Abstract: The present invention pertains to a process for the production of a specific crystal modification of a polymorphic, organic substance by precipitation of the specific crystal modification from the aqueous solution of the salt of the polymorphic substances using ordinary water-soluble organic solvents as additives as well as an acid or base.

Abstract: The present invention relates to a process for the preparation of compounds of the formula (I) by reacting compounds of the formula (II) in which R1, R2, R4 and Het are as defined in the description, with anhydrous hydrogen halide in the presence of a nitrile.

Abstract: The present invention pertains to a process for the production of a specific crystal modification of a polymorphic, organic substance by precipitation of the specific crystal modification from the aqueous solution of the salt of the polymorphic substances using ordinary water-soluble organic solvents as additives as well as an acid or base.

Abstract: The present invention relates to a process for the preparation of compounds of the formula (I) 1

Abstract: The present invention relates to a novel process for the preparation of N-methyl-N′-nitroguanidine by reacting nitroguanidine with aqueous methylamine solution buffered by the addition of inorganic or organic acids.

Abstract: The invention relates to a novel process for preparing optically active trimethyllactic acid and/or its esters by catalytic hydrogenation of trimethylpyruvic acid and/or its esters in the presence of noble metal complex catalysts containing phosphorus ligands.

Abstract: The present invention relates to a process for the preparation of compounds of the formula (I) by reacting compounds of the formula (II) in which Het, R1, R2 and R4 are as defined in the description, with anhydrous hydrogen chloride or compounds which generate hydrogen chloride.

Abstract: The present invention relates to a novel process for the preparation of N-methyl-N′-nitroguanidine by reacting nitroguanidine with aqueous methylamine solution buffered by the addition of inorganic or organic acids.

Abstract: The invention relates to the preparation of enantiomerically pure bis-diphenylphosphine oxides in a particularly advantageous manner by (1) reacting an aromatic bromine compound with a diphenylphosphinic chloride in a mixture of tetrahydrofuran and an aromatic hydrocarbon to give a diphenylphosphine oxide, which is isolated from a solution in an aromatic hydrocarbon by adding a saturated aliphatic hydrocarbon; (2) metalating the resulting diphenylphosphine oxide in the 6-position and reacting the metalated diphenylphosphine oxide with iodine at temperatures not less than −25° C.

Abstract: The invention relates to the preparation of enantiomerically pure bis-diphenylphosphine oxides in a particularly advantageous manner by (1) reacting an aromatic bromine compound with a diphenylphosphinic chloride in a mixture of tetrahydrofuran and an aromatic hydrocarbon to give a diphenylphosphine oxide, which is isolated from a solution in an aromatic hydrocarbon by adding a saturated aliphatic hydrocarbon; (2) metalating the resulting diphenylphosphine oxide in the 6-position and reacting the metalated diphenylphosphine oxide with iodine at temperatures not less than −25° C.

Abstract: The invention relates to a novel process for preparing optically active trimethyllactic acid and/or its esters by catalytic hydrogenation of trimethylpyruvic acid and/or its esters in the presence of noble metal complex catalysts containing phosphorus ligands.

Abstract: The invention relates to chiral polymers which are bonded to a support and have improved properties, a process for the preparation of these materials and their use as chiral stationary phases in the chromatograhic separation of optical isomers, in particular of racemates into their enantiomers.

Abstract: The invention relates to novel bisphosphonates and to processes for their preparation and for their resolution into the enantiomers. The bisphosphonates according to the invention are valuable intermediates for the preparation of bisphosphine compounds, especially chiral bisphosphine ligands. These in turn are constituents of transition metal complexes which are used as catalysts inter alia in asymmetric hydrogenation.The novel bisphosphonates have the general formula (I) ##STR1## in which R.sup.1 is linear or branched alkyl having up to 6 carbon atoms, aryl or aralkyl, each of which can optionally be substituted, or two radicals R.sup.1 together are a bridging hydrocarbon radical having up to 6 carbon atoms,and can exist in the form of their racemates or as enantiomers.