bluuebunny/crossref_metadata_2025 huggingface dataset:
Reaction of 4‐hydrazinoquinolines with β‐diketones. Synthesis and spectroscopy (1h, 13c nmr, ms) of some pyrazolylquinolines
Authors: Singh S. P. , Tarar L. S. , Vaid R. K. , Elguero J. , Martínez A.
Published: March 2009

A series of 4‐pyrazolylquinolines have been prepared from 4‐hydrazinoquinolines and β‐dicarbonyl compounds and the previously proposed diazepine structure for the reaction products has been ruled out. A 13C nmr study established the 3‐position of the methyl group when two isomers were possible. Finally, a careful 1H nmr study of 2‐ and 4‐pyrazolylquinolines led to the conclusion that intramolecular hydrogen bonds between aromatic (or heteroaromatic) C‐H and pyridine like nitrogens is the factor that determines the conformation of these compounds.
Double quantum filtered zero quantum coherence with broadband homonuclear f1 Decoupling
Authors: Soltero Luis R. , Martin Gary E. , Johnston Milton D. , Castle Raymond N.
Published: March 2009

A pulse sequence is described which combines double quantum filtration and broadband homonuclear F1 decoupling in a two‐dimensional zero quantum (ZQCOSY) nmr experiment.
A facile one pot synthesis of 1‐alkylbenzimidazoline‐2‐thiones
Authors: Lee Tae Ryong , Kim Kyongtae
Published: March 2009

Reactions of benziraidazoline‐2‐thione with alkyl halides in the presence of sodium naphthalenide in tetra‐hydrofuran at room temperature under a nitrogen atmosphere afforded 1‐alkyl‐2‐alkylthiobenzimidazoles in excellent yields, which underwent a bond cleavage between S and C of alkyl group to give excellent yields of 1‐alkylbenzimidazoline‐2‐thiones by the treatment with an additional amount of sodium naphthalenide.
Reaction of nitriles under acidic conditions. Part VI. Synthesis of condensed 4‐chloro‐ and 4‐aminopyrimidines from ortho‐aminonitriles
Authors: Shishoo C. J. , Devani M. B. , Bhadti V. S. , Jain K. S. , Ananthan S.
Published: March 2009

Condensation of a nitrile with benzene, furan and thiophene ortho‐aminonitriles in the presence of dry hydrogen chloride yields condensed 4‐chloropyrimidines, condensed 4‐aminopyrimidines or a mixture of the two condensed pyrimidines in varying proportions depending upon the nature of the nitrile and the substrate, ortho‐aminonitrile.
Studies in organic mass spectrometry. VIII. The electron impact mass spectra of 2,4‐substituted‐3‐diazo‐5‐phenylpyrroles
Authors: Ceraulo L. , Agozzino P. , Ferrugia M. , Plescia S. , Sprio V.
Published: March 2009

The electron impact mass spectra (75 eV) of the β‐diazopyrroles always show the molecular ions and undergo as the main fragmentation process the elimination of nitrogen followed by ring opening reactions leading to benzonitrile either as neutral or charged species. The peaks at 26 amu below the molecular ions, which are a general feature of these spectra, are due to the presence of the corresponding pyrroles which are formed by reductive reactions during the vaporization process of the samples.
Synthesis of 4,4′‐divinyl‐2,2′‐bipyridine
Authors: Ciana Leopoldo Delia , Dressick Walter J. , Von Zelewsky A.
Published: March 2009

4,4′‐Divinyl‐2,2′‐bipyridine (2) was prepared in 12% overall yield from 4,4′‐dimethyl‐2,2′‐bipyridine (3) via a 5 step reaction sequence involving the intermediate 4,4′‐R2‐2,2′‐bipyridines: R = COOH, 4; CO2CH3, 5; CH2OH, 6; CHO, 7. The newly synthesized compounds 2, 6 and 7 were characterized by melting point, infrared, 1H nmr, mass spectrometry and elemental analysis.
9‐Deazapurine nucleosides. The synthesis of certain N‐5‐β‐d‐ribofuranosylpyrrolo[3,2‐d]pyrimidines
Authors: Girgis Nabih S. , Robins Roland K. , Cottam Howard B.
Published: March 2009

Several N‐5 ribofuranosyl‐2,4‐disubstituted pyrrolo[3,2‐d]pyrimidine (9‐deazapurine) nucleosides were prepared by the single phase sodium salt glycosylation of 2,4‐dichloro‐5H‐pyrrolo[3,2‐d]pyrimidine (3) using 1‐chloro‐2,3‐O‐isopropylidene‐5‐O‐(t‐butyl)dirnethylsilyl‐α‐D‐ribofuranose (2). Use of 2 for the glycosylation avoided the formation of “orthoamide” products 1 and provided an excellent yield of the β nucleoside, 2,4‐dichloro‐5‐[2,3‐O‐isopropylidene‐5‐O‐(t‐butyl)dimethylsilyl‐β‐D‐ribofuranosyl]‐5H‐pyrrolo[3,2‐d]pyrimidine (4), along with a small amount of the corresponding α anomer, 5. Compound 4 served as the versatile intermediate from which the N‐7 ribofuranosyl analogs of the naturally‐occurring purine nucleosides adenosine, inosine and guanosine were synthesized. Thus, controlled amination of 4 followed by sugar deprotection and dehalogenation yielded the adenosine analog, 4‐amino‐5‐β‐D‐ribofuranosyl‐5H‐pyrrolo[3,2‐d]pyrimidine (8) as the hydrochloride salt. Base hydrolysis of 4 followed by deprotection gave the 2‐chloroinosine analog, 10, and subsequent dehalogenation provided the inosine analog, 5‐β‐D‐ribofuranosyl‐5H‐pyrrolo[3,2‐d]‐pyrimidin‐4(3H)‐one (11). Amination of 10 furnished the guanosine analog, 2‐amino‐5‐β‐D‐ribofuranosyl‐5H‐pyrrolo[3,2‐d]pyrimidin‐4(3H)‐one (12). Finally, the α anomer in the guanosine series, 16, was prepared from 5 by the same procedure as that used to prepare 12. The structural assignments were made on the basis of ultraviolet and proton nmr spectroscopy. In particular, the isopropylidene intermediates 9 and 14 were used to assign the proper configuration as β and α, respectively, according to Imbach's rule.
Synthesis of acenaphtho[1,2‐x]heterocycles and spiro[acenaphthylene 1‐isoxazoles]
Authors: Lefkaditis D. A. , Nicolaides D. N. , Papageorgiou G. K. , Stephanidou‐Stephanatou J.
Published: March 2009

Methyl (Z)‐(1,2‐dihydro‐2‐oxo‐1‐acenaphthylenylidene)acetate 1 gives with hydroxylamine the oximes 2 and the pyrrole derivative 4, whereas with hydrazines affords the pyridazinones 5 and 6. A pyridazine derivative 8 is also isolated from the reaction of (1,2‐dihydro‐2‐oxo‐1‐acenaphthylenylidene)acetone 7 with hydrazine hydrate. Reaction between the spiro‐derivative 9 and hydroxylamine hydrochloride gives oxime 10, whereas Wittig olefination of 9 with ylide 11 yields compound 12 which by reaction with 2,4,6‐trimethylbenzonitrile oxide (13) affords the dispiro‐derivatives 14. Finally from the reaction of acenaphthylene‐1,2‐quinone (17) with the bisylide 16 the acenaphtho[1,2‐c]thiophene (18) is formed.
Structure and spectroscopic characterization of 1‐ and 2‐hydrazonoyl‐1,2,3‐triazoles
Authors: Bojilova Anka , Rodios Nestor A. , Alexandrou Nicholas E. , Terzis A. , Mentzafos D.
Published: March 2009

