bluuebunny/crossref_metadata_2025 huggingface dataset:
Nucleophilic vinylic substitution of halocoumarins and halo‐l,4‐naphthoquinones with morpholine
Authors: Oh Changsok , Yi Inwoo , Park Kyong Pae
Published: March 2009

Reactions of morpholine with 4‐halocoumarins 1, 3‐halocoumarins 3, and 2‐halo‐l,4‐naphthoquinones 8 yield two different products, one where halogen is replaced by a nucleophile at the same carbon and the other where the nucleophile is attached to the vicinal carbon away from that bearing the halogen. It is considered that reactions proceeds through nucleophilic vinylic substitution by comparision of the reaction products and deuterium exchange experiments. Plausible mechanisms for these routes are suggested.
The reaction of N,N‐dimethyldichloromethyleniminium chloride (phosgeniminium chloride) with 6‐N‐arylaminouracils. A new and convenient “one pot” synthesis of l,3‐dimethyl‐5‐ dimethylaminopyrimido[4,5‐b]quinoline‐(1H,3H)‐2,4‐diones, 1,3‐dimethyl‐5‐chloropyrimido[4,5‐b]quinoline‐(1H,3H)‐2,4‐diones and 3‐methyl‐10‐alkyl‐5‐chloropyrimido[4,5‐b]quinoline‐(3H,10H)‐2,4‐diones (3‐methyl‐10‐alkyl‐5‐chloro‐5‐deazaflavins)
Authors: Kokel Bruno
Published: March 2009

The 1,1,1‐tricondensation of N,N‐dimethyldichloromethyleniminium chloride (phosgeniminium chloride) with various 1,3‐dimethyl‐6‐N‐arylaminouracils and 3‐methyl‐6‐N‐(alkylaryl)aminouracils, which gives only 5‐dimethylaminopyrimido[4,5‐b]quinoline‐2,4‐diones when performed in the presence of triethylamine, affords also the corresponding 5‐chloropyrimido[4,5‐b]quinoline‐2,4‐diones, including 3‐methyl‐10‐alkyl‐5‐chloro‐5‐deazaflavins, when carried out in the absence of a base and under appropriate solvent and temperature reaction conditions. With regard to the selectivity of the transformation, these reaction conditions have been found to be especially dependent on the nature and the position of the starting arylaminouracil substituents.
Remarkable selectivity in the reaction of l‐trityl‐2‐lithioimidazoles with t‐butyl halogenoacetates
Authors: Coutts Ian G. C. , Jieng Shende , Khandelwahl Ghanshyam D. , Wood Michael L.
Published: March 2009

2‐Lithio‐1‐triphenylmethylimidazoles react with t‐butyl halogenoacetates to give a variety of products, the nature of which is cleanly determined by the halogen atom. With chloroacetate the products are chloromethyl ketones, while bromacetate gives di‐t‐butyl imidazolesuccinates, and iodoacetate yields iodoimidazoles. In each case 50% of the parent triphenylmethylimidazole is recovered from the reaction. When the triphenylmethyl substituent is replaced by the N,N‐dimethylsulfamoyl group, reaction with bro‐moacetate is suppressed, but t‐butyl chloroacetate and iodoacetate again give chloroketones and aryl iodides respectively.
Synthesis of oligonucleotides containing 7‐(2‐deoxy‐β‐d‐erythro‐pentofuranosyl)guanine and 8‐amino‐2′‐deoxyguanosine
Authors: Rao T. Sudhakar , Durland Ross H. , Revankar Ganapathi R.
Published: March 2009

The synthesis of oligonucleotides containing 7‐(2‐deoxy‐β‐D‐erythro‐pentofuranosyl)guanine and 8‐amino‐2′‐deoxyguanosine was accomplished. The viable intermediate N2‐isobutyryl‐7‐(2‐deoxy‐β‐D‐erythro‐pentofuranosyl)guanine (6) was prepared via a four step deoxygenation procedure from 7‐β‐D‐ribofuranosylguanine (1). The 5′‐hydroxyl group of 6 was protected as 4,4′‐dimethoxytrityl ether and then converted to the target phosphoramidite (8) via conventional phosphitylation procedure. The amino groups of 8‐amino‐2′‐deoxyguanosine (9) were protected in the form of N‐(dimethylainino)methylene functions to give the protected nucleoside 10, which was subsequently converted to the target phosphoramidite 12 via dimethoxytritylation followed by phosphitylation. The phosphoramidites 8 and 12 were incorporated into a 26‐mer and a 31‐mer G‐rich oligonucleotide using solid‐support, phosphoramidite methodology. Analysis of antiparallel triplex formation by the oligonucleotides containing 7‐(2‐deoxy‐β‐D‐erythro‐pentofura‐nosyl)guanine in place of 2′‐deoxyguanosine showed no enhancement in triple helix formation.
Synthesis of N‐substituted 3‐hydroxy‐2‐methyl‐4‐pyridones and ‐pyridonimines
Authors: Färber M. , Osiander H. , Severin T.
Published: March 2009

Carbohydrates with 1,4 glycosidic bonds like maltose, lactose, dextrin or starch react with primary amines as well as amino acids or proteins to give i.e. 3‐hydroxy‐2‐methyl‐4‐pyridones 5 and 3‐hydroxy‐2‐methyl‐4‐pyridonimines 7. A generally applicable synthesis of compounds of this type is described. The pyridones 5 and pyridonimines 7 are strongly complexing agents. Molybdenum‐derivatives, for instance, are suitable as fairly stable oxidation catalysts.
Synthesis and photophysical properties of fluorescent 2‐aryl‐1,3‐dialkylbenzimidazolium ions and a l‐alkyl‐2‐arylbenzimidazole with excited state intramolecular proton‐transfer
Authors: Kauffman Joel M. , Khalaj Ali , Litak Peter T. , Novinski John A. , Bajwa Gurdip S.
Published: March 2009

To improve the solubility, photostability and fluorescence quantum yield (Φ) of 2‐arylbenzimidazolium ions the N‐1 hydrogen was replaced by an alkyl group before N‐3 was quatemized; this substitution did not reduce Φ, proving the absence of steric inhibition to attainment of coplanarity in the excited state. A related symmetrical 2,2′‐arylenebis(1,3‐dimethyldibenzimidazolium ion) had Φ = 0.86. The related 2,5‐bis(1‐methyl‐2‐benzimidazolyl)phenol had Φ = 0.38 at 22° as well as a very large Stokes' shift due to proton‐transfer. These findings supported a new insight into the electron distribution of the first excited singlet state of oligophenylenes. The compounds are of interest as laser dyes and scintillation fluors.
Formation of pyrimidine‐5‐carboxaldehydes, 1‐aminoethylene‐2,2‐dicarboxaldehyde and 2‐amino‐4‐anilino‐1,3,5‐triazine from triformylmethane and amidines
Authors: Takagi Kaname , Bajnati Abdelilah , Hubert‐Habart Michel
Published: March 2009

Triformylmethane (1) reacted with benzamidine, guanidine and S‐methylisothiourea to give the corresponding 2‐substituted pyrimidines‐5‐carboxaldehydes. However, reactions of 1 with acetamidine (or for‐mamidine) and phenylbiguanide gave the unexpected 1‐aminoethylene‐2,2‐dicarboxaldehyde (5) and 2‐amino‐4‐anilino‐1,3,5‐triazine (9), respectively.
Synthesis of C‐4 substituted pyrimidine nucleoside analogs. Preparation of several 4‐(2‐oxoalkylidene)‐2(1H)‐pyrimidinone ribonucleosides
Authors: Acevedo Oscar L. , Andrews Robert S. , Dunkel Martin , Dan Cook P.
Published: March 2009

