bluuebunny/crossref_metadata_2025 huggingface dataset:
The synthesis of benzofuroquinolines. IV. Some halobenzofuro[2,3‐B]‐ and [3,2‐C]quinoline derivatives
Authors: Yamaguchi Seiji , Tsuzuki Kunihiro , Kinoshita Minoru , Oh‐Hira Yutaka , Kawase Yoshiyuki
Published: March 2009

Some 8‐ or 9‐halobenzofuro[2,3‐b]quinolines (1a, 8‐F, 8‐C1, 9‐F, 9‐Cl) and 9‐halobenzofuro[2,3‐b]quinoline‐11‐carboxylic acid (1b, F, Cl) were synthesized from 6‐ or 7‐halo‐3‐(2‐methoxyphenyl)‐2‐oxo‐1,2‐dihydroquino‐line‐4‐carboxylic acids (3). And, some 9‐halo‐11(6H)‐benzofuro[2,3‐b]quinolinone (8, F, Cl, Br) and 2‐halo‐6(5H)‐benzofuro[3,2‐c]quinolinone (9, F, Cl, Br) were synthesized from 6‐halo‐4‐hydroxy‐3‐(2‐methoxyphenyl)‐2(1H)‐quinolinone (7), and they were converted to the corresponding chlorohalobenzofuroquinolines (1c, 9‐F, 9‐C1, 9‐Br, and 2, F, Cl, Br).
Preparation of crown compounds containing allyloxymethyl or butenyl groups for attachment to silica gel or containing long chain lipophilic groups for use in liquid membrane systems
Authors: Mcdaniel Christopher W. , Bradshaw Jerald S. , Krakowiak Krzysztof E. , Izatt Reed M. , Savage Paul B. , Tarbet Bryon J. , Bruening Ronald L.
Published: March 2009

Several new macrocyclic polyether ligands have been prepared for use in the separation of metal ions from aqueous solutions. Four of the crown ethers reported contain 1,2,4‐triazole or 4‐pyridone protonionizable subcyclic units and lipophilic groups. The remaining crown ethers are not proton‐ionizable but contain alkene groups and were prepared for attachment to silica gel. The crowns were prepared by reacting the appropriate glycols with the appropriate ditosylates or dichloride in the case of the 1,2,4‐triazole subcyclic unit. The crowns with proton‐ionizable and lipophilic substituents were tested in liquid membrane transport systems and some of the crowns with alloxymethyl or butenyl substituents were attached to silica gel. The log K values for the interaction of these silica gel‐bound macrocycles with certain metal ions were nearly the same (± 10%) as those for the association of the unbound macrocycles with the same metal ions.
1,3‐dipolar cycloaddition of diazomethane to azolopyridazines. The synthesis of isomeric 7‐methyl‐7h‐ and 8‐methyl‐8h‐pyrazolo[4,3‐d]azolopyridazmes
Authors: Merslavič Marjo , Petrič Andrej , Rozman Damjana , Stanovnik Branko , Tišler Miha
Published: March 2009

1,3‐Dipolar cycloaddition of diazomethane to 6‐chloro substituted azolopyridazines 1‐4 produces isomeric pairs of 7‐methyl‐7H‐ 9‐12 and 8‐methyl‐8H‐pyrazolo[4,3‐d]azolopyridazines 13‐16. The nucleophilic substitution of chlorine at position 6 affords the corresponding 6‐amino 17, 20, 23, 26, 29,32,35 and 38, 6‐methoxy 18, 21, 24, 27, 30,33, 36, and 39 and 6‐hydrazino derivatives 19, 22, 25, 28, 31, 34, 37, and 40 of these tricyclic systems.
Synthesis of a benzodiazepine analogous sydnotriazepine
Authors: Fleischhacker Wilhelm , Urban Ernst
Published: March 2009

Starting from 3‐benzylamino‐4‐benzoylsydnone (1) acylation to N‐acetyl (2a), N‐chloroacetyl (2b) and N‐bromoacetyl (2c) derivatives was successful. Treatment of 2b or 2c with liquid ammonia resulted in cleavage of the N‐acyl group to give sydnone imine 3 instead of cyclisation to sydnotriazepine 8. Condensation of 1 with protected glycines 5a‐5c by dicyclohexylcarbodiimide yielded glycineamides 6a, 6b and 6c. Compound 6c was selectively deprotected and converted to sydnotriazepine 7, a benzodiazepine analogous sydnotriazepine.
Studies concerning pyrrolo[2, 1‐a]phthalazines and related compounds
Authors: Uff Barrie C. , Ghaem‐Maghami Ghobad , Budhram Ronald S. , Wilson Claire L. , Apatu Jonas O.
Published: March 2009

A series of pyrrolo[2, 1‐a]phthalazine derivatives has been prepared including examples carrying a variety of O‐ and N‐substituents at position‐6. A number of the products and related tricyclic structures show mild anti‐hypertensive activity including 6‐allyloxy‐1, 2‐dichloro‐3‐phenylpyrrolo[2, 1‐a]phthalazine.
Palladium‐catalyzed furylation and thienylation of activated alkenes with 2‐furoyl chloride and 2‐thenoyl chloride
Authors: Kasahara Akira , Izumi Taeko , Ogihara Takao
Published: March 2009

2‐Furoyl or 2‐thenoyl chlorides readily react with activated alkenes in the presence of a tertiary amine and a catalytic amount of palladium(II) acetate to give 2‐furylated or 2‐thienylated alkenes. Under similar conditions, 2‐benzofuroyl chloride undergoes facile alkenylation to produce 2‐alkenylated benzofurans. The reaction involves a highly efficient decarbonylation of furoyl or thenoyl‐palladium species.
A new route to 2‐amino‐ or 2‐hydroxy‐3‐pyridinecarboxylic acid derivatives
Authors: Ito Kunio , Yokokura Seiichi , Miyajima Shingo
Published: March 2009

Schiff's bases derived from ketones and t‐butylamine (1) reacted with methyl methoxymethylenemalonate to give 2‐hydroxy‐3‐pyridinecarboxylates. Similarly, treatment of 1 with ethoxymethylenemalononitrile gave 2‐amino‐3‐pyridinecarbonitriles. Compounds 1 on reaction with ethyl 2‐cyano‐3‐ethoxypropenoate afforded 2‐amino‐3‐pyridinecarboxylates.
Some derivatives of benz[f]azepine. Part III
Authors: James Robert A. , Kohn Charlotte A. , Rees Alun H. , Verschuren Rex E.
Published: March 2009

We report the synthesis by two routes, of hitherto unknown 3, 4‐epoxy‐2, 3, 4, 5‐tetrahydrobenz[f]azepine‐2, 5‐dione and hence a new route to 2, 3, 4, 5‐tetrahydrobenz[f]azepine‐2, 4, 5‐triones which are precursors of 2‐quin‐olonecarboxylic acids.
Preferable tautomer of dihydropyrazolo[5, 1‐c][1, 2, 4]triazines in solution
Authors: Kurasawa Yoshihisa , Kamigaki Yumiko , Kim Ho Sik , Yonekura Keiko , Takada Atsushi , Okamoto Yoshihisa
Published: March 2009

Dihydropyrazolo[5, 1‐c][1, 2, 4]triazines 6, 7 and 8 were found to predominate as the 4, 6‐dihydro tautomeric form in solution by the measurement of ID NOE different spectra.
Synthesis and derivatization of 4‐arylsulfonylthiophene‐ and furan‐2‐sulfonamides
Authors: Hartman George D. , Halczenko Wasyl
Published: March 2009

