Abstract: What is described is a process for brominating alkylthiophene, in which an alkylthiophene of the general formula (I) where R is a branched or unbranched alkyl radical having 1 to 12 carbon atoms is contacted with stoichiometric amounts of HBr and H2O2, optionally in the presence of a solvent.

Abstract: A process is described for preparing alkyl thiodiglycolates of the general formula (I) R—OOC—CH2-S—CH2-COO—R??(I) where R is a radical of branched or unbranched C1 to C10-alkyl, characterized in that an alkyl haloacetate of the general formula (II) X—CH2-COO—R??(II) where X is a chlorine or bromine atom and R is as defined for compounds of the formula (I) is reacted with an aqueous solution of alkali metal sulphide or alkali metal hydrogensulphide in the presence of an aqueous pH buffer solution in the pH range between 5 and 8, optionally in the presence of a phase transfer catalyst.

Abstract: What is described is a process for brominating alkylthiophene, in which an alkylthiophene of the general formula (I) where R is a branched or unbranched alkyl radical having 1 to 12 carbon atoms is contacted with stoichiometric amounts of HBr and H2O2, optionally in the presence of a solvent.

Abstract: A process is described for preparing alkyl thiodiglycolates of the general formula (I) R—OOC—CH2-S—CH2-COO—R ??(I) where R is a radical of branched or unbranched C1 to C10-alkyl, characterized in that an alkyl haloacetate of the general formula (II) X—CH2-COO—R ??(II) where X is a chlorine or bromine atom and R is as defined for compounds of the formula (I) is reacted with an aqueous solution of alkali metal sulphide or alkali metal hydrogensulphide in the presence of an aqueous pH buffer solution in the pH range between 5 and 8, optionally in the presence of a phase transfer catalyst.

Abstract: A process for preparing specific 1-substituted 5-hydroxy-imidazoline-2,4-diones by reacting glyoxylic acid with N-substituted ureas is provided, where this process is carried out in a 10-80% strength aqueous solution and in the presence of an acid catalyst. The 1-substituted 5-hydroxy-imidazoline-2,4-diones can subsequently be converted in a further reaction step to give 1-substituted 5-alkoxy-imidazoline-2,4-diones.

Abstract: Substituted chloroaromatics are obtained in a simple manner in virtually isomer-free form when substituted phenols of the formula (II) ##STR1## where R.sup.1 to R.sup.5 are each, independently of one another, hydrogen, C.sub.1 -C.sub.10 -alkyl, unsubstituted or substituted C.sub.6 -C.sub.10 -aryl or halogen, with at least one of these radicals being different from hydrogen,are reacted with dichlorotriphenylphosphorus.