituted‐thiocarbonyl)sulfides 8 and 9.
Synthesis of 2‐(β‐D‐ribofuranosyl)pyrimidines, A new class of C‐nucleosides
Authors: Riley Timothy A. , Hennen William J. , Dalley N. Kent , Wilson Bruce E. , Robins Roland K. , Larson Steven B.
Published: April 2009

A new C‐glycosyl precursor for C‐nucleoside synthesis, 2,5‐anhydroallonamidine hydrochloride (4) was prepared and utilized in a Traube type synthesis to prepare 2‐(β‐D‐ribofuranosyl)pyrimidines, a new class of C‐nucleosides. The anomeric configuration of 4 was confirmed by single‐crystal X‐ray analysis. Reaction of 4 with ethyl acetoacetate gave 6‐methyl‐2‐(β‐D‐ribofuranosyl)pyrimidin‐4‐(1H)‐one (5). Reaction of 4 with diethyl sodio oxaloacetate gave 2‐(β‐D‐ribofuranosyl)pyrimidin‐6(1H)‐oxo‐4‐carboxylic acid (6). Esterification of 6 with ethanolic hydrogen‐chloride gave the corresponding ester 7 which when treated with ethanolic ammonia gave 2‐(β‐D‐ribofuranosyl)pyrimidin‐6(1H)‐oxo‐4‐carboxamide (8). Condensation of 2,5‐anhydroallonamidine hydrochloride (4) with ethyl 4‐(dimethylamino)‐2‐oxo‐3‐butenoate (9), gave ethyl 2‐(β‐D‐ribofuranosyl)pyrimidine‐4‐carboxylate (10). Treatment of 10 with ethanolic ammonia gave 2‐(β‐D‐ribofuranosyl)pyrimidine‐4‐carboxamide (11). Single‐crystal X‐ray analysis confirmed the β‐anomeric configuration of 11. Acetylation of 11 followed by treatment with phosphorus pentasulfide and subsequent deprotection with sodium methoxide gave 2‐(β‐D‐ribofuranosyl)pyrimidine‐4‐thiocarboxamide (14). Dehydration of the acetylated amide 12 with phosphorous oxychloride provided 2‐(β‐D‐ribofuranosyl)pyrimidine‐4‐carbonitrile (15). Treatment of 15 with sodium ethoxide gave ethyl 2‐(β‐D‐ribofuranosyl)pyrimidine‐4‐carboximidate (16), which was converted to 2‐(β‐D‐ribofuranosyl)pyrimidine‐4‐carboxamidine hydrochloride (17) by treatment with ethanolic ammonia and ammonium chloride. Treatment of 16 with hydroxylamine yielded 2‐(β‐D‐ribofuranosyl)pyrimidine‐4‐N‐hydroxycarboxamidine (18). Treatment of 2‐(β‐D‐ribofuranosyl)pyrimidine‐4‐carboxamide (11) with phosphorus oxychloride gave the corresponding 5′‐phosphate, 19, Coupling of 19 with AMP using the carbonyldiimidazole activation procedure gave the corresponding NAD analog, 2‐(β‐D‐ribofuranosyl)pyrimidine‐4‐carboxamide‐(5′ ⇋ 5′)‐adenosine pyrophosphate (20).
Benzofuran derivatives. Part 3 On the reactivities of the intermediates in benzofuran synthesis
Authors: Horaguchi Takaaki , Matsuda Shinichi , Tanemura Kiyoshi , Suzuki Tsuneo
Published: April 2009

3‐Methyl‐5‐nitrobenzofuran (2) and 3‐methyl‐5‐nitrobenzofuran‐2‐carboxylic acid (3) were obtained by heating 2‐acetyl‐4‐nitrophenoxyacetic acid (1) with various bases in acetic anhydride. It appeared that 3‐hydroxy‐3‐methyl‐5‐nitro‐2,3‐dihydrobenzofuran‐2‐carboxylic acid (4) was the intermediate in the benzofuran synthesis. The properties of 4 were examined under various conditions. Using strong bases such as triethyl‐amine in place of sodium acetate, 3‐methyl‐5‐nitrobenzofuran‐2‐carboxylic acid (3) was obtained exclusively. However, in the presence of acetic acid in the reaction mixture 3‐methyl‐5‐nitrobenzofuran (2) was obtained in good yield. The reaction pathways for the formation of 2 and 3 are discussed.
Synthesis of 2H‐indazole‐4,7‐dione derivatives from 3‐phenylsydnone and p‐toluquinone. The crystal and molecular structure of 6‐bromo‐5‐methyl‐2‐phenyl‐2H‐indazole‐4,7‐dione
Authors: Nan'ya Seiko , Katsuraya Kaname , Maekawa Eturǒ , Kondo Kazumoto , Eguchi Shoji
Published: April 2009

The 1,3‐dipolar cycloaddition of 3‐phenylsydnone with p‐toluquinone afforded 5‐methyl‐ and 6‐methyl‐2‐phenyl‐2H‐indazole‐4,7‐diones 3a and 3b. No regioselectivity was observed in this cycloaddition yielding an equimolar amount of the regioisomers. Reactions of 3a and 3b with bromine gave the corresponding mono‐4a and 4b and dibromo derivatives 5a and 5b, respectively. The crystal structure of 6‐bromo‐5‐methyl‐2‐phenyl‐2H‐indazole‐4,7‐dione (4a) has been determined by the single crystal X‐ray method. The crystals are monoclinic, space group PI with two molecules in a unit cell of dimensions a = 8.029(1), b = 14.309(1), c = 5.895(1)Å, β = 90.24(1)° and V = 621 Å3. The structure has been solved by the direct method using 1827 reflections and refined by full‐matrix least‐squares calculations to R = 0.0739.
Syntheses of 1‐, 2‐, 3‐ and 4‐acridinecarbaldehydes
Authors: Takahashi Kazufumi , Castle Raymond N. , Lee Milton L.
Published: April 2009