Novel 4‐arylsulfonylthiophene‐ and furan‐2‐sulfonamides are prepared from the 3‐arylsulfonyl heterocycle via chlorosulfonation with chlorosulfonic acid/phosphorus pentachloride. Free radical bromination affords bromomethyl analogues that are precursors to amine derivatives of the parent thiophenesulfonamides. Instability of the furansulfonyl chlorides to free radical bromination necessitated a sequence employing bromomethyl group generation prior to chlorosulfonation. Demethylation of methoxyl substituted sulfonamides afforded phenols that underwent efficient mono‐ and bis‐alkylation with Mannich reagents.
Studies on structurally simple α,β‐butenolides. VIII. 5‐Haloalkyl‐ and 3‐bromo‐5‐hydroxyalkyl‐2(5H)‐furanones
Authors: Font J. , Sánchez‐Ferrando F. , Segura C. , Piniella Joan F. , Jeffrey George A. , Ruble John R.
Published: March 2009

Bromine and NBS react with sorbic acid to yield bromohydrin 5 and bromolactones 4, respectively. The erythro and threo isomers 4a,b were separated and the crystal structure of the former was determined. Bromolactone 7, as a single erythro stereoisomer, was prepared by photolactonization of 5.
Reaction of N‐nitroaryl‐1,2,3,4‐tetrahydroisoquinoline derivatives with oxygen
Authors: Shawcross A. P. , Stanforth S. P.
Published: March 2009

Heating N‐4′‐methyl‐2′‐nitrophenyl‐1,2,3,4‐tetrahydroisoquinoline (1) in the presence of oxygen gave both products derived from cleavage of the C8aCl bond and oxidation at the 1‐position. Under similar conditions N‐4′‐nitrophenyl‐1,2,3,4‐tetrahydroisoquinoline (4) gave only the oxidation product.
The synthesis and transformations of 2‐ethoxycarbonyl‐3‐isothiocyanatopyridine. Pyrido[3,2‐d]pyrimidines and some azolopyrido[3,2‐d]pyrimidines
Authors: Urleb UroŠ , Stanovnik Branko , Tišler Miha
Published: March 2009

2‐Ethoxycarbonyl‐3‐isothiocyanatopyridine (2), prepared from 3‐amino‐2‐ethoxycarbonylpyridine (1) by the thiophosgene method, was converted with nucleophiles into pyrido[3,2‐d]pyrimidine derivatives 6–11 and 25–30 either directly, or through thiourethane 3. Tricyclic systems 18 and 19 were obtained from 3, and tricyclic systems 12–17 from pyrido[3,2‐d]pyrimidine derivative 11. Pyrrole reacted with 2 at C2 to give 20, and by further cyclization 21 and 22.
Synthesis of 4‐[3‐(1H)‐indolyl]‐2‐[N‐guanidinomethyl]thiazole dihydrochloride
Authors: Zawistoski Michael P.
Published: March 2009

The title compound 3b was synthesized in three steps from acetaminothioacetamide (4b) in 15% overall yield. This represents the first synthesis of a 2‐guanidinomethylthiazole, which is a homolog of an important pharmacophore, 2‐guanidinothiazole.
Polarized ethylenes. IV. Synthesis of polarized ethylenes using thioamides and methyl dithiocarboxylates and their application to syntheses of pyrazoles, pyrimidines, pyrazolo[3,4‐d]pyrimidines, and 5‐aza[2.2.3]cyclazines
Authors: Tominaga Yoshinori , Matsuoka Yoshiki , Oniyama Yukio , Uchimura Yoshimitsu , Komiya Hirofumi , Hirayama Michiyo , Kohra Shinya , Hosomi Akira
Published: March 2009

Polarized ethylenes having both electron‐donating (an amino or a methylthio group) and electron‐accepting (cyano, carbamoyl, methyl ester) groups on the adjacent two olefinic carbon atoms were prepared by the condensation of S‐alkylthioamidinium salts or methyl dithiocarboxylates with the corresponding active methylene compounds in good yields. These polarized ethylenes were alternatively synthesized by the reaction of thioamides or methyl dithiocarboxylates with tetracyanoethylene oxide in good yields. Reactions of these polarized ethylenes with hydrazine or guanidine derivatives occurred smoothly to give the corresponding pyrazole and pyrimidine derivatives in good yields. The synthesis of 5‐aza[2.2.3]cyclazine derivatives using polarized ethylenes is also described.
Synthesis of cns potentially active bicyclic and tricyclic derivatives of pyrazolo[1,5‐a][1,3]diazepines
Authors: Costanzo Annarella , Bruni Fabrizio , Auzzi Gabriella , Selleri Silvia , Vettori Lorenzo Pecori
Published: March 2009

Reaction of 5‐ethylamino‐3‐phenylpyrazole with dicarboxylic acid anhydrides in tetrahydrofuran in the presence of 1,3‐dicyclohexylcarbodiimide, afforded bicyclic and tricyclic derivatives of pyrazolo[1,5‐a][1,3]‐diazepines. The tricyclic derivatives constitute a new class of compounds. Characterisation of these products was effected with ir, pmr, and 13C nmr spectral data.
A convenient synthesis of 3‐aryl‐4H‐ Benzopyrano[3,4‐d]isoxazol‐4‐ones
Authors: Litinas Konstantinos E. , Nicolaides Demetrios N. , Varella Evangelia A.
Published: March 2009

Regioselective 1,3‐dipolar cycloaddition of nitrile oxides 5a‐c to ethyl o‐hydroxycinnamate (3) gave the corresponding ethyl trans‐3‐aryl‐4,5‐dihydro‐5‐(2‐hydroxyphenyl)‐4‐isoxazolecarboxylates 6a‐c. Their structure was confirmed by reductive cleavage to 1 and compounds 9a‐c. Compounds 6a‐c afforded upon heating in the presence of pyridine the 3‐aryl‐4H‐[1]benzopyrano[3,4‐d]isoxazol‐4‐ones 11a‐c. Compound 10c was also isolated from 6c and transformed thermally into 11c.
Cyclic guanidines: Synthesis of 4,6,7,8‐tetrahydro‐1H‐imidazo[1,2‐a]pyrazolo[3,4‐d]pyrimidin‐7‐ones and 1,4,6,7,8,9‐hexahydropyrazolo[3′,4′:4,5]pyrimido[2,1‐c] [1,2,4]triazin‐7‐ones
Authors: Ferroni R. , Simoni D. , Orlandini P. , Guarneri M. , Bertolasi V. , Ferretti V.
Published: March 2009

The synthesis of potential platelet aggregation inhibitors 4,6,7,8‐tetrahydroimidazo[1,2‐a]pyrazolo[3,4‐d]‐pyrimidin‐7‐ones and 1,4,6,7,8,9‐hexahydropyrazolo[3′,4′:4,5]pyrimido[2,1‐c] [1,2,4]triazin‐7‐ones derivatives is described starting from 4,6‐dichloropyrazolo[3,4‐d]pyrimidines.
A New and simple synthesis of 2‐aryl‐4,9‐dihydrocyclohepta[b]pyran‐4,9‐diones
Authors: Wang Dao‐Lin , Jin Zhong‐Tian , Imafuku Kimiaki
Published: March 2009