The synthesis of some 1‐ and 2‐hydroazonoyl‐1,2,3‐triazoles by reaction of the corresponding 1,2,3‐triazoles and nitrilimines is described and their characterization by 13C nmr and mass spectroscopy is provided. The structure of a 2‐hydrazonoyl derivative 6b was determined by X‐ray analysis.
Polarized ethylene. V. Synthesis of 1‐substituted indolizine, pyrazolo[1,5‐a]pyridine, and their related compounds using methoxyethylene derivatives
Authors: Tominaga Yoshinori , Ichihara Yuichi , Mori Tomoko , Kamio Chizuko , Hosomi Akira
Published: March 2009

The reaction of pyridinium or isoquinolinium N‐ylides with methoxy‐substituted ethylenes gave the corresponding indolizine and pyrrolo[2,1‐a]isoquinoline derivatives bearing acetyl, aroyl, cyano, ester group at the 1‐position in one step. Pyrazolo[1,5‐a]pyridine, pyrazolo[1,5‐a]quinoline, and pyrazolo[5,1‐a]isoquinolines were also synthesized in good yields from the corresponding aromatic N‐imines and methoxyethylene derivatives.
Diheterocyclic compounds from dithiocarbamates and derivatives thereof. II. 2,2′‐Diamino‐6,6′‐bibenzoazoles
Authors: Garín Javier , Meléndez Enrique , Merchán Francisco L. , Merino Pedro , Orduna Jesús , Tejero Tomás
Published: March 2009

The readily available dithiocarbamates and dithiocarbonimidates 4, 8, 14 and 15 afford in one step the title compounds in medium to very good yields. In each case, the choice of reagent depends on the nature of the group to be introduced. Their usefulness as synthetic equivalents of weakly reactive or unavailable isothiocyanates is also discussed.
An unusual oxazole formation
Authors: Freedman Jules , Huber Edward W.
Published: March 2009

The reaction of 2‐propargyloxybenzamide with strong base has been shown to lead to formation of an oxazole and not a benzoxazepinone as reported. The structure has been confirmed by synthesis.
Condensed 1,3‐benzothiazinones 3. Synthesis of 3‐substituted 1,2,4‐triazolo[3,4‐b][1,3]benzothiazin‐5‐ones
Authors: Liu Kang‐Chien , Shih Bi‐Jane , Chern Ji‐Wang
Published: March 2009

Refluxing 2‐hydrazono‐3,4‐dihydro‐2H‐1,3‐benzothiazin‐4‐one 3 with triethyl orthoformate neat or with trimethyl orthoformate 4a, triethyl orthoacetate, orthopropionate, orthobenzoate 4b‐d in xylene gave 1,2,4‐triazolo[3,4‐b][1,3]benzothiazin‐5‐one 2a and its 3‐substituted derivatives 2b‐d in 56–95% yields. On the other hand, when 3 was treated with trifluoro‐, trichloroacetic anhydride 4e,f, dichloro‐, chloroacetyl chloride 4g,h, 2‐chloropropionyl and ethoxyoxalyl chloride 4i,j, the corresponding open‐chain condensates were produced, together with the title compounds 2g‐i, or the Dimroth rearrangement isomers 1e,g,i,j each depending on the reaction conditions. Nevertheless efficient preparation of 2h and 3‐hydroxy‐derivative 2k to get rid of such rearrangement was developed.
Heterocyclic compounds with a bridgehead nitrogen atom. Synthesis in the imidazo[1,2‐c]quinazoline series
Authors: Gueiffier A. , Viols H. , Chapat J. P. , Chavignon O. , Teulade J. C. , Dauphin G.
Published: March 2009

The structures of imidazo[1,2‐c]quinazolines were reexaminated and established by spectroscopic studies with the aid of high‐field 1H and 13C nmr and mass spectra. In acidic media, 3 reacts to give the products of electrophilic substitution reaction and ring opening compound 5, leading to the imidazo[1,2‐c]benzo[e]‐[1,2,3]triazine ring.
Reactivity of 2‐methyl‐4‐(1‐pyrrolidinyl)‐2H‐1,2‐benzothiazine 1,1‐dioxide towards p‐toluenesulphonyl azide
Authors: Consonni Roberto , Croce Piero Dalla , Ferraccioli Raffaella
Published: March 2009

The 2‐methyl‐2H‐1,2‐benzothiazin‐4‐(3H)‐one 1,1 dioxide (2), obtained according to a new, one‐pot method, is transformed into the pyrrolidino enamine 3. Reaction of p‐toluenesulphonyl azide with 3 gives, via an unstable triazoline adduct which loses nitrogen, the two isomeric tosylamino derivatives 4 and 5. The structures have been assigned by exhaustive nmr analysis and some aspects on their formation and chemical behaviour are discussed.
Synthesis and properties of conformationally locked 1,3‐bisalkyl‐7‐deazaxanthine 2′‐deoxy‐d‐ribofuranosides
Authors: Seela F. , Kretschmer U.
Published: March 2009

1,3‐Dimethyl‐7‐deazaxanthine 2′‐deoxyribofuranosides 1a and 6a and their N‐3 isopropyl congeners 1b and 6b have been prepared employing the nucleobase anions 7a or 7b and 2‐deoxy‐3,5‐di‐O‐(p‐toluoyl)‐α‐D‐erythropentofuranosyl chloride (8) upon glycosylation. The reaction was not stereoselective as found in case of other pyrrolo[2,3‐d]pyrimidine nucleosides induced by the bulky N‐3 substituent. Configuration of anomers was established by 1H‐nmr nOe difference spectroscopy. Those data also indicated that the conformation around the N‐glycosylic bond was locked by the bulky N‐3 substituent. Contrary to the purine nucleoside such as wyosine (2a) the hydrolytic stability of the N‐glycosylic bond of the pyrrolo[2,3‐d]pyrimidine nucleosides was increased by N‐3 alkylation. Moreover, it was shown by 15N‐nmr spectroscopy that different to purine nucleosides the aglycon was not protonated in acidic medium. As a result the N‐glycosylic bond hydrolysis did not follow an A‐1 but an A‐2 mechanism.
A convenient synthesis of 3‐aryl‐1,2,4‐triazolo[4,3‐c]quinazolines
Authors: El‐Kerdawy Mohamed M. , Ismaiel Abd El‐Kader M. , Gineinah Magdy M. , Glennon Richard A.
Published: March 2009

The synthesis and characterization of several 3‐aryl‐1,2,4‐triazolo[4,3‐c]quinazolines is described. The first step comprises the condensation of aromatic aldehydes with 2‐(H or Cl)‐4‐hydrazinoquinazolines 2 to afford the corresponding hydrazones 3. The second step involves the cyclization to the title compounds 4 in bromine/acetic acid. Reaction of 4 (X = Cl) with cyclic amines gave the corresponding 5‐cyclicamino 5 or 5‐alkoxy derivatives 6.
The synthesis of hexahydro‐6H‐dibenzo[b,d]pyrans: Derivatives of 9‐Nor‐9β‐hydroxyhexahydrocannabinol
Authors: Melvin Lawrence S. , Bordner Jon , Hada William A. , Johnson M. Ross
Published: March 2009