The four acridinecarbaldehydes, namely, acridine‐1‐carbaldehyde, acridine‐2‐carbaldehyde, acridine‐3‐carbaldehyde, and acridine‐4‐carbaldehyde have been synthesized for the first time.
Synthesis of nitro and amino N‐heterocycles via ring transformation of 2‐methyl‐3‐nitrochromone
Authors: Takagi Kaname , Tanaka Masaaki , Murakami Yukitoshi , Ogura Kuniyoshi , Ishii Katsuyuki , Morita Hikari , Aotsuka Tomoji
Published: April 2009

2‐Methyl‐3‐nitrochromone (1) reacted with acid hydrazides, S‐methylisothiourea, hydroxylamine and ethyl aminoethanoate to give the nitro derivatives of pyrazole 2, pyrimidine 6, isoxazole 11 and pyrrole 13, respectively. These nitro compounds were reduced by catalytic hydrogenation to the corresponding amino derivatives. In the case of 2, a rearrangement of the acyl group took place during the reduction. Substitution reactions of the 2‐methylthio group in 6 were also described.
Synthesis of [1]benzothienonaphthyridines
Authors: Kudo Hirotaka , Takahashi Kazufumi , Castle Raymond N. , Lee Milton L.
Published: April 2009

3‐Chlorobenzo[b]thiophene‐2‐carbonyl chloride reacted readily with 2‐amino‐, 3‐amino‐, or 4‐aminopyridine to give the corresponding amides. Photocyclization of the amides afforded the following lactams: [1]ben‐zothieno[2,3‐c][1,5]naphthyridin‐6(5H)‐one (14), [1]benzothieno[2,3‐c][1,6]naphthyridin‐6(5H)‐one (7), [1]benzo‐thieno[2,3‐c][1,7]naphthyridin‐6(5H)‐one (11), and [1]benzothieno[2,3‐c][1,8]naphthyridin‐6(5H)‐one (3). These lactams have been converted to other derivatives including in two instances the unsubstituted ring system.
A comparison of nucleophilic reactions of 3‐benzenesulfonyloxyalloxazine and its 1‐methyl analog
Authors: Hamby James M. , Bauer Ludwig
Published: April 2009

Reactions of 3‐benzenesulfonyloxyalloxazine (1a) and its 1‐methyl analog1bwith a number of nucleophilic reagents are reported. Relatively small nucleophiles, such as hydroxide ion, methanol, ethanol, methylamine, hydrazine and hydroxylamine converted1ato 4‐carboxy‐s‐triazolo[4,3‐a]quinoxalin‐1(2H)‐ones and the corresponding esters or amides. As the size of the amine increased from methylamine to ethylamine, dimethylamine, propylamine and isopropylamine, there were obtained 4‐(carboxamido)‐s‐triazolo[4,3‐a]quin‐oxalin‐1(2H)‐ones, (1‐carboxamido)imidazolo[4,5‐b]quinoxalines and 2,3‐bis(ureido)quinoxalines. Sodium hydride or potassium cyanide in hot DMF degraded1ato imidazolo[4,5‐b]quinoxaline. However, methylmer‐captide and benzylmercaptide ions attacked the sulfonate group of1ato form 3‐hydroxyalloxazine.

1‐Methyl‐3‐benzenesulfonyloxyalloxazine (1b) reacted with methanol, ethanol, 1‐propanol, and to some degree 2‐propanol, in the presence of triethylamine to furnish anhydro‐1‐hydroxy‐3‐methyl‐4‐(alkoxycarbonyl)‐s‐triazolo[4,3‐a]quinoxalinium hydroxides. However, sodium methoxide in methanol converted this starting material to a mixture of anhydro‐1‐hydroxy‐3‐methyl‐s‐triazolo[4,3‐a]quinoxalinium hydroxide and 1‐methyl‐3‐hydroxyflavazole. A saturated aqueous solution of triethylamine transformed1bto anhydro‐1‐hydroxy‐3‐methyl‐s‐triazolo[4,3‐a]quinoxalinium hydroxide, apparentlyviathe corresponding unstable 4‐carboxylic acid. The reactions of1bwith a number of aliphatic amines yielded either amides based on the above mesoionic system or on the 3‐carboxamido‐2‐quinoxalyl semicarbazide structure. The reaction of1bwith potassium cyanide furnished 1‐methylimidazolo[4,5‐b]quinoxaline. Mechanisms to explain all of the degradations are advanced.
Mass spectral fragmentation pattern of 4‐carboxy‐and 4‐methoxycarbonyl‐5‐methyl(or phenyl)‐2‐aryl‐2H‐1,2,3‐triazoles
Authors: Keats Neil G. , Singh Shyam K. , Summers Lindsay A.
Published: April 2009

4‐Carboxy‐5‐methyl‐2‐aryl‐2H‐1,2,3‐triazoles undergo considerable fragmentation on electron impact including loss of OH and H2O from the molecular ions and rupture of the triazole ring. 4‐Carboxy‐5‐phenyl‐2‐aryl‐2H‐1,2,3‐triazoles, on the other hand, show no loss of H2O from the molecular ions.
Pyrrolocoumarin derivatives as potential photoreagents toward DNA
Authors: Rodighiero P. , Chilin A. , Pastorini G. , Guiotto A.
Published: April 2009

A number of new methyl derivatives of linear and angular pyrrolocoumarins were synthesized by direct Fischer's indole synthesis. In the same way some linear 2H,10H‐pyrano[2,3‐b]carbazol‐2‐one and angular 2H,7H‐pyrano[3,2‐c]carbazol‐2‐one were prepared. The synthesis was performed starting from the 4‐methyl‐7‐aminocoumarin and methyl groups were introduced into positions which look most promising for the photoreactivity of the compounds toward DNA.
Nitrogen bridgehead compounds. Part 72 Straightforward synthesis of 1,2,3,4‐tetrahydrorutaecarpine and derivatives
Authors: Hermecz István , Horváth ágnes , Podányi Benjamin , Vasvári‐Debreczy Lelle , Mészáros Zoltán , Szász György , Kökösi József
Published: April 2009