A series of 4‐(1‐alkynyl)‐2(1H)‐pyrimidinone ribonucleosides were synthesized from the Pd‐catalyzed coupling of terminal alkynes to the 4‐chloropyrimidin‐2‐one ribonucleoside (2). These compounds were hydrated, using three different methods, to afford the 4‐(2‐oxoalkylidene)‐2(1H)‐pyrimidinones. The 4‐enol‐pyrimidin‐2‐one structure of the title compounds offers functional groups with the potential for Watson‐Crick hydrogen bonding.
1,4‐Benzodioxin‐2(3H)‐one and some of its derivatives
Authors: Sampson Peter , Crook Michelle , Piórko Adam
Published: March 2009

The methods of synthesis of 1,4‐benzodioxin‐2(3H)‐one have been reexamined. Frequently quoted in the literature the method of Ghosh has been found to give impure (2‐hydroxyphenoxy)acetic acid rather than the lactone. Using various methods some simple derivatives of the title lactone substituted in the benzene ring have been prepared and characterized. The bromination of the lactone with NBS gives predominantly 7‐bromo‐1,4‐benzodioxin‐2(3H)‐one under electrophilic conditions, while 6‐bromo‐1,4‐benzodioxin‐2(3H)‐one is obtained as a major isomer under photolytic conditions.
Synthesis and characterization of a novel unsymmetrical metal‐free phthalocyanine with donor‐acceptor substituents
Authors: Liu Yunqi , Zhu Daoben , Wada Tatsuo , Yamada Akira , Sasabe Hiroyuki
Published: March 2009

A novel unsymmetrical metal‐free phthalocyanine with a nitro group as an acceptor substituent and three t‐butyl groups as donor groups, namely nitro‐tri‐t‐butylphthalocyanine (NtBuPc) was synthesized for the first time by mixed condensation of two corresponding diiminoisoindolines. The NtBuPc can be separated by common column chromatography on silica gel using chloroform‐hexane as the elution solvent. The structure was confirmed by elemental analysis, nmr, uv‐vis, ir and mass spectroscopy. No contamination of either symmetrical or other related phthalocyanines was observed.
Self‐condensation of ortho‐hydroxy‐β‐chloro‐β‐nitrostyrenes: Synthesis of some z‐11‐nitromethylene‐11H‐benzofurol[3,2‐b] benzopyrans
Authors: Dauzonne Daniel , Grandjean Cyrille
Published: March 2009

The triethylamine‐promoted self‐condensation of several 2‐(2‐chloro‐2‐nitroethenyl)phenols gives the so far unknown Z‐11‐Nitromethylene‐11H‐benzofuro[3,2‐b][1]benzopyrans.
Synthesis of new v‐triazolopyrimidinium salts
Authors: Bátori S. , Messmer A.
Published: March 2009

New v‐triazolo[1,5‐α]‐ and v‐triazolo[1,5‐c]pyrimidinium salts 12a‐e, 13a‐c have been synthesized via oxidation (i.e. cyclodehydrogenation) of the appropriate pyrimidyl ketone arylhydrazones 3a‐e, 6a‐c using TBB (2,4,4,6‐tetrabromocyclohexa‐2,5‐dien‐1‐one) as the reagent. The arylhydrazones were obtained by standard reactions; the Grignard reaction of 2‐cyano‐ and 4‐cyanopyrimidine 1a,b, 4a‐c gave 2‐pyrimidyl‐ and 4‐pyrimidyl ketones 2a‐e, 5a‐c, which reacted with arylhydrazines to yield the desired ketone arylhydrazones 3a‐e, 6a‐c.
New pyrimidino‐crown ether ligands
Authors: Redd J. Ty , Bradshaw Jerald S. , Huszthy Peter , Izatt Reed M.
Published: March 2009

Eight new macrocyclic ligands containing the pyrimidine subcyclic unit (3‐10, Figure 1) have been prepared. Two of these new crown ethers are chiral. Pyrimidino‐crowns 3‐8 were prepared by treating the di‐tosylate derivative of the appropriate oligoethylene glycol with 4‐methoxy‐5‐raethyl‐2,6‐pyrimidinedimeth‐anol in basic conditions. The yields were in the 30‐50% range giving the crowns as viscous oils. Chiral dimethyl‐substituted pyrimidino‐crown 9 was prepared from 4‐methoxy‐5‐methyl‐2,6‐pyrimidinedimethyl di‐tosylate and chiral dimethyl‐substituted tetraethylene glycol. Treatment of dimethyl 4‐methoxy‐5‐methyl‐2,6‐pyrimidinedicarboxylate with the diamine derivative of chiral dibenzyl‐substituted tetraethylene glycol gave the chiral dibenzyl‐substituted pyrimidino‐crown diamide 10. Starting 4‐methoxy‐5‐methyl‐2,6‐pyrimidinedi‐methanol was prepared by a six step process from acetamidine hydrochloride and diethyl oxalpropionate.
An unexpected product during synthesis of 3‐phenylisoquinoline: Improved preparation of 4‐hydroxy‐3‐phenylisoquinoline
Authors: Sard Howard
Published: March 2009

During repetition of the Bradsher procedure for the preparation of 3‐phenylisoquinoline (1) an unexpected by‐product was isolated, 4‐hydroxy‐3‐phenylisoquinoline (3). This product is likely formed via allylic oxidation of a 1,4‐dihydroisoquinoline intermediate. By minor modification of the reaction conditions, 3 can be obtained in up to 50% yield. This represents a much improved method for the preparation of 3, as compared with previously reported syntheses.
Preparation of 3‐bromo‐2‐methylfuran and 4‐bromo‐2‐methylfuran
Authors: Koyanagi Jyunichi , Yamamoto Katsumi , Nakayama Kouji , Tanaka Akira
Published: March 2009

4‐endo‐5‐exo‐Dibromo‐3‐methyl‐3,6‐endo‐oxyperhydrophthalic anhydride 3b and 4‐exo‐5‐endo‐dibro‐mo‐3‐methyl‐3,6‐endo‐oxyperhydrophtbalic anhydride 3c were isolated from the bromo‐adducts of 3‐methyl‐3,6‐endo‐oxy‐1,2,3,6‐tetrahydrophthalic anhydride 2. When 3b or 3c was heated in quinoline, only 3‐bromo‐2‐methylfuran 4 was obtained from 3b and only 4‐bromo‐2‐methylfuran 5 from 3c.
Haloacetylated enol ethers: 4 [6]. Synthesis of 4‐trihalomethyl‐2‐methylthiopyrimidines
Authors: Madruga Claudia Da C. , Clerici EdÍLia , Marcos A. P.
Published: March 2009

The synthesis of a series of 5‐ and 6‐substituted 4‐trihalomethyl‐2‐methylthiopyrimidines, prepared from the cyclocondensation reaction of β‐alkoxyvinyl tri[fluoro]chloromethyl ketones with 2‐methyl‐2‐thiopseudourea sulfate, are reported. A systematic study to find the best reaction conditions were carried out.
Hydrolysis of 4‐cyano‐1‐ethoxypyrimido[1,6‐a]benzimidazole: Formation of a ynaminonitrile and benzimidazolidines
Authors: Zama Yoshimi , Okamoto Yoshibisa , Takagi Kaname , Kurasawa Yoshihisa , Takada Atsushi
Published: March 2009

