bluuebunny/crossref_metadata_2025 huggingface dataset:
Ring transformation of pyrimidines to pyridines. Synthesis of 4‐alkylaminopyridin‐2‐ones by alkaline hydrolysis of 6‐(2‐dimethylaminovinyl)uracils
Authors: Hirota Kosaku , Abe Yoshio , Asao Tetsuji , Senda Shigeo , Kitade Yukio , Maki Yoshifumi
Published: April 2009

Alkaline hydrolysis of 1,3‐disubstituted 6‐(2‐dimethylaminovinyl)uracils 2 induced a novel ring transformation giving 4‐alkylaminopyridin‐2‐ones 3 via ring‐opening and ring‐closure processes. The 4‐methylamino‐3‐nitropyridin‐2‐one (3a) thus obtained was employed for the synthesis of 3‐deazahypoxanthine derivative 8. 4‐Alkylamino‐3‐cyanopyridin‐2‐ones 11, ricinine analogs, were also prepared by the reaction of 4‐chloro‐3‐cyano‐1‐methylpyridin‐2‐one (10) with amines.
Synthesis of pyrrolo[1,2‐b]cinnolines
Authors: Hamer R. Richard L. , Sekerak Danette , Effland Richard C. , Klein Joseph T.
Published: April 2009

The synthesis of the pyrrolo[1,2‐b]cinnoline analogs 2 and 4–13 is described. The key step of this synthesis involves an intramolecular aromatic halide displacement on [2‐(2‐halobenzoyl)pyrrol‐1‐yl]carbamic acid esters. Several reactions of these cinnoline analogs with electrophilic reagents have been investigated.
Facile synthesis and antifungal activity of 3‐substituted 4‐amino‐8‐ethoxycarbonylpyrazolo[5,1‐c][1,2,4]triazines and pyrazolo[1′,5′:3,4][1,2,4]triazino[5,6‐b][1,5]benzodiazepines
Authors: Kurasawa Yoshihisa , Kanoh Megumi , Kamigaki Yumiko , Okiyama Mari , Takada Atsushi , Okamoto Yoshihisa
Published: April 2009

The reactions of the pyrazole‐5‐diazonium salt 3 with malononitrile and ethyl cyanoacetate gave 4‐amino‐3‐cyano‐8‐ethoxycarbonylpyrazolo[5,1‐c][1,2,4]triazine 7 and 4‐amino‐3,8‐bisethoxycarbonylpyrazolo[5,1‐c]‐[1,2,4]triazine 8, whose reactions with p‐chloroaniline hydrochloride afforded 4‐amino‐8‐ethoxycarbonyl‐3‐(p‐chlorophenyl)amidinopyrazolo[5,1‐c][1,2,4]triazine 9 and 4‐amino‐8‐ethoxycarbonyl‐3‐(p‐chlorophenyl)car‐bamoylpyrazolo[5,1‐c][1,2,4]triazine 10, respectively. The reactions of 7 and 8 with o‐phenylenediamine di‐hydrochloride provided 9‐ethoxycarbonyl‐13H‐spiro[benzimidazole‐2′(3′H),6(5H)‐pyrazolo[1,5′:3,4][1,2,4]tri‐azino[5,6‐b][1,5]benzodiazepine] hydrochloride 11a and 9‐ethoxycarbonyl‐6‐oxo‐13H‐5,6‐dihydropyrazolo‐[1′,5′:3,4][1,2,4]triazino[5,6‐b][1,5]benzodiazepine 12, respectively. The antifungal activity of the above compounds was described.
New derivatives of pyrimidine nucleosides: Synthesis, physico‐chemical properties and biological activity
Authors: De Napoli Lorenzo , Mayol Luciano , Bartolucci Simonetta , Piccialli Gennaro , Rossi Mosé , Santacroce Ciro
Published: April 2009

The paper reports the synthesis and physico‐chemical data of eight new pyrimidine nucleosides C‐4 substituted and two imidazo[1,2‐c]pyrimidine nucleosides as well as preliminary results of their biological effects on neuroblastoma cells in culture.
A convenient synthesis of 5‐substituted‐7‐β‐D‐arabinofuranosylpyrrolo[2,3‐d]pyrimidines structurally related to the antibiotics toyocamycin and sangivamycin
Authors: Ramasamy Kandasamy , Robins Roland K. , Revankar Ganapathi R.
Published: April 2009

4‐Amino‐7‐(2,3,5‐tri‐O‐benzyl‐β‐D‐arabinofuranosyl)pyrrolo[2,3‐d]pyrimidine‐5‐carbonitrile (6a), prepared from 2‐ethoxymethyleneamino‐5‐bromopyrrole‐3,4‐dicarbonitrile (4), was debenzylated with boron trichloride to give ara‐toyocamycin (6b). Further functional group transformation of 6b provided a route to 4‐amino‐7‐β‐D‐arabinofuranosylpyrrolo[2,3‐d]pyrimidine‐5‐thiocarboxamide (ara‐thiosangivamycin, 7a), and the corresponding 5‐carboxamidoxime 8a and 5‐carboxamidine 8b derivatives. Phosphorylation of unprotected 7a with phosphorus oxychloride gave ara‐thiosangivamycin 5′‐monophosphate (7b). 2′‐O‐Acetyl‐ara‐thiosangivamycin (10b) was prepared as a prodrug by acetylation of 9a, followed by deprotection of the t‐butyldimethylsilyl groups under acidic conditions without acyl migration.
Relative reactivity in the condensation of 2H‐isoindole‐ and 2H‐indazole‐4,7‐dione derivatives with o‐aminobenzenethiol and its derivatives
Authors: Nan'Ya Seiko , Katsuraya Kaname , Ueno Yoshio , Maekawa Eturô
Published: April 2009

The effects of substituents on the condensation of o‐aminobenzenethiol derivatives with 2H‐isoindole‐ and 2H‐indazole‐4,7‐dione derivatives were studied by competitive reactions.
The preparation of 3‐hydrazino‐4‐hydroxy‐ and 3‐hydrazino‐4‐methoxypyridine from sydnones
Authors: El‐Bakoush M. M. , Parrick J.
Published: April 2009

3‐Hydrazino‐4‐hydroxy‐ and 3‐hydrazino‐4‐methoxypyridines, which could not be obtained by reduction of the corresponding diazonium salts, have seen prepared by decomposition of N‐(4‐substituted‐pyrid‐3‐yl)‐syndones.
A novel approach to synthesis of the cinnoline ring system via organoiron(cyclopentadienyl) complexes
Authors: Sutherland Ronald G. , Abd‐El‐Aziz Alaa S. , Piórko Adam , Gill Udai S. , Lee Choi Chuck
Published: April 2009

An efficient synthesis of 3‐mono or 3,4‐disubstituted cinnolines from (o‐dichlorobenzene)(cyclopentadienyl)iron hexafluorophosphate in three or four steps has been achieved. o‐Chlorophenyl‐alkyl or alkylaryl ketone complexes obtained from the o‐dichlorobenzene complex upon treatment with enolate anions, react with hydrazine forming 3‐mono or 3,4‐disubstituted 1,4‐dihydrocinnoline complexes. Treatment of the later with sodium amide leads to an aromatization‐demetallation reaction resulting in formation of cinnolines, i.e. 3‐methyl‐, 3‐phenyl‐ and 3,4‐dimethylcinnoline. The influence of substituents bonded to the carbon atom adjacent to the complexed benzene ring in o‐chlorophenyl ‐alkyl or ‐alkylaryl ketone prior to cyclization on the cyclization reaction is discussed.
Reaction of N‐(4‐pyridylmethyl)‐3,5‐dimethylbenzamide N‐oxide with acidic compounds in the presence of acetic anhydride: Discussion of the mechanism
Authors: Braña Miguel F. , Castellano José M. , Donoso Rosa , Rodríguez María L. López , Yunta Maria J. R.
Published: April 2009