In polyphosphoric acid, the Fischer indolization of 6‐arylhydrazono‐1,2,3,4,6,7,8,9‐octahydro‐11H‐pyrido‐[2,1‐b]quinazolin‐11‐ones, obtained from 1,2,3,4,6,7,8,9‐octahydro‐11H‐pyrido[2,1‐b]quinazolin‐11‐ones by three pathways, afforded substituted 1,2,3,4,7,8‐hexahydro‐5H‐13H‐indolo[2′,3′:3,4]pyrido[2,1‐b]quinazolin‐5‐ones in high yields. The structures of the 6‐substituted octahydropyridoquinazolinones and hexahydroindo‐lopyridoquinazolinones were characterized by uv, 1H and 13C nmr data.
Quaternary salts and polymethine dyes from 2‐(methylpyridyl)‐X‐azolo[4,5‐b]pyridine
Authors: Savarino Piero , Viscardi Guido , Barni Ermanno , Di Modica Gaetano
Published: April 2009

If picoline and X‐azolo[4,5‐b]pyridine are linked, an assembled system arises which has a particular behaviour towards various quaternizing agents. As soon as picolinium salts could be obtained, the corresponding styryl dyes were prepared. The structures of bases, salts and dyes were clarified and their physical and spectroscopic data were correlated and compared with those of similar systems previously studied.
Flash vacuum pyrolysis of 3‐t‐butylindeno[1,2‐c]isoxazol‐4‐one. Formation of 2‐carbonyl‐1,3‐indandione 2‐azine
Authors: Pérez Jorge D. , Wunderlin Daniel A. , Lemke Thomas L. , Sawhney Kailash N.
Published: April 2009

Flash Vacuum Pyrolysis (FVP) of 3‐t‐Butylindeno[1,2‐c]isoxazol‐4‐one (1) and 3‐t‐Butylspiro[2H‐azirine‐2,2′‐(2H)indene]‐1′,3′‐dione (2) were carried out. Reaction of 1 from 300–400° afford 2 and 2‐carbonyl‐1,3‐indandione 2‐azine (3) as the major products, whereas 2‐t‐Butylindeno[1,3‐c]oxazol‐4‐one (4) was the main products in FVP of 2 together with minor amounts of 3.
Proton‐ionizable crown compounds. 13. Synthesis and structural studies of crown compounds containing the triazole subcyclic unit and lipophilic substituents
Authors: Bradshaw Jerald S. , Mcdaniel Christopher W. , Skidmore Brett D. , Nielsen Ralph B. , Wilson Bruce E. , Dalley N. Kent , Izatt Reed M.
Published: April 2009

Eight new macrocyclic polyether ligands containing the proton‐ionizable triazole subcyclic unit have been prepared. Most of these compounds contain octyl, benzo or cyclohexano lipophilic groups. The unsubstituted triazolo‐18‐crown‐6 (5) formed an unusual complex with silver ion. The crystal structure of this silver complex showed one crown complexed with one silver cation and two associated silver nitrate molecules. The new lipophilic triazolo‐crowns are being tested as cation carriers for alkali and other metal cations in a bulk liquid membrane system.
The synthesis of halogenated pyridines substituted at the carbon atom C‐3
Authors: Sutter Peter , Weis Claus D.
Published: April 2009

Arylation of α‐methyleneglutaronitrile (MGN) occurred when arylamines, aminopyridines and 3‐aminothiophene were treated with alkylnitrites and copper(I) chloride in dimethyl methylphosphonate (DMMP) solutions. Results from this study exemplified the synthetic advantage of DMMP as a solvent in Meerwein reactions with an olefin of low reactivity, yielding 1‐aryl‐2 chloro‐2,4‐dicyanobutanes, and its 3‐pyridyl‐ and thiophen‐3‐yl analogues. Partial hydrolysis, followed by subsequent ring closure of the substituted 2,4‐dicyanobutanes to 2,6‐piperidinediones (glutaric acid imides) was effected with a solution of sulfuric acid in acetic acid. The aromatization of the substituted 2,6‐piperidinediones with phosphorus oxychloride in the presence of hexamethylphosphoric acid triamide (HMPT) yielded the 2,6‐dichloropyridine moiety substituted at the carbon atom C‐3.
The synthesis of monomethoxy[1]benzothieno[2,3‐c]quinolines
Authors: Castle Steven L. , Buckhaults Phillip J. , Baldwin Larry J. , McKenney J. Dew , Castle Raymond N.
Published: April 2009

A series of monomethoxy[1]benzothieno[2,3‐c]quinolines 24‐28 were prepared by photocylization of the appropriate 3‐chloro‐N‐phenylbenzo[b]thiophene‐2‐carboxamides 9–13 to [1]benzothieno[2,3‐c]quinolin‐6(5H)‐ones 14‐18 followed by chlorination to 6‐chloro[1]benzothieno[2,3‐c]quinolines 19‐23 then dechlorination resulting in the title compounds except for 25 which was achieved by direct reduction of 15. Reaction of 24‐28 with methyl iodide provided the corresponding N‐methyl quaternary salts 29‐33. Also, conversion of 4‐meth‐oxy[1]benzothieno[2,3‐c]quinolin‐6(5H)‐one 16 to 4‐methoxy‐6‐methylthio[1]benzothieno[2,3‐c]quinoline 35 and 4,6‐dimethoxy[1]benzothieno[2,3‐c]quinoline 36 is described.
Mass spectral fragmentation patterns of 2‐methyl‐, 2,3‐methyl‐, 2,3‐dimethyl‐, 2‐aryl‐ and 3‐phenylindole derivatives
Authors: Erra‐Balsells Rosa
Published: April 2009