To assess the importance of the phenol functionality in cannabinoids for analgetic activity a new series of 9‐nor‐9β‐hydroxyhexahydrocannabinoids was prepared. The synthesis of 1‐substituted (H, CH2OH, OH, NH2) 6aβ,7,8,9,10,10aα‐hexahydro‐9β‐hydroxy‐6,6‐dimethyl‐3‐[1‐methyl‐4‐phenylbutoxy]‐6H‐dibenzo[b,d]pyrans from 3,5‐dihydroxystilbene, 3,3′,5,5′‐tetrahydroxystilbene or 1,3,5‐trihydroxybenzene is described. Relative stereochemistry and structure confirmations were obtained by nmr and X‐ray crystal analysis.
Synthesis of 6‐substituted‐4,5‐dihydro‐3(2H)‐pyridazinones
Authors: Baraldi P. G. , Chiarini A. , Leoni A. , Manfredini S. , Simoni D. , Zanirato V.
Published: March 2009

A convenient synthetic method for the pharmaceutically important 6‐substituted‐4,5‐dihydro‐3(2H)‐pyridazinones is described. The synthetic strategy is based on Δ‐soxazolines chemistry which were in turn unmasked by NO bond cleavage and cyclized to the target compounds.
Murexide reaction of caffeine with hydrogen peroxide and hydrochloric acid. II
Authors: Koyama Matajiro , Kozuka Hiroshi
Published: March 2009

In continuation of the study on the murexide reaction of caffeine with 3% hydrogen peroxide/hydrochloric acid and then with ammonia giving a purple coloration, we investigated the oxidation reaction of caffeine with 6% hydrogen peroxide/hydrochloric acid to isolate ten reaction products, 3‐hydroxy‐4,6‐dimethyloxazolo[4,5‐d]pyrimidine‐2,5,7(3H,4H,6H)‐trione 1, 1,3‐dimethylalloxan 2, murexoin 3, 1,3,7‐trimethyl‐2,6,8‐trioxo‐9‐hydroxy‐1H,3H,7H‐xanthine 5, 1,3,7‐trimethyl‐2,6,8‐trioxo‐1H,3H,7H‐xanthine 6, 1,3,7‐trimethyl‐2,6‐dioxo‐8‐chloro‐1H,3H,7H‐xanthine 7, 5‐(1,3‐dimethyl‐1,2,3,4,5,6‐hexahydro‐2,4,6‐trioxopyrimidin‐5‐yl)‐aminomethylene‐1,3‐dimethyl‐1,2,3,4,5,6‐hexahydro‐2,4,6‐trioxopyrimidine ammonium salt 9, 1,3‐dimethylpalabanic acid 10, 1‐methyl‐2,4,5‐trioxoimidazole 11, 3‐hydroxy‐5,7‐dimethyloxazolo[5,4‐d]pyrimidine‐2,4,6(3H,5H,7H)‐trione 12 and 4,6,8‐trimethyl‐1,2,4‐dioxazino[6,5‐d]pyrimidine‐3,5,7(4H,6H,8H)‐trione 13.

The oxidation reaction using 6% hydrogen peroxide/hydrochloric acid was found to produce a similar purple coloration to that of the murexide reaction despite no subsequent addition of ammonia, indicating the liberation of ammonia by the oxidation of caffeine.

Among the above compounds, the purple colored substance murexoin 3 and the yellow colored compound 9 were both ammonium salts, and compound 5 was the red colored substance. In the present investigation, these three compounds were found to contribute to the coloration.
Intramolecular cyclization of 4‐acetyl‐2,2‐diethoxycarbonyl‐2,3‐dihydro‐1‐(2‐nitrobenzoyl)pyrrole by catalytic reduction
Authors: De Caprariis P. , De Martino G. , Abignente E. , Sacchi A.
Published: March 2009

Catalytic hydrogenation of 4‐acetyl‐2,2‐dicthoxycarbonyl‐2,3‐dihydro‐1‐(2‐nitrobenzoyl)pyrrole 2 afforded 3‐acetyl‐1,1‐diethoxycarbonyl‐1,2,3,3a,4,9‐hexahydro‐9‐oxopyrrolo[2,1‐b]quinazoline 3 and the 4‐hydroxy derivative 4, together with two tetrahydro analogs 5 and 6 of 3. Compounds 5 and 6 were also obtained by dehydration of 4.
Mesoionic 1,2,4‐triazolo[4,3‐c]quinazolines
Authors: Gineinah Magdy M. , Ismaiel Abd El‐Kader M. , El‐Kerdawy Mohamed M. , Glennon Richard A.
Published: March 2009

Because of the close structural similarity between triazoloquinazolines and certain 5‐membered ring mesoionic heterocycles, all of which possess antiinflammatory activity, we prepared several examples of the novel mesoionic 1,2,4‐triazolo[4,3‐c]quinazoline ring system for their therapeutic potential. These compounds can be prepared by the cyclization of the appropriately substituted 4‐hydrazinoquinazolines with phosgene. When the mesoionic product was unsubstituted at the 5‐position (i.e., quinazoline 2‐position), it could only be isolated as its hydrochloride salt and not as its unstable free base. None of the mesoionic products were sufficiently stable in solution to allow for evaluation of their antiinflammatory activity.
Synthesis of pyrazolo[3,4‐d]pyrimidine derivatives using ketene dithioacetals
Authors: Tominaga Yoshinori , Honkawa Yasumasa , Hara Mayumi , Hosomi Akira
Published: March 2009

The cyclization of 5‐amino‐3‐methylthiopyrazole‐4‐carbonitriles or 4‐carboxamides 3a‐j, which were prepared by the reaction of ketene dithioacetals 1a,b [1a: bis(methylthiomethylenemalononitrile; 1b: bis(methylthio)methylenecyanoacetamide] with hydrazines (hydrazine hydrate, phenylhydrazine, p‐chlorophenylhydrazine, p‐nitrophenylhydrazine), with formamide or carbon disulfide proceeded to give the corresponding 4‐amino‐ or 4‐hydroxy‐3‐methylthiopyrazolo[3,4‐d]pyrimidines 6a‐h in good yields. 3‐Aminopyrazolo[3,4‐d]pyrimidine derivatives 6i‐1 were also obtained by the application of the cyclization reaction of 3,5‐diaminopyrazoles with formamide.
An easy two‐step synthesis of 1‐imidazolylmethyl esters
Authors: Banfi Aldo , Benedini Francesca , Sala Alberto
Published: March 2009

A new synthesis of 1‐imidazolylmethyl esters is described starting from the appropriate carboxylic acids via imidazolide intermediates.
3‐(2‐Pyrrolidinyl)‐2,4‐furandione analogs
Authors: Coppola Gary M. , Damon Robert E.
Published: March 2009

The reaction of 4,4‐dimethyl‐3‐oxobutanoic (or pentanoic) acid esters with the lactim ether of 2‐pyrrolidone in the presence of 2‐hydroxypyridine produces condensation products 4 in 57–72% yield. Acidic hydrolysis of 4 affords the furandione system 5 in 75–81% yield.
A Facile synthesis of 3‐alkylthio‐(or arylthio‐)pyridines and 3,5‐bis(alkylthio)pyridines
Authors: Chen Ted K. , Flowers William T.
Published: March 2009