3‐Acetyltropolone (1) reacted with 2‐methoxybenzaldehyde (2a) in the presence of ethyl orthoformate and perchloric acid to afford 2‐(2‐methoxyphenyl)‐4,9‐dihydrocyclohepta[b]pyran‐4,9‐dione (3a). The reactions with 3,4‐dimethoxybenzaldehyde (2b), vanillin (2c), and piperonal (2d) gave respectively the corresponding products 3b‐d. The reaction with benzaldehyde (2e) gave uncyclized 3‐cinnamoyltropolone (4).
Preparation of large macrocyclic tetra‐amines consisting of a methylene backbone and a cyclophane type skeleton
Authors: Uoto Kouichi , Tomohiro Takenori , Okuno Hiroaki (Yohmei)
Published: March 2009

Efficient synthetic routes to 1,10,19,28‐tetraazacyclohexatriacontane, a 36‐membered ring compound with a methylene backbone, and bis(N,N‐octamethylene‐4,4′‐diaminodiphenylmethane), a 38‐membered tetra‐amine with a cyclophane skeleton, have been developed via reduction of tetralactam and via a double condensation reaction, respectively. Overall yields are 51% with 5 steps for the former, and 46% with 6 steps for the latter, while the corresponding 2 + 2 cyclization gave the cyclic compounds in poor yields, 9% and 4%, respectively, for the 36‐membered tetra‐aza ring and for the 38‐membered cyclophane derivative.
Reaction of isocyanates with 2‐phenyliminotetrahydro‐1,3‐thiazines and oxazines
Authors: Nabeya Aiko , Endo Tadatoshi , Saito Jun , Mitsuishi Takatoshi , Inahara Masashi
Published: March 2009

It has been found that the reaction of isocyanates with 2‐phenyliminotetrahydro‐1,3‐thiazines and oxazines 3–8 occurs at the ring nitrogen to give the endo carbamoylated compound first, and then the carbamoyl group migrates to the exo nitrogen with differing rates depending upon the structure of the thiazines or the oxazines. Though the carbamoylated thiazines (both endo and exo) were found to exist in equilibrium with the isocyanate and the thiazine in solution, crossover experiments showed that the rearrangement proceeded by an intramolecular mechanism.
Synthesis of novel 1H‐imidazo[5,1‐B][3]benzazepine‐1,3(2H)‐dione and pyrimido[6,1‐B][3]benzazepine‐1,3,4(2H)‐trione
Authors: Gallaschun Randall J. , Schnur Rodney C.
Published: March 2009

Two novel tricyclic ring systems derived from 3‐benzazepines were synthesized; the first, a 6,7,5‐ring, 1H‐imidazo[5,1‐b][3]benzazepine‐1,3(2H)‐dione was obtained using an unusual Stiles reaction while the second, an analogous 6,7,6‐ring, pyrimido[6,1‐b][3]benzazepine‐1,3,4(2H)‐trione was prepared with base and oxalyl chloride.
Studies on the chemistry of O,N‐ and S,N‐containing heterocycles. 12 [1]. Investigations on the synthesis of tricyclic 1,5‐benzoxazepines
Authors: Bartsch Herbert , Erker Thomas
Published: March 2009

The reaction of methylthiolactim 1 with weak basic N‐nucleophiles led to the substituted benzoxazepines 2,3 and 6a‐d, respectively. Compound 4 was obtained by condensation of 3 with carbonyldiimidazole, whereas 6a‐d were transformed thermically into the triazolobenzoxazepines 7a‐d. Treatment of 6b with thionyl chloride afforded 8. Compound 9 directly was obtained from 1 with anthranilic acid.
Synthesis of pyridazino[3,4‐b]quinoxalines and pyrazolo[3,4‐b]‐quinoxaline by 1,3‐dipolar cycloaddition reaction
Authors: Kim Ho Sik , Kurasawa Yoshihisa , Yoshii Chiemi , Masuyama Minako , Takada Atsushi , Okamoto Yoshihisa
Published: March 2009

The pyridazino[3,4‐b]quinoxalines 6a,b and pyrazolo[3,4‐b]quinoxaline hydrochloride 9 were synthesized by the 1,3‐dipolar cycloaddition reaction of 6‐chloro‐2‐(1‐methylhydrazino)quinoxaline 4‐oxide 5 with dimethyl or diethyl acetylenedicarboxylate and 2‐chloroacrylonitrile, respectively. The reaction mechanisms were postulated for the formation of 6a,b and 9.
Synthesis of pyrrolo[1,2‐a]quinoxalines by 1,3‐dipolar cycloaddition reaction. An additional reaction mechanism via an aziridine intermediate
Authors: Kim Ho Sik , Kurasawa Yoshihisa , Yoshii Chiemi , Masuyama Minako , Takada Atsushi , Okamoto Yoshihisa
Published: March 2009

The reaction of the 2‐substituted 6‐chloroquinoxaline 4‐oxides 1a or 1b with 2‐fold molar amount of methyl propiolate resulted in the 1,3‐dipolar cycloaddition reaction to give 8‐chloro‐1,3‐bismethoxycarbonyl‐4‐(piperidin‐1‐yl)pyrrolo[1,2‐a]quinoxaline 4a or 8‐chloro‐1,3‐bismethoxycarbonyl‐4‐(morpholin‐4‐yl)pyrrolo‐[1,2‐a]quinoxaline 4b, respectively. Compound 4a or 4b was transformed into 8‐chloro‐3‐methoxycarbonyl‐4‐(piperidin‐1‐yl)pyrrolo[1,2‐a]quinoxaline 5a or 8‐chloro‐3‐methoxycarbonyl‐4‐(morpholin‐4‐yl)pyrrolo[1,2‐a]‐quinoxaline 5b, respectively. The structure of 4a,b was confirmed by the NOE measurement among the C1‐H, C2‐H and C9‐H proton signals of 5a,b. An additional reaction mechanism was proposed for the ring transformation of isoxazolo[2,3‐a]quinoxalines into pyrrolo[1,2‐a]quinoxalines.
Synthesis of isoxazolo[2,3‐a]quinoxalines and pyrrolo[1,2‐a]quinoxalines by 1,3‐dipolar cycloaddition reaction
Authors: Kim Ho Sik , Kurasawa Yoshihisa , Yoshii Chiemi , Masuyama Minako , Takada Atsushi , Okamoto Yoshihisa
Published: March 2009

The isoxazolo[2,3‐a]quinoxalines 11a,b and pyrrolo[1,2‐a]quinoxalines 12a,b were selectively synthesized from the 2‐substituted 6‐chloroquinoxaline 4‐oxides 10a,b. The pyrrolo[1,2‐a]quinoxalines 12a,b were clarified to be produced by the ring transformation of the isoxazolo[2,3‐a]quinoxalines 11a,b. The pyrrolo[1,2‐a]quinoxalines 14a,b were obtained from both 2,6‐dichloroquinoxaline 4‐oxide 9 and compounds 12a,b.
Transaminations of enaminones:A Synthesis of tricyclic, N‐aryl, 1,2,3‐triazole‐fused pyridones
Authors: Chan Tze‐Ming , Friary R. , Jones H. , Schwerdt J. H. , Seidl V. , Watnick A. S. , Williams S. M.
Published: March 2009

1‐Phenylmethyl‐ and 1‐(4‐methoxyphenylmethyl)‐5‐chloro‐1,2,3‐triazole‐4‐carbonyl chlorides acylated the pyrrolidine enamines of cyclopentanone and cyclohexanone, and the resulting enaminones underwent transaminations with aryl amines under acidic conditions. The products then cyclized under basic conditions to linearly fused, tricyclic 3‐phenylmethyl‐ and 3‐(4‐methoxyphenylmethyl)‐4‐aryl‐8‐oxo‐4,5,6,7‐tetrahydrocyclopenta[6]‐1,2,3‐triazolo[4,5‐e]pyridines, and to 5,6,7,8‐tetrahydro‐4‐aryl‐3H‐1,2,3‐triazolo[4,5‐b]quinolin‐9(4H)‐ones. Similar transaminations afforded the related 8‐phenyl‐ and 8‐(3‐chlorophenyl)‐1,5,7,8‐tetrahydro‐1‐(phenylmethyl)‐4H‐thieno[3,4‐e]‐1,2,3‐triazolo[4,5‐b]pyridin‐4‐ones. Phase‐transfer and catalytic hydrogenolyses of some of these intermediates furnished 4‐aryl‐8‐oxo‐4,5,6,7‐tetrahydrocyclopenta[b]‐1,2,3‐triazolo[4,5‐e]pyridines and 4‐aryl‐5,6,7,8‐tetrahydro‐3H,2,3‐triazolo[4,5‐b]quinoline‐9‐(4H)‐ones.