The mechanism of N‐(4‐pyridylmethyl)‐3,5‐dimethylbenzamide N‐oxide with acidic compounds in the presence of acetic anhydride is presented.
Pyridinethiones. XV. 3‐Methylthio‐2‐pentene‐1,5‐diones as synthons for 4‐methylthio‐2(1H)‐pyridinethiones, and synthesis of 4‐methylene‐1,4‐dihydropyridines
Authors: Becher Jan , Hansen Poul
Published: April 2009

Starting from α‐oxoketene dithioacetals the 3‐methyithio‐1,5‐pentenedione enolates 4 obtained from ketones 3 give 4‐methylthio‐2(1H)‐pyridinethiones with isothiocyanates. Enolates 4 can be alkylated with methyl iodide at C‐2, giving 5‐methyl‐4‐methylthio‐2‐(1H)‐pyridmethiones with isothiocyanates. The S‐alkylated pyridinethiones react with the anion of malodinitrile, giving 4‐(1,1‐dicyanomethylene)‐1,4‐dihydropyridines.
Synthesis of substituted pyrroles from ketones
Authors: Chelucci Giorgio , Marchetti Mauro
Published: April 2009

A number of substituted pyrroles have been prepared through a four step reaction sequence based on the regiospecific alkylation of N,N‐dimethylhydrazones with 2‐iodomethyl‐1,3‐dioxolane.
Condensed 1,2,4‐triazines. Synthesis and reactions of some condensed benzo[e]as‐triazines
Authors: Eid Mohga M. , Mansour A. K.
Published: April 2009

2‐o‐Chlorophenyl‐2H‐naphtho[1,2‐d]v‐triazole‐4,5‐quinone condenses with semicarbazide and some of its derivatives at the 4 position and the products cyclize into the corresponding 1,2,4‐triazines. Reactions of these triazines with some reagents are described.
Furopyridines. VIII. Molecular structure and two‐dimensional NMR spectral assignment of 2,14‐dimethyl‐8aβ‐hydroxy‐7,10‐dioxo‐5β,6β‐(propano)‐6α,8α‐(ethanoimino)‐trans‐perhydroisoquinoline
Authors: Shiotani Shunsaku , Morita Hiroyuki , Ishida Toshimasa , In Yasuko , Tatemitsu Hitoshi
Published: April 2009

This paper reports the two‐dimensional nmr spectral assignment and the X‐ray structural determination of 2,14‐dimethyl‐8β‐hydroxy‐7,10‐dioxo‐5β,6β‐(propano)‐6α,8α‐(ethanoimino)‐trans‐perhydroisoquinoline V which was obtained from 7,10‐dimethyl‐2β‐hydroxy‐14‐oxo‐2,3‐(methanoiminoethano)‐3β,4β‐(propano)‐3,4,5,6,7,8‐hexahydro‐2H‐pyrano[2,3‐c]pyridine IV by isomerization with hydrochloric acid. Both the compounds IV and V afforded the same dimethiodide IV‐2MeI, while the configurational isomer 2,14‐dimethyl‐8aβ‐hydroxy‐7,10‐dioxo‐5α,6β‐(propano)‐6α,8α‐(ethanoimino)‐trans‐perhydroisoquinoline III gave monomethiodide III‐Mel. The structures of these methiodides were also confirmed by X‐ray analysis.
13C NMR spectra of 1‐(N‐arylidene)amino‐1,2,3‐triazoles
Authors: Rodios N. A. , Tsoleridis C. A. , Alexandrou N. E.
Published: April 2009

The 13C nmr spectra of several 1‐(N‐arylidene)amino‐1,2,3‐triazoles were determined. The long range influence of substituents on 13C resonances of triazole and C = N carbon atoms was examined and a correlation of their chemical shifts with net charge densities (qπ + σ) calculated by the CNDO/2 method was made. It was also shown that the dependence of the coupling constants 1J(CH) for C = N carbon on the substituents is better correlated using electrons in bond values instead of charge densities.
Reaction of 4‐styryl‐1,2,3‐benzoxathiazine 2,2‐dioxides with diazomethane: Synthesis of a novel heterocyclic system
Authors: Tripathi Manisha , Dhar Durga Nath
Published: April 2009

A new class of heterocyclic system, 3a‐f, has been synthesized by reacting diazomethane with 4‐styryl‐1,2,3‐benzoxathiazine 2,2‐dioxides 1a‐f. Diazomethane adds to the > C = S group of these compounds.
Synthesis of heterocyclic compounds from 3‐acetyl‐3‐chloropropyl acetate
Authors: D'Amico John J. , Bellinger Frederic G. , Thompson Michael , Freeman John J. , Dahl William E. , Pustinger John V.
Published: April 2009

The reaction of the potassium salt of 2‐mercaptobenzimidazole with 3‐acetyl‐3‐chloropropyl acetate afforded the novel heterocyclic compound 1. When solutions of 1 in deuteriodimethylsulfoxide or deuteriomethanol were allowed to stand at room temperatures for 15 minutes and 19 days, respectively, ring opening of 1 occurred to give the precursor, 3‐acetyl‐3‐(2‐benzimidazolthio)propyl‐1‐ol. The treatment of 1 with p‐fluorophenyl isocyanate furnished the carbanilate 2. The reaction of ammonium dithiocarbamate with the above chloroketone afforded the 2‐thiazolethione 3. Possible mechanisms and supporting nmr, ir, mass spectral data for 1–3 and single crystal X‐ray analysis for 2 are discussed.
Regioselective proton‐catalyzed diarylmethylation of indoles with 9H‐xanthydrol, dibenzosuberenol, and bis[4‐dimethylaminophenyl]methanol
Authors: Pindur Ulf , Deschner Rainer
Published: April 2009

3‐Isopropylindole (4) is xanthenylated both at N‐1 (stereocontrolled major reaction), C‐2, and on the phenyl nucleus of the indole skeleton by xanthydrol (1). Other carbinols such as dibenzosuberenol (2) and bis[4‐dimethylaminophenyl]methanol (3) with lower electrophilic SN1 activities than 1 do not react with 4 but do react very selectively with simple methylindoles to form diarylmethylated derivatives.
Furopyridines. IX. Syntheses and properties of 3‐ethoxy derivatives of furo[2,3‐b]‐, furo[3,2‐b]‐, furo[2,3‐c]‐ and furo[3,2‐c]pyridine
Authors: Shiotani Shunsaku , Morita Hiroyuki , Ishida Toshimasa , In Yasuko
Published: April 2009