The electron impact mass spectrometric fragmentation pathways for several 2‐methyl‐, 3‐methyl‐, 2,3‐dimethyl‐, 2‐aryl‐ and 3‐phenylindole derivatives were investigated. An interesting relationship between the substitution pattern in the framework of the indole derivatives and the fragmentation patterns was observed.
Studies on the synthesis and interconversion of isomeric triazolothienopyrimidines. Part III. Cyclization reactions of 2‐amino‐3‐(1H‐1,2,4‐triazol‐3‐yl)thiophenes
Authors: Shishoo C. J. , Devani M. B. , Ullas G. V. , Ananthan S. , Bhadti V. S.
Published: April 2009

Isolation of 2‐amino‐3‐(1H‐1,2,4‐triazol‐3‐yl)thiophenes in the hydrolytic cleavage reactions of isomeric triazolothienopyrimidines is reported. The 2‐amino‐3‐triazolylthiophenes on reaction with one carbon donors were found to cyclize to 1,2,4‐triazolo[1,5‐c]thienopyrimidines, exclusively.
Synthesis of the new pyrido[1,2‐c]benzo‐v‐triazinium system via valence bond isomerization
Authors: Messmer A. , Hajós Gy. , Giber J. , Holly S.
Published: April 2009

α‐Pyridylphenyl diazonium salts 2 were found to undergo valence bond isomerization and gave the new pyrido[1,2‐c]benzo‐v‐triazinium salts 3. The ir and nmr studies on the products showed that isomers 2 and 3 form an equilibrium, and the ring closure is favoured by electron withdrawing substituents.
Synthesis of some new 4‐imino‐3,5,7‐trisubstituted‐pyrido[2,3‐d]pyrimidine‐2(1H)‐thiones
Authors: Verma S. S. , Taneja P. , Mital R. L. , Prakash L.
Published: April 2009

The synthesis of 4‐imino‐3,5,7‐trisubstituted‐pyrido[2,3‐d]pyrimidine‐2(1H)‐thiones is described. The elemental analysis, ir and nmr spectral data confirm the structure of the products.
Selenium dioxide oxidation of tetrahydro‐β‐carboline derivatives
Authors: Gatta Franco , Misiti Domenico
Published: April 2009

The oxidation of some tetrahydro‐β‐carboline derivatives with selenium dioxide led to the formation of 1,4‐dihydro or fully aromatic β‐carbolines, depending on the nature and the number of substituents at 1 position. The oxidation of 2‐acetyl derivatives followed a different course and the products originated by the attack at C‐1 of the ring C of the tetrahydro‐β‐carboline were obtained.
Photochemistry of 4‐phenyl‐1,3‐dioxolan‐2‐one
Authors: White Rick C. , Ma Sha
Published: April 2009

The photolysis of the mono substituted cyclic carbonate ester 4‐phenyl‐1,3‐dioxolan‐2‐one has been studied. The direct irradiation results in loss of carbon dioxide with the formation of the corresponding ox‐irane, styrene oxide as well as phenylacetaldehyde and bibenzyl. Photolysis in methanol produces the same compounds in addition to phenethyl alcohol and 2‐methoxy‐2‐phenylethanol. Triplet sensitized photolyses resulted in the products derived entirely from benzyl radicals with none of the oxirane being detected.
Tandem arylation‐reduction of acyl heterocycles. Convenient synthesis of benzyl heterocycles
Authors: Hall Stan S. , Farahat Sami E.
Published: April 2009

Tandem arylation‐reduction of a series of acyl heterocycles using phenyl‐, 4‐methylphenyl‐, and 4‐methoxy‐phenyllithium reagents followed by lithium‐ammonia‐ammonium chloride reduction afforded the corresponding benzyl heterocycles. The acyl heterocycles surveyed in this study contained furan, 2,3‐dihydro‐4H‐1‐benzopyran, 4H‐1‐benzopyran, thiophene, 4,5,6,7‐tetrahydrobenzo[b]thiophene, 2,3‐dihydro‐4H‐1‐benzothiopyran, and pyridine nuclei. All acyl heterocycles yielded the corresponding benzyl heterocycles except 2,3‐dihydro‐4H‐1‐benzothiopyran‐4‐one, which selectively cleaved during reduction to give the corresponding 2‐(1‐arylpropyl)benzenethiols.
Further study on 1,3‐dialkylaminouracil with dimethyl acetylenedicarboxylate
Authors: Itoh Tsuneo , Fujii Ikuko , Tomii Yasuo , Ogura Haruo , Mizuno Yoshihisa , Kawahara Norio
Published: April 2009

On the treatment of 1,3‐dialkyl‐6‐alkylaminouracil (1) with dimethyl acetylenedicarboxylate (DMAD), we were able to develop a new synthesis of deazapurine (pyrrolo[2,3‐d]pyrimidine, 4), and proposed the plausible mechanism for the formation of 3 and 4 from the adduct [dimethyl 2‐(1,3‐dialkyl‐6‐alkylamino‐2,4‐dioxopyrimidin‐5‐yl)fumarate, 2] of 1 with DMAD.
A convenient synthesis of novel pyridazino[3,4‐b]quinoxalines
Authors: Kurasawa Yoshihisa , Arai Harumi , Arai Kiyoko , Satoh Atsushi , Ninomiya Satoyuki , Okamoto Yoshihisa , Takada Atsushi
Published: April 2009

Novel 4‐chlorophenylhydrazono‐3‐oxo‐1,2,3,4‐tetrahydropyridazino[3,4‐b]quinoxalines 10a‐c were synthesized by the cyclization of the α‐hydrazonohydrazides 8a‐c. The chlorination of 10a with phosphoryl chloride afforded 3‐chloro‐4‐[2‐(o‐chlorophenyl)hydrazino]pyridazino[3,4‐b]quinoxaline 12.
The synthesis of 5‐ and 6‐acyl‐2(1H)‐pyrimidinones
Authors: Jones Winton D. , Huber Edward W. , Grisar J. Martin , Schnettler Richard A.
Published: April 2009