The title compound 4 was hydrolyzed to a new type of ynaminonitrile 5 and benzimidazolidines 7 and 9 under acidic or basic conditions. Reaction mechanisms were proposed.
Synthesis of 2‐aryl‐3‐trifluoromethylsulfonylpyrroles
Authors: Barnes Keith D. , Ward Randall
Published: March 2009

A general method for the preparation of 2‐aryl‐3‐trifluoromethylsulfonylpyrroles 2 has been developed. Procedures for the construction of the key enamine intermediates 9 and their cyclizations to pyrroles are reported.
Cyclic imides. 16. Hydroxy and methoxy derivatives of aminophthalimide and phthalhydrazide
Authors: Caswell Lyman R. , Cavasos Gayle
Published: March 2009

Treatment of N‐alkyl derivatives of 3,6‐dichlorophthalimide and 4,5‐dichlorophthalimide with potassium nitrite gave 3‐hydroxy‐6‐nitro‐ and 4‐hydroxy‐5‐nitrophthalimides. The potassium salts of these phenols were alkylated by dialkyl sulfates. The products were reduced to the 3‐amino‐6‐alkoxy‐ and 4‐amino‐5‐alkoxyphthalimides, and the fluorescence emission spectra of these products were measured. Hydrazinolysis of the phthalimides in a toluene medium gave phthalhydrazides. The luminescence spectra of several aminophthalhydrazides were measured. The infrared and proton magnetic resonance spectra of these and of some nitrophthalhydrazides were measured and aspects of these spectra characteristic of phthalhydrazides were identified.
Polyfunctional pyridines from nitroacetamidine and β‐diketones. A useful synthesis of substituted imidazo [4,5‐b] pyridines and related compounds
Authors: Batt Douglas G. , Houghton Gregory C.
Published: March 2009

Nitroacetamidine undergoes a useful cyclocondensation with β‐diketones to produce substituted 2‐amino‐3‐nitropyridines. Use of an acylpyruvate generates hitherto unreported 2‐amino‐3‐nitropyridine‐4‐carboxylates. These may be converted easily to functionalized imidazo[4,5‐b]pyridines and oxazolo‐[5,4‐b]pyridines.
Ring transformations of heterocyclic compounds. XI. 2,4,6‐triarylphenylquinolinium salts from methyl substituted derivatives via (thio)pyrylium ring transformations
Authors: Zimmermann Thomas
Published: March 2009

The preparation of hitherto unknown 2,4,6‐triarylphenyl substituted quinolinium perchlorates 3 from methylquinolinium derivatives 2 by a 2,6‐[C5+C] ring transformation of 2,4,6‐triaryl(thio)pyrylium salts 1/4 in the presence of triethylamine/acetic acid is described. Spectroscopic data of the quinolinium perchlorates 3 and their formation via anhydrobases of the salts 2 are discussed.
Molecular modeling, NMR spectroscopy, and conformational analysis of 3′,4′‐anhydrovinblastine
Authors: Andrews C. Webb , Wisowaty James , Davis Ann O. , Crouch Ronald C. , Martin Gary E.
Published: March 2009

The assignment of the proton spectrum of 3′,4′‐anhydrovinblastine is reported. Assignments are made for several protons for which only approximate assignments were available previously. Homonuclear TOCSY and ROESY spectra were utilized in conjunction with HMQC and HMBC spectra in making the assignment. Correlations in the ROESY spectrum suggested a preferred conformation of the cleavamine (upper) portion of 3′,4′‐anhydrovinblastine in which the 21‐methyl of the 20/21 ethyl group of the vindo‐line (lower) portion is in proximity to the H14′ and 16′‐NH resonances of the cleavamine. In a Monte Carlo search, the global minimal energy structure was oriented with the 16‐methoxyl group oriented toward the H14′ and 16′‐NII resonances. Two other structures, the second and tenth lowest in energy, 0,2 kJ and 8 kJ higher in energy, respectively, brought the 21‐methyl group in proximity to the H14′ and 16′‐NH resonances in a fashion consistent with the ROESY data. The preferred solution conformation of 3′,4′‐anhy‐drovinblastine is consistent with the reported solution conformation of vinblastine.
Total 1H and 13C chemical shift assignment of indolizino[3,4,5‐a,b]‐isoindole and 2‐methylthiobenz[f]imidazo[5,1,2‐c,d]indolizine
Authors: Castle Lyle W. , Tominaga Yoshinori , Castle Raymond N.
Published: March 2009

The 1H and 13C nmr spectral assignment of indolizino[3,4,5‐a,b]isoindole and 2‐methylthiobenz[f]‐imidazo[5,1,2‐c,d]indolizine are described. A concerted interpretation of the HMQC, HMQC‐TOCSY, HMBC and nOe‐difference experiments were used to assign the 1H and 13C resonances of indolizino‐[3,4,5‐a,b]isoindole, whereas for 2‐methylthiobenz[f]imidazo[5,1,2‐c,d]indolizine a concerted interpretation of the COSY, HMQC and HMBC experiments were used to generate spectral assignments.
Synthesis of certain alkenyl purines and purine analogs
Authors: Sudhakar Rao T. , Revankar Ganapathi R.
Published: March 2009

Synthesis of alkenyl derivatives of certain purines and purine analogs is described. Direct alkylation of the sodium salt of 6‐chloropurine (1) either with 1‐bromo‐2‐pentene or 4‐bromo‐2‐methyl‐2‐butene in N,N‐dimethylformamide furnished N‐7, 4a and N‐9, 3a, 3b alkenyl derivatives. Similar alkylation of 2‐amino‐6‐chloropurine (2) provided the corresponding N‐7, 4c‐4e and N‐9, 3c‐3e alkenyl derivatives. Acid hydrolysis of these chloro derivatives 3a‐3e, 4a,c‐e furnished the corresponding alkenyl hypoxan‐thines 6a, 6b and 7a or alkenyl guanines 6c‐6e and 7c‐7e. Treatment of 3a‐3d with thiourea in absolute ethanol provided the corresponding 6‐thio derivatives 5a‐5d. Alkylation of the sodium salt of either purine‐6‐carboxamide (8) or 1,2,4‐triazole‐3‐carboxamide (10) gave mainly one isomer 9a, 9b and 11a, 11b. The direct alkylation of pyrrolo[2,3‐d]pyrimidin‐4(3H)‐one (12) gave N‐3 alkenyl derivatives 13a, 13b, and the N‐7 alkenyl derivatives 16a, 16b have been prepared starting from the 4‐chloro derivative 14. Synthesis of 2‐amino‐7‐(2‐penten‐1‐yl)pyrrolo[2,3‐d]pyrimidin‐4(3H)‐one (19a) has been accomplished starting from 2‐amino‐4‐methoxypyrrolo[2,3‐d]pyrimidine (17). These alkenyl derivatives were found to be devoid of anti‐HCMV activity in vitro.
On the formation of estrone lactam esters of N,N‐bis(2‐chloroethyl)aminocinnamic acid isomers, p‐N,N‐bis(2‐chloroethyl)aminophenylbutyric acid and their antitumor activity
Authors: Catsoulacos P. , Pairas G. , Papageorgiou A.
Published: March 2009