Reaction of ethyl 3‐ethoxycarbonylmethoxyfuropyridine‐2‐carboxylates 2a‐2d with sodium ethoxide afforded 3‐ethoxy derivatives 3a‐3d which converted to 3‐ethoxyfuropyridines 5a‐5d by hydrolysis and decarboxylation of the ester group. Vilsmeier reaction of 5a and 5b gave 2‐formyl‐3‐ethoxy derivatives 6a and 6b and 2‐formyl‐3‐chloro derivatives 7a and 7b, while 5c and 5d did not give any formyl compound. Bromination of 3‐ethoxyfuropyridines with 1 equivalent mole of bromine gave 2‐bromo‐3‐ethoxyfuropyridines 9a‐9d, whereas reaction with 3 equivalents of bromine yielded 2,2‐dibromo‐3,3‐diethoxy‐2,3‐dihydrofuropyridines (10a and 10b) and/or 2‐bromo‐3,3‐diethoxy‐2,3‐dihydrofuropyridines 11b, 11c and 11d. Treatment of compounds 5a‐5d with n‐butyllithium in hexane‐tetrahydrofuran at −70° and subsequent addition of N,N‐dimethylformamide yielded 2‐formyl derivatives 6a‐6d.
Condensed 1,3‐benzothiazinones. 1. Facile synthesis of 2‐amino‐1,2,4‐triazolo[5,1‐b][1,3]‐benzothiazin‐9‐one
Authors: Liu Kang‐Chien , Shih Bi‐Jane , Chern Ji‐Wang
Published: April 2009

Treating 2‐mercaptobenzohydrazide (1a) with cyanogen bromide gave 3‐amino‐2‐imino‐3,4‐dihydro‐2.H‐1,3‐benzothiazin‐4‐one (2a). This compound underwent further cyclocondensation with a second molecule of cyanogen bromide or S‐methylisothiourea sulfate to afford the biologically interesting 2‐amino‐1,2,4‐triazolo‐[5,1‐b][1,3]benzothiazin‐9‐one (3c). Compound 3c could also be prepared directly from 1a by treating with excess amount of cyanogen bromide in more satisfactory yield.
Studies of the reaction of substituted 1,2‐dithiole‐3‐thiones and ‐3‐ones with sodium cyanide in acetonitrile
Authors: Largeron M. , Martens T. , Fleury M. B.
Published: April 2009

The reactions of substituted 1,2‐dithiole‐3‐thiones and ‐3‐ones with sodium cyanide, in acetonitrile, afford convenient routes to indolizine, pyrrolo[1,2‐a]pyrazine and 4H‐1,3‐thiazin‐4‐one species.
Synthesis of unsymmetric bile pigments: Mesobilirubin‐VIIIα, 17‐desvinyl‐17‐ethyl‐bilirubin‐VIIIα and 12‐despropionic acid‐12‐ethyl‐mesobilirubin‐XIIIα
Authors: Trull Francesc R. , Lightner David A.
Published: April 2009

The unnatural bile pigments 17‐desvinyl‐17‐ethylbilirubin‐VIIIα, mesobilirubin‐VIIIα and 12‐despropionic acid‐12‐ethyl mesobilirubin‐XIIIα were synthesized via (1) “reverse scrambling” of bilirubin‐XIIIα or mesobilirubin‐IXα with mesobilirubin‐IVα or etiobilirubin‐IV‐γ or (2) following coupling of xanthobilirubic acid methyl ester with ψ‐xanthobilirubic acid methyl ester, or coupling of xanthobilirubic acid methyl ester with kryptopyrromethenone.
A new and convenient synthesis of alkyl and aryl pyrimidines
Authors: Martínez A. García , Herrera A. , Martínez R. , Teso E. , García A. , Osío J. , Pargada L. , Unanue R. , Subramanian L. R. , Hanack Michael
Published: April 2009

Vinyl triflates 1, which are obtained easily from the corresponding ketones, react in an excess of pure nitrile (80°/20 hours) to form tri‐ and tetra‐substituted alkyl and arylpyrimidines 4 and 5 in good yields (45–87%). An isomeric mixture of pyrimidines 4 and 5 is formed from Inflate 1 when R1 ≠ R2 ≠ H. The reaction proceeds by nitrile‐catalyzed elimination‐addition mechanism.
Photochemistry of ommochromes and related compounds. Part II
Authors: Bolognese A. , Liberatore R. , Scherillo G.
Published: April 2009

The visible light irradiated solutions of the 1‐methyl‐1‐(1′‐[11‐(β‐aspartoyl‐methyl ester‐imino)]ethenyl]‐ketal‐1H,5H‐pyrido[3,2‐a]phenoxazin‐5‐one (1) and the 1,5‐dimethoxy‐11‐(β‐aspartoyl‐N‐acetyl‐methyl ester)‐pyrido[3,2‐a]phenoxazine (2) [1], in methanol and acidic methanol, are examined. Both methanolic solutions undergo light induced transformation according to an opening of the phenoxazinone and phenoxazine systems, not reversible in darkness. On the contrary, 1 and 2 in methanol‐acid solutions, under visible light irradiation, yield a solvent photoaddition, reversible in darkness.

Some phototransformation products are examined and a plausible mechanism, for the reactions explanation, is suggested.
Synthesis and anticonvulsant activity of 1‐benzyl‐4‐alkylamino‐1H‐imidazo[4,5‐c]pyridines
Authors: Kelley James L. , Linn James A. , Hideout Janet L. , Soroko Francis E.
Published: April 2009

Four 3‐deaza analogues of the potent anticonvulsant purine, BW A78U, were synthesized and tested for anticonvulsant activity. The imidazo[4,5‐c]pyridines 9–12 were prepared in two steps from 4‐chloro‐1H‐imidazo[4,5‐c]pyridine (2). The compounds were potent anticonvulsant agents against maximal electroshock‐induced seizures in rats with i.p. ED50 ranging from 2 to 3.5 mg/kg. However, these 3‐deazapurines were appreciably more toxic than BW A78U, which precluded their development as potential antiepileptic agents.
Ring transformation of 1,5‐benzoxazepines into spirobenzoxazoles. Synthesis of pyrazolo[1′,5′:3,4][1,2,4]triazino‐[5,6‐b][1,5]benzoxazepines and spiro[benzoxazole‐2′(3′H),4(1H)‐pyrazolo[5,1‐c][1,2,4]triazines]
Authors: Kurasawa Yoshihisa , Okiyama Mari , Kamigaki Yumiko , Kanoh Megumi , Takada Atsushi , Okamoto Yoshihisa
Published: April 2009

The reactions of the 3‐substituted 4‐amino‐8‐ethoxycarbonyl[5,1‐c][1,2,4]triazines 1 and 2 with o‐amino‐phenol hydrochloride gave the pyrazolo[1′,5′:3,4][1,2,4]triazino[5,6‐b][1,5]benzoxazepines 5 and 8. The alkylation of 5 with methyl iodide and isopropyl iodide afforded the 6‐alkoxylpyrazolo[1′,5′:3,4][1,2,4]triazino‐[5,6‐b][1,5]benzoxazepines 6a and 6b, respectively. Refluxing of 5, 6a, 6b and 8 in hydrochloric acid/acetic acid resulted in ring transformation to produce the spiro[benzoxazole‐2′(3′H),4(1H)pyrazolo[5,1‐c][1,2,4]‐triazines] 7a, 7b and 9. The screening data of the above compounds was described.
Conjugated azoalkenes. Part V. Facile synthesis of new 1‐aroylamino‐3‐sulfonylpyrroles by reaction of aroylazoalkenes with 1,3‐ketosulfones
Authors: Attanasi Orazio A. , Grossi Mario , Serra‐Zanetti Franco
Published: April 2009

The easy one‐pot synthesis of the interesting 1‐aroylamino‐3‐sulfonylpyrroles by reaction of some aroylazo‐alkenes with 1,3‐ketosulfones is reported.
Derivatives of 3,4‐dihydro‐β‐carboline‐3‐carboxylic acid from c‐terminal tryptophan‐containing peptides. Synthesis and properties
Authors: Letellier Sabine , Fleury Bernard , Torreilles Jean , Previero Aldo
Published: April 2009

