Abstract:
A process for producing an esterificated condensate, wherein a monomeric ester or thioester, or a polyester or polythioester is produced by carrying out a direct condensation reaction from a carboxylic acid and an equimolar amount of an alcohol or a little excess amount of a thiol in a non-polar solvent such as toluene using, as a (poly)condensation catalyst, a tetravalent hafnium compound, typically, hafnium(IV) chloride, in particular hafnium(IV) chloride . (THF)2 and hafnium(IV) butoxide in an oxygen-free atmosphere under reflux. During refluxing with heating, water being distilled as an azeotropic mixture is preferably removed from the reaction system. The process permits a catalytic esterification using equimolar amounts of a carboxylic acid and an alcohol and a catalytic thioesterification using a carboxylic acid and an equimolar or a little excess amount of a thiol, and accordingly is greatly promising as a commercial process for a large scale production from the view point of green chemistry.
Abstract:
The present invention relates to precious metal (Pd/Pt/Rh/Ru) free, preferably Pd free, processes for preparing a compound having formula (1) wherein: R1, R2, and X are as defined in the specification, or a salt thereof. Preferably, the compound is an iodo acrylate compound.
Abstract:
Provided is a process for making nitrated hydrocarbons by reacting aqueous nitric acid with a hydrocarbon feedstock and a carboxylic acid under specific reaction conditions.
Abstract:
The present invention is directed to protected amino acid halide monomers and oligomers, and to their use in the efficient sythesis of polyamides. The present invention is further directed to the use of -haloenamine reagents, which may optionally be immobilized, for the preparation of the amino acid halides.
Abstract:
The present invention relates to a novel simple, efficient and single-step process for esterification of aldehydes using a heterogeneous catalyst with high yields. More particularly, the present invention relates to a novel simple, efficient and single-step process for esterification of aldehydes using Titanium superoxide with greater than 80% yields.
Abstract:
Disclosed is a process for preparing dihydro-2H-pyran derivatives of formula I: wherein R 1 and R 2 are defined herein. The process of the invention provides the compound of formula I in concise cascade reactions and in one pot. The compound of formulae I prepared by the process of the invention and its further transformed derivatives are useful for making pharmaceutical composition for the treatment of proliferative diseases.
Abstract:
The invention relates to novel triazene compounds, the use thereof and novel alkylation methods. Said triazene compounds have the general formula, X-Y-Z-N=N-NH-R, where X = an insoluble support material, Y = an atom, or group of atoms, functioning as an electron donor, Z = a preferably electron-rich aryl group, substituted aryl group, heteroaryl group, or substituted heteroaryl group and R is chosen from the group alkyl, cycloalkyl, allyl and benzyl. Said compounds are suitable as alkylating reagents.
Abstract:
The invention relates to novel triazene compounds, the use thereof and novel alkylation methods. Said triazene compounds have the general formula, X-Y-Z-N=N-NH-R, where X = an insoluble support material, Y = an atom, or group of atoms, functioning as an electron donor, Z = a preferably electron-rich aryl group, substituted aryl group, heteroaryl group, or substituted heteroaryl group and R is chosen from the group alkyl, cycloalkyl, allyl and benzyl. Said compounds are suitable as alkylating reagents.