New estrone‐lactam esters, 17α‐aza‐D‐homo‐Δ1,3,5(10)‐estratrien‐3‐ol‐17‐one‐N,N‐bis(2‐chloroethyl)‐aminocinnamic isomers and p‐N,N‐bis(2‐chloroethyl)aminophenylbutyrate have been synthesized and tested in P388 leukemia in vivo and P388 and L1210 leukemias in vitro. The effect of these compounds on SCE rates and on cell kinetics in cultured human lymphocytes was studied also.
Synthesis and characterization of 4‐hydroxy‐3‐phenylprolines
Authors: Sacchi Antonia , De Caprariis Paolo , Mayol Luciano , De Martino Giovanni
Published: March 2009

4‐Hydroxy‐3‐phenylprolines were synthesized via 1‐acetyl‐2,2‐diethoxycarbonyl‐2,3‐dihydro‐3‐phenyl‐1H‐pyrrole. Reversed phase hplc resulted in the isolation of the products which were characterized by 1H and 13C nmr spectroscopy.
Two new indoloquinoline alkaloids from cryptolepis sanguinolenta: Cryptosanguinolentine and cryptotackieine
Authors: Sharaf Maged H. M. , Schiff Paul L. , Tackie Albert N. , Phoebe Charles H. , Martin Gary E.
Published: March 2009

The roots of the indigenous West African shrub Cryptolepis sanguinolenta have proved to be a rich source of indoloquinoline alkaloids. To date, all of the alkaloids isolated have been analogs of indolo[3, 2‐b]quinoline. We now wish to report examples of two new indoloquinoline alkaloids which differ in the fusion of the indole and quinoline rings. The first, cryptosanguinolentine, is an angular indolo[3, 2‐c]quinoline. The second, cryptotackieine, is a linear indolo[2, 3‐b]quinoline system. Both of these families of alkaloids are without precedent from C. sanguinolenta. The structures of both were established through the extensive use of inverse‐detected micro nmr methods.
Hydroxide‐promoted redox reactions in water of α‐Phenyl‐4‐nitro‐benzenemethanol, α‐(p‐Nitrophenyl)‐4‐pyridinemethanol, and α‐(p‐Nitrophenyl)‐4‐Pyridinemethanol N‐Oxide steric inhibition of resonance
Authors: Muth Chester W. , Yang Kaipeen E.
Published: March 2009

α‐Phenyl‐4‐nitrobenzenemethanol (3) reacted with 1 M sodium hydroxide to yield 4, 4′‐dibenzoyl‐azoybenzene (5) (51%), 4‐hydroxy‐4′‐benzoylazobenzene (6) and benzoic acid (12% each), and smaller amounts of 4‐aminobenzophenone and 4‐nitrobenzophenone. Both α‐phenyl‐2‐nitrobenzenemethanol (9) and 3, 5‐dimethyl‐4‐nitrobenzenemethanol (10a) did not react with 1 M sodium hydroxide, presumably due to steric hindrance. α‐(p‐Nitrophenyl)‐4‐pyridinemethanol (14) and its N‐oxide 11 with 1 M sodium hydroxide yielded 4,4′‐diaroylazoxybenzenes 15a and 12a, respectively, 4,4′‐diaroylazobenzenes 15b and 12b, respectively, as well as 4‐hydroxy‐4′‐aroylazobenzenes 16 and 13, respectively. The relative reaction rates were 11 > 14 > 3. Studies with 11 showed that the nitro group is involved in the redox reaction in preference to the N‐oxide group.
Reactions of 1‐aryl‐2,2,2‐trifluoroethanone oximes with tetrasulfur tetranitride: Novel synthesis of 5‐aryl‐5‐trifluoromethyl‐4H‐1,3,2,4,6‐dithiatriazines and 1‐aryl‐2,2,2‐trifluoro‐ethanonylidenaminosulfenamides
Authors: Kim Kil‐Joong , Lee Hyi‐Seung , Kim Kyongtae
Published: March 2009

The reactions of 1‐aryl‐2,2,2‐trifluoroethanone oximes with tetrasulfur tetranitride (S4N4) in toluene at reflux gave 5‐aryl‐5‐trifluoromethyl‐4H‐1,3,2,4,6‐dithiatriazines 2, 1‐aryl‐2,2,2‐trifluoroethanonyliden‐aminosulfenamides 3 and sulfur in 0–37%, 7–53%, and 2–41% yields, respectively. Treatment of 2 with tributyltin hydride in the presence of azobisisobutyronitrile in benzene at 80° afforded 3 in excellent yields.
Syntheses of 8‐aminoimidazo[4′,5′:5,6]pyrido[2,3‐d]pyrimiciines: Linear tricyclic analogs of adenine
Authors: Harris Philip A. , Pendergast William
Published: March 2009

The syntheses of 8‐aminoimidazo[4′,5′:5,6]pyrido[2,3‐d]pyrimidines (7), stretched‐out versions of the naturally occuring nucleoside base adenine, are reported. Their preparation involves conversion of purine into 5‐arninoimidazo[4,5‐b]pyrimidine‐6‐carbonitrile (1) by reaction with malononitrile, followed by construction of the pyrimidine ring in two stepsviathe ethoxymethylene derivative3. 8‐Azapurine can be converted to 8‐amino‐1,2,3‐triazolo[4′,5′:5,6]pyrido[2,3‐d]pyrimidines8in a similar fashion.
1‐(Azidomethyl)benzotriazole and ‐5‐phenyl‐1,2,3,4‐tetrazole as 1, 3‐dipolar cycloaddition components
Authors: Katritzky Alan R. , Fali Clara N. , Shcherbakova Irina V. , Verin Sergei V.
Published: March 2009

1‐(Azidomethyl)benzotriazole reacts with alkynes to give mixtures of isomeric 1,2,3‐triazoles, whereas the interactions of 1‐(azidomethyl)benzotriazole and ‐5‐phenyl‐1,2,3,4‐tetrazole with alkenes proceed regioselectively to form 1,2,3‐triazolines and/or aziridines and enamines in good yields. Diheterocyclosubstituted methanes thus obtained were investigated with respect to thermolysis, α‐lithiation, and reactions with Grignard reagents.
1,6‐ and 1,7‐naphthyridines. I. Rearrangement of quinolinimidoacetic acid derivatives
Authors: Blanco Mercedes , Lorenzo M. Gabriela , Perillo Isabel , Schapira Celia B.
Published: March 2009

The reaction of N‐substituted quinolinimides 1a‐d with sodium alkoxides afforded a mixture of 1,6‐naphthyridines 2 and 1,7‐naphthyridines 3 which were isolated by chromatographic methods. Structure assignment for each pair of isomers was made by comparison of their 1H nmr spectra with those of picolinamide and nicotinamide. When esters 1a‐c were treated with alkoxides from primary alcohols, other than that of the ester, total transesterification took place. Experimental results suggest that transesterification occurs in open intermediary species.
Nitration of sydnones. Reaction with 3‐Arylsydnones containing electron‐donors on the aryl ring
Authors: Turnbull Kenneth , Blackburn Thomas L. , Miller John J.
Published: March 2009

Exclusive aryl ring nitration of a series of 3‐arylsydnones 1 with electron donors (di‐ or tri‐methyl) on the aryl ring is reported.
Fused heterocycles. 8. An efficient procedure for the stereoselective synthesis of trans‐2,3,3a,4‐tetrahydro‐3‐aryl‐2‐phenyl[1]benzopyrano[4,3‐c]pyrazoles and their [1]benzothiopyrano analogues
Authors: Lévai Albert
Published: March 2009