3‐Alkylthio‐ (or 3‐arylthio‐)pyridines and 3,5‐bis(alkylthio)pyridine can be conveniently prepared by the reaction of 3‐thiocyanato‐ or 3,5‐bis(thiocyanato)pyridines with tri‐n‐butylphosphine in the presence of alcohol.
Furan derivatives. Part 12 . Synthesis of 2,5‐dioxacyclohepta[jkl]‐as‐indacenes
Authors: Horaguchi Takaaki , Miyazawa Kazuhiro , Hasegawa Eietsu , Shimizu Takahachi , Suzuki Tsuneo , Tanemura Kiyoshi
Published: March 2009

A variety of 2,5‐dioxacyclohepta[jkl]‐as‐indacenes 5, 7–14 were synthesized as a new heterocycle by the treatment of diethyl (5,9‐dioxobenzocyclohepten‐1,4‐diyloxy)diacetates 4a‐e with potassium hydroxide or sodium hydride in dioxane. The mechanism of furan‐ring formation from 4a‐e was discussed.
Polycondensed nitrogen heterocycles. Part 23. Pyrrolo[3,2‐c]cinnolines by a japp‐klingemann type reaction
Authors: Cirrincione Girolamo , Almerico Anna Maria , Aiello Enrico , Dattolo Gaetano
Published: March 2009

Pyrrolo[3,2‐c]cinnoline derivatives were obtained by an unusual Japp‐Klingemann reaction involving an intramolecular azadehalogenation on the pyrrole nucleus. Such an azadehalogenation represents the first example of Japp‐Klingemann reaction in which the extrusion of positive chlorine ion is verified.
Structure and synthesis of the metribuzin blue dye. Synthesis and reactions of 2,5‐dihydrazino‐1,3,4‐thiadiazole and its derivatives
Authors: Jackman Dennis Earl
Published: March 2009

A blue pigment which sometimes accompanies the manufacture of the triazine herbicide metribuzin (5) was identified as the novel thiadiazole formazan 10 which arises from the reaction of two impurities 3 and 7. The latter compound is a keto acid derivative of 2,4‐dihydrazinothiadiazole which in turn is an impurity in carbonothioic dihydrazide. Compound 7 has the interesting property of undergoing a facile oxidative decarboxylation in the presence of alcohols to form hydrazonate esters and in the presence of aliphatic amines to form red amidrazone dyes 9. The N‐substituted dyes can be oxidized to ditriazolothiadiazoles 12.
On the synthesis of thieno[3,2‐c]quinoline N‐oxide and thieno‐[3,2‐C]isoquinoline N‐oxide. The nmr spectra of the six isomeric thieno‐fused quinoline and isoquinoline N‐oxides
Authors: Gronowitz Salo , Timari Géza
Published: March 2009

The synthesis of the two remaining isomeric monothieno‐analogues of phenanthridine N‐oxide, thieno‐[3,2‐c]quinoline N‐oxide and thieno[3,2‐c]isoquinoline N‐oxide, is described. The 1H and 13C nmr spectra of all six isomeric thieno‐fused quinoline and isoquinoline N‐oxides are discussed.
Synthesis of 5‐benzyl and 5‐benzyloxybenzyl‐3′‐azido‐2′,3′‐dideoxyuridine and their analogues as potential anti‐AIDS agents
Authors: Pan Bai‐Chuan , Weng Zum‐Yao , Chen Zhi‐Hao , Rowe Elizabeth C. , Chu Shih‐Hsi
Published: March 2009

5‐Benzyl and 5‐benzyloxybenzyl‐substituted 3′‐azido‐2′,3′‐dideoxyuridine, (8a and 8b), 3′‐halogeno‐2′,3′‐dideoxyuridine, 9a, 9b, 10a, 10b, 11a and 11b, and 2′,3′‐dideoxyuridine, 12a and 12b, of Scheme I were synthesized as potential anti AIDS agents. Synthesis of epimers of 8a and 8b, 5‐benzyl‐ and 5‐benzyloxybenzyl‐1‐(3′‐azido‐2′,3′‐dideoxy‐β‐D‐threo‐pentafuranosyl)uracil, 15a and 15b, and 5‐benzyl‐ and 5‐benzyloxy‐5′‐azido‐2′,5′‐dideoxyuridine, 16a and 16b, shown in Scheme II, were also reported.
A novel synthetic route to 2‐halo‐3,4‐dicyanopyridines
Authors: Lee Ju‐Yeon , Hall H. K.
Published: March 2009

2‐Bromo‐3,4‐dicyanopyridine 2 was obtained in moderate yield by reacting 1,1,2,2‐tetracyano‐3‐trimethylsiloxycyclobutane 1 with phosphorus tribromide. Similarly, reaction of 1 with chlorinating reagents such as thionyl chloride and oxalyl chloride led to the corresponding 2‐chloro‐3,4‐dicyanopyridine 3 in 40% yield. A reaction mechanism is suggested.
Orientational effect of the phenylsulfonyl group in the thermal spiroketalization of dihydroxyketone equivalents
Authors: Alzérreca Arnaldo , Avilés Mayra , Collazo Luis , Prieto Antonio
Published: March 2009

The thermal cyclization of a dihydroxyketone equivalent 4b leads to the predominant formation of crystalline 4‐(benzenesulfonyl)‐1,6‐dioxaspiro[4.5]decane (8). Under similar reaction conditions the tetrahydrofuranylidene derivative 6 is obtained from ketone 4c. It does appear that the phenylsulfonyl group is a factor which influences the course of the reaction leading to the preferential formation of one of the possible stereoisomers.
Synthesis of 9‐(hexane‐1,6‐diol‐3‐yl)purines, a novel series of acyclic nucleoside analogs and antiviral evaluation
Authors: Legraverend Michel , Boumchita Hassane , Bisagni Emile
Published: March 2009

New acyclic purine nucleoside analogs lacking the C(3′)C(4′) bond, have been prepared from 4‐aminocyclohexene and evaluated for antiviral activity. A new synthesis of 4‐aminocyclohexene from cyclohex‐3‐ene‐1‐carbonyl chloride is also reported via a Curtius reaction. None of the two compounds exhibited any antiviral activity in vitro against HSV‐1, HCMV and HIV‐1.
Acetylenic chemistry. Part 17 Acetylenic amides as precursors for the synthesis of 3‐propynylquinazolinones
Authors: Reisch J. , Usifoh C. O. , Oluwadiya J. O.
Published: March 2009

Cyclocondensation of acetylenic amides with triethylorthoformate and triethylorthoacetate in boiling glacial acetic acid under nitrogen gave 3‐propynylquinazolinones. 2‐Ethoxy‐2‐methyl‐3[1,1‐dimethylpropynyl]quinazolin‐4(1H,3H)‐one (3b) and 2‐ethoxy‐2‐methyl‐3‐[1‐cyclohexylpropynyl]quinazolin‐4(1H,3H)‐one (3c) in refluxing ethanolic sodium hydroxide afforded the corresponding oxazoloquinazolinones.
Synthèse de L'hydroxy‐9 pyrimido[1,6‐a]pyrimidine one‐4 et dérivés
Authors: Dennin F. , Blondeau D. , Sliwa H.
Published: March 2009

