Abstract: A process for preparing enantiopure E-(2S)-alkyl-5-halopent-4-enoic acids and their esters of the formula (I), in which R is a C1-C6-alkyl radical, R1 is H or C1-C4-alkyl and X is chlorine, bromine or iodine, in which the corresponding racemic 2-alkyl-5-halopent-4-enoic acid a) is reacted in a suitable solvent first with (S)-3-Methyl-2-phenylbutylamine, quinine or with N-methyl-D-glucamine, after which b) the corresponding (S)-3-Methyl-2-phenylbutylamine salt, quinine or glucamine salt of the (R)-pentenoic acid is precipitated and removed, and c) the remaining filtrate is mixed with a second chiral base or an inorganic salt, after which the corresponding salt of the (S)-pentenoic acid is precipitated and d) is then converted into the corresponding E-(2S)-alkyl-5-halo-4-pentenoic acid and subsequently where appropriate into the corresponding ester of the formula (I) in which R1 is C1-C4-alkyl.

Abstract: A process for preparing substituted pyridine N-oxide compounds of the formula in which R1, R2, R3 and R4 are each H, a carboxyl group or a C1-C12-alkyl radical which may contain atoms from the group of N, O and S, or R1 and R2 and/or R3 and R4 together may each form an optionally substituted C4-C20-alkylene radical which may contain atoms from the group of N, O and S, A is benzyl or a (CH2)m group where m may be an integer from 1 to 12, Z1 and Z2 are each independently O or S, and Y is H, a C1-C12-alkyl radical which may optionally contain atoms from the group of N, O and S, a C6-C20-aryl radical or a C5-C20-heterocycle, and the radicals may optionally be substituted, or Z2 and Y together form an optionally substituted ring or ring system, in which case the ring or ring system may contain atoms from the group of N, O and S, from the corresponding 4-halopyridine N-oxide of the formula in which X is chlorine, bromine or iodine, by reacting the compound of the formula (II)

Abstract: A process for preparing substituted pyridine N-oxide compounds of the formula 1

Abstract: Process for the preparation of asymmetrically substituted ureas, carbamates, thiocarbamates or substituted isocyanates by reaction of an adduct of isocyanic acid and a tertiary amine with a primary and secondary amine, an alcohol, a thiol or a compound having one or two non-cumulated olefinic double bonds, and a process for the preparation of N-mono- or N,N-disubstituted ureas by reaction of ammonium isocyanates with a primary or secondary amine in a diluent.

Abstract: A process for the dissolution of chemical compounds by use of ureas in which at least one of the urea's two nitrogen atoms is part of a non-aromatic ring which can be broken by an oxygen or sulphur atom as a chemical solvent, and a method of producing tri- or tetraalkylated ureas or bis ureas wherein at least one of the urea's nitrogen atoms is part of a non-aromatic ring which can be broken by an oxygen or sulphur atom by means of dialkylating the --NH.sub.2 group of a urea with an alkene or alkene arylene alkene dihalogenide, disulphonate or dihydrogen sulphonate in the presence of a solid base and a phase-transfer catalyst.

Abstract: Process for the preparation of asymmetrically substituted ureas, carbamates, thiocarbamates or substituted isocyanates by reaction of an adduct of isocyanic acid and a tertiary amine with a primary and secondary amine, an alcohol, a thiol or a compound having one or two non-cumulated olefinic double bonds, and a process for the preparation of N-mono- or N,N-disubstituted ureas by reaction of ammonium isocyanate with a primary or secondary amine in a diluent.

Abstract: Process for the preparation of asymmetrically substituted ureas, carbamates, thiocarbamates or substituted isocyanates by reaction of an adduct of isocyanic acid and a tertiary amine with a primary and secondary amine, an alcohol, a thiol or a compound having one or two non-cumulated olefinic double bonds.

Abstract: Process for the preparation of asymmetrically substituted ureas by reaction of a gaseous mixture of isocyanic acid and ammonia having a temperature of 260.degree. to 600.degree. C. with a primary or secondary amine.