The 3‐(4‐methoxyphenylmethyl)‐4‐aryl intermediates were sterically crowded. Two protons from the methoxyphenylmethylphenylmethylgroups were dramatically shielded because of anisotropic effects exerted by the 4‐aryl substituents.
Preparation, characterization and reactions of novel vicinal dibenzotriazol‐1‐yl derivatives of benzotriazole and glyoxal
Authors: Katritzky Alan R. , Fan Wei‐Qiang
Published: March 2009

A variety of novel 1,2‐disubstituted‐1,2‐di(benzotriazol‐1‐yl)ethane and 1,2‐di(benzotriazol‐1‐yl)ethylene derivatives were prepared from the adduct of benzotriazole and glyoxal.
Preparation of a variety of macrocyclic Di‐ and tetraamides and their peraza‐crown analogs using the crab‐like cyclization reaction
Authors: Krakowiak Krzysztof E. , Bradshaw Jerald S. , Izatt Reed M.
Published: March 2009

Twelve new macrocyclic di‐ and tetraamides have been synthesized from the reaction of a bis(α‐chloroamide) with a primary amine or with a diamine. Some of these cyclic di‐ and tetraamides contained pendant aminoalkyl groups attached on one or more ring nitrogen atoms. Two macrocyclic dithiadiamides were prepared from the reaction of a bis(α‐chloroamide) and a dimercaptan. In every case, 12‐, 14‐ and 15‐membered cyclic di‐ and tetraamides were isolated in good yields. The 9‐, 17‐ and 18‐membered macrocycles were prepared in lower yields. Four of the amide‐containing macrocycles were reduced by diborane to the perazacrown compounds.
Fused s‐triazino heterocycles. XVI. 13H‐1,3,7,8,12a, 13c‐hexaazabenzo[de]naphthacene and 1,3,7,8,11b, 12,14,14d‐octaazadibenzo[de,hi]naphthacene, two new ring systems
Authors: Shaw John T. , Egler Mallory F. , Peciulis Victoria S. , Pustover Regina , Ruth William G.
Published: March 2009

The reaction of 7,9‐dibromo‐5‐tribromomethyl‐2‐t‐butyl‐4‐cyano‐1,3,6,9b‐tetraazaphenalene (1a) with 2‐amino‐5‐picoline is shown to give 4,6‐dibromo‐2‐t‐butyl‐13‐imino‐11‐methyl‐13H‐1,3,7,8,12a,13c‐hexaazabenzo[de]naphthacene (3) and the isomeric 7,9‐dibromo‐2‐t‐butyl‐4‐cyano‐5N‐(5‐methyl‐2‐pyridyl)amino‐1,3,‐6,9b‐tetraazaphenalene (2a). A related annulation reaction of 7,9‐dibromo‐2‐t‐butyl‐5‐chloro‐4‐cyano‐1,3,6,9b‐tetraazaphenalene (1g) with 2‐amino‐6‐trimethylacetamidopyridine leads in two steps to 4,6‐dibromo‐2,13‐di‐t‐butyl‐1,3,7,8,11b,12,14,14d‐octaazadibenzo[de,hi]naphthacene (4a). The preparation of 1g, 5‐azido‐7,9‐dibromo‐2‐t‐butyl‐4‐cyano‐1,3,6,9b‐tetraazaphenalene (1c) and the reaction of the latter with pyrrolidine leading to 7,9‐dibromo‐2‐t‐butyl‐4‐cyano‐5‐(1‐pyrrolidino)‐1,3,6,9b‐tetraazaphenalene (1e) are also reported. Attempted displacement of the azido‐group on 1c by 2,6‐diaminopyridine affords surprisingly 5‐amino‐7,9‐dibromo‐2‐t‐butyl‐4‐cyano‐1,3,6,9b‐tetraazaphenalene (1d).
Synthèse et étude physicochimique des 1,2,4‐triazolo[4,3‐a]‐pyridines et des 1,2,4‐triazolo[2,3‐a]pyridines
Authors: Bouteau Brigitte , Lancelot Jean‐Charles , Robba Max
Published: March 2009

Les 8‐nitro‐1,2,4‐triazolo[4,3‐a] et [2,3‐a]pyridines 7–8 sont accessibles par cyclisation de la 2‐hydrazino‐8‐nitropyridine 3a dans l'acide formique. Leur réduction par l'hydrogène sous pression en présence de charbon palladié conduit suivant les conditions aux triazolopyridines 9–13 où à la triazolopyridine 10 par action du chlorure stanneux en milieu acide. Les spectres de rmn confirment la structure des dérivés obtenus.
Synthesis and spectral data of 4,5‐bis[5‐aryl‐1,3,4‐oxadiazol‐2‐yl]‐1‐benzyl‐1,2,3‐triazoles
Authors: Theocharis A. B. , Alexandrou N. E.
Published: March 2009

The synthesis of the title compounds 3 upon cyclodehydration with thionyl chloride of the corresponding bis‐aroylhydrazides 2 is described and their spectral properties are examined.
Assembled systems [picoline]‐[X‐azolopyridine]: Bases, salts and polymethine dyes
Authors: Savarino Piero , Viscardi Guido , Barni Ermanno , Carpignano Rosarina
Published: March 2009

A series of assembled heterocyclic bases containing picolines and X‐azolopyridines was synthesized, thus widening the outline of available compounds for a comparison of their chemical, physical and spectroscopic properties. In particular, the competition of three different sites toward quaternizing agents has been explored and individual behaviours have been clarified by 1H nmr spectroscopy. Styryl dyes have been prepared and characterized. The effect of cationic and anionic surfactants on deaggregating one unsymmetrical cyanine has been successfully tested.
Oxygen‐17 and carbon‐13 nuclear magnetic resonance spectra of thiophene‐ and pyrrole‐2‐carboxaldehyde condensation products prepared from ephedrine derivatives
Authors: Eggleton Gordon L. , Cooper Bill A. , Sturch Chris L. , Trent Jonathan C. , Mulekar Satish V.
Published: March 2009

Natural abundance 17O nmr (acquired in acetonitrile at 70°) and 13C nmr (acquired in deuteriochloroform at 37°) spectroscopic data for four oxazolidines and related imino alcohols are reported: relationships of chemical shifts and 17O line widths at half‐heights to structures are discussed.
Electron impact induced synthesis of benzo[2,1‐b:3,4‐b′]dithiophene
Authors: Sturaro Alberto , Traldi Pietro , Audisio Guido , Destri Silvia , Catellani Marinella
Published: March 2009

