Abstract: A method for the preparation of a pyridazinone derivative having the general formula I: ##STR1## where: R.sup.1 is a phenyl group, optionally substituted, R.sup.2 is H, alkyl or carboxy, R.sup.3 is H, alkyl or alkoxy and R.sup.4 is alkyl; said method comprising reacting a hydrazone of glyoxylic acid halide having the formula VII: ##STR2## in which X is halogen, with an ester of formula VIII; ##STR3## in the presence of an alkaline earth base.

Abstract: A process for the preparation of a fluoroaromatic or fluoroheterocyclic compound, which comprises diazotizing the corresponding amino-aromatic or amino-heterocyclic compound in hydrogen fluoride and decomposing the diazonium salt in the diazotization mixture so formed, characterized in that decomposition is carried out at super atmospheric pressure.

Abstract: Fluoromethylpyridines of the formula: ##STR1## wherein the group F.sub.n H.sub.3-n C-- may be ortho, meta or para to the ring nitrogen atom, n is 1, 2 or 3, m is 1 to 4, X is Cl, Br, I or F and, when m is 2, 3 or 4 the substituents represented by X may be the same or different, at least one X being ortho or para to the F.sub.n H.sub.3-n C-- group, are prepared by reacting a compound of the formula: ##STR2## wherein Y is Cl, Br, I or F and m is 1 to 4, with potassium fluoride in a polar aprotic solvent under substantially anhydrous conditions. These fluoromethylpyridines are useful as intermediates for herbicides. 3,4,5-trifluoro-2-trifluoromethylpyridine and 2,6-difluoro-3-difluoromethylpyridine are novel compunds.

Abstract: A process for the purification of esters of phosphorus thioacids having the formula: ##STR1## wherein R is an organic radical which is attached via a carbon atom thereof to X;R.sup.1 and R.sup.2 are optionally substituted hydrocarbon radicals which may be the same or different, andX is O or S,and which contains as an impurity a thiolo isomer having the formula: ##STR2## in which R, R.sup.1, R.sup.2 and X have the previously defined meanings, which comprises washing the ester with an aqueous solution of an acid or an acid salt.Particularly applicable to esters in which R is a substituted pyrimidinyl, phenyl or benzyl radical and R.sup.1 and R.sup.2 are alkyl radicals containing from 1 to 4 carbon atoms, especially methyl or ethyl radicals, which are useful as insecticides.

Abstract: m-Phenoxybenzyl esters of carboxylic acids are prepared from the methyl or ethyl esters of the acids by reaction of the latter with m-phenoxybenzyl alcohol in the presence of a tetra-aryl titanate as catalyst.

Abstract: m-Phenoxybenzyl esters of carboxylic acids are prepared from the methyl or ethyl esters of the acids by reaction of the latter with m-phenoxybenzyl alcohol in the presence of a transesterification catalyst of the formula Ti(O.CO.R).sub.2 Z.sub.2 in which R is a hydrocarbon radical and Z is a bidentate chelate compound.