The synthesis of 5‐acyl‐2(1H)‐pyrimidinones is described. In addition, one example of the hitherto unknown 6‐acyl‐2(1H)‐pyrimidinones has been prepared.
A new method for the synthesis of novel 6‐quinoxalinylpyrazolo[5,1‐c][1,2,4]triazines
Authors: Kurasawa Yoshihisa , Satoh Atsushi , Ninomiya Satoyuki , Arai Harumi , Arai Kiyoko , Okamoto Yoshihisa , Takada Atsushi
Published: April 2009

The reaction of the quinoxaline 1 with 4‐ethoxycarbonyl‐1H‐pyrazole‐5‐diazonium chloride 7 at room temperature gave 3‐[α‐(4‐ethoxycarbonyl‐1H‐pyrazol‐5‐ylhydrazono)methoxycarbonylmethyl]‐2‐oxo‐1,2‐dihydroquinoxaline 8. The pmr spectrum of 8 in deuteriodimethylsulfoxide supported the presence of two tautomers 8‐I and 8‐II. Refluxing of 8 in N,N‐dimethylformamide or acetic acid resulted in cyclization to afford 8‐ethoxycarbonyl‐4‐oxo‐3‐(3‐oxo‐3,4‐dihydroquinoxalin‐2‐yl)‐1,4‐dihydropyrazolo[5,1‐c][1,2,4]triazine 9. Compound 9 was also obtained directly by the reaction of 1 with 7 under reflux in better yield. The reaction of 9 with hydrazine hydrate provided the hydrazinium salt 10, while the reactions of 9 with triethyl and trimethyl orthoformates in the presence of 1,8‐diazabicyclo[5,4,0]‐7‐undecene produced 8‐ethoxycarbonyl‐4‐ethoxyl‐3‐(3‐oxo‐3,4‐dihydroquinoxalin‐2‐yl)pyrazolo[5,1‐c][1,2,4]triazine 11a and 8‐ethoxycarbonyl‐4‐methoxyl‐3‐(3‐oxo‐3,4‐dihydroquinoxalin‐2‐yl)pyrazolo[5,1‐c][1,2,4]triazine 11b, respectively. The chlorination of 11a with phosphoryl chloride gave 3‐(3‐chloroquinoxalin‐2‐yl)‐8‐ethoxycarbonyl‐4‐ethoxylpyrazolo[5,1‐c]‐[1,2,4]triazine 12, whose reaction with morpholine afforded 8‐ethoxycarbonyl‐4‐ethoxyl‐3‐[3‐(morpholin‐4‐yl)‐quinoxalin‐2‐yl]pyrazolo[5,1‐c][1,2,4]triazine 13.
Asymmetric synthesis via heterocyclic intermediates. I. Synthesis of 3,4‐dihydro‐11a‐(S)‐methyl‐4‐(R)‐phenyl‐1,4‐oxazino[4,3‐b]isoquinolin‐1(6H,11H)‐one
Authors: Marco José L.
Published: April 2009

The synthesis of 3,4‐dihydro‐11a‐(S)‐methyl‐4‐(R)‐phenyl‐1,4‐oxazino[4,3‐b]isoquinoline‐1(6H,11H)‐one 1 is described.
N‐Arylation of isatins. A direct route to N‐arylisatoic anhydrides
Authors: Coppola Gary M.
Published: April 2009

The synthesis of N‐arylisatoic anhydrides 3 has been accomplished by using a two‐step process. The key reaction in the sequence is the direct N‐arylation of isatin with an aryl bromide in the presence of cupric oxide. Subsequent oxidation of the resulting N‐aryl isatin 2 with m‐chloroperoxybenzoic acid furnishes the desired products.
Reduction products of 3(2H)‐cinnolinones
Authors: Zey Robert L.
Published: April 2009

Reduction of 3(2H)‐cinnolinone with zinc and ammonium hydroxide forms 1,4‐dihydro‐3(2H)‐cinnolinone which rapidly rearranges to 1‐amino‐2‐indolinone (1‐aminooxindole) in acid solution. 1,4‐Dihydro‐2‐methyl‐3(2H)‐cinnolinone is formed from 2‐methyl‐3(2H)‐cinnolinone under the same conditions, but its rearrangement to 1‐(N‐methylamino)‐2‐indolinone (1‐(N‐methylamino)oxindole) in acid solution is much slower.
Pseudoesters and derivatives. XXV. 1,3‐Dipolar cycloaddition of diazomethane to 5‐methoxy‐3‐pyrrolin‐2‐ones
Authors: Fariña Francisco , Martín M. Victoria , Paredes M. Carmen , Tito Amelia
Published: April 2009

Cycloaddition of diazomethane to pyrrolinones 1a,b,d,e affords only one regioisomer as a mixture of the epimeric pyrrolopyrazolines 2 and 2′,4‐Halo derivatives 1f,g react with diazomethane to give the two possible regioisomers 2 and 3. The regio‐ and stereochemistry of the adducts is evidenced by the 1H‐nmr data. The primary adducts originated from the halopyrrolinones suffer dehydrohalogenation to give aromatized products, which by further methylation give derivatives of type 7, 8, 10 and 11.
Fused v‐triazolo‐heterocycles. Part 2. Synthesis of 4H‐v‐triazolo[1,5‐d] [1,3,4]oxadiazin‐4‐ones from the 1‐aroylamino‐v‐triazole‐5‐carboxylic acids
Authors: Rodios Nestor A.
Published: April 2009

The synthesis of some 4H‐v‐triazolo[1,5‐d] [1,3,4]oxadiazin‐4‐ones is described. They are prepared by the reaction of the corresponding 1‐aroylamino‐v‐triazole‐5‐carboxylic acids with thionyl chloride in the presence of pyridine. The spectroscopic data of these new compounds are also reported.
Mesoionic isoxazolo[2,3‐a]pyrimidinediones and 1,3,4‐oxadiazolo[3,2‐a]pyrimidinediones as potential adenosine antagonists
Authors: Shehata Ihsan A. , Glennon Richard A.
Published: April 2009