The photochemical behaviour of cis and trans 1,2‐bis(2‐bromo‐3‐thienyl)ethene has been separately studied with respect to cyclization to benzo[2,1‐b:3,4‐b′]dithiophene (BDT). The gc/ms analysis of the mother liquors of the two isomers photoreaction shows the opposite direction of isomerization followed by production of intractable materials resulting by the radical breaking of one of the two C‐Br bonds on the thiophene moiety. On the contrary, in EI mass spectrometry both the isomers give rise to fragment ions at m/z 190 studied and compared to BDT with the aid of mass analysed ion kinetic energy spectrometry and collisional spectroscopy.
Synthesis, alkylation and ring opening of two differently fused pyridoquinazolones
Authors: Timári Géza , Hajós György , Messmer András
Published: March 2009

Alkylation of two differently (linearly and angularly) fused pyridoquinazolones 7 and 10 have been investigated. The linear 7 afforded exclusively N‐alkyl derivatives 4, whereas the angular 10 gave both N‐ and O‐alkyl products 5 and 11, respectively depending on the type of the reagent used. Reaction of the new alkylated salts 4, 5, and 11 with nucleophiles was found strongly dependent on the fusion type of the substrates: the reaction of the linear salt 4 led to opening of the pyrimidine moiety, and the angularly fused salts 5, 11 reacted at the pyridine site to give quinazolyldieneamines 17, 19. Regioselectivities of the observed conversions were interpreted on FMO basis.
The synthesis of substituted 2,3‐dihydrothieno[2,3‐b]‐thiophenes via intramolecular michael addition
Authors: Williams Theresa M. , Hudcosky Ronald J. , Hunt Cecilia A. , Shepard Kenneth L.
Published: March 2009

The first regiospecific synthesis of the 2,3‐dihydrothieno[2,3‐b]thiophene ring system was achieved using an intramolecular Michael addition in the key cyclization step. This strategy represents a novel and potentially general method for dihydrothiophene and dihydrothiophene S,S‐dioxide annellation.
Synthesis of 3‐substituted 2‐hydroxybenz[f]indolequinones and benz[f]isatinquinone ‐ A new π‐acceptor system
Authors: Shakhnovich A. I.
Published: March 2009

Starting from 2,3‐dichloro‐1,4‐naphthaquinone a series of 2‐hydroxy‐1‐methylbenz[f]indolequinones bearing benzyl‐, amino‐ and hydroxy substituents in position 3, and benz[f]isatinquinone have been synthesised and their reactions have been studied.
Reactions with hydrazidoyl halides. IV. Synthesis of thiazolo[3,2‐a]benzimidazoles, imidazo[2,1‐6]thiazoles and pyrazolo[4,3‐b]thiazines
Authors: Abdelhamid Abdou O. , Attaby Fawzy A.
Published: March 2009

Hydrazidoyl halides were condensed with 2‐mercaptobenzimidazole yielding 4a‐c and 7a,b which were cyclized to the corresponding 2‐arylhydrazonothiazolo[3,2‐a]benzimidazol‐3‐ones 5a,b and 3‐substituted 2‐arylazo thiazolo[3,2‐a]benzimidazoles 8a,b respectively. Imidazo[2,1‐b]thiazoles were obtained by the reaction of hydrazidoyl halides with 2‐mercapto‐4,5‐dihydroimidazole. Also, hydrazidoyl halides 6a,b were reacted with 3‐amino‐4‐mercapto‐5‐phenylpyrazole to give pyrazolo[4,3‐b]thiazines 15a,b. The structures of the products were assigned on the basis of their elemental analysis and spectral data.
Acid‐catalyzed reactions of 1‐ and 3‐(α‐hydroxybenzyl)indolizines
Authors: Miki Yasuyoshi , Hiroishi Yuji , Hachiken Hiroko , Takemura Shoji
Published: March 2009

Treatment of 1‐(α‐hydroxybenzyl)‐ and 3‐(α‐hydroxybenzyl)indolizines with trifluoroacetic acid in dichloromethane gave phenylbis(α‐indolizinyl)methanes, bis[α‐(indolizinyl)benzyl] ethers and indolizines, depending upon the presence or absence of the substituent at the 2‐ or 5‐position and the reaction conditions used.
Synthesis and identification of new thieno[3,2‐b] benzothiophenes
Authors: Jackson Johnny L.
Published: March 2009

The reaction of 2‐lithiobenzo[b]thiophenes with ketones produced 2‐hydroxyalkylbenzo[b]thiophenes which were cyclized in thionyl chloride to give novel thieno[3,2‐b][1]benzothiophenes. Oxidation with peroxyacetic acid gave the S,S‐dioxides whose regiochemistry was identified from 1H nmr model studies using substituted benzo[b]thiophenes and their corresponding‐1,1‐dioxides [1].
Chemistry of condensed thiophenes. V. Sulfonation and sulfonyl bridging of m‐terphenyl. Conversion to sulfonamides
Authors: Klemm L. H. , Lane Will , Hall Eliot
Published: March 2009

Reaction of m‐terphenyl with 20% oleum at 100° gives both disulfonation and double sulfonyl bridging to yield benzo[1]thieno[2,3‐b]dibenzothiophene‐3,9‐disulfonic acid 5,5,7,7‐tetraoxide, isolated as the disodium salt (24%) and convertible (via the disulfonyl chloride) to the bis‐sulfonanilide (44%) and the bis‐N‐butylsulfonamide (40%). Analogously, reaction of m‐terphenyl with chlorosulfonic acid at 100° gives disulfonation plus only single sulfonyl bridging to produce 2‐(4‐chlorosulfonyl)‐7‐chlorosulfonyldibenzothiophene 5,5‐dioxide (80%), convertible to the corresponding bis‐sulfonanilide (63%) and the bis‐N‐butylsulfonamide (45%).
Metallation of diazines. III. New synthesis of analogues of trimethoprim and of bacimethrin
Authors: Ple N. , Turck A. , Fiquet E. , Queguiner G.
Published: March 2009

4‐Chloro‐2,6‐dimethoxypyrimidine was lithiated by lithium 2,2,6,6‐tetramethylpiperidide. The resulting lithio derivative was submitted to reaction with carbonyl derivatives, iodine and trimethyltin chloride. Synthesis of analogues of trimethoprim and of bacimetrin are reported.
Nouvelle synthèse des composés polysubstitués d'esters de l'acide pyrrolecarboxylique‐3 par réarrangement d'époxy‐1,2 pyrrolidines
Authors: Dehnel André , Kanabus‐Kaminska Jolanta M.
Published: March 2009

Sous Taction des acides (en particulier fluorure d'hydrogène/pyridine) les éthoxycarbonyl‐3 oxa‐6 aza‐1 bicyclo[3,1,0]hexanes polysubstitués 1 se transforment de façon stéréospécifique en éthoxycarbonyl‐3 pyrroles polysubstitués 3. Les substrate 1 spiranniques conduisent dans ces conditions aux produits polycycliques.
Directed regiospecificity of 1,3‐dipolar cycloaddition of 2‐diazopropane to 4‐ and 5‐substituted pyridazin‐3(2H)‐ones
Authors: Jelen Boris , Štimac Anton , Stanovnik Branko , Tišler Miha
Published: March 2009