C‐Terminal tryptophan containing peptides have been converted into 1‐peptidyl‐3,4‐dihydro‐β‐carboline‐3‐carboxylic acids by acid catalyzed isomerization of their azlactone derivatives. The main properties of these abnormal peptides are a strong absorption around 360 nm an intense yellow fluorescence and ability to generate reactive carbanions when dissolved in basic media. This tryptophan conversion takes place with high yield and is of general applicability.
Phosphonomethylation of 2‐aminoethanethiol and thiazolidine. An unexpected product
Authors: Dhawan Balram , Redmore Derek
Published: April 2009

Phosphonomethylation of 2‐aminoethanethiol and thiazolidine gives the unexpected dimethylene diphosphonic acid 6.
Synthesis of cyclic oxoenaminoesters
Authors: Celerier J. P. , Marx E. , Lhommet G.
Published: April 2009

Ammonia and primary amines react with dimethyl 3‐oxo‐1,ω‐alkanedioates to give cyclic,N‐acylated enaminoesters.
On 6‐(thenoyl)‐7,8‐dichloro‐4‐oxo‐4H‐1‐benzopyran‐2‐carboxylic acid
Authors: Montanari Paola , Da Re Paolo , Valenti Piero
Published: April 2009

The annulation of the oxyacetic chain of thienylic acid into a γ‐pyrone ring is described. The resulting 6‐(2‐thenoyl)‐7,8‐dichloro‐4‐oxo‐4H‐1‐benzopyran‐2‐carboxylic acid retains almost 80% of the diuretic activity of the parent compound.
A simple synthesis of 5‐methoxyindole and 5‐methoxy‐2‐oxindole
Authors: Sakamoto Takeshi , Hosoda Isao , Kikugawa Yasuo
Published: April 2009

1‐Methoxy‐ and 1‐hydroxy‐2‐oxindoles rearranged in acidic solution to 5‐substituted 2‐aminophenylacetic acid derivatives which were cyclized to the corresponding 2‐oxindoles with heating. The synthesis of 5‐methoxyindole from 5‐methoxy‐2‐oxindole was also described.
Bridged cyanine dyes. Part 1. 1‐(N‐methyl‐4‐pyridinio)‐3‐(N‐methylpyridylene)cyclopenta‐1,4‐dienes
Authors: Katritzky Alan R. , Fan Wei‐Qiang , Li Qiao‐Ling
Published: April 2009

1,3‐Bis(N‐methyl‐4‐pyridinio)propane is condensed with a series of α‐diketones to form deep red monocyanine dyes 8. In strongly acidic solutions C‐protonation occurs at the central carbon atom. A similar condensation with α‐ketoesters yields zwitterionic cyanines 12 with extinction coefficients exceeding 105.
Bridged cyanine dyes. Part 2. 1‐(N‐methyl‐2‐benzothiazolylinio)‐3‐(N‐methyl‐2‐benzothiazolylene) and 1‐(N‐methyl‐4‐pyridinio)‐3‐(N‐methyl‐4‐pyridylene)cyclopenta‐1,4‐dienes with fused rings
Authors: Katritzky Alan R. , Liang De‐Sheng , Fan Wei‐Qiang
Published: April 2009

1,3‐Bis(N‐methyl‐4‐pyridyl)‐ and 1,3‐bis(N‐methyl‐2‐benzothiazolyl)‐propane diiodides react with 1,2‐cyclohexanedione, tetrachloro‐1,2‐ and ‐1,4‐benzoquinone, 2,3‐dichloronaphthoquinone, 3,4‐dichloromaleimide and 2,3‐dichloroquinoxaline to give novel fused ring bridged cyanine dyes.
A convenient synthesis of 1,3,6‐dioxazocine, 1,3,7‐dioxazonine, 1,3,8‐dioxazecine and 1,3‐dioxa‐6,10‐diazadodecane
Authors: Krakowiak Krzysztof E. , Kotelko Barbara , Bradshaw Jerald S. , Dalley N. Kent
Published: April 2009

A series of perhydro heterocycles of eight to ten ring members containing one nitrogen and two oxygen atoms has been prepared. These include four 1,3,6‐dioxazocines, and 1,3,7‐dioxazonine and one 1,3,8‐dioxazecine. A twelve‐membered ring containing two oxygen and two nitrogen atoms was also prepared. An X‐ray structure of one of the 1,3,6‐dioxazocines,5, was determined. This compound crystallized in the orthorhomic space group Pccn with a = 25.922(15)Å, b = 12.150(4)Å and C = 9.342(4)Å. Two of the 1,3,6‐dioxazocines have the benzylidine acetal structure which will hydrolyze to give benzaldehyde.
Selective α‐cleavage cycloaddition of oxiranes with heterocumulenes catalyzed by tetraphenylstibonium iodide
Authors: Fujiwara Masahiro , Baba Akio , Matsuda Haruo
Published: April 2009

A catalytic amount of tetraphenylstibonium iodide (1) promoted unusual cycloadditions of oxiranes with isocyanates or carbodiimides, forming 3,4‐disubstituted oxazolidin‐2‐ones 2 and oxazolidin‐2‐imines 4 under very mild conditions, respectively. In particular, carbodiimides gave 4 exclusively. Either oxazolidine, 3,4‐disubstituted or 3,5‐disubstituted ones could be obtained independently from the same reactants by the compensatable use of 1 and organotin iodide‐Lewis base complexes as catalysts.
The synthesis of novel polycyclic heterocyclic ring systems via photocyclization. 1. Thieno[3′,2′:4,5]thieno[2,3‐c]quinoline and thieno[2′,3′:4,5]thieno[2,3‐c]quinoline
Authors: Castle Steven L. , Luo Jiann‐Kuan , Kudo Hirotaka , Castle Raymond N. , Lee Milton L.
Published: April 2009

The synthesis of two previously unknown heterocyclic ring systems, namely, thieno[3′,2′:4,5]thieno[2,3‐c]‐quinoline and thieno[2′,3′:4,5]thieno[2,3‐c]quinoline is reported. These two novel ring systems were assembled by photocyclization of the appropriate anilides.
Condensation of 2H‐indazole‐4,7‐dione derivatives with 2‐aminophenol derivatives
Authors: Nan'ya Seiko , Katsuraya Kaname , Itamoto Yoshie , Maekawa Eturǒ , Ueno Yoshio
Published: April 2009

A new type of 9‐substituted‐5‐methyl‐2‐phenyl‐4H‐pyrazolophenoxazin‐4‐one derivatives was prepared by the condensation of 5‐methyl‐ and 6‐methyl‐2‐phenyl‐2H‐indazole‐4,7‐diones with 4‐substituted‐2‐aminophenols in pyridine. Relative reactivity of 2‐aminophenol derivatives in the condensation was studied.
A facile synthesis of substituted 4,5,6,7‐tetrahydropyrazolo[3,4‐d]‐pyrimidine and 1,2,3,4‐tetrahydropyrazolo[1,5‐a]triazine derivatives
Authors: Vishwakarma J. N. , Mofizuddin M. , Ila H. , Junjappa H.
Published: April 2009

Cyclocondensation of 3(5)‐alkylamino‐ and 3(5‐arylaminopyrazoles 1a‐c and 1d‐e with formaldehyde and primary amines affords novel tetrahydropyrazolo[3,4‐d]pyrimidines 2 and tetrahydropyrazolo[1,5‐a]triazine derivatives 3 respectivley in good yields.
β‐Carbolines as agonistic or antagonistic benzodiazepine receptor ligands.1. Synthesis of some 5‐, 6‐ and 7‐amino derivatives of 3‐methoxycarbonyl‐β‐carboline (β‐CCM) and of 3‐ethoxycarbonyl‐β‐carboline (β‐CCE)
Authors: Settimj Guido , Del Giudice Maria Rosaria , Ferretti Rosella , Gatta Franco
Published: April 2009

Condensation of diethyl formylamino‐ or diethyl acetylaminomalonate with 4‐, 5‐ or 6‐nitrogramine1afforded the diethyl formylamino‐ or the diethyl acetylamino[(nitroindol)‐3‐ylmethyl]malonates2; reduction of the nitro group followed byN‐formylation or acetylation of the resulting amino compounds3, led to the 4‐, 5‐and 6‐acylamino derivatives4.