Several derivatives of two novel mesoionic ring systems, i.e., isoxazolo[2,3‐a]pyrimidinedione and 1,3,4‐oxadiazolo[3,2‐a]pyrimidinedione, were prepared for evaluation as adenosine antagonists. Whereas both ring systems are relatively stable when the 6‐position (i.e., that position corresponding to the purine 1‐position) is substituted by an alkyl group, neither ring system is stable when this position is unsubstituted. An example of a 6‐unsubstituted non‐mesoionic isoxazolopyrimidinedione exhibited similar behavior. As adenosine antagonists, the mesoionic compounds were found to be less potent than their previously evaluated mesoionic thiadiazolo[3,2‐a]pyrimidinedione counterparts.
Synthesis of perhydro‐2(1H)‐quinoxalinones and perhydropyrrolo[1,2‐a]quinoxalin‐4(5H)‐one derivatives
Authors: Rees David C.
Published: April 2009

The noveltrans‐bicyclic‐perhydro‐2(1H)‐quinoxalinones4, 6and7and the tricyclic‐perhydropyrrolo[1,2‐a]‐quinoxalin‐4(5H)‐one derivatives8and9are preparedviaa ring opening and spontaneous ring closing reaction of the aziridines2and3with the α‐amino acids glycine, L‐alanine, L‐proline and L‐phenylalanine. This methodology was used to prepare5and10which are novel rigid analogues of the kappa opioid compound1.Treatment of aziridine3with methyl carbamate gave the cyclic urea11.
Reactions of methyl 3‐hydroxythiophene‐2‐carboxylate. Part 4. Synthesis of methyl 5‐azolyl‐3‐hydroxythiophene‐2‐carboxylates
Authors: Corral Carlos , El‐Ashmawy Mahmoud B. , Lissavetzky Jaime , Manzanares Ignacio
Published: April 2009

The indirect introduction of an azolyl group in position 5 of compound 1 by an easy two‐step procedure taking place at room temperature is described. A similar procedure yields the 4‐chloro derivatives of these 5‐azolyl compounds. The same method is applied for the introduction of a 5‐azido group and from the 5‐azido compounds, 5‐v‐triazolyl derivatives are obtained by a known method.
A convenient synthesis of 2‐substituted 4‐amino‐5‐pyrimidinecarbonitriles
Authors: Schmidt Hans‐Werner , Koitz Gerald , Junek Hans
Published: April 2009

Synthesis of the novel 2‐halogenated 4‐amino‐5‐pyrimidinecarbonitriles 3a,b starting from ethoxy‐methylenemalononitrile 1 and cyanamide is described. Nucleophilic substitution of the reactive halogen atom leads to the derivatives 5a‐g, 6 and 7a‐h.
Enzymatic halogenation of pyrazoles and pyridine derivatives
Authors: Franssen M. C. R. , Van Boven H. G. , Van Der Plas H. C.
Published: April 2009

Pyrazole, 1‐methylpyrazole and 3‐methylpyrazole are chlorinated by the enzyme chloroperoxidase from Caldariomyces fumago, in the presence of potassium chloride and hydrogen peroxide at pH 2.7, yielding the corresponding 4‐chloro derivatives in good yields. A 4H‐pyrazole is proposed as an intermediate in this reaction. 2‐Aminopyridine was converted regiospecifically by the same enzyme into 2‐amino‐3‐chloropyridine, and 8‐hydroxyquinoline gave its 5,7‐dibromo‐derivative in very good yield when bromide ion was used as the halide substrate.
The fischer indolisation of (±)‐3‐methylcyclopentanone phenylhydrazone
Authors: Robinson Brian
Published: April 2009

Fischer indolisation of (±)‐3‐methylcyclopentanone phenylhydrazone under three different conditions affords in each case a mixture of (±)‐1‐and 2‐methyl‐1,2,3,4‐tetrahydrocyclopent[b]indoles 4b and 4a, respectively. These mixtures were quantitatively analysed using proton nuclear magnetic resonance spectroscopy and their recrystallisation led to the isolation of compound 4a. The structure of this was distinguished from the isomeric structure 4b by its oxidation with 2,3‐dichloro‐5,6‐dicyano‐1,4‐benzoquinone to afford compound 4c, the ultraviolet spectrum of which was characteristic of a 3‐ and not a 2‐ acylindole chromophore and was almost superimposable upon that of the model compound 4d.
Synthesis and reactions of 7‐substituted 1‐cyclopropyl‐6‐fluoro‐1,4‐dihydro‐4‐oxo‐1,8‐naphthyridine‐3‐carboxylic acids as an antibacterial agent
Authors: Miyamoto Teruyuki , Egawa Hiroshi , Shibamori Koh‐Ichiro , Matsuraoto Jun‐Ichi
Published: April 2009

1‐Cyclopropyl‐ and 1‐ethyl‐6‐fluoro‐1,4‐dihydro‐4‐oxo‐1,8‐naphthyridine‐3‐carboxylic acid derivatives having a sulfinyl or sulfonyl group at C‐7 were synthesized from 2,6‐dichloro‐5‐fluoronicotinic acid derivatives by the route involving the Dieckmann‐type cyclization. The displacement reactions of these compounds with pyrrolidine and piperidine gave mainly the 7‐(1‐pyrrolidinyl)‐ and 7‐(1‐piperidinyl)‐1,8‐naphthyridine derivatives 24‐27, respectively. Enoxacin, a potent antibacterial agent, was also synthesized with the analogous route.
Regioselectivity in lateral deprotonation of an isoxazolecarboxamide of (S)‐prolinol. Conformational correlation by crystal structure solid state solution 13C NMR
Authors: Schlicksupp Ludwig , Natale N. R.
Published: April 2009

