Synthesis of aryl ω-(1-methyl-5-imidazolyl and 1H-5-tetrazolyl)alkyl ketones

Successful syntheses of 2,4-dichlorophenyl 2-(1-methyl-5-imidazolyl)ethyl and 2,4-dichlorophenyl 3-(1-methyl-5-imidazolyl)propyl ketones are described. In addition, syntheses of 2,4-dichlorophenyl and 4-chlorophenyl 3-(1-methyl-1H-5-tetrazolyl)propyl ketones are reported.     

N1-Substitution in 2-methyl-4(5)nitroimidazole. III. New syntheses of 1-(2′-(ethylsulfonyl)ethyl)-2-methyl-5-nitroimidazole

Some new syntheses of 1-[2′-(ethylsulfonyl)ethyl]-2-methyl-5-nitroimidazole (IV), a new antitrichomonal agent are described. The most successful method proved to be alkylation of sodium ethanesulfinate (XXI) with 1-(2′-haloethyl)-2-methyl-5-nitroimidazoles (1a,b) in dimethylformamide.     

Products of mercuric salt addition to dis ubstituted acetylenes

Summary The syntheses and properties of cls and trans-1-methyl-2-acetoxy -1-propen-1-ylmercury acetate, 1-methyl2-acetoxy-2-propen-1-ylmercury acetate and 1,2-diphenyl-2-acetoxy-1-ylmercury acetate are described.     

Structure and synthesis of goudotianine,a new 7-methyldehydroaporphine from guatteria goudotiana

Total syntheses of 2,9-dihydroxy-1,3-dimethoxy-7-methyl-6a,7-dehydroaporphine 1a and 3,9-dihydroxy-1,2-dimethoxy-7-methyl-6a,7-dehydroaporphine 1b are described. Direct comparison of both with natural goudotianine isolated from Guatteria goudotiana R. E. Fries showed the latter to be identical with 1b .     

N-(2-formyl-1-methylimidazol-4-yl)-2,2-dimethylpropanamide: a versatile reagent for preparing imidazole-amine ligands with variable second-coordination spheres

Two synthetic pathways to N-(2-formyl-1-methylimidazol-4-yl)-2,2-dimethylpropanamide from 1-methyl-2-carboxaldehyde are described. The reagent serves as a useful synthon for reductive amination reactions with primary and secondary amines in the presence of sodium cyanoborohydride to yield a series of ligands with second coordination sphere functional groups. Protocols for the syntheses of related imidazole synthons functionalized in the 4-position with amino acids, Schiff bases, and other amides are also reported.     

Synthetische Juvenilhormone 3. Mitteilung. p-Substituierte 4-Phenyl-buten(1)-carbonsäurederivate

The syntheses of p-substituted 2-methyl-4-phenylbuten(1)-carboxylic acid derivatives are described, using Blanc's chloromethylation reaction, the Friedel-Crafts alkylation of unsaturated ketones or the Meerwein arylation; the formed intermediates react in subsequent steps to the title compounds.     

Dicobalt octacarbonyl-catalyzed tandem cycloaddition reaction between diyne and diene under CO

Treatment of 1,7-diphenyl-1,6-heptadiyne and a symmetric butadiene such as 2,3-dimethyl-1,3-butadiene and 1,3-cyclohexadiene with Co(2)(CO)(8) (5 mol%) in CH(2)Cl(2) at 110 degrees C under 30 atm CO for 18 h afforded a 5.5.6 tricyclic enone in high yields. For unsymmetrical dienes such as 2-methyl-1,3-butadiene, 2-methyl-1, 3-pentadiene, and 3-methyl-1,3-pentadiene, two separable regioisomers were obtained. The catalytic reactions described are experimentally quite simple and provide a very useful synthetic procedure for the syntheses of [5.5.6] tricyclic enones.     