Cyclization of4in the presence of polyphosphoric esters gave the 3,3‐bis(ethoxycarbonyl)‐3,4‐dihydro‐β‐carbolines5, which underwent lithium chloride/water catalyzed monodeethoxycarbonylation to the corresponding 5‐, 6‐ and 7‐acylamino‐3‐ethoxycarbonyl‐β‐carbolines6, whose acidic hydrolysis led finally to the 5‐, 6‐ and 7‐amino‐3‐ethoxycarbonyl‐β‐carbolines9. The 6‐amino compounds9b‐ewere obtained also by direct nitration of 3‐methoxycarbonyl‐β‐carboline7aand of 3‐ethoxycarbonyl‐β‐carboline7c, followed by the nitro group reduction of the resulting nitro carbolines8.

Preliminary studies of the binding to rabbit brain benzodiazepine receptor sites indicate compounds9band9cto inhibit the3H‐diazepam binding at 10−8Mconcentrations.
Studies on the chemistry of O,N‐ and S,N‐containing heterocycles. 4. Investigations on the nucleophilic substitution of activated 1,5‐benzothiazepines
Authors: Bartsch Herbert , Erker Thomas
Published: April 2009

The reaction of the activated 1,5‐benzothiazepine 1a with various amines is studied. In contrast to the phenylsubstituted derivative 1b no ring contraction but nucleophilic substitution is observed. Two novel ring systems 8 and 9 are obtained by nitrosation of 3g and by reaction of 1a with anthranilic acid, respectively.
Curcumol and its one‐step formation from curdione
Authors: Li Xian , Wu Lijun , Ji Zhizong , Harigaya Yoshihiro , Konda Yaeko , Iguchi Mieko , Takahashi Hiroshi , Onda Masayuki
Published: April 2009

The absolute stereochemistry of curcumol (1) is confirmed on the basis of the spectroscopic data. The existence of two conformations in curdione (4) is revealed by nOe experiments at ambient temperature. One‐step conversion of 4 into 1 stereospecifically proceeds via the ene‐reaction without epimerization at any asymmetric center in 4.
A new synthesis of 4‐aminooxazoles from α‐oxonitriles
Authors: Lakhan Ram , Singh Ram Lakhan
Published: April 2009

A general synthesis is described for the preparation of 4‐amino‐2,5‐disubstituted oxazoles 2. The interaction of α‐oxonitriles 1 with equimolecular amounts of aromatic or aliphatic aldehydes, and excess of anhydrous ammonium acetate in glacial acetic acid at 110–120° for 3–6 hours gives 2 in 40–65% yields. A plausible reaction mechanism for the formation of 2 is also suggested.
A convenient synthesis of functionalized 1H‐pyrimidine‐2‐thiones
Authors: Akcamur Yunus , Altural Behzat , Saripinar Emin , Kollenz Gert , Kappe Oliver , Peters Karl , Peters Eva‐Maria , Von Schnering Hans‐Georg
Published: April 2009

The furan‐2,3‐dione 1 and the thiosemicarbazones 2 combine with loss of carbon dioxide and water yielding the 1‐methylenaminopyrimidine‐2‐thione derivatives 3 in moderate yields (30–60%). Their molecular skeleton is confirmed with aid of an X‐ray structure determination of 3c. Hydrolysis of 3 leads to the 1‐aminopyrimidine‐2‐thione 5.
Synthesis and 1H‐NMR spectra of halogenated spiro[isobenzofuran‐1(3H),9′(9H)‐6′‐(methylcyclohexylamino)‐3′‐methyl‐2′‐anilinoxanthene]‐3‐ones
Authors: Nakazumi Hiroyuki , Kitao Teijiro , Ohnishi Katsuaki
Published: April 2009

Reaction of spiro[isobenzofuran‐1(3H).9′(9H)‐6′‐(methylcyclohexylamino)‐3′‐methyl‐2′‐anilinoxanthene]‐3‐one (1), which is typical leuco fluoran dye, with N‐bromosuccinimide and N‐chlorosuccinimide leads to halogenated derivatives 2a–2c and 3, respectively. Their structures were established by two‐dimensional proton‐proton (COSY) experiment and their thermal properties examined by means of DSC and compared with commercially available 1.
Chemistry of sulfonyl isocyanates and sulfonyl isothiocyanates. XI. Cyclizations with epoxides
Authors: Mcfarland J. W. , Beaulieu J. J. , Arrey L. N. , Frey L. M.
Published: April 2009

4‐Toluenesulfonyl isocyanate cyclized with 1,2‐epoxy‐3‐phenoxypropane and 2,3‐epoxypropyl 4‐methoxyphenyl ether, respectively, to give 3‐(4‐toluenesulfonyl)‐5‐phenoxymethylene‐2‐oxazolidone (I) and 3‐(4‐toluenesulfonyl)‐5‐(4‐methoxyphenoxymethylene)‐2‐oxazolidone (II). Compounds I and II were hydrolyzed in 2 M sodium hydroxide solution to the corresponding uncyclized hydroxy amides, VII and VIII. Compound I was remarkably stable toward 6 M hydrochloric acid and amines. Styrene oxide, 1,2‐epoxybutane, 3‐chloro‐1,2‐epoxypropane, and 1‐methoxy‐2‐methylpropylene oxide reacted with the isocyanate to afford 3‐(4‐toluene‐sulfonyl)‐4‐phenyl‐2‐oxazolidone (III), 3‐(4‐toluenesulfonyl)‐4‐ethyl‐2‐oxazolidone (IV), 3‐(4‐toluenesulfonyl)‐5‐chloromethyl‐2‐oxazolidone (V), and 3‐(4‐toluenesulfonyl)‐4,4‐dimethyl‐5‐methoxy‐2‐oxazolidone (VI), respectively. The yield of VI was constant over a temperature range of 25–90°.
Chemistry of sulfonyl isocyanates and sulfonyl isothiocyanates. XII. Cyclizations with epoxides
Authors: Mcfarland J. W. , Beaulieu J. J. , Arrey L. N. , Frey L. M.
Published: April 2009