La condensation d'alcoxy‐5 amino‐4 pyrimidines avec l'éthoxyméthylènemalonate de diéthyle et avec le méthoxyméthylènemalonate d'isopropylidène conduit après cyclisation thermique des intermédiaires énaminoesters résultants aux alcoxy‐9 pyrimido[1,6‐a]pyrimidines one‐4 substituées par un groupe éthoxycarbonyle en 3 dans le premier cas. L'hydrogénolyse des éthers benzyliques correspondants permet d'obtenir de nouveaux phénols hétérocycliques: l'hydroxy‐9 pyrimido[1,2‐a]pyrimidine one‐4 et son dérivé éthoxycarbonylé en 3.
Synthesis of α‐(aminomethylene)‐9‐(methoxymethyl)‐9H‐purine‐6‐acetic acid derivatives
Authors: Hamamichi Norimitsu , Miyasaka Tadashi
Published: March 2009

α‐(Aminomethylene)‐9‐(methoxymethyl)‐9H‐purine‐6‐acetamide and the ethyl acetate, 3 and 8, have been synthesized by catalytic hydrogenation of 6‐cyanomethylene‐9‐methoxymethylpurine derivatives 2 and 7 which were obtained by the substitution of 6‐chloro‐9‐(methoxymethyl)purine (1) with α‐cyanoacetamide and ethyl cyanoacetate, respectively. Substitution of 3 and 8 with amines gave the corresponding N‐substituted α‐(aminomethylene)‐9‐(methoxymethyl)‐9H‐purine‐6‐acetamide and the ethyl acetate 4 and 10. Reaction of 3 with piperidine gave 9‐(methoxymethyl)‐9H‐purine‐6‐acetamide (5).
Molecular rearrangements of 4‐iminomethyl‐1,2,3‐triazoles. Replacement of 1‐aryl substituents in 1H‐1,2,3‐triazole‐4‐carbaldehydes
Authors: L'abbé Gerrit , Bruynseels Maria , Delbeke Pieter , Toppet Suzanne
Published: March 2009

The two structural isomers, 4 and 5, of 1‐substituted‐4‐iminomethyl‐1,2,3‐triazoles are interconvertible when heated in dimethyl sulfoxide at 80°. The equilibrium position depends on the electronic properties of the R‐substituent, favoring 5 for R = alkyl, benzyl and anisyl, and 4 for p‐chlorophenyl and p‐nitrophenyl. An interesting application is the synthesis of 1‐alkyl‐1,2,3‐triazole‐4‐carbaldehydes from 1‐phenyl‐1,2,3‐triazole‐4‐carbaldehyde by Scheme I. The hydrazones 4ij and the oxime 4k do not rearrange due to an unfavorable Z‐configuration around the C  N bond, whereas the acyloximino derivative 4m is converted into the nitrile 11. The structures of the products have been fully characterized by 13C nmr spectroscopy and the mechanistic details of the rearrangement are discussed.
Preparation of β‐hydroxysulfides from 1,2,3‐thiadiazoles. Comparison of the effect of phenylmagnesium bromide on α‐Thio‐ and α‐selenoketones
Authors: Ganjian Iraj
Published: March 2009

Base decomposition of 4‐substituted‐phenyl‐1,2,3‐thiadiazoles at 78° resulted in 2‐(4‐substituted‐phenyl)‐ethynylthiolate anions which were immediately reacted with α‐bromoketones to give a series of α‐(2‐[4‐substituted‐phenyf]ethynyl) thioketones. Unlike the selenophilic reaction of the Grignard reagents with α‐selenoketones, the carbonyl group was the site of nucleophilic attack and the reaction of the α‐thioketones with phenylmagnesium bromide gave the corresponding β‐hydroxysulfides. The difference in mode of action toward the Grignard reagents was attributed to the difference in the bond strengths between carbon and the heteroatoms.
Synthesis of diastereomeric ketoconazole analogs
Authors: Chapman David R. , Bauer Ludwig , Waller Donald P. , Zaneveld Lourens J. D.
Published: March 2009

Syntheses of trans‐isomers of ketoconazole, and the corresponding des‐acetyl, 1‐methyl‐, 1‐formyl and 1‐methanesulfonyl analogs were investigated. These isomers, along with the corresponding cis‐diastereomers were characterized by their carbon‐13 nmr spectra.
Synthesis and preliminary biological evaluation of 5‐fluoro‐5,8‐dideazaisoaminopterin
Authors: Tomažič Alenka , Hynes John B. , Gale Glen R. , Freisheim James H.
Published: March 2009

The new folate antagonist, 5‐fluoro‐5,8‐dideazaisoaminopterin was synthesized in four steps beginning with 2,4‐diamino‐5‐fluoroquinazoline. It was found to be a potent inhibitor of human dihydrofolate reductase. Against L1210 leukemia in mice, 5‐fluoro‐5,8‐dideazaisoaminopterin was equiactive with methotrexate at approximately one half of the total dose employed.
A facile synthesis of 5,14‐methano‐16‐oxo‐1,5,6‐benzoxadiazonino[3,4‐b]quinoxalines by a 1,3‐dipolar cycloaddition reaction and an intramolecular alcoholysis
Authors: Kurasawa Yoshihisa , Kim Ho Sik , Katoh Ritsuko , Kawano Tae , Takada Atsushi , Okamoto Yoshihisa
Published: March 2009

The reaction of the hydrazones 5a‐c with 2‐chloroacrylonitrile gave the 1,2‐diazepino[3,4‐b]quinoxaline hydrochlorides 6a‐c, which were converted into the 5,14‐methano‐16‐oxo‐1,5,6‐benzoxadiazonino[3,4‐b]‐quinoxalines 7a‐c, respectively.
Ring‐opening reaction in acidic conditions of tetraazapentalene derivatives containing a hypervalent sulfur
Authors: Tomura Masaaki , Matsumura Noboru , Mori Osamu , Chikusa Hisashi , Kamitani Shigeki , Inoue Hiroo
Published: March 2009

The 10‐S‐3 type tetraazapentalene derivatives in acidic conditions were converted to the ring‐opeining products, 1,3‐disubstituted perhydropyrimidin‐2‐ones, in high yields with the release of a hypervalent sulfur.
Synthesis of 2,3,11,12,20,21,29,30‐octadodecylthio‐2,3‐naphthalocyanines
Authors: Kitahara Kiyoshi , Asano Toyofumi , Hamano Ken‐ichi , Tokita Sumio , Nishi Hisao
Published: March 2009

The title compounds were synthesized. They were soluble in organic solvents and their Q bands showed bathochromic shifts compared with unsubstituted 2,3‐naphthalocyanines.
Reduction of the 1,2,5‐thiadiazole ring of 3,6:12,15‐di‐1,4‐benzo[6.6](3,4)‐1,2,5‐thiadiazolo‐ and 3,5:11,13‐di‐1,3‐benzo‐[6.6](3,4)‐1,2,5‐thiadiazolocyclophanes. Selective preparation of cis‐ and trans‐[23]cyclophane‐1,2‐diacetoamide
Authors: Hatta Taizo , Mataka Shuntaro , Tashiro Masashi , Numano Katsutoshi , Suzuki Hiroshi , Tori‐I Akiyoshi
Published: March 2009