Synthesis of some oxadiazole derivatives of d-mannose

The syntheses of 2-methyl-5-[1′,2′,3′,4′,5′-penta-O-benzoyl-D-manno-pentitol-1′-yl]-1,3,4-oxadiazole and 5-methyl-3-[1′,2′,3′,4′,5′-penta-O-benzoyl-D-manno-pentitol-1-′yl]-1,2,4-oxadiazole, as well as their intermediate products, are described. Their ¹H and ¹³C nmr and ms spectra are presented and their preferential conformation in solution are proposed.     

Aktivierte Chinone: O- versus C-Addition von Phenolen; eine neue,regiospezifische Synthese von Xanthonen,Thioxanthonen und N-Methyl-9-acridonen

Activated quinones: O- versus C-addition of phenols. New regiospecific syntheses of xanthones, thioxanthones and N-methyl-9-acridones The acid catalyzed reaction of phenols with activated quinones, e.g. 2-methoxycarbonyl-1, 4-benzoquinone or 2-acetyl-1, 4-benzoquinone, leads to substituted biphenylderivatives (C, C-addition) as has been previously described [1]. O, C-Addition of phenols has now been achieved by using 2-methoxypyridin or 4-dimethyl-aminopyridin [4] as basic catalysts. The resulting substituted diphenylethers can serve as convenient starting materials for regiospecific syntheses of substituted xanthones, especially for 1, 4-dimethoxyxanthones. Arylthiols and N-methyl-N-arylamines also react readily with activated quinones to give substituted di-aryl-thioethers and N-methyl-N, N-diarylamines respectively; both types of compounds are convenient materials for regiospecific syntheses of substituted thioxanthones and N-methyl-9-acridones.     

Synthesis of pyrrolopyridines (azaindoles)

Improved, convenient, and reliable routes for the synthesis of 4-, 5-, 6-, and 7-azaindole, 7-methyl-4-azaindole, 7-methyl-6-azaindole, and the hitherto unreported 7-amino-4-azaindole are described. The syntheses have been accomplished either by significant modifications to established procedures or by new methods which afford the compounds in improved yields.     

Cyclometalation of Arylazo Compounds. Part 1 synthesis and cyclopalladation of some substituted 1-arylazonaphthalenes. 1st Communication on compounds with a metal-arene σ-bond

The syntheses of 1-phenylazonaphthalene ( 1a ) and its [3′-methyl- ( 1b ), 4′-methoxy- ( 1c ), 3′-methoxy- ( 1d )] derivatives are described. Cyclopalladation of these azo ligands with Pd(II) acetate or Na₂PdCl₄ leads to complexes with Pd(II) coordinated on the azo N_β-atom and a Pd? C σ-bond at C(2) in the naphthalene moiety. The preference of Pd(II) for this type of metalation at C(2) over the palladation at the ortho positions of the phenyl ring or at the peri position of the naphthyl ring is believed to be largely due to steric effects and the different reactivities of the two arene moieties. Substitution of the acetato-bridge with bromide or iodide allows the syntheses of the corresponding bromo- and iodo-bridged complexes, and a chloro-bridged dimer complex can be converted to a monomeric ethylenediamino-Pd(II)-azo species with ethylenediamine. Cyclopalladation of sulfonated azo ligands leads to water-soluble Pd(II) complexes with a Pd-C σ-bond at C(2).     

Synthesis of 1H-3-pyrazolines

Two syntheses of the 1H-3-pyrazoline system 17 are described. The syntheses make use of the ability of the azine system to act as 1,3-dipolar species in [3+2] cycloaddition reactions. The spectra data of the new compounds are discussed (IR, ¹H NMR and ¹⁹F NMR).     

