Abstract: The present invention relates to a process for the preparation of a compound of formula (I) or a pharmaceutically acceptable salt thereof: wherein R represents one or more groups independently selected from fluorine, chlorine, bromine, and iodine, said process comprising the cyclopropanation of a compound of formula (II) with ethylene carbonate or ethylene sulfate: wherein X is chlorine, bromine, iodine or a triflate group (CF3SO3) or a group ?wherein R is as defined above and G is —CN or —COOR2 wherein R2 is a C1-C4 straight or branched alkyl chain.

Abstract: The cobalt(II) complex of new D2-symmetric chiral porphyrin 3,5-DiMes-ChenPhyrin, [Co(P2)], has been shown to be a highly effective chiral metalloradical catalyst for enantioselective cyclopropenation of alkynes with acceptor/acceptor-substituted diazo reagents such as ?-cyanodiazoacetamides and ?-cyanodiazoacetates. The [Co(P2)]-mediated metalloradical cyclopropenation is suitable to a wide range of terminal aromatic and related conjugated alkynes with varied steric and electronic properties, providing the corresponding tri-substituted cyclopropenes in high yields with excellent enantiocontrol of the all-carbon quaternary stereogenic centers. In addition to mild reaction conditions, the Co(II)-based metalloradical catalysis for cyclopropenation features a high degree of functional group tolerance.

Abstract: The present invention relates to improved covalent coupling of two or more entities such as biomolecules, polymer compositions, organic/inorganic molecules/materials, and the like, including their combinations, through one or more novel reactive groups attached to linker groups of 2-1000 atoms length. The present invention also contemplates the use of bifunctional bridge molecules to link two or more entities, wherein the functional groups of the bridge molecules are the novel reactive groups of the present invention.

Abstract: The present invention relates to improved covalent coupling of two or more entities such as biomolecules, polymer compositions, organic/inorganic molecules/materials, and the like, including their combinations, through one or more novel reactive groups attached to linker groups of 2-1000 atoms length. The present invention also contemplates the use of bifunctional bridge molecules to link two or more entities, wherein the functional groups of the bridge molecules are the novel reactive groups of the present invention.

Abstract: The present invention relates to improved covalent coupling of two or more entities such as biomolecules, polymer compositions, organic/inorganic molecules/materials, and the like, including their combinations, through one or more novel reactive groups attached to linker groups of 2–1000 atoms length. The present invention also contemplates the use of bifunctional bridge molecules to link two or more entities, wherein the functional groups of the bridge molecules are the novel reactive groups of the present invention.

Abstract: A 4-membered compound is represented by the following formula (I) is disclosed (in the formula, X1 and X2 each independently represent an oxygen atom, a sulfur atom or a substituted or unsubstituted imino group, Y1 and Y2 each independently represent a single bond, an oxygen atom or a substituted or unsubstituted imino group, B1 and B2 each independently represent an optionally substituted aliphatic, aliphatic carbonyl, aromatic or aromatic carbonyl group having 1-20 carbon atoms, and A1 and A2 each independently represent a group represented by the following formula (II) (Ar1, Ar2 and Ar3 each independently represent a cyclic group having 5-14 carbon atoms, L1 and L2 each independently represent a single bond or a divalent linking group, and p represents an integer of 0-2)). There is also disclosed a birefringence medium containing a 4-membered compound represented by the formula (I) and an optical element comprising the birefringence medium.

Abstract: In a process for preparing a Diels-Alder addition product of a conjugated diolefin and acrylonitrile by reacting the conjugated diolefin with acrylonitrile, a vessel type reactor is used. The pressure of the gaseous phase in the reactor is increased by using an inert gas in the reaction. A premixed solution of the conjugated diolefin or a compound which produces the conjugated diolefin in the reactor and acrylonitrile is released through an upper portion of the reactor into the gaseous phase and then dropped into a liquid phase to react. A reaction product is taken out through a lower portion of the reactor. The process can be carried out continuously in a safe manner over an extended period of time without any adhesion of an insoluble polymer to the reactor or to the inlet or outlet pipes, and without sudden pressure fluctuations.

Abstract: Process for preparing a nitrile of the formula (I) ##STR1## in which R.sub.1, R.sub.2 and R.sub.3 are for example hydrogen, halogen, cyano, hydroxyl, carboxyl, alkyl, alkoxy, alkylthio, alkylamino, dialkylamino, aryl, aryloxy, arylthio or arylamino, or R.sub.2 and R.sub.3 together form a substituted or unsubstituted 4-membered carbon bridge,by reacting an aldehyde of the formula (II) ##STR2## with a hydroxylammonium salt followed by dehydration by heating to an elevated temperature, wherein the reaction takes place in the presence of an anhydrous inorganic sulfate and in the absence of diluents from the group consisting of carboxylic acids, strongly polar aprotic solvents, sulfur compounds and heteroaromatic basic nitrogen compounds.The nitriles obtainable by the process of the invention are valuable intermediates for, in particular, the preparation of diketopyrrolopyrrole pigments.

Abstract: The magnesium complexes of cyclic hydrocarbons, such as 1,2-dimethylenecycloalkanes, are readily prepared in high yields using highly reactive magnesium. Reactions of these (2-butene-1,4-diyl)magnesium reagents with electrophiles such as dibromoalkanes, alkylditosylates, or bromoalkylnitriles serve as a convenient method for synthesizing spirocyclic systems. Significantly, spirocarbocycles prepared by thisThe present invention was made with Government support under Contract No. GM35153 awarded by the National Institute of Health. The Government has certain rights in the invention.

Abstract: Substituted vinylcyclopropane carboxylates, useful precursors to pyrethroid insecticides, are prepared by noble metal catalyzed addition of 1-methyl-3-buten-2-yl or 4-methyl-3-penten-1-yl carbonates or carboxylic acid esters to malonic acid diesters, alkyl acetates or alkyl cyanoacetates.