The effect of the [2.2.2]cyclophane ring structure on the reduction of 1,2,5‐thiadiazole ring incorporated in cyclophanes 1a‐c and 2a‐c was investigated. When reduced by sodium metal in ethanol followed by acetylation, para[23]cyclophane 1 gave a mixture of the expected cis‐ and trans‐diamides, 3 and 4, in which 4 was the major product. On the other hand, reduction of 1 with lithium aluminum hydride proceeded in a cis‐selective manner and gave 3 as a major product after a treatment of the reduced products with acetic anhydride. The reduction of metacyclophane 2, which is less strained than 1, proceeded exclusively in cis‐fashion and a subsequent treatment of the reduction product with acetic anhydride gave only cis‐diamide 6.
Synthese de pyrrolo[1,2‐a]quinoleines
Authors: Bouyazza Lahboub , Lancelot Jean‐Charles , Rault Sylvain , Robba Max
Published: March 2009

Les 4‐acétoxy pyrrolo[1,2‐a]quinoléines 26‐30 sont accessibles par cyclisation des acides 2‐(1‐pyrrole)phénylacétiques 21‐25 par chauffage dans l'anhydride acétique. Les chlorures d'acides 11‐15 constituent les intermédiaires permettant l'accès aux 2‐(1‐pyrrolyl) diazoacétophénones 16‐20 et aux acides phénylacétiques. Les spectres de rmn confirment la structure des dérivés obtenus.
4,5,6,7‐Tetrahydro‐1H‐imidazo[4,5‐c]pyridine‐6‐carboxylic acids (spinacines)
Authors: Klutchko Sylvester , Hodges John C. , John Blankley C. , Colbry Norman L.
Published: March 2009

New derivatives of the naturally occurring amino acid 4,5,6,7‐tetrahydro‐1H‐imidazo[4,5‐c]pyridine‐6‐carboxylic acid (spinacine) are reported. These include amide, ester, 5‐alkyl and acyl, and regiospecificNim‐alkyl and aralkyl derivatives. Synthesisviathe Pictet‐Spengler reaction onNim‐substituted histidines is described. Cyclic hydantoin derivatives of spinacines are included.
Nouvelle méthode d'accès aux benzo[h]furo[3,2‐c]quinoléines, analogues isostériques des benzo[c]phénanthridines
Authors: Duval O. , Mavoungou Gomès L.
Published: March 2009

Une synthèse originale des benzo[h]furo[3,2‐c]quinoléines est décrite. L'hydrogénation des dérivés d'addition diénique 5 conduit aux composés 6. Leur pyrolyse suivie d'une saponification permet d'isoler les diacides 9. Les lactames 12 sont alors obtenus par chauffage en présence d'acétate d'ammonium et d'acide acétique anhydres et les lactones 10 par ébullition dans l'anhydride acétique. Des dérivés du noyau benzo[h]‐furo[3,2‐c]quinolone sont alors obtenus par modulation de la fonction acide carboxylique introduite en position 7 ou par fonctionnalisation de la position 6.
Novel 7‐substituted quinolone antibacterial agents. Synthesis of 7‐alkenyl, cycloalkenyl, and 1,2,3,6‐tetrahydro‐4‐pyridinyl‐1,8‐naphthyridines
Authors: Laborde Edgardo , Kiely John S. , Lesheski Lawrence E. , Schroeder Mel C.
Published: March 2009

A convergent synthesis of 1,8‐naphthyridine antibacterials bearing a carbon‐carbon bonded, acyclic or cyclic vinyl substituent at the C‐7 position has been achieved. The synthetic methodology is based upon the palladium‐catalyzed cross coupling of a 7‐chloro‐1,8‐naphthyridine with an appropriately substituted organotin reagent.
Reactions of 2,3‐disubstituted 6,7‐dihydro‐5H‐2a‐thia(2a‐SIV)‐2,3,4a,7a‐tetraazacyclopent[cd]indene‐1,4(2H,3H)‐dithiones with isothiocyanates and isocyanates
Authors: Tomura Masaaki , Mori Osamu , Matsumura Noboru , Inoue Hiroo
Published: March 2009

12π‐Tetraazapentalenes, 2,3‐disubstituted 6,7‐dihydro‐5H‐2a‐thia(2a‐SIV)‐2,3,4a,7a‐tetraazacyclopent‐[cd]indene‐1,4(2H,3H)‐dithiones, 1 and 7, reacted with excess alkyl or aryl isothiocyanates and isocyanates to afford mono‐ and di‐alkyl or aryl substituted tetraazapentalene derivatives which have the thiocarbonyl and carbonyl groups.
Polycyclic N‐hetero compounds. XXXVI. Syntheses and antidepressive evaluation of 11,13,15,17‐tetraazasteroids and their 17‐oxides
Authors: Hirota Takashi , Sasaki Kenji , Yamamoto Hiroshi , Nakayama Taiji
Published: March 2009

Syntheses of 11,13,15,17‐tetraazasteroids, their B‐homologues, and 17‐oxide derivatives are described. Antidepressive evaluation of these compounds and their precursors were screened by inhibitory action of reserpine‐induced hypothermia.
Synthesis of unsymmetrical diheteroarylbenzenes: Benzoazole and quinazoline derivatives
Authors: Garín Javier , Meléndez Enrique , Merchán Francisco L. , Merino Pedro , Orduna Jesús , Tejero Tomás
Published: March 2009

Four different types of structures, namely 8, 14, 17 and 18 have been prepared for the first time. No more than five steps are needed to synthesize them using 4‐nitroaniline as starting material. In order to confirm the proposed structures, some independent syntheses have been carried out.
Synthesis of new imidazole derivatives as potential inhibitors of thromboxane synthetase. II
Authors: Banfi Aldo , Benedini Francesca , Sala Alberto
Published: March 2009

The preparation of new imidazole derivatives containing ether or amide functions into the side chain, is reported starting from the suitable imidazole intermediates.
The synthesis of some benzo[d,d']diisothiazoles
Authors: Mckinnon David M. , Abouzeid Azza A.
Published: March 2009

Four examples of benzo[d,d']diisothiazoles have been made by cyclisation of appropriate o‐alkylthioaryl‐ketoximes by simultaneous or consecutive ring formation.
Intermolecular 1,3‐dipolar cycloaddition of benzonitrile oxide to 2H‐1,3‐benzothiazines and hexahydro‐4H‐1,3‐benzothiazine
Authors: Szabó János , Fodor Lajos , Bernáth Gábor , Talpas Gizella S. , Bani‐Akoto Ernest , Sohár Pál
Published: March 2009

The thermal [3 + 2] intermolecular cycloaddition of benzonitrile oxide to 2H‐1,3‐benzothiazines 1a‐g and hexahydro‐4H‐1,3‐benzothiazine (5) gives new types of tricyclic angularly and linearly condensed 1,2,4‐oxadiazolo‐1,3‐benzothiazine‐fused nitrogen‐bridgehead ring systems 2a‐g, 6.
An anomalous reaction of 7‐chloro‐2‐hydrazono‐5‐phenyl‐1,2‐dihydro‐3H‐1,4‐benzodiazepine with sodium acetate and 1,1′‐carbonyldiimidazole
Authors: Banks William R. , Hawi Amale A. , Digenis George A.
Published: March 2009