The conformation at the amide functional group in 3,5‐dimethylisoxazole‐4‐(S‐2′‐hydroxymethyl‐N‐pyrrolidino) carboxamide (1) has been determined by a single crystal X‐ray determination. The 13C nmr in both deuteriochloroform solution and solid state show close agreement. The metalation behaviour of the amide is dependent upon the substitution on the 2′‐hydroxymethyl moiety. Dianion studies indicate C‐5 lateral metalation under both thermodynamic and kinetic conditions. Protection of this substituent as the methyl ether, 2, gives rise to predominant C‐3 lateral metalation under kinetic conditions and C‐5 lateral metalation on equilibration. These observations can be explained using the Ireland‐Evans model for chelation directed deprotonation.
Formation of reissert analogs from benzimidazole and use of carboxylic acids in a retro‐reissert reactionReissert Analogs from Benzimidazole
Authors: Uff Barrie C. , Ho Yee‐Ping , Burford Donald L. W. , Popp Frank D.
Published: April 2009

Reissert analogs have been formed in high yields from benzimidazole using trimethylsilyl cyanide and chloroformates. A retro‐Reissert reaction can be effected on the products, their carbon‐2 alkylated derivatives and benzothiazole analogs, by treatment with hexanoic or benzoic acids.
1‐Alkoxycarbonyl‐ and 1‐acyl‐v‐triazolo[4,5‐b]‐pyridine/hydrogen peroxide oxygenating systems
Authors: Zecchini Giampiero Pagani , Torrini Ines , Paradisi Mario Paglialunga
Published: April 2009

Epoxidation of alkenes and oxidation of thioanisole to the corresponding sulfoxide was achieved using the 1‐alkoxycarbonyl‐ or 1‐acyl‐v‐triazolo[4,5‐6]pyridine/hydrogen peroxide systems. High yields of epoxide or sulfoxide were observed when some amide‐type triazolides were employed for the oxidizing method.
A new synthesis of imidazo[1,2‐a]pyridine and imidazo[2,1‐a]isoquinoline derivatives
Authors: Tominaga Yoshinori , Motokawa Shigenori , Shiroshita Yoshihide , Hosomi Akira
Published: April 2009

A new synthesis of imidazo[1,2‐a]pyridine and imidazo[2,1‐a]isoquinoline derivatives 4 and 8, respectively by 1,5‐dipolar cyclization reactions of stabilized pyridinium N‐ylides 3a‐e or isoquinolinium N‐ylide 7 is described. The starting N‐ylides 3a‐e and 7 are prepared by the reaction of the corresponding pyridinium salts 1a‐e or isoquinolinium salts 6 with N‐bis(methylthio)methylene‐p‐toluenesulfonamide (2).
Studies on pyrazines. 16 . Palladium‐catalyzed cyanation of 2‐amino‐5‐bromopyrazines
Authors: Sato Nobuhiro , Suzuki Masakazu
Published: April 2009

We report here a synthesis of 2‐amino‐5‐cyano‐ 3 and 2‐amino‐3,5‐dicyanopyrazines 4 by palladium(0)‐catalyzed cyanation of the corresponding pyrazine amino bromides 1 and 2.
An improved, large‐scale synthesis of xanthothricin and reumycin
Authors: Black T. Howard
Published: April 2009

Xanthothricin (toxoflavin) has been synthesized in high yield and on a large (over 100 g) scale; this was selectively demethylated at N‐1 to produce reumycin (1‐demethyltoxoflavin) employing an optimized purification protocol also amenable to large‐scale production.
Fluorescence reagents. I. Derivatization of carboxylic acids, imides and alcohols with 1‐chloromethylbenz[c,d]indol‐2(1H)‐one (CMBI)
Authors: Wendelin Winfried , Gübitz Gerald , Pracher Ulrike
Published: April 2009

The derivatization and fluorodensitometric determination of carboxylic acids (CA), imides and alcohols with 1‐chloromethylbenz[c,d]indol‐2(1H)‐one (19, CMBI) have been studied. Out of a series of fluorescent fused lactams 9‐11, 13‐15 and 17, benzindolone 17 was selected and transformed via hydroxymethylbenzin‐dolone 18 into CMBI 19. CMBI reacts with CA, diCA and alcohols respectively to yield strongly fluorescent benz[c,d]indol‐1‐ylmethyl esters 20, 21 (BIM esters) and BIM ethers 22. Phenobarbital is transformed by action of CMBI into fluorescent 1,3‐bisBIM phenobarbital 25. Studies on the applicability of the derivatization reactions to the fluorodensitometric determination of CA, alcohols and imides showed that CA with more than 3 carbon atoms can be determined via BIM esters down to the low picomole range. In the case of alcohols and imides the results were not satisfying. The ir, uv, fluorescence, nmr and mass spectra of the prepared benzindole derivatives are also presented.
Synthesis of trifluoromethyltriazoles from trifluoroacetohydrazonoyl bromide
Authors: Tanaka Kiyoshi , Honda Osamu , Minoguchi Kazumi , Mitsuhashi Keiryo
Published: April 2009

N‐Phenyltrifluoroacetohydrazonoyl bromide (1) reacted with potassium isothiocyanate and isocyanate to give 5‐imino‐4‐phenyl‐2‐trifluoromethyl‐δ2‐1,3,4‐thiadiazoline and 1‐phenyl‐3‐trifluoromethyl‐δ2‐1,2,4‐triazolin‐5‐one, respectively. On treatment with several types of cumulative double bonds such as alkyl isothiocyanate, isocyanate, and carbodiimide, 1 afforded regioselectively the corresponding trifluoromethylthiadiazoline, ‐oxadiazoline, and ‐triazoline, respectively. These cycloadducts were assumed to form through the stepwise path involving the addition of 1 toward the cumulative double bond followed by the intramolecular cyclization. Concerning cyanamides, the corresponding triazoles were obtained and the reactions with pyridines afforded the triazolopyridinium bromides. The reactivity of the latter was found to depend on the substituents on the pyridine nucleus.
Crystal and molecular structure of 5,5‐dimethyl‐δ1‐1,2,4‐triazolin‐3‐one
Authors: Schantl Joachim G. , Gstach Hubert , Lanznaster Norbert , Gieren Alfred , Lamm Viktor
Published: April 2009

