Abstract:
The present invention is an improved process for preparing 2-nitro-4'-fluorobenzophenone which comprises contacting 2-nitrobenzoyl chloride and fluorobenzene in a reaction medium the presence of anhydrous ferric chloride. The process is typically performed at a temperature of -20°C to 25°C.
Abstract:
A palladium-catalysed carbon-carbon bond forming reaction in compressed carbon dioxide is provided wherein at least one of the reagents used in said reaction is bounded to a solid polymer support. In a second aspect, a palladium-catalysed carbon-carbon bond forming reaction in compressed carbon dioxide is provided wherein said reaction is performed in the presence of a tetra-alkylammonium acetate. In a third aspect, a palladium-catalysed carbon-carbon bond forming reaction in compressed carbon dioxide is provided wherein said palladium catalyst does not have any fluorinated phosphine ligands but does have at least one phosphine ligand that has at least one substituent that is selected from tert-alkyl groups, cycloalkyl groups and optionally substituted phenyl groups or 1'-diphenylphosphino-biphenyl. In a fourth aspect, there is provided a palladium-catalysed Suzuki or Heck reaction in compressed carbon dioxide wherein both of the substrates being combined in said reactions are boronic acids.
Abstract:
The present invention provides prodrugs of GABA analogs, pharmaceutical compositions of prodrugs of GABA analogs and methods for making prodrugs of GABA analogs. The present invention also provides methods for using prodrugs of GABA analogs and methods for using phannaceutical compositions of prodrugs of GABA analogs for treating or preventing common diseases and/or disorders.
Abstract:
The invention relates to the production of nitro benzoic acids by oxidation of special nitro toluenes, nitro benzyl alcohols, esters and/or ethers in the presence of nitric acid at a high temperature and high pressure. The special nitro toluenes, nitro benzyl alcohols, esters and/or ethers can be oxidized in a particularly secure and economic manner in order to form benzoic acid derivatives with high yields when added to nitric acid.
Abstract:
The invention relates to a method for the catalytic oxidation of alkyl-aromatic compounds of formula (I): Ar-C(H)n-R, to obtain the corresponding aromatic aldehydes and ketones. In said formula, Ar represents an optionally substituted, aromatic or heteroaromatic five- or six-membered ring, or a ring system comprising up to 20 C atoms, whereby Ar can be optionally annellated with a C1-C6 alkyl group, in which up to 2 C atoms can be substituted by a heteroatom, n represents 1 or 2, and R represents hydrogen, C1-C20-alkyl or C1-C20-alkenyl or phenyl, or forms together with Ar an optionally substituted ring system, which can contain one or several optionally substituted heteroatoms. The oxidation of alkyl-aromatic compounds of formula (I) takes place in a solvent, using ozone, in the presence of a transition metal catalyst and optionally in the presence of an acid, at a temperature of between - 70 °C and 100 °C or under reflux conditions, to obtain the corresponding aldehyde or ketone.
Abstract:
The invention pertains to the use of Group 8 transition metal carbene complexes as catalysts for olefin cross-metathesis reactions. In particular, ruthenium and osmium alkylidene complexes substituted with an N-heterocyclic carbene ligand are used to catalyze cross-metathesis reactions to provide a variety of substituted and functionalized olefins, including phosphonate-substituted olefins, directly halogenated olefins, 1,1,2-trisubstituted olefins, and quaternary allylic olefins. The invention further provides a method for creating functional diversity using the aforementioned complexes to catalyze cross-metathesis reactions of a first olefinic reactant, which mayor may not be substituted with a functional group, with each of a plurality of different olefinic reactants, which may or may not be substituted with functional groups, to give a plurality of structurally distinct olefinic products. The methodology of the invention is also useful in facilitating the stereoselective synthesis of 1,2-disubstituted olefins in the cis configuration.
Abstract:
There is disclosed a process for the preparation of a compound of general formula (I), wherein Y and Z each independently represent a fluorine atom or a hydroxy group, and a, b, c and d independently represent 0, 1, 2 or 3 provided that the sum of a, b, c, and d is 1, 2, 3 or 4; the process comprising treating a compound of general formula (II), wherein a, b, c, and d are as described above and L?1 and L2¿ each independently represent an active group provided that either Y and L1 are different or Z and L2 are different, with a fluorinating system in the presence of oxygen. A preferred compound of general formula (I) is 4,4'-difluorobenzophenone which may be prepared from 4,4'-dinitrophenylmethane using tetramethylammonium fluoride.
Abstract:
The 3- and 4-methylcatechols are converted to the corresponding benzaldehyde by first alkylating the hydroxyl groups to form an alkylated methylcatechol. The methyl group is then converted to a methyl dibromide group using 1,3-dibromo-5,5-dimethylhydantoin in the presence of a non-polar, non-reactive solvent such as carbon tetrachloride and heptane and a radical initiator having a ten hour half-life temperature in the range of 47° to 55 °C. The dibromide is then hydrolyzed to form the aldehyde.