Stereoselective synthesis of trans‐2,3,3a,4‐tetrahydro‐3‐aryl‐2‐phenyl[1]benzopyrano[4,3‐c]pyrazoles 13–18 and their [1]benzothiopyrano analogues 19–24 has been performed by the reaction of 3‐arylidenechromanones 1–6 and 3‐arylidene‐1‐thiochromanones 7–12 with phenylhydrazine in hot pyridine. The structure and stereochemistry of the compounds prepared have been elucidated by ir, lH and 13C nmr measurements.
Syntheses of new pyridonecarboxylic acid derivatives containing 1‐ or 2‐naphthyl substituents at n‐1 and their anti‐hiv‐rt activities
Authors: Oh Yoon‐Seok , Cho Sung‐Hye
Published: March 2009

A series of new pyridonecarboxylic acid derivatives containing 1‐ or 2‐naphthyl substituents at N‐1 were synthesized and their in vitro anti‐HIV‐RT activities were evaluated. Several compounds in this series showed better activity than Atevirdine.
Synthesis and studies on spectral behaviour and molecular dynamics of 7‐Aryl‐4,5‐Dihydro‐2‐Oxo‐3H,8H‐Furo[3,4‐b] [1,4]diazepines
Authors: Zimmer Hans , Nauss Jeffrey L. , Amer Adel
Published: March 2009

A new series of 7‐aryl‐4,5‐dmydro‐2‐oxo‐3H,8H‐furo[3,4‐b][1,4] diazepines were prepared. Their lH nmr spectra have been interpreted in terms of the interconversion of two pseudo‐boat conformers. Molecular‐dynamics simulations at different temperatures on this type of compounds revealed a very small energy difference between these two conformers.
Resolution of four k‐region arene imines and mutagenicity of the optically pure aziridines
Authors: Blum Jochanan , Cohen Yaron , Levin Shulamit , Katschak Andrea , Glatt Hansruedi
Published: March 2009

Racemic K‐region imines of benz[a]anthracene, 7‐methylbenz[a]anthracene, chrysene and benzo[a]pyrene (1–4, respectively) have been resolved by high performance liquid chromatography on a column packed with amylose tris(3,5‐dimethylphenylcarbamate) on silica gel. The absolute configuration of the resolved aziridines was assigned by comparison of their circular dichromism spectra to those of the corresponding enantiomerically pure arene oxides. The mutagenicity of the enantiomers of the arene imines was investigated using Salmonella typhimurium strains TA98 and TA100. Although all arene imines investigated were potent mutagens, quantitative and qualitative differences in the mutagenic activity were observed between enantiomers.
Iminium carbonic acid derivative salts. XII. electrophilic reactions of 2‐methylthio‐4,5‐dihydrothiazolium iodides, 5‐methyl‐2‐methylthiothiazolium iodides and 2‐methylthio‐5,6‐dihydro‐1,3‐thiazinium iodides. part III. With Vinylogous and Phenylogous Active Methylene Compounds
Authors: Hanefeld Wolfgang , Harms Helge
Published: March 2009

3‐Benzyl‐2‐memyltmo‐4,5‐dmydrothiazolium iodide (1), 5‐metlyl‐2‐methylthio‐3‐phenethylthiazolium iodide (4) and 3‐methyl and 3‐benzyl‐2‐methylthio‐5,6‐dihydro‐1,3‐thiazinium iodides 7a, b were reacted with the vinylogous doubly activated CH‐acidic compounds 2a‐d and the phenylogous doubly activated components 8, 11, 16, 19 and 21 to yield new types of S, N‐heterocycles 3, 5, 6, 9, 10, 12, 13, 14, 15 with the partial structure of push‐pull substituted butadienes and 17, 18, 20, 22, 23 and 24 with the character of push‐pull substituted phenyl ketene S, N‐acetals.
Synthesis of pyrazolo[1,5‐a]pyrimidines in the reaction of 5‐amino‐3‐arylpyrazoles with methoxymethylene meldrum's acid derivatives and thermolysis of their pyrazolylaminomethylene derivatives
Authors: Quiroga Jairo , Hormaza Angelina , Insuasty Braulio , Saitz Claudio , Cañete Alvaro , Jullian Carolina
Published: March 2009

A series of pyrazolo[1,5‐a]pyrimidin‐3‐ones 3 was prepared from Meldrum's acid and 5‐amino‐3‐arylpyrazoles 1 by cyclization in nitrobenzene of the corresponding 5‐pyrazolylaminomethylene Meldrum's acid derivatives 2. The structure of pyrazolo[1,5‐a]pyrimidin‐3‐ones and their precursors were determined by nmr measurements.
Synthesis of some azeto[2,1‐a]isoquinolin‐2‐ones
Authors: Cho Su‐Dong , Kim Sung‐Kyu , Yoon Yong‐Jin
Published: March 2009

Some azeto[2,1‐a]isoquinolin‐2‐ones were synthesized from 2‐(3,4‐dimethoxyphenyl)ethylamine in three steps in good yield.
The synthesis of some pyrano[2,3‐g]chromene‐2,7‐diones and furo[2,3‐g]chromen‐6‐ones
Authors: Nicolaides D. N. , Fylaktakidou K. C. , Litinas K. E. , Adamopoulos S. G.
Published: March 2009

The o‐hydroxyformylcoumarin 5b, easily prepared from compound 1, is further transformed to the title coumarin derivatives 7, 10, 19a‐c via its initial Wittig olefination with ylides 2b, 8, 18a‐c respectively. Coumarins 16a, b were also formed by treatment of 5b with compounds 15a, b. The preparation of the interesting furocoumarin derivatives 11, 14, 20b, c as well as of compound 13 is also described.
1,6‐π‐Electrocyclization of 3‐Vinyl‐Functionalized N,N‐Dimethyl‐2,2′‐Bisindolyl: Some analysis of the educt transformation process
Authors: Pindur U. , Kim Y.‐S.
Published: March 2009

The thermally and photochemically induced 1,6‐π‐electrocyclization reaction of 3‐vinyl‐functionalized N, N'‐dimethyl‐2,2′‐bisindolyls 4 has been analysed and some reactivity aspects are presented. On the basis of time dependent 1H nmr and uv spectroscopic measurements the educt transformations can be observed in detail. Some results of the isomerization process of the educts are also given.
Acylation of a novel quinoxalinyl substituted pyrazole derivative. synthesis, quantum chemistry calculations, and x‐ray structure analysis
Authors: Matuszczak Barbara , Langer Thierry , Mereiter Kurt
Published: March 2009

The preparation of N‐acetylpyrazolyl‐quinoxalines and results of semiempirical MO calculations are presented. The structure determination of the isomers 3a, b was achieved by X‐ray analysis.
Synthesis of new 2H,4H‐benzopyrano[3,4‐b]yridine‐1,3,5‐trione derivatives via carbon suboxide
Authors: Bonsignore Leonardo , Loy Giuseppe
Published: March 2009

The new 2H,4H‐[1]benzopyrano[3,4‐b]pyridine‐1,3,5‐trione derivatives 10a‐f were prepared in the following three steps: first the preparation of new N‐(tert‐butoxycarbonyl)‐3‐amino‐2H‐1‐benzopyran‐2‐one derivatives 5a‐f by reaction of coumarin‐3‐carboxylic acids and diphenylphosphorylazide, then hydrolysis of 5a‐f with gaseous hydrogen chloride to give the corresponding amines 7a‐f, and finally the preparation of 10a‐f by reaction of 7a‐f and carbon suboxide in the presence of a Lewis acid.
Synthesis and unexpected reactions of 2‐Hydroxy‐3‐pyridinylacetic hydrazides. Formation of 2H‐Pyrrolo[2,3‐b]pyridin‐2‐ones
Authors: Teleha Christopher A. , Greenberg Roger A. , Chorvat Robert J.
Published: March 2009