The spectroscopic and X‐ray data of the title compound are presented and discussed. Some anomalies are attributed to the lack of conjugation between the diazene and carbonyl group, and to the association of the molecules in the solid state through an unusual intermolecular hydrogen bond between the amide nitrogen atom and the diazene nitrogen atom N2.
Potential DNA bis‐intercalating agents: Synthesis and antitumor activity of novel, conformationally restricted bis(9‐aminoacridines)
Authors: Jaycox Gary D. , Gribble Gordon W. , Hacker Miles P.
Published: April 2009

A series of bis(9‐aminoacridines) bridged by conformationally restricted tethers was synthesized and evaluated against L1210 in vitro. Several of these compounds were found to be highly active in this test system, with ID50 values below 10−7 M. CPK molecular models suggest that this antitumor activity can be correlated to the ability of these bis(9‐aminoacridines) to form bis‐intercalative complexes with DNA.
Acetylenchemie 6. Mitt.: Propinylierung von N‐Methylbarbitursäuren nach dem PTC‐ und phosphoroxychlorid‐verfahren ‐ nachweis zweier mechanismen bei der chromenbildung von pyrano[3,2‐c]chinolin‐alkaloiden
Authors: Reisch Johannes , Bathe Andreas
Published: April 2009

Der Mechanismus der Furan‐/Pyrananellierung von 1,3‐Dicarbonylverbindungen via Propinyl‐Zwischen‐stufen wird am Barbitursäuremodell studiert; er wechselt mit der Alkylierungsbedingung: Bei phasentransferkatalysierter (PTC) Umsetzung von N,N′‐Dimethylbarbitursäure mit 3‐Bromprop‐1‐in erfolgt Dipropinylierung, während mit 3‐Chlor‐3‐methylbut‐1‐in ein Furopyrimidon entsteht. Eine Variante mit dem Alkylans 3‐Hydroxy‐3‐methylbut‐1‐in/Phosphoroxytrichlorid führt zur 3′‐Methylbuta‐5,2′‐dienyl‐Anordnung, der Pyranvorstufe. Diese entsteht auch mit N‐Methylbarbitursäure. Die unterschiedlichen Entstehungswege werden diskutiert, die Ergebnisse mit früheren Arbeiten verglichen.
Heterocycles. XIII. Nls orbital binding energies of some quinazolines and pyrimidines by XPS
Authors: El‐Rayyes N. R. , Katrib A. , Al‐Kharafi F. M. , El‐Issa B. D.
Published: April 2009

The X‐ray photoelectron spectra of some quinazolin‐2(1H)‐ones IIa,b, show only one relatively symmetrical line in the N1s binding‐energy region, where as the corresponding dehydrogenated products IIIa,b and the pyrimidin‐2‐(1H)‐ones Va,b revealed two well‐resolved spectral lines with an energy difference of more than 1 eV. However, compounds IIc and IIIc gave only one broad unsymmetrical line.

Quantum mechanical calculations on compounds IIa and IIIa as well as analogues IIc and IIIc supported the experimental findings.
Part 4. Fused pyrimidines. Annelation using formamide to synthesize 2,4‐disubstituted‐pyrimido[4,5‐d]pyrimidines
Authors: Delia Thomas J. , Niedzinski Jill
Published: April 2009

A one‐step synthesis of 2,4‐disubstituted‐pyrimido[4,5‐d]pyrimidines has been investigated. Cyclization of 6‐amino‐2,4‐disubstituted‐pyrimidines with formamide as solvent and reagent affords the title compounds in 50‐70% yield. Strongly electron‐donating groups are required. Based on model compounds, a pathway for the cyclization is suggested. The method is an improvement on previous methods of synthesis, albeit a limited one.
The mass spectral fragmentation of isoxazolyldihydropyridines
Authors: Knerr Gary , Mckenna John I. , Quincy David A. , Natale N. R.
Published: April 2009

The mass spectral fragmentation of 4‐isoxazolyl‐1,4‐dihydropyridines has been examined with the aid of linked metastable scanning. Three prominent pathways involve (i) O‐N bond cleavage of the isoxazole followed by the loss of R2CN, (ii) loss of carboalkoxy from the 3‐ and/or 5‐ position of the dihydropyridine and, (iii) loss of the 4‐isoxazolyl‐substituent.
Triazolotriazines as potential chemotherapeutic agents. VI
Authors: Ram Vishnu J. , Dube Vidyohama , Vlietinck A. J.
Published: April 2009

Several new 1,2,4‐triazolo[4,3‐b]triazino[7,6‐b]indoles were prepared in anticipation that they would have better chemotherapeutic activities, but in the Screening test none of the Compounds was found to be active.
Studies on decarboxylation reactions. Part 5. Micellar catalysis and mixed solvents effects on the decarboxylation of some N‐alkyl‐ or N‐aryl‐substituted 5‐amino‐1,3,4‐oxadiazole‐2‐carboxylic acids
Authors: Noto Renato , Buscemi Silvestre , Werber Giuseppe , Spinelli Domenico
Published: April 2009

The effect of micelles and mixed solvents on the decarboxylation of some N‐alkyl‐ or N‐aryl‐substituted 5‐amino‐1,3,4‐oxadiazole‐2‐carboxylic acids has been studied. The data support the unimolecular decarboxylation mechanism proposed by us. Moreover, they show that mixed solvents and micelles have different effects on reactivity of the amino acids under study.
Synthesis and mass spectra of 1‐arylideneamino‐1,2,3‐triazoles
Authors: Rodios Nestor A. , Adamopoulos Spyros G.
Published: April 2009

The synthesis of the title Compounds is described. Their mass spectra upon electron impact are given and the main fragmentation pathways are described.