4‐Toluenesulfonyl isothiocyanate reacted with 1,2‐epoxy‐3‐phenoxypropane and 2,3‐epoxypropyl 4‐methoxyphenyl ether to give, respectively, 3‐(4‐toluenesulfonyl)‐5‐phenoxymethylene‐2‐oxazolidmethione (I) and 3‐(4‐toluenesulfonyl)‐5‐(4‐methoxyphenoxymethylene)‐2‐oxazolidinethione (II) in high yields. The sulfonyl isothiocyanate reacted further with styrene oxide to give a mixture of oxazolidinethiones from which a solid III was isolated. The structure of III is either the 4‐ or 5‐phenyl derivative of 3‐(4‐toluenesulfonyl)‐2‐oxazolidinethione. Reactions of the isothiocyanate with 3‐chloro‐1,2‐epoxypropane and 1,2‐epoxybutane afforded, respectively, 3‐(4‐toluenesulfonyl)‐5‐chloromethyl‐2‐oxazolidinethione (IV) and 3‐(4‐toluenesulfonyl)‐4‐ethyl‐2‐oxazolidinethione (V). Evidence for structures was by pmr, ir, and elemental analyses.
Synthesis of tetra‐aza macrocycles with remarkably high efficiency
Authors: Tomohiro Takenori , Uoto Kouichi , Shimura Takehiko , Okuno Hiroaki
Published: April 2009

Tetra‐aza macrocycles with 28‐ to 44‐membered rings can be readily synthesized by reaction of dibromide and ditosyldiamide without use of a high dilution method. The reaction proceeded very smoothly with a 10 mM concentration in DMF, and gave the macrocycles in excellent yields (60–80%). Favorable effects of cesium ion on the cyclization have been observed.
Derivatives of 2‐oxo‐3(2H)‐benzothiazolineacetonitrile and related compounds. II. Synthesis of 2‐oxo‐alkyl esters of 3(2H)‐benzothiazolineacetimidic acids and related products
Authors: D'Amico John J. , Bollinger Frederic G.
Published: April 2009

The reaction of the appropriate 2‐benzothiazolinone or 2‐benzoxazolinone under basic conditions with (1) 2‐chloropropionitrile, (2) acrylonitrile, (3) 4‐chlorobutyronitrile or (4) chloroacetonitrile afforded the nitriles 1–8. The reaction of various nitriles with alcoholic‐hydrogen chloride solutions at low temperatures afforded the hydrogen chloride salts of the imino‐ester which upon neutralization with potassium carbonate yielded the titled compounds.
Synthesis of 2‐oxo and 2‐thioxo‐3(2H)‐benzothiazoleethanimic acid anhydride with acetic acid and related products
Authors: D'Amico John J. , Bellinger Frederic G. , Freeman John J.
Published: April 2009

The reaction of the appropriate 2‐benzothiazolinone with 2‐chloroacetamide under basic conditions afforded the 2‐oxo‐3(2H)‐benzothiazolineacetamides 6–9. The 2‐thioxo‐3(2H)‐benzothiazolineacetamide (10) was prepared by the reaction of 3‐(carbethoxymethyl)benzothiazoline‐2‐thione with ammonium hydroxide. The reaction of acetamides 6–10 with the appropriate anhydride containing a catalytic amount of the sodium salt of the acid corresponding to the anhydride afforded the titled compounds 11–18 in excellent yields. The omission of the catalyst in the same reaction furnished a mixture containing 57% of the titled compound, 37% of the nitrile and 6% of an unknown. Possible mechanism and supporting nmr, ir and mass spectral data are discussed.
Synthesis and structure elucidation of the condensation products between thiophene dicarbaldehydes and aromatic amines. Potential analgesic and anti‐inflammatory agents
Authors: Benachenhou F. , Mesli M. A. , El Borai M. , Hanquet B. , Guilard R.
Published: April 2009

Thiophene‐3,4‐dicarbaldehyde 1 reacts in the presence of 2‐mercaptoethanol to yield N‐aryl‐5,6‐dihydro‐4‐oxo‐4H‐thieno[3,4‐c]pyrroles 2 and N‐aryl‐4‐arylimino‐5,6‐dihydro‐4H‐thieno[3,4‐c]pyrroles 3, while thiophene 2,3‐dicarbaldehyde 4 reacts with aromatic amines to give N‐aryl‐5,6‐dihydro‐6‐oxo‐4H‐thieno[2,3‐c]pyrroles 5 in good yields. Labeling experiments and nmr spectral analysis give evidences for the possible reaction mechanism.
Some aspects of the chemistry of pyrimido[1,2‐B]pyridazinones
Authors: Mátyus Péter , Szilágyi Géza , Kasztreiner Endre , Rabloczky György , Sohár Pál
Published: April 2009

On reacting the 3‐aminopyridazines1a,d,ewith dimethyl acetylenedicarboxylate (DMAD), the pyrimido[1,2‐b]pyridazin‐2‐(2H)‐ones2e‐g, whereas starting from1f, the 4(4H)‐ones5aand3b,dwere prepared. In the 2(2H)‐one series, the reactions of2bwith various amino compounds resulted in various types of products. The reaction ofN‐methylaminopyridazines1g,hwith DMAD led to theendo‐N‐substituted derivatives8a,b, whereas1hwith diethyl ethoxymethylenemalonate (DEM) gave theexo‐N‐substituted compound1k.The constitution of the compounds was proved by spectroscopic and chemical evidences.
Convenient synthesis of 3‐methyl‐1‐(4‐pyridinyl)‐2‐butanone using phenyllithium as a metalating agent
Authors: Léon P. , Garbay‐Jaureguiberry C. , Roques B. P.
Published: April 2009

3‐Methyl‐1‐(4‐pyridinyl)‐2‐butanone has been synthesized via a short and convenient method based upon acylation of 4‐picoline by phenyllithium followed by reaction with ethyl isobutyrate. This procedure can be extended to the preparation of various alkyl pyridyl ketones, intermediates in the synthesis of potential anti‐tumor 6‐substituted 7H‐pyridocarbazole dimers.
Heterocyclic photorearrangements. Photoinduced rearrangements of 1,2,4‐oxadiazoles substituted by an XYZ side chain sequence
Authors: Buscemi Silvestre , Vivona Nicolò
Published: April 2009

Photoinduced rearrangements of 1,2,4‐oxadiazoles substituted by an XYZ side chain sequence at position 3 of the ring have been recognized. Examples taken out from previous results have been emphasized and some other patterns dealing with a 3‐phenoxy and 3‐enaminoketone sequence have been investigated. An intermediate species derived from photolysis of the ring O‐N bond and characterized by a continuous 6π electron system involving the side chain sequence, was suggested to give ring closure to the rearrangement product.
Crystal structure of 5,10‐(diphenyl)‐5,10‐dihydrophenarsazine
Authors: Siriwardane Upali , Razzuk Aziz , Khanapure Subhash P. , Biehl Edward R. , Chu Shirley S. C.
Published: April 2009

The crystal structure of the title compound 1, the first phenarsazine possessing a 10‐phenyl substituent to be synthesized, has been determined by single crystal x‐ray methods. The crystals are monoclinic, space group P21/c with four molecules in a cell of dimensions a = 10.737(3), b = 8.561(4), c = 20.523(7)Å, β = 91.91(3)° and V = 1885(1)Å3. The structure has been refined by full matrix least‐squares to R = 0.046 using 2087 observed reflections. The folding angle between the two benzo planes is 151.7(4)° indicating that 1 is significantly more puckered than phenarsazines substituted with 5‐aryl groups. Moreover, although both phenyl groups adopt a boat‐axial conformation, the planes of the aryl rings are nearly perpendicular to each other with the 10‐phenyl group adopting the usual conformation (i.e. in the plane bisecting the phenarsazine ring which contains As(5) and N(10)) and the 5‐phenyl group assuming the a typical conformation (i.e. very nearly perpendicular to the plane bisecting phenarsazine ring). The bond distance between As and the carbon atom of the 5‐phenyl ring is approximately the same as that found in other 5‐arylphenarsazine compounds indicating little resonance interactions between As and the aromatic ring in 1.
Structure and synthesis of goudotianine, a new 7‐methyldehydroaporphine from guatteria goudotiana
Authors: Castedo L. , Granja J. A. , De Lera A. Rodríguez , Villaverde M. C.
Published: April 2009