Treatment of 2‐hydroxy‐3‐pyridinylacetic hydrazides under mild mesylation conditions provided 2H‐pyrrolo[2,3‐b]pyridin‐2‐ones as unexpected products. This rearrangement is believed to result from an intramolecular attack of the hydrazide on a reactive pyridinium species formed under the reaction conditions.
Synthesis and structure of dinitroazofurazan
Authors: Zelenin Alexander K. , Trudell Mark L. , Gilardi Richard D.
Published: March 2009

The synthesis of dinitroazofurazan (3) was achieved from readily available diaminofurazan (6) in two steps and 20% overall yield. The structure of the energetic material 3 was unequivocally confirmed by X‐ray crystallography and found to have a crystal density of 1.742 g/cm3.
Structure elucidation and 13c NMR assignment of an 1,2,4‐oxadiazole substituted pyrazole
Authors: Neidlein Richard , Kramer Walter , Li Sheng
Published: March 2009

The orientation of the substituent groups in an 1,2,4‐oxadiazole substituted pyrazole, formed by reaction of a phenylnitrile oxide with an unsymmetrically substituted hydrazine is determined. One‐dimensional methods as the selective INEPT and 13C{1H} nOe experiments are used. Both techniques provide also an unambiguous assignment of the 13C nmr spectrum.
Synthesis of thiazole‐containing benzo‐crown ethers
Authors: Kim Hong‐Seok , Koh Young Kook , Choi Jun‐Hyeak
Published: March 2009

A series of benzo‐crown ethers containing the thiazole subcyclic moity have been synthesized. Reaction of 1,2‐bis(thioamidomethyloxy)benzene 2 with ethyl bromopyruvate in ethanol provided 1,2‐bis(thiazolyl)benzene 4 (80%) along with thiazole 5 (14%). Reduction of 4 with lithium aluminum hydride followed by mesylationbromination gave 7. Similar treatment of 5 with lithium aluminum hydride followed by bromination resulted in 12. Benzo‐crown ethers 8, 9, 10, and 13 were prepared from the reactions of 4‐bromomethylthiazole derivatives 7 and 12 with catechol and resorcinol derivatives in the presence of potassium hydride.
4‐Methyl‐3,4‐dihydrospiro[cycloheptane‐1′,2(1H)‐quinoline] and 4‐methyl‐3,4‐dihydrospiro[cyclooctane‐1′,2(1H)‐quinoline]. synthesis of derivatives and chemical transformations
Authors: Palma Alirio , Rozo Wilson , Stashenko Elena , Molina Daniel , Kouznetsov Vladimir
Published: March 2009

New derivatives of 3,4‐dihydrospiro[cycloalkane‐1′,2(1H)‐quinolines] were obtained from cycloheptanone and cyclooctanone via facile three steps hetero spiro annulation process. Their nitro derivatives were prepared through electrophilic substitution reactions.
Reactivity of p‐phenyl substituted β‐enamino compounds using k‐10/ultrasound. I. synthesis of pyrazoles and pyrazolinones
Authors: Valduga Claudete J. , Braibante Hugo S. , Braibante Mara E. F.
Published: March 2009

The reactivity of the β‐enamino ketones, 3‐amino‐1‐(p‐phenyl‐substituted)‐2‐buten‐1‐ones 1a‐d and β‐enamino esters. Ethyl‐3‐amino‐3‐(p‐phenyl‐substituted)‐2‐propenoates 5a‐d were evaluated by systematic studies of the reactions with hydrazine and methylhydrazine by reactions with solid support K‐10/ultrasound and homogeneous media (reflux in ethanol or dichloromethane) yielding pyrazole rings 2a‐d, N‐methylpyrazoles 3a‐d, 4a‐d and N‐methylpyrazolinones 6a‐c and 7a‐c. The regiochemistry of the cyclization showed dependence of the reaction conditions employed as well as the substituent in the aromatic ring.
The synthesis of aminimide‐containing azole antifungals
Authors: Abel Mark D. , Hewgill Randy T. , Malczyk Katherine J. , Micetich Ronald G. , Daneshtalab Mohsen
Published: March 2009

The synthesis of a series of azole antifungal compounds which incorporate the aminimide functional moiety is described. The procedure involves the reaction of an epoxide intermediate with 1,1‐disubstituted hydrazines to form aminimines which are subsequently treated with acyl chlorides resulting in the desired zwitterionic aminimides. The aminimides were tested for in vitro antifungal activity and found to be moderately active against Candida and Cryptococcus species, but inactive versus Aspergillus.
Synthesis and properties of a new series of trögerophanes
Authors: Ibrahim Alhussein A. , Matsumoto Mutsumi , Miyahara Yuji , Izumi Kenji , Suenaga Masahiko , Shimizu Nobujiro , Inazu Takahiko
Published: March 2009

A new series of macrocyclic compounds with one or two Tröger base skeletons has been synthesized by condensing mono‐, di‐, tri‐, and teraethyleneglycol bis(p‐aminophenoxy) ethers with formalin in the presence of concentrated hydrochloric acid in ethanol at room temperature for 13 days. This simple one‐step cyclization provided 19 in remarkably high yield (46%) and 17, 18, and 20 in yields reflecting the strain of the rings and statistical factors. Complexation with lithium thiocyanate was observed for 20, the structure of which was elucidated by X‐ray crystallography.
Synthesis of 2,3,8,9‐Dibenzo‐5,6‐(substituted)benzo‐1,4‐dithio‐7‐oxacyclonona‐2,5,8‐trienes and some electrophilic substitution reactions
Authors: Kim Man Nyoung , Kim Kyongtae
Published: March 2009

Treatment of 5‐(2‐hydroxyaryl)thianthreniumyl perchlorates 1 with sodium hydride in tetrahydrofuran at reflux gave the title compounds 5 in excellent yields. For the reactivities of the compounds 5, the selected compounds 5 were subjected under the conditions of electrophilic substitution reactions. Bromination of 5,6‐{3‐(2‐butyl)benzo}‐2,3,8,9‐dibenzo‐1,4‐dithio‐7‐oxacyclonona‐2,5,8‐triene (5f) in acetic acid at 60° afforded two bromo compounds 9 (22%) and 10 (69%), which were oxidized by m‐chloroperbenzoic acid to give tetraoxides 11 (95%) and 12 (97%), respectively. Treatment of 5f with acetyl chloride in the presence of aluminum chloride in carbon disulfide at 0° gave an acetylated compound 13 (58%). Nitration of 5f with nitric acid in acetic acid at 50° gave a nitro compound 17 (15%) together with 1,4‐dioxide 7e (22%) and a 5‐oxide 18 (3%) whose regiochemistry has not been established. On the other hand, 5,6‐(3‐methylbenzo)‐2,3,8,9‐dibenzo‐1,4‐dithio‐7‐oxacyclonona‐2,5,8‐triene (5a) reacted with acetyl chloride under the same conditions to give two acetylated compounds 15 (33%) and 16 (18%). The mechanism for the formation of 5 and the structural elucidation of these compounds are discussed.
Structural assignment of 2,3,7,8‐tetrahydro‐5H,10H‐[1,5,3]dioxazepino[3,2‐c]indolo[3,2‐g]pteridin‐7‐one, a New heterocyclic ring system
Authors: Ge Ping , Kalman Thomas I.
Published: March 2009