6‐Methoxy‐2‐methylpyridazin‐3(2H)‐one (1) gave with 2‐diazopropane (8) a mixture of 3H‐pyrazolo[3,4‐d]‐pyridazin‐4(5H)‐one derivative 12, as the main product, and ‐7(6H)‐one derivative 10, as the minor product. On the other hand, 4‐substituted pyridazin‐3(2H)‐ones 2, 3, and 4 gave 3H‐pyrazolo[3,4‐d]pyridazin‐7(6H)‐one 10, exclusively, while 5‐substituted pyridazin‐3(2H)‐ones 5, 6, and 7 produced only the isomeric 3H‐pyrazolo[3,4‐H]pyridazin‐4(5H)‐one 12. The 5‐phenylsulfonyl derivative 13 gave with 8 by elimination of a molecule of nitrogen, followed by rearrangement, 1,2‐diazepine derivative 15 and with an excess of 8 3H‐pyrazolo[3,4‐d][1,2]diazepine derivative 16. 1,2‐Dimethylpyridazine‐3,6‐(1H,2H)‐dione and its derivatives 18 and 19 produced 3H‐pyrazolo[3,4‐d]pyridazine‐4,7(5H,6H)‐dione derivative 23, while from 17 and 1‐diazoindane (24) the spiro compound 27 was obtained. The 1,2‐dihydro and 3a,7a‐dihydro intermediates 21 and 25 were isolated.
Synthesis of various 5‐substituted 2′‐deoxy‐3′‐5′‐di‐O‐acetyluridines
Authors: Peters Dan , Hörnfeldt Anna‐Britta , Gronowitz Salo , Johansson Nils Gunnar
Published: March 2009

The Pd(0)‐catalyzed coupling reaction of β‐5‐iodo‐2′‐deoxy‐3′,5′‐di‐O‐acetyluridine with various heteroaryltrimethylstannyl compounds gave the corresponding β‐5‐heteroaryl‐2′‐deoxy‐3′,5′‐di‐O‐acetyluridines in moderate yields. This direct coupling approach for nucleosides represented an interesting alternative to the 5‐heteroaryl functionalization of pyrimidines followed by the Hilbert‐Johnson glycosylation reaction which often yields mixtures of the α and β anomers.
Pyrazoles. 5. Novel pyrazole analogues of flavanone, flavone and flavane
Authors: Heinisch Gottfried , Hollub Christian , Holzer Wolfgang
Published: March 2009

The synthesis of the new pyrano[2,3‐c]pyrazole derivatives 4, 5, and 7 starting from (E)‐(1,3‐dimethyl‐5‐hydroxy‐4‐pyrazolyl)‐3‐phenyl‐2‐propen‐1‐one (2) is reported.
Synthesis and antibacterial activities of novel oxazine and thiazine ring‐fused tricyclic quinolonecarboxylic acids: 10‐(Alicyclic amino)‐9‐fluoro‐7‐oxo‐7H‐pyrido[1,2,3‐de][1,4]benzoxazine‐6‐carboxylic acids and the corresponding 1‐thia congeners
Authors: Okada Tetsuo , Tsuji Teruji , Tsushima Tadahiko , Ezumi Kiyoshi , Yoshida Tadashi , Matsuura Shinzo
Published: March 2009

Several analogs 4 and 5 of Ofloxacin (1) which contain the oxazine and thiazine rings fused with a quinolone carboxylic acid moiety, respectively, were prepared and their in vitro and in vivo antibacterial activities were compared with those of 1 and its previously prepared 3‐exo‐methylene analogs 2 and 3. Unlike 1, 2, and 3, analogs 4 and 5 possess an antiaromatic oxazine and thiazine moiety and show markedly lower antibacterial activities. Alteration of their C‐10 amino‐substituent groups from piperazine to azetidine significantly improved the in vitro antibacterial activities, particularly in the case of the thiazine derivative 5, but not the in vivo ones. The antibacterial activities of these three types of tricyclic quinolonecarboxylic acids are briefly discussed on the basis of the molecular properties revealed by molecular orbital calculation. The molecular dipole moment was suggested to be one possible factor controlling the binding affinity of these compounds with DNA gyrase.
Synthesis of condensed quinoxalines
Authors: Sabnis R. W. , Rangnekar D. W.
Published: March 2009

A novel efficient synthesis of fluorescent, fused quinoxalines was achieved. 6‐Triazolylthiazolo[4,5‐b]quinoxalines were synthesized by the diazotisation of 6‐amino‐2‐methylthiazolo[4,5‐b]quinoxaline and coupling with selected aromatic amines followed by air oxidation. Diazotised aryl amines were coupled with 6‐amino‐2‐methylthiazolo[4,5‐d]quinoxaline followed by subsequent air oxidation afforded 1,2,3‐triazolo[5,4‐f]quinoxalino[2,3‐d]thiazoles. 6‐Amino‐2‐methylthiazolo[4,5‐b]quinoxaline was condensed with conjugated enol ethers followed by cyclization in dowtherm resulted in thiazolo[4,5‐b]quinoxalino[6,5‐b]pyridine.
3‐Substituted 2‐pyridinecarbaldoximes
Authors: Kao Bo‐Chan , Doshi Haresh , Reyes‐Rivera Hector , Titus Donald D. , Yin Mali , Dalton David R.
Published: March 2009

A series of 2‐pyridinecarbaldoximes and salts derived from them by methylation of the pyridine nitrogen, all of which are substituted at the 3‐position with carbon (i.e., derivatives of nicotinic acid and its homologues) or oxygen, have been prepared.
Products from furans. VII. A General Route for the Synthesis of α‐(1,2‐cis) and β‐(1,2‐trans) Glycoconjugates via 1‐O‐Acyl and 1‐O‐Ethoxycarbonyl‐2‐azido‐2,3‐dideoxyglycopyranosides
Authors: Georgiadis Minas P. , Couladouros Elias A.
Published: March 2009

A methodology for the synthesis of 2,3,6‐trideoxy‐ and 2,3‐dideoxy‐2‐aminoglycosides is presented. 2,3‐Dideoxyhex‐2‐enopyranos‐4‐uloses (named also as 2H‐pyran‐3(6H)‐ones) were used for the synthesis of 1‐O‐acetyl, 1‐O‐ethyloxycarbonyl and 1‐S‐phenyl‐2,3,6‐trideoxy‐(or 2,3‐dideoxy)‐2‐azidoglycopyranosyl donors. Glycosidation of the above thio‐ethers with a variety of alcohols in the presence of N‐bromosuccinimide as activator yielded predominantly α‐glycosides, while acetates afforded β‐glycosides when TMSOTf was used as a promoter. The coupling of carbonates using tin tetrachloride or TMSOTf proved to be the most successful procedure, yielding the β‐glycoside as the predominant product. Thus, glycoconjugates of aminosugars, steroids and aminoacids have been synthesized.
Further studies on the synthesis of quinazolines from 2‐fluorobenzonitriles
Authors: Hynes John B. , Tomažič Alenka , Parrish Christie A. , Fetzer Oliver S.
Published: March 2009

Recently, we reported that appropriately substituted 2‐fluorobenzonitriles undergo cyclization with guanidine carbonate to afford 2,4‐diaminoquinazolines usually in good to excellent yield. This paper describes the preparation of a variety of new 2,4‐diaminoquinazolines substituted at positions five or seven. In addition, the reactions of selected 2‐fluorobenzonitriles with formamidine acetate or acetamidine acetate were examined. The results obtained demonstrate that the analogous 4‐amino‐ and 2‐methyl‐4‐aminoquinazolines can be prepared by this approach but that the yields are considerably lower than when guanidine carbonate is employed as the cyclization reagent.
Synthesis of 1,3,4‐thiadiazin‐2‐one and 1,3,4‐selenadiazin‐2‐one derivatives as new cardiotonic drugs
Authors: Morvan Marcel , Nadler Guy , Zimmermann Richard G.
Published: March 2009