The addition of 7‐chloro‐2‐hydrazono‐5‐phenyl‐1,2‐dihydro‐3H‐1,4‐benzodiazepine 3 to a mixture of sodium acetate and 1,1′‐carbonyldiimidazole 1 at room temperature gave, in moderate yields, carbonyl‐1,1′‐bis[7‐chloro‐5‐phenyl‐1,2‐dihydro‐3H‐1,4‐benzodiazepin‐2‐ylidene hydrazone] 7 instead of the expected 2‐acetylhydrazono‐7‐chloro‐5‐phenyl‐1,2‐dihydro‐3H‐1,4‐benzodiazepine 4.
Cycloaddition von benzothiet an oxime, oximether und oximester
Authors: Meier Herbert , Saul Klaus , Mengel Rudolf , Niedermann Hans‐Peter
Published: March 2009

Benzothiete 1 generates by thermal ring opening an 8π electron system 2 which undergoes [8π + 2π] cycloaddition reactions with the oxime systems 3a‐g. In accordance with the FMO theory the 1,3‐thiazine derivatives 4a‐g are formed in a regiospecific and 4f additionally in a stereospecific manner. The O‐acylated adducts 4h‐j enter the same cycloaddition; however, an elimination reaction 4 ← 5, 6 can provoke the addition of a second benzothiete, yielding the tetracyclic compounds 7j, and 8i,j.
Studies on silyl furans. II. Halodesilylation of 2‐trimethylsilyl‐3,4‐bis(methoxycarbonyl)furans
Authors: Nakayama Koukji , Harigaya Yoshiharu , Okamoto Hiroshi , Tanaka Akira
Published: March 2009

Reactions of 2‐trimethylsilyl‐3,4‐bis(methoxycarbonyl)furans 1a,b with sulfuryl chloride, bromine, and iodine monochloride in acetonitrile afforded the corresponding 2‐halo‐3,4‐bis(methoxycarbonyl)furans 2a‐f via chloro‐, bromo‐, and iododesilylation in good yields, respectively. However, the reaction of 1a with bromine in carbon tetrachloride mainly gave 2‐bromo‐ 2b and 2‐bromo‐5‐trimethylsilyl‐3,4‐bis(methoxycarbonyl)furan (3) in 37% and 45% yields. Similarly, the reaction of 1a with iodine monochloride afforded 1a, 2‐chloro‐ 2a and 2‐iodo‐3,4‐bis(methoxycarbonyl)furan (2c) in 50%, 27%, and 23% yield.
Stereochemistry of cycloadducts from 3,4‐dihydro‐6,7‐dimethoxyisoquinoline ylide and olefins
Authors: Janke Frank , Himmelreich Uwe , Tóth Gábor , Tischer Thomas , Kádas István , Bende Zoltán , Töke László
Published: March 2009

Cycloaddition of 2‐methoxycarbonylmethyl‐3,4‐dihydro‐6,7‐dimethoxyisoquinolinium ylide with various E‐substituted olefin type dipolarophiles gave products of 10b‐H, 1‐H, 2‐H and 3‐H α,α,β,β‐relative configuration with one exception. Relative configuration of compounds prepared has been determined by 1D and 2D 1H and 13C nmr techniques. It has also been detected that a triple trans ⇌ cis‐1 ⇌ cis‐2 conformation equilibrium exists in solution.
Reaction of α,β‐unsaturated carbodiimides with enamines leading to fused pyridine derivatives
Authors: Noguchi Michihiko , Onimura Kenjiro , Isomura Yuji , Kajigaeshi Shoji
Published: March 2009

The treatment of (5,5‐dimethyl‐3‐oxo‐1‐cyclohexenyl)iminotriphenylphosphorane (2) with phenyl isocyanate (3a) gave N‐(5,5‐dimethyl‐3‐oxo‐1‐cyclohexenyl)‐N'‐phenylcarbodiimide (4a) in situ. The reaction of 4a with enamines proceeded smoothly to afford the pyridine ring formation with the elimination of amine. This means that 4a is regarded as a new class of 2‐aza‐1,3‐butadiene. The scopes and limitation of this reaction are also discussed.
Syntheses of tetraoxaquaterene derivatives
Authors: Tanaka Sanae , Tomokuni Hidehiko
Published: March 2009

Several new dimethyl and tetramethyl tetraoxaquaterenes, 3d and 3e, have been prepared in order to synthesize the oxygen analogues of porphyrin. The reaction between furan and a ketone using an acidic catalyst gave the cyclic tetramer, tetraquaterene, and oligomers. On the other hand, in the case of furan and an aldehyde, only linear oligomers were isolated. The condensation of furan‐containing dimers with carbonyl compounds, both ketone and aldehyde, except formaldehyde, gave the tetraoxaquaterene. In the case of formaldehyde, the yield of cyclic tetramer was negligible.
Sulfenylation of some pyrroles and indoles
Authors: Gilow Helmuth M. , Brown Christopher S. , Copeland John N. , Kelly Keith E.
Published: March 2009

Methylsulfenylation of 1‐substituted pyrroles and indoles was observed using 1‐(methylthio)morpholine and an acid catalyst or with methylsulfenyl chloride and excess pyridine. 1‐Substituents which are activating or weakly deactivating towards electrophilic substitution such as alkyl, 2‐cyanoethyl, dimethylamino, trialkylsilyl, 2‐chloroethyl and 2‐phenylsulfonylethyl were used. The 2‐chloroethyl and 2‐phenylsulfonylethyl groups which can be removed with a strong base can be used to obtain 1H‐methylthiopyrroles and indoles. 1‐Phenylsulfonyl and 1‐acetyl substituents are too strongly deactivating for these sulfenylations to be successful. Mono and disubstituted pyrroles and monosubstituted indoles can be isolated from these reactions, however, because the methylthio group is activating towards electrophilic substitution the main advantage of these reactions is the synthesis of tri and tetrasubstituted pyrroles and disubstituted indoles. 1‐Methyl‐2,3,4,5‐tetra‐methylthiopyrrole and 1‐methyl‐2,3‐dimethylthioindole are oxidized to the corresponding 3,4‐disulfoxide and 3‐sulfoxide and with excess oxidizing agent to the tetrasulfone and disulfone, respectively.
Regioselectivity in SNH reactions of some 3‐nitro‐1,8‐naphthyridines with chloromethyl phenyl sulfone
Authors: Grzegozek Maria , Woźniak Marian , Barański Andrzej , Van Der Plas Henk C.
Published: March 2009

A number of 2‐X‐3‐nitro‐1,8‐naphthyridines (X= H,D,OH,Cl,NH2, OEt) react with the anion of chloromethyl phenyl sulfone exclusively into 2‐X‐3‐nitro‐4‐(phenylsulfonylmethyl)‐1,8‐naphthyridines in high yield. The reaction is found by quantum chemical calculations to be controlled by the interactions of the HOMO of the nucleophile with the LUMO of the substrate, and not by charge.
Studies on the reaction of 2‐aminoacetophenone with thiophosgene
Authors: Morgenstern Olaf , Richter Peter , Rouvinen Juha , Mälkönen Pentti J. , Vainiotalo Pirjo , Hänninen Kari , Ahlgrén Markku , Vepsäläinen Jouko
Published: March 2009