The structure of a new heterocyclic ring system, 2,3,7,8‐tetrahydro‐5H,10H‐[1,5,3]dioxazepino[3,2‐c]‐indolo[3,2‐g]pteridin‐7‐one, derived from isatins and 5‐aminocytidine was assigned by establishing the regiochemistry with the aid of model reactions and 13C nmr techniques.
Furopyridines. XXVII. Reactions of 2‐methyl and 2‐cyano derivatives of furo[2,3‐b]‐, ‐[3,2‐b]‐, ‐ [2,3‐c]‐ and ‐[3,2‐c]pyridine
Authors: Yamaguchi Seiji , Kurosaki Masahide , Orito Keiko , Yokayama Hajime , Hirai Yoshiro , Shiotani Shunsaku
Published: March 2009

Bromination of 2‐methylfuropyridines 1a‐d‐Me gave the 3‐bromo derivatives 2a‐d, while the 2‐cyano compounds 1a‐d‐CN resulted in the recovery of the starting compounds. Nitration of 1a‐d‐Me and 1a‐d‐CN did not yield the corresponding nitro derivative, except for 1‐c‐CN giving 3‐nitro derivative 3c in 7% yield. N‐Oxidation of 1a‐d‐Me and 1b‐d‐CN with m‐chloroperbenzoic acid yielded the N‐oxides 4a‐d‐Me and 4b‐d‐CN, whereas 1a‐CN did not afford the N‐oxide. Cyanation of N‐oxides 4a‐d‐Me and 4b‐d‐CN with trimethylsilyl cyanide gave the corresponding α‐cyanopyridine compounds 5a‐d‐Me and 5b‐d‐CN. Chlorination of 4a‐d‐Me and 4b‐d‐CN with phosphorus oxychloride also gave the α‐chloropyridine compounds 6b‐d‐Me and 6b‐d‐CN, accompanying formation of γ‐chloropyridine 6a‐Me, 6′b‐Me and 6′b‐CN, β‐chloropyridine 6′b‐CN, and α'‐chloropyridine derivatives 6′c‐Me and 6′c‐CN. Acetoxylation of 4a‐d‐Me and 4b‐d‐CN with acetic anhydride yielded α‐acetoxypyridine compounds 7a‐Me and 7b‐CN, pyridone compounds 11d‐Me, 11c‐CN and 11d‐CN, 3‐acetoxy compounds 8, 9b, 9c, and 2‐acetoxymethyl derivatives 10b and 10c.
Furopyridines. XXVIII. Reactions of 3‐bromo derivatives of furo[2,3‐b]‐, ‐[3,2‐b]‐, ‐[2,3‐c]‐ and ‐[3,2‐c]pyridine and their N‐oxides
Authors: Yamaguchi Seiji , Awajima Kazuaki , Hirai Yoshiro , Yokoyama Hajime , Shiotani Shunsaku
Published: March 2009

Bromination of 3‐bromofuro[2,3‐b]‐ 1a, ‐[3,2‐b]‐ 1b and ‐ [3,2‐c]pyridine 1d afforded the 2,3‐dibromo derivatives 2a, 2b and 2d, while the ‐[2,3‐c]‐ compound 1c did not give the dibromo derivative. Nitration of 1a‐d gave the 2‐nitro‐3‐bromo compounds 3a‐d. The N‐oxides 4a‐d of 1a‐d were submitted to the cyanation with trimethylsilyl cyanide to yield the corresponding α‐cyanopyridine compound 6a‐d. Chlorination of 4a and 4d with phosphorus oxychloride gave mainly the chloropyridine derivatives 7a, 7′a and 7d, while 4b and 4c gave mainly the chlorofuran derivatives 7′b and 7′c accompanying formation of the chloropyridine derivatives 7b, 7′b and 7c. Acetoxylation of 4a and 4b with acetic anhydride yielded the acetoxypyridine compounds 8a, 8′a and 8b, while 4c and 4d gave the acetoxypyridine 8′c, 8′d and 8′d, pyridone 8c and 8d, acetoxyfuran 8′c and dibromo compound 9c and 9′c.
Reaction of 1‐chloromethyl‐4,5‐dichloropyridazin‐6‐one
Authors: Chung Hyun‐A , Kang Young‐Jin , Yoon Yong‐Jin
Published: March 2009

Reaction of 1‐chloromethyl‐4,5‐dichloropyridazin‐6‐one with some nucleophiles such as sodium methoxide, sodium azide, 2‐mercaptopyrimidine and phenol gave 2, 3, 4, 7, 8 and 10. 5‐Chloro‐4‐phenoxypyridazin‐6‐one (10) was also synthesized from 8 through 9.
The synthesis of ethyl 2‐[(2,2‐dibenzoyl)ethenyl]amino‐3‐dimethyl‐aminopropenoate and its application to the synthesis of fused 3‐aminopyran‐2‐ones and 3‐aminoazolo‐ and ‐azinopyrimidin‐4(4H)‐ones
Authors: Soršak Gorazd , Stanovnik Branko , Grdadolnik Simona GoliČ
Published: March 2009

Ethyl 2‐[(2,2‐dibenzoyl)ethenyl]amino‐3‐dimethylaminopropenoate (3) was prepared from dibenzoylmethane (1) in two steps, and used as a reagent for preparation of fused substituted 3‐aminopyranones 12–15 in over 90% yield, quinolizin‐4‐one 16 in over 79% yield, and fused pyrimidin‐4‐ones 17–19 in 40–50% yield. Deprotection of (2,2‐dibenzoyl)ethenyl group with either diethylamine or hydrazine hydrate produced free amino compounds 20, 21 and 22 in 35%, 91% and 71% yield, respectively.
Transformation of 4‐(1‐dimethylaminoethylidene)‐2‐phenyl‐5(4H)‐oxazolone into methyl 2‐benzoylamino‐3‐oxobutanoate. The synthesis of 1‐substituted 4‐benzoylamino‐3‐methyl‐5(2H)‐pyrazolones
Authors: Bratušek UrŠKa , Hvala AleŠ , Stanovnik Branko
Published: March 2009

Methyl 2‐benzoylamino‐3‐oxobutanoate (3) was prepared from hippuric acid (1) which was converted with N,N‐dimethylacetamide and phosphorus oxychloride into 4‐(1‐dimethylaminoethylidene)‐2‐phenyl‐5(4H)‐oxazolone (2) followed by hydrolysis with hydrochloric acid in methanol. Compound 3 was treated with hydrazines 4 to give 4‐benzoylamino‐3‐methyl‐1H‐pyrazol‐5(2H)‐one (6a) and its 1‐substituted derivatives 6b‐j. The corresponding hydrazones 5f, i, j were isolated as intermediates.
The birch reduction of heterocyclic compounds. IV. Birch reduction of 3‐acylfurans. Competition between ring reduction, carbonyl reduction, and dimer formation
Authors: Takano Daisuke , Nakajima Yoshitaka , Miyahara Ikuko , Hirotsu Ken , Tanaka Rika , Okada Keiji , Morimoto Yoshiki , Kinoshita Takamasa , Yoshihara Kazuo
Published: March 2009

The Birch reduction of 3‐acylfurans 1, 3 and 10 and their reaction path ways are described.
Furopyridines. XXV. Synthesis of 5‐substituted furo [2,3‐b]pyridines
Authors: Yamaguchi Seiji , Kurosaki Masahide , Yokoyama Hajime , Hirai Yoshiro , Shiotani Shunsaku
Published: March 2009