The Synthesis and Characterization of Poly Oxy(2-methyl-1,3-phenylene) oxyisophthaloxyl-b-Oxy(2-methyl-1,3-phenylene)oxyterephthaloxyl

The syntheses and characterizations of poly[oxy(2-methyl-1,3-phenylene) oxyisophthaloyl-b-oxy (2-methyl-1,3-phenylene)oxy-terephthaloyl] and the corresponding homopolymers are described. The synthesis involves the coupling of dihydroxy-terminated homo-polymers with terephthaloyl chloride. The resulting block copoly-ester was characterized by infrared spectroscopy, proton and carbon- 13 nuclear magnetic resonance spectroscopy, solution viscosity, differential scanning calorimetry, and thermogravimetric analysis.     

New regional isomers of 1-methyl-5-(trifluoromethyl)pyrazoles

Utilizing the recently reported compound, 1-methyl-5-(trifluoromethyl)-2,3,4,5-tetrahydropyrazol-3-one, 4 , a series of regional isomers of 1-methyl-5-(trifluoromethyl)-3-chloropyrazole, newly substituted in the 4-position were prepared by original syntheses. Chief among them was the new regional 4-hydroxy isomer, 3a , a linkage reagent valuable for preparing new SAR candidates in the bio-active pyrazole phenyl ether series.     

General synthetic approach to bicyclo[9.3.0]tetradecenone: a versatile intermediate to clavulactone and clavirolides

An efficient and stereoselective approach to the bicyclo[9.3.0]tetradecenone core structure of clavulactone starting from readily and abundantly available 2-methyl-1,3-cyclopentandione employing microbial desymmetrization and cyanohydrin alkylation as the key steps is described. The synthetic route described herein is applicable to the syntheses of the core structures of Clavirolides A-F.     

Syntheses,characterization and x-ray crystal structures of copper(II) and nickel(II) complexes of tridentate monocondensed diamines

The syntheses and characterization of three compounds involving tridentate “half-units” 7-amino-4-methyl-5-aza-3-hepten-2-one (HAMAH) and 8-amino-4-methyl-5-aza-3-octen-2-one (HAMAO) are described. Cu(II) and Ni(II) complexes with HAMAH have been isolated as four-coordinate complexes, the fourth coordination site being taken by imidazole, and have been structurally characterized. A Cu(II) complex involving HAMAO has been isolated as a highly insoluble polymeric species. Hydroxo bridging between the metal centres is indicated.     

Synthesis and characterization of 5H-1,3-dioxolo[4,5-f]indoleethylamines

Twelve new N, N-dialkylated-5, 6-methylenedioxytryptamines and N-cyclopropyl-5, 6-methylenedioxytrypt-amine were prepared as hybrids of known psychoactive phenylethylamines and tryptamines. Novel, more convenient syntheses of N-methyl- and N-benzylcyclopropylamine are described.     

Some fused-ring succinimides as potential anticonvulsants

The syntheses of two compounds, which are fused-ring succinimides, prepared as potential anticon-vulsants, are described. The compounds are 3,4,5,6-tetrahydro-7-methyl-6-oxoindeno[7,1-bc]thiepin-4a,5-(2H)dicarboximide and 6,7,8,9-tetrahydro-2-oxo-1H-benz[cd]azulene-1,9a-(2H)dicarboximide. The spirodioxolane of the latter compound was also prepared by ketalization.     

1-Methylgalanthamine Derivatives

Summary. The syntheses of pharmaceutically interesting galanthamine analogues bearing a methyl group at the C1 position are described.     

Dodeca(carboranyl)-substituted closomers: toward unimolecular nanoparticles as delivery vehicles for BNCT

The syntheses of the dodeca(carboranyl)-substituted closomers, dodeca[7-(2-methyl-1,2-dicarba-closo-dodecaboran-1-yl)heptanoate]-closo- dodecaborate(2-) and dodeca[7-(8-methyl-7,8-dicarba-nido-dodecaboran-7-yl)- heptanoate]-closo-dodecaborate(14-) are reported. These boron-rich, unimolecular nanospheres possess great potential for future use as drug-delivery platforms for boron neutron capture therapy (BNCT).