The synthesis of the new heterocycle 1,3,4‐selenadiazin‐2‐one is described, based on the preparation of the analogue heterocycle 1,3,4‐thiadiazin‐2‐one. The related cyclization between an α‐haloketone and a thiocarbazate cannot readily be employed within the selenium series. Therefore a new route was developed based upon a diazotization/hydrolysis sequence of the related 2‐amino‐1,3,4‐selenadiazine.
13C and 1H NMR analysis of the nitration products of 2‐amino‐4‐oxo‐(3H)‐5‐trifluoromethylquinazoline and 2‐amino‐4‐oxo‐(3H)‐5‐fluoroquinazoline
Authors: Singh Shyam K. , Fetzer Oliver S. , Hynes John B. , Williams Thomas C.
Published: March 2009

Nitration of 2‐amino‐4‐oxo‐(3H)‐5‐trifluoromethylquinazoline is shown to occur exclusively at C6 as determined from an analysis of long range 1H and 19F scalar couplings to ring carbons. Nitration of 2‐amino‐4‐oxo‐(3H)‐5‐fluoroquinazoline is found to occur both at C6 and C8 as evident from an analysis of the 19F and 1H couplings of the ring protons.
Simple synthetic routes to 5‐(3,6‐dihydro‐2‐oxo‐2H‐1,3,4‐thiadiazin‐5‐yl)‐1H‐indole‐2,3‐diones and their Derivatives
Authors: Delimoge Isabelle , Morvan Marcel , Nadler Guy , Zimmermann Richard G.
Published: March 2009

Two different synthetic routes to 5‐(3,6‐dihydro‐2‐oxo‐2H‐1,3,4‐thiadiazin‐5‐yl)‐1H‐indole‐2,3‐diones are described. The reaction sequences represent a facile entry into these series of isatin derivatives.
Synthesis of 5‐chloropyrazoles by chlorodediazoniation with sulfur dioxide
Authors: Yamamoto Susumu , Morimoto Katsushi , Sato Toshiaki
Published: March 2009

A facile synthesis of 5‐chloropyrazoles 4a‐e from 5‐aminopyrazoles 2a‐e via diazotization followed by chlorodediazoniation is described. A new application of sulfur dioxide as a catalyst was demonstrated to be the best for the chlorodediazoniation of diazonium chlorides 3a‐e.
On triazoles. XXV. The reaction of methyl (5‐amino‐3‐Q‐1H‐1,2,4‐triazolyl)dithiocarbonates with amines
Authors: Barkóczy József , Reiter József
Published: March 2009

Different “functionalised” triazolylthioamides 3 and ‐thioureas 4 were synthesised. The ring closure of the ω‐hydroxyalkylthioamides 3/2–5 led to the corresponding 2‐thiazoline 5/2–4 and 5,6‐dihydro‐4H‐1,3‐thiazine 5/5 derivatives, respectively. Unexpectedly, the ring closure of the corresponding 2,2‐dimethoxyethyl derivative 3/18 led depending on the reaction conditions to a thiazole derivative 6 or to its 1,2,4‐triazolo[3,4‐b]‐1,3,5‐triazepin‐5(9H)‐thione isomer 7 representing a novel ring system. To corroborate its structure 7 was methylated to the corresponding S‐methyl derivative 8. Spectroscopical evidence is given for the structure of derivatives 3–8 obtained.
Synthesis of 5‐cyclopropyluracil and 5‐cyclopropylcytosine by the Pd(0)‐catalyzed coupling reaction
Authors: Peters Dan , Hörnfeldt Anna‐Britta , Gronowitz Salo
Published: March 2009

5‐Cyclopropyluracil and cyclopropylcytosine were prepared by the Pd(0)‐catalyzed coupling reaction of 5‐bromo‐2,4‐di(trimethylsilyloxy)pyrimidine and 5‐bromo‐2,4‐O,N‐bis‐trimethylsilylcytosine with tributylstan‐nylcyclopropane. The reactions also gave dehalogenated pyrimidine bases as by‐products. Attempts to use 2,4‐O,N‐bis‐trimethylsilyl‐5‐iodocytosine as the halide gave complete dehalogenation.
Oxidation of 1,3,4,6‐tetrakis(alkylthio)thieno[3,4‐c]‐thiophenes with iodine in the presence of aniline
Authors: Tsubouchi Akira , Kitamura Chitoshi , Matsumura Noboru , Inoue Hiroo
Published: March 2009

1,3,4,6‐Tetrakis(alkylthio)thieno[3,4‐c]thiophenes were oxidized by iodine in the presence of aniline in dry benzene to give 1,4,6‐tris(alkylthio)thieno[3,4‐c]thiophen‐3(1H)‐imines in high yields through the intermediary formation of their cation radicals.
Linked porphyrin systems
Authors: Fleischer Everly B. , Shachter Amy M.
Published: March 2009

Porphyrin monomers, 5‐(monopyridyl)‐10,15,20‐(triphenyl)porphyrin (1), 5,10‐(dipyridyl)‐15,20‐(diphenyl)‐porphyrin (2), and 5,15‐(dipyridyl)‐10,20‐{diphenyl)porphyrin (3), were linked by hydrocarbon chains to form a series of dimers, trimers and polymers. The 5‐(monopyridyl)‐10,15,20‐(triphenyl)porphyrin monomers were linked by 2, 4, 6, 8 and 10 carbon chains through the alkylation of the pyridine nitrogens using the appropriate diiodoalkane to form positively charged linked dimers 4–8. A trimer 12 was synthesized from two 5‐(monopyridyl)‐10,15,20‐(triphenyl)porphyrin and one 5,10‐(dipyridyl)‐15,20‐(diphenyl)porphyrin linked by a six carbon chain. Hydrocarbon linked (5,10‐(dipyridyl)‐15,20‐(diphenyl)porphyrin)n (13) and (5,15‐(dipyridyl)‐10,20‐(diphenyl)porphyrin)n (14) were also prepared.
Heterocycles from amino acids. A novel synthetic approach for imidazo[1,5‐a]pyridines and imidazo[1,5‐a]quinolines
Authors: Kolar Patrik , Petrič Andrej , Tišler Miha , Felluga Fulvia
Published: March 2009

From the corresponding heterocyclic amino acids 2 and 9a the heterocyclic systems imidazo[1,5‐a]pyridine (3) and imidazo[1,5‐a]quinoline (10) are easily accessible. From compound 7 the tricyclic system 11 was prepared and from compound 17a a pyridyl‐1,2,4‐triazinone (18) could be obtained.
17O NMR spectroscopy: Intramolecular hydrogen bonding in hydroxypyridine carboxy esters
Authors: Boykin David W. , Kumar Arvind
Published: March 2009

Natural abundance 17O nmr chemical shift data for 8 aryl esters and 10 pyridine carboxy esters, including 6 ortho‐hydroxy esters, recorded in acetomitrile at 75° are reported. The carbonyl group 17O nmr chemical shift data for methyl 2‐, 3‐ and 4‐pyridinecarboxylate are correlated with σ+ constants. The hydrogen bonding component (ΔδHB) to the ester carbonyl 17O nmr chemical shift for the intramolecular hydrogen bonded ortho‐hydroxy systems are 9.8 ppm, 13.6 ppm and 4.3 ppm for benzoates, 2‐pyridinecarboxylates and 4‐pyridinecarboxylates, respectively. The relationships of the ester ΔδHB values to other hydrogen bond acceptor ΔδHB values are discussed.
Analogues of the antibiotic puromycin as potential prodrugs of 3′‐amino‐3′‐deoxythymidine
Authors: Wengel Jesper , Motawia Mohammed S. , Pedersen Erik B. , Nielsen Carsten M.
Published: March 2009