Derivatives (2–8) of furo[2,3‐b]pyridine having a substituent at the β‐position to the ring nitrogen were prepared from the 5‐nitro compound 1 via the Sandmeyer reaction.
A new tautomeric zwitterion form of 2‐acylamino‐4H‐1,3,4‐oxadiazino[5,6‐b]quinoxalines in solution
Authors: Kurasawa Yoshihisa , Mitomi Takako , Okamoto Yoshihisa , Kim Ho Sik
Published: March 2009

The reaction of 2‐acyiamino‐8‐chloro‐4‐methyl‐4H‐1,3,4‐oxadiazino[5,6‐b]quinoxalines 2a‐d with methyl iodide/base gave the 8‐chloro‐4,10‐dimethyl‐4H‐1,3,4‐oxadiazino[5,6‐b]quinoxalin‐10‐ium‐2‐acylamidates 4a‐d, respectively. Comparison of the nmr spectral data between compounds 2a‐d and 4a‐d in deuteriodimethyl sulfoxide or in deuteriotrifluoroacetic acid established that compounds 2a‐d existed as the zwitterionic tautomers 2′a‐d in solution.
Synthesis of 2‐styrylthiazolo[4,5‐b]quinoxaline based fluorescent dyes
Authors: Rangnekar D. W. , Sonawane N. D. , Sabnis R. W.
Published: March 2009

A novel efficient synthesis of 2‐styrylthiazolo[4,5‐b]quinoxaline based fluorescent dyes was achieved by the condensation of 2‐alkylthiazolo[4,5‐b]quinoxaline with selected 4‐N,N‐dialkylamino‐substituted aryl‐aldehydes or hetarylaldehydes in the presence of piperidine or acid anhydride. The coloristic, fluorophoric and dyeing properties of these dyes were studied.
Stereoselective photo[4+2]cycloadditions of 2‐pyrone‐5‐carboxylates with maleimides in the solid state and in solution
Authors: Obata Tom , Shimo Tetsuro , Suishu Takaaki , Somekawa Kenichi
Published: March 2009

Solid state photoreactions and thermal reactions of 2‐pyrone‐5‐carboxylates with maleimides gave endo‐[4+2]cycloadducts, while the sensitized photoreactions gave exo‐[4+2]cycloadducts stereo‐selectively.
Synthesis of new heterocyclic derivatives of retinoids
Authors: Sottofattori Enzo , Anzaldi Maria , Balbi Alessandro
Published: March 2009

Reaction of α‐ and β‐ionones 1 and 2 with dialkylformamide/phosphorus oxychloride affords enamines 6 and 7 along with the expected chloro derivatives 4 and 5. Reaction of 6a with hydrazines, hydroxylamine and guanidine furnished pyrazoles, isoxazole, pyrimidine 8–10 showing the potential of these enaminones as key intermediates in the synthesis of synthetic retinoids.
Synthesis of new proton‐ionizable and neutral macrocyclic, macrobicyclic and macrotricyclic crown compounds containing dibenzo‐16‐crown‐5 units
Authors: Xia Michael X. B. , Wai Chien M. , Natale N. R. , Elshani Sadik , Bartsch Richard A. , Bartsch Richard A. , Widener Rexford W.
Published: March 2009

Fifteen new macrocyclic, macrobicyclic and macrotricyclic crown ether compounds with sym‐dibenzo‐16‐crown‐5 units have been prepared. The series includes macrocyclic polyether and bis(crown ether) compounds with proton‐ionizable carboxylic or phosphonic acid monoethyl ester groups and bis(crown ether) and macrotricyclic polyether compounds with two sym‐dibenzo‐16‐crown‐5 units linked by amide, diamide, or diester functions.
Synthesis of 4‐aryl‐2,3,6,7‐tetrahydro‐1H‐pyrimido[4,5‐b][1,4]‐diazepin‐6‐ones from 4,5‐diamino‐1H‐pyrimidin‐6‐ones and 1‐aryl‐3‐(dimethylamino)‐1‐propanones
Authors: Insuasty Braulio , Quiroga Jairo , Argoti Juan Carlos , Gómez Samuel , Martínez Roberto , Angeles Enrique , Gabiño Rubén , Nogueras Manuel , Sánchez Adolfo
Published: March 2009

The reaction of 1‐aryl‐3‐(dimethylamino)‐1‐propanones 1 with one equivalent of 4,5‐diamino‐1H‐pyrimidin‐6‐ones 2, in acidic medium, leads to the formation of 4‐aryl‐2,3,6,7‐tetrahydro‐1H‐pyrimido[4,5‐b]‐[1,4]diazepin‐6‐ones 3. The structure elucidation of the products is based on detail nmr analysis of experiments such as 13C, 1H and DEPT including selective 13C{1H} decoupling experiments.
Reactions of 3‐acetyltropolone with benzaldehydes in trimethyl orthoformate in the presence of perchloric acid: Synthesis of 2‐aryl‐4‐methoxy‐9‐oxocyclohepta[b]pyrylium perchlorates
Authors: Wang Dao‐Lin , Imafuku Kimiaki
Published: March 2009

3‐Acetyltropolone (1) reacted with benzaldehydes in trimethyl orthoformate in the presence of perchloric acid to afford 2‐aryl‐4‐methoxy‐9‐oxocyclohepta[b]pyrylium perchlorates 3a‐c in 25–37% yields. From the filtrates, 3‐(3,4‐diaryl‐3‐butenoyl)tropolones 4a,b and 3‐(2‐methoxycinnamoyl)tropolone (5) were also isolated.
Synthesis of perimidine and fused perimidine derivatives from reaction of 1,8‐naphthalenediamine with an iminoisocoumarin
Authors: Deady Leslie W. , Rodemann Thomas
Published: March 2009

The isocoumarin derivative 1H‐1‐acetylimino‐3‐methylbenzo[c]pyran‐4‐carbonitrile reacts with 1,8‐naphthalenediamine under basic conditions to give, primarily, 12‐acetylisoquino[2,1‐a]perimidin‐13‐amine. This undergoes a variety of reactions to give other isoquino[2,1‐a]perimidine derivatives, ring opening to 2‐(1H‐perimidin‐2‐yl)phenylacetic acid derivatives and, in polyphosphoric acid, a new hexacyclic system, 6‐methyl‐7,13,13d‐triazadibenzo[def,qr]chrysene.
Synthetic and spectroscopic study of 5‐amino‐2‐acyl‐1,2,4‐thiadiazolin‐3‐ones
Authors: Ra Do Young , Cho Nam Sook , Moon Jung Hyun , Kang Sung Kwon
Published: March 2009

5‐Amino‐2‐acyl‐1,2,4‐thiadiazolin‐3‐ones 2–1 can be synthesized from 5‐amino‐2H‐1,2,4‐thiadiazolin‐3‐one (1–1) via a selective acylation with an acid anhydride in pyridine. The 1H nmr spectral characteristics of 5‐amino‐2‐acyl‐1,2,4‐thiadiazolin‐3‐ones 2–1 is in particular, compared with 5‐amino‐2H‐1,2,4‐thiadiazolin‐3‐one (1–1) and 5‐amino‐2‐alkyl‐1,2,4‐thiadiazolin‐3‐ones 1–2, 1–3. The 5‐amino group of 2–1 appeared as two peaks in its 1H nmr spectrum, which merged to a single peak at a higher temperature, while those of compound 1–1, 1–2 and 1–3 appear only as a single peak. The restricted rotation of the C(5)‐N(5) (at amino) bond of 5‐amino‐2‐acetyl‐1,2,4‐thiadiazolin‐3‐one (2a‐1) is about 14.5 Kcal/mol.