Total syntheses of 2,9‐dihydroxy‐1,3‐dimethoxy‐7‐methyl‐6a,7‐dehydroaporphine 1a and 3,9‐dihydroxy‐1,2‐dimethoxy‐7‐methyl‐6a,7‐dehydroaporphine 1b are described. Direct comparison of both with natural goudotianine isolated from Guatteria goudotiana R. E. Fries showed the latter to be identical with 1b.
Thiophene systems. 10. The synthesis and chemistry of some thienopyridinols
Authors: Press Jeffery B. , Mcnally James J.
Published: April 2009

Substituted thieno[2,3‐c]‐, thieno[3,2‐c]‐ and thieno[3,4‐c]pyridinols have not been described despite the fact that a few descriptions of the parent ring systems have appeared in the literature. As part of our ongoing program to investigate the synthesis of thiophene derivatives with potential biological activity, we became interested in the preparation of the various thienopyridinols. Syntheses of the title compounds 2a, 3 and 25 were achieved starting from thiophene‐3‐acetic acid and 3‐acetylthiophene. The two isomeric systems 2a and 3 were reacted with electrophiles to give products substituted at the position α to the hydroxy group on the pyridine ring (the 4‐ and 6‐positions, respectively). Lack of stability of 25 precluded studies on this system. Compounds 2a, 3 and 25 reacted with acetic anhydride to give O‐acetyl derivatives while reaction of the anion of 2a and 3 with methyl iodide gave mixtures of O‐ and N‐methylation. The N‐methylated products are the novel thienopyridones 45 and 47.
Synthesis of enantiomers of 2′‐aminomethyl‐5‐benzylacyclouridine (AM‐BAU) and 2′‐aminomethyl‐5‐benzyloxybenzylacyclouridine (AM‐BBAU). Potent inhibitors of uridine phosphorylase
Authors: Pan Bai‐Chuan , Chu Shih‐Hsi
Published: April 2009

Racemic 2′‐aminomethyl‐5‐benzyl‐acyclouridine (AM‐BAU, 5) and 2′‐aminomethyl‐5‐benzyloxybenzyla‐cyclouridine (AM‐BBAU, 6) have been found to be very active inhibitors of uridine phosphorylase [1]. Their enantiomers were synthesized from chiral 2,2‐dimethyl‐1,3‐dioxolane‐4‐methanol (7a,b). S‐(—)‐AM‐BAU (5a) and S‐(—)‐AM‐BBAU (6a) were prepared from the R‐(—) isomer 7a, and R(+)‐AM‐BAU (5b) and R‐(+)‐AM‐BBAU (6b) from the S‐(+) isomer 7b. A different route from the S‐(+) isomer 7b to S‐(—)‐AM‐BBAU (6a) was also determined to be feasible.
The reaction of phenyliodonium bis‐(phenylsulfonyl)methylide with some thiophenes
Authors: Hatjiarapoglou Lazaros , Varvoglis Anastasios
Published: April 2009

The title iodonium ylide gives with thiophenes C‐H insertion products of the C(SO2Ph)2 group and with benzothiophenes transylidation products.
Formation of bishomoazasteroids by the beckmann rearrangement
Authors: Camoutsis Charalambos , Catsoulacos Panayotis
Published: April 2009

Beckmann rearrangement of the geometrical isomer of 5α‐androstanolone oximes gives the 3‐aza‐17β‐hydroxy‐A‐homo‐5α‐androstan‐4‐one and the 4‐aza‐17β‐hydroxy‐A‐homo‐5α‐androstan‐3‐one. These lactams were converted to the corresponding ketones by Jones reagent oxidation. Treatment with hydroxylamine produced the corresponding ketoximes. Beckmann rearrangement of the ketoximes generated the diaza compounds and the corresponding “second order” Beckmann cleavage ω‐cyanoolefin. The mixture of the compounds produced, was separated by column chromatography. The structure of the compounds was apparent from spectral data.
Tetraacetylethylene and nitrile oxides: Synthesis of spirofuranisoxazoles
Authors: Adembri G. , Di Tommaso A. , Lampariello L. R. , Scotton M.
Published: April 2009

trans and cis‐3‐Hexen‐2,5‐dione, 2, reacted with nitrile oxides to give 4,5‐dihydroisoxazoles 3a‐c with the trans configuration. On the contrary the reaction between 3,4‐diacetyl‐3‐hexen‐2,5‐dione, 1, with nitrile oxides yielded 3‐aryl‐8,9‐diacetyl‐7‐hydroxy‐7‐methyl‐1,6‐dioxa‐2‐azaspiro[4.4]nona‐3,8‐dienes 9a‐e. The reaction is completely regiospecific. The cycloadducts show ring‐open chain tautomerism.
Synthesis of 6,7‐dimethoxypyrimido[4,5‐b]‐indoles as potential antihypertensive agents
Authors: Venugopalan B. , Desai P. D. , De Souza N. J.
Published: April 2009

Using ethyl 5,7‐dimethoxy‐2‐amino‐3‐indolecarboxylate as a synthon, routes are described for the synthesis of the title compounds bearing alkylamino moieties in the 2 and 4‐positions. Some of the compounds displayed antihypertensive activity.
Decarbonylation of some pyrimidine‐5‐carboxaldehydes
Authors: Delia Thomas J. , Polenz Barry , Martin Mary C.
Published: April 2009

In the course of determining the ultraviolet spectra of some 2,4,6‐trisubstituted‐pyrimidine‐5‐carboxalde‐hydes we discovered the facile loss of the formyl group. The reaction appears to be restricted to pyrimidine‐5‐carboxaldehydes containing three strongly electron donating substituents. Loss of the formyl group occurs at room temperature only in methanol with large excess of acid. Other alcohols and water fail to afford the decarbonylated product. A suggested pathway for this reaction is offered.
The nucleophilic substitution of methylthio group on the 1,4‐dihydro‐2‐methylthiopyrimidine rings
Authors: Kashima Choji , Shimizu Masao , Harada Kazuo , Omote Yoshimori
Published: April 2009

N‐Substituted 2‐alkylthio‐1,4‐dihydro‐4,4,6‐trimethylpyrimidines easily reacted with methanol to give corresponding 2‐methoxy‐1,4‐dihydropyrimidines, while the other nucleophiles did not react on the C‐2 carbon of the pyrimidine rings. However, the substitution of alkylthio group easily proceeded intramolecularly even with weak nucleophilic groups, e.g., phenolic oxygen, thiophenolic sulfur, and anilino nitrogen atom, to yield bi‐ or tricyclic pyrimidine derivatives.
Synthesis of 2‐methylthioindolizine‐3‐carbonitriles using nitro ketene dithioacetal
Authors: Tominaga Yoshinori , Shiroshita Yoshihide , Hosomi Akira
Published: April 2009