Condensation of L‐ and D‐3′‐amino‐2′,3′‐dideoxynucleosides 2–5 with N‐BOC‐protected aminoacids 6 and 13 using dicyclohexylcarbodiimide and N‐hydroxysuccinimide in DMF is reported to give the N‐BOC‐protected acylamino aminonucleosides 7–9 and 14 in 51–81% yield. After deprotection using trifluoroacetic acid the corresponding unprotected new analogues of puromucin 10–12 and 15 were obtained in 43–56% yield. These compounds did not show any significant antiviral activity using HIV (stain HTLV‐III B)‐infected MT‐4 cells as target system.
First transformations of pyrano[3,4‐b]indol‐3‐ones to salvadoricine and 2,3‐diacylindoles
Authors: Pindur Ulf , Erfanian‐Abdoust H.
Published: March 2009

The readily available methylated pyrano[3,4‐b]indol‐3‐ones 1a and 1b were hydrolyzed to furnish the 2‐acetylindol‐3‐alkanoic acids 2 and 4. Compound 2 was easily transformed selectively to 2‐acetyl‐3‐methylindole (3, salvadoricine). Substrate 1b reacts with molecular oxygen from the air only in the presence of a catalyst to give 2,3‐diacetylindole (5) while 1a reacts with nitrosobenzene via a proposed Diels‐Alder step to yield 2‐acetylindole‐3‐carbaldehyde (6). The latter product can also be obtained in low yield from the reaction of 1a with molecular oxygen from the air.
Amidrazones. 14. The formation of 1,1‐disubstituted hydrazines from the base‐promoted hydrolysis of 1,l‐disubstituted‐3‐amino‐4,5‐dihydro‐1H‐pyrazolium halides: Mechanistic considerations
Authors: Smith Richard F. , Dennis Lisa A. , Ryan William J. , Rodriguez George , Brophy Keith A.
Published: March 2009

Three mechanistic pathways are considered for the hydroxide‐promoted conversion of 1,1‐disubstituted‐3‐amino‐4,5‐dihydro‐1H‐pyrazolium halides 1 to 1,1‐disubstituted hydrazines, ammonia and sodium 3‐hydroxypropanoate. Evidence presented in this paper supports a hydrolysis mechanism c that is initiated by hydroxide ion addition to the 3‐position of 1 to form a tetrahedral intermediate 7.
One‐pot synthesis of 4‐acylimino‐2‐aminothieno[2,3‐d][1,3]‐thiazines from 2‐thioureidothiophene‐3‐carbonitriles
Authors: Gütschow Michael , Leistner Siegfried , Pink Maren
Published: March 2009

A new one‐pot synthesis of 4‐acylimino‐2‐aminothieno[2,3‐d][1,3]thiazines 4 and 5, respectively, from 2‐thioureidothiophene‐3‐carbonitriles 1, acetic, propionic anhydride, respectively, and concentrated sulfuric acid is reported. The structure of 4a is confirmed by X‐ray structure analysis.
Carbazoledioxazines having long alkyl groups. 3. Syntheses and properties of halogen free carbazoledioxazines
Authors: Ikeda Masaaki , Kitahara Kiyoshi , Nishi Hisao
Published: March 2009

Long chain derivatives of halogen free carbazoledioxazine which is a typical organic pigment with a linear type structure (5,15‐dialkyl‐5,15‐dihydrodiindolo[3,2‐b:3′,2′‐m]triphenodioxazines) and an angular type structure (5,15‐dialkyl‐7,17‐dialkoxy‐5,15‐dihydrodiindolo[2,3‐c:2′,3′‐n]triphenodioxazines) were newly synthesized. Their structures were confirmed by 1H‐nmr, ms and elemental analysis. The thermal, spectroscopical and electrochemical properties were investigated by means of DSC, uv‐vis and cyclic voltammetry.
Synthesis of novel 1,3‐oxazino[6,5‐b]indole‐2,4‐(3H,9H)‐dione and 2H‐1,3,5‐oxadiazino[3,2‐a]indole‐2,4‐(3H)‐dione from oxindoles
Authors: Gallaschun Randall J. , Schnur Rodney C.
Published: March 2009

Two novel tricyclic ring systems were designed as serine protease inhibitors and synthesized from oxindoles; the first series, 1,3‐oxazino[6,5‐b]indole‐2,4‐(3H,9H)‐diones, were prepared from 2,3‐dihydro‐2‐oxo‐(1H)‐indole‐3‐carboxamides and phosgene in tetrahydrofuran with triethylamine. The second, a 2H‐1,3,5‐oxadiazino[3,2‐a]indole‐2,4‐(3H)‐dione was made using a similar cyclization on 2,3‐dihydro‐2‐oxo‐N‐phenyl‐(1H)‐indole‐1‐carboxamide.
Addition‐rearrangement reactions of 5‐amino‐3‐oxo‐Δ4–1,2,4‐thiadiazolines
Authors: L'Abbé Gerrit , Albrecht Ernestine
Published: March 2009

Bond‐switching rearrangement via hypervalent sulfur occurs during the reactions of 5‐anilino‐2‐benzyl‐3‐oxo‐Δ4–1,2,4‐thiadiazoline 5 with electrophilic nitriles, isothiocyanates, carbon disulfide and ketenes, yielding the products 6 and 7. In contrast, N,N'‐ditolylcarbodiimide reacts with 5 to give the normal addition product 8, which rearranges only partially to 9 in several solvents (chloroform, acetonitrile and dimethyl sulfoxide). The equilibrium position depends on the temperature, favoring 9 at higher temperatures.
The synthesis of a new polycyclic heterocyclic ring system: Pyrimido[5,6,1‐d,e]acridine
Authors: Antonini Ippolito , Martelli Sante
Published: March 2009

The synthesis of a new heterocylic ring system is reported. The condensation of 9,10‐dihydro‐9‐oxo‐4‐acridine carboxamide (7) with diethoxymethyl acetate gave pyrimido[5,6,1‐d,e]acridine‐3,7‐dione (8). The amide 7 reacts with ethyl chloroformate to afford 2H‐pyrimido[5,6,1‐d,e]acridine‐1,3,7‐trione (9).
Heterotricyclic systems. Part I. Synthesis of new dipyridopyrazines
Authors: Savelli Francesco , Boido Alessandro
Published: March 2009

Pursuing our previous research on azaquinoxalinones (1,2‐dihydropyrido[2,3‐b]/[3,4‐b]pyrazinones) we prepared, through a reductive cyclization of N‐(3′‐nitropyridin‐2′‐yl)piperidine‐2‐carboxylic acids 3a‐c, a set of derivatives of a new tricyclic structure, 7,8,9,10‐tetrahydro‐5H‐dipyrido[1,2‐a:3′,2′‐e]pyrazin‐6(6aH)‐ones 4a‐c. Starting from these compounds we obtained substituted amides 5a‐c and, from 4a, the amidines 6a‐c. In the synthesis of 6, a dehydrogenation reaction occurred giving rise to 7. The compounds 9 and 10, characterized by a different ring‐fusion between the pyridine and pyrazine rings, were synthesized in a similar manner.
Stereoselective synthesis of new spirobenzodihydropyrancyclohexanes
Authors: Bédoui Ahmed , Mayrargue Joëlle , Moskowitz Henri , Thal Claude
Published: March 2009

A stereoselective synthesis of unknown spirobenzodihydropyrancyclohexanes is described starting from arylcyclohexenes alkylated and cyclized via a coumarin intermediate and leading to new amino derivatives which are rigid analogs of dopamine.