The reaction of 3‐ and 4‐aminoacetophenone with thiophosgene in a chloroform‐water‐calcium carbonate mixture at room temperature results in good yields of the related, known isothiocyanates. At first, however, we failed in all our attempts to produce 2‐isothiocyanatoacetophenones with this reaction. Closer inspection of the reaction showed, that the product distribution depends upon the concentration of hydrogen ions pro‐ducted and on the reaction time. When the reaction was followed with thin‐layer chromatography, it was observed that the isothiocyanates formed first. In the further course of the reaction, they were converted to the 4‐methylene‐2‐oxo‐3,1‐benzothiazines by the action of protons. The final products of the reaction were the 4‐(3,1‐benzothiazin‐4‐yl)‐methylene‐3,1‐benzothiazines, formed from the monomer in a dimerization process. Depending upon the time the protons were removed from the reaction mixture, different products could be isolated.
Some novel S‐mono‐ and S,S'‐unsymmetrical di‐substituted derivatives of 1,3,4‐thiadiazoledithione
Authors: Katritzky Alan R. , Borowiecka J. , Fan Wei‐Qiang , Brannigan Lawrence H.
Published: March 2009

Preparations of S‐mono‐ and unsymmetrical S,S‐di‐substituted derivatives of 1,3,4‐thiadiazole‐2,5‐dithione are described.
Studies on pyrrolidones. Convenient syntheses of methyl, methylN‐methyl‐ and methylN‐methoxymethylpyroglutamate
Authors: Cauliez Pascal , Rigo Benoǐt , Fasseur Dominique , Couturier Daniel
Published: March 2009

Facile methods to prepare methyl pyroglutamate (2), methylN‐methylpyroglutamate (1) and methylN‐methoxymethylpyroglutamate (7) inone‐stepfrom pyroglutamic acid are described.
Synthesis and binding activity of 4‐azanicotine
Authors: Howell Amy R. , Martin W. R. , Sloan J. W. , Smith Walter T.
Published: March 2009

4‐Azanicotine (1) has been synthesized by the cyclopropylimine rearrangement. A study of several Lewis acids as possible catalysts for the NMF‐mediated cyclopropyl imine rearrangement of cyclopropyl‐2‐pyrazinylmethanone (4) indicated that both aluminum chloride and magnesium chloride are suitable catalysts, lithium bromide shows only a trace of activity and zinc chloride, titanium tetrachloride, and titanium tetra‐isopropoxide show no activity. Compound 1, in which the aromatic ring is less basic than in nicotine, and 6‐aminonicotine (5), in which the aromatic ring is more basic, have been compared with the binding properties of nicotine in the P2 rat brain preparation. Compound 1 binds with an affinity very similar to that of nicotine at two of the receptor sites, 5 binds at these sites but with a lower affinity. Unlike nicotine, 1 and 5 do not bind at the very high affinity ‘upregulatory’ site.
Synthesis of 2‐ and 4‐substituted 5,12‐dihydroxy‐6,11‐dioxo‐1‐azanaphthacenes from 2‐aminoquinizarine
Authors: Chauhan S. M. S. , Gupta Mamta , Nizar P. N. H.
Published: March 2009

The reaction of 2‐aminoquinizarine with α,β‐unsaturated carbonyl compounds in presence of 10N‐hydrochloric acid gives 2‐ and 4‐substituted 5,12‐dihydroxy‐6,11‐dioxo‐1‐azanaphthacenes.
Ring transformations of heterocycles. Part 1. Transformation of 4‐amino‐Δ2‐1,2,4‐oxadiazolines into 1,3,4‐oxadiazoles
Authors: El‐Abadelah M. M. , Nazer M. Z. , Hussein A. Q. , Awadallah A. M. , Rademacher P. , Woydt M.
Published: March 2009

3‐Aryl‐4‐amino‐δ2‐1,2,4‐oxadiazolines 3 and their N‐chloroacetyl derivatives 4, upon treatment with chloroacetic anhydride in refluxing toluene, afford 2‐chloromethyl‐5‐aryl‐1,3,4‐oxadiazoles 5, suggesting the conversion sequence 3 → 4 → 5. The generality of the new ring transformation 4 → 5 is supported similar conversion of other 4‐(acylamino)‐1,2,4‐oxadiazolines 8 to 1,3,4‐oxadiazoles 9.
New peptide synthesis using the ozonolysate of 2‐(1‐phthalimido)alkyl‐5‐phenyloxazoles
Authors: Kashima Choji , Okada Rieko , Arao Hideki
Published: March 2009

It was proved that 2‐(1‐phthalimido)alkyl‐5‐phenyloxazoles 3 were useful synthetic intermediates for peptide synthesis, where the oxazole ring acted as not only the carboxyl protecting group but also the carboxyl activating group upon ozonolysis.
Action of (2‐benzothiazolyl) methyllithium with organic polar functions
Authors: Costa Maria Virginia , Brembilla Alain , Roizard Denis , Lochon Pierre
Published: March 2009

(2‐Benzothiazolyl) methyllithium reacts quickly at low temperature (‐78°) with a variety of organic electrophiles like aldehydes, ketones, carboxylic esters, nitriles and acylchlorides. Such reactions lead to an easy introduction of alcohol, keto‐enol or amine‐enamine functional groups in extracyclic position with a stereoselective preference. These polyfunctional compounds whose synthesis is difficult by other pathways, are interesting, in particular, because of their ability to form intramolecular hydrogen bonds.
Side‐chain chlorination of methylquinolines
Authors: Kóródi Ferenc
Published: March 2009

Methylquinolines 1–4 were chlorinated by heating with phosphorus pentachloride in chlorobenzenes to side‐chain halogen derivatives 5–14. Methyl groups of compounds 1–4 can be chlorinated to chloromethyl, dichloromethyl or trichloromethyl groups depending on their positions and the reaction conditions.
A macrocyclic amide from dehydrochlorination of indole‐3‐carbonyl chloride
Authors: Oliver J. E. , Waters R. M. , Lusby W. R. , Flippen‐Anderson J. L.
Published: March 2009

Indolyl‐3‐ketene 3 was generated from two precursors and was found to form a symmetrical tetramer 4 consisting of a sixteen‐membered ring amide. The tetramer was characterized by mass spectrometry, infrared, 1H and 13C‐nmr spectroscopy, and single crystal X‐ray crystallography.
Unexpected chlorination products as a result of self‐diazotization of three amino‐dinitro‐2,3,4,5‐tetrahydrobenzo[b][1,4]dioxocin Derivatives
Authors: Takakis Ioannis M. , Hadjimihalakis Phaedon M.
Published: March 2009

Diazotization of the dinitroaryl amines 1 with nitrous acid (generated from hydrochloric acid and sodium nitrite) furnished the unexpected chloronitro azides 3 as a result of self‐diazotization. Subsequent heating of 3 in ethylene glycol afforded the corresponding chloro‐nitro amines 5 and/or the deaminated products 4. Some mechanistic aspects of these transformations are discussed.
Synthesis of 4H‐1,4‐benzothiazine 1‐oxide and 1,1‐dioxide. Analogs of quinolone antibacterial agents
Authors: Culbertson Townley P.
Published: March 2009

4‐Cyclopropyl‐5,7‐difluoro‐6‐(4‐methyl‐1‐piperazinyl)‐4H‐1,4‐benzothiazine‐2‐carboxylic acid 1‐oxide (2c) and 4‐cyclopropyl‐5,7‐difluoro‐6‐(4‐methyl‐1‐piperazinyl)‐4H‐1,4‐benzothiazine‐2‐carboxylic acid 1,1‐dioxide (2d) were prepared and assayed for antibacterial activity and inhibition of DNA gyrase.