The reaction of 1‐cyanomethylpyridinium chloride or bromide,1a‐i, with 1,1‐bis(methylthio)‐2‐nitroethylene (2) in the presence of triethylamine as a base in ethanol gave the corresponding 2‐methylthioindolizine‐3‐carbonitrile3and 2‐methyl‐thio‐1‐nitroindolizine‐3‐carbonitrile4in good yields, respectively. Compounds3a,fwere key intermediates for the synthesis of cycl[3.2.2]azine derivatives.
On triazoles XVI. The reaction of 5‐amino‐1,2,4‐triazoles with β‐ and γ‐oxo esters. A novel N‐carbonylation reaction
Authors: Reiter József , Vágáa Pál , Esses‐Reiter Klóra , Pongó László , Molnár Hilda
Published: April 2009

5‐Amino‐1,2,4‐triazoles reacted with alifatic β‐oxo‐esters to yield besides the unexpected 1,2,4‐triazolo‐[1,5‐a]‐1,3,5‐benzotriazepin‐5‐one derivative 7 either the corresponding esters 5 and 6 or a 1:2 condensation product 8. To the contrary alicyclic and heterocyclic β‐oxo‐esters formed in the above reaction only derivatives 7. The proposed mechanism of the formation of 7 involving a novel N‐carbonylation reaction was proved by the isolation of the by‐products and the intermediate of the reaction. Repeating the above reaction with a γ‐oxo‐ester, namely the ethyl levulinate, derivatives 17 and 18, respectively, representing two new ring systems were obtained.
A three‐step pyridoannelation of carbonyl compounds
Authors: Chelucci Giorgio , Gladiali Serafino , Marchetti Mauro
Published: April 2009

The elaboration of a pyridine nucleus onto an α‐methylene carbonyl compound can be accomplished through a three step reaction sequence based on the regiospecific alkylation of N,N‐dimethylhydrazones with bromoethyl‐1,3‐dioxolane. Scope and limitations of the new method are considered.
Photolysis of cis‐1,2‐dihydroxyindane carbonate and cw‐1,2‐dihydroxy‐1,2,3,4‐tetrahydronaphthalene carbonate
Authors: White Rick C. , Drew Phil , Moorman Richard
Published: April 2009

Cyclic carbonate esters 2 and 3 were prepared and the photochemistry studied. The direct irradiation of these esters produces 1,3‐diradicals which undergo either ring closure to form epoxides, H migration to form ketones or Grob type fragmentation processes which lead to products via ring expansion or contraction.
Synthesis of 2/6‐(polychloromethyl)pyridine‐carboxylates
Authors: Chupp John P. , Smith Lowell R.
Published: April 2009

Due to their relationship to certain bio‐active 2,6‐(polyfluoromethyl)‐3,5‐pyridinedicarboxylates 12, methodology was developed to prepare new, but analogous 2/6 (polychloromethyl)pyridinecarboxylates 6, 9, 10, 13, 18 and 20. Successful methods to prepare these materials include several chlorination procedures, mixed Hantzsch sequences, and aluminum chloride interchanges with 12 and 16.
A reassignment of the 13C‐NMR spectrum of the alkaloid ajmaline through the use of two‐dimensional nmr techniques
Authors: Johnston Milton D. , Soltero Luis R. , Martin Gary E.
Published: April 2009

The reassignment of the 13C chemical nmr spectrum of the alkaloid, ajmaline, is reported. An earlier assignment based on analogy to other alkaloids and deductions from molecular orbital theory was found to be partially in error. The present study uses broadband decoupled (both dimensions) proton‐carbon shift correlation and long‐range proton‐carbon chemical shift correlation techniques. These experiments, in conjunction with earlier work by others on the assignment of the proton spectra, suffice to now unequivocably assign the 13C nmr spectrum of the title compound.
An improved synthesis of galanthamine
Authors: Szewczyk Jerzy , Lewin Anita H. , Carroll F. I.
Published: April 2009

Modifications in the total synthesis of the Amarylidaceae alkaloid of galanthamine from commercially available isovanillin and tyramine have resulted in a shortened reaction sequence, which is amenable to upscaling and in improved product yield.
Acid induced reactions of a sydnone ketoxime
Authors: Saljoughian Manouchehr , Turnbull Kenneth
Published: April 2009

3‐(2‐Acetylphenyl)sydnone oxime 1a reacts with acids (methanesulfonic‐, p‐toluenesulfonic, trifluoroacetic‐acid or Amberlite IR 118) to give products apparently derived from protonation of the oxime oxygen or nitrogen atom followed by cyclization to the sydnone ring or interception by water.
Meso‐[2.2]paracyclophanyltriphenylporphyrin: A simple representative of cyclophanylporphyrins
Authors: Czuchajowski Leszek , Goszczynski Stefan , Wheeler Dale E. , Wisor Antoni K. , Malinski Tadeusz
Published: April 2009

(R + S)Meso‐[2.2]Paracyclophanyltriphenylporphyrin 3, a member of a novel class of cyclophanylporphyrins, was obtained and characterized by spectroscopic and electrochemical methods. Compared to meso‐tetra[2.2]paracyclophanylporphyrin 1, it represents a simplified structure designed for the investigation of electronic interactions between the [2.2]paracyclophane moiety and porphyrin core and for use in metallation reactions.
Synthesis and cycloaddition reactions of ethyl glyoxylate imines. Synthesis of substituted furo‐[3,2‐c]quinolines and 7H‐indeno[2,1‐c]quinolines
Authors: Borrione Elisabetta , Prato Maurizio , Scorrano Gianfranco , Stivanello Mariano , Lucchini Vittorio
Published: April 2009

Lewis acid catalyzed cycloaddition reactions of ethyl glyoxylate imines to dihydrofuran and indene yield substituted hexahydrofuro[3,2‐c]‐ and tetrahydro‐7H‐indeno[2,1‐c]quinolines respectively. Oxidation of the adducts with 2,3‐dichloro‐5,6‐dicyanobenzoquinone affords the corresponding aromatic compounds.
Fused s‐triazino heterocycles. XV. 13H‐4,6,7,13a,13c‐pentaazabenzo[hi]chrysene, 13H‐4,7,13a,13c‐tetraazabenzo[hi]chrysene, and 7H‐3,7,10,10b‐tetraazacyclohepta[de]naphthalene, three new ring systems
Authors: Shaw John T. , Corbett Wendy L. , Layman Deanna L. , Cuny Gregory D. , Kerschner Judith L.
Published: April 2009

The reaction of N‐cyano‐N′‐(6‐amino‐2‐pyridyl)acetamidine (5a) and homophthalic anhydride followed by ring closure of the 2‐[2‐(carboxymethyl)phenyl]‐5‐methyl‐1,3,4,6,9b‐pentaazaphenalene intermediate (4a) gave 5‐methyl‐13‐oxo‐13H‐4,6,7,13a,13c‐pentaazabenzo[hi]chrysene (8a). An analogous series starting with 3‐N‐(6‐amino‐2‐pyridyl)amino‐2‐cyano‐2‐butenenitrile (5b) in place of 5a gave in two steps 5‐methyl‐13‐oxo‐13‐H‐4,7,13a,13c‐tetraazabenzo[hi]chrysene‐6‐carbonitrile (8b). Elemental analysis, ir and pmr spectra of 8a, 8b and several new model compounds aided in confirming the structures of 8a and 8b. The synthesis of one of these model compounds for 5b and phenylacetic anhydride led surprisingly to 2‐methyl‐9‐phenyl‐7H‐3,7,‐10,10b‐tetraazacyclohepta[de]naphthalene (10) in addition to the expected 2‐benzyl‐4‐cyano‐5‐methyl‐1,3,‐6,9b‐tetraazaphenalene (7b).