摘要:
The present invention relates to a preparation process for 2-arylbenzimidazolesulfonic acids of the formula I: Ar is a substituted or unsubstituted phenyl or naphthyl radical and R is a C1-8-alkyl or C1-8-alkoxy radical. n is 1-4, m is 1-3 and o is 0-2. o-phenylenediamine is reacted in the presence of oleum with an arylcarboxylic acid or an arylcarboxylic acid derivative. Compounds prepared in this way can be used as UV filters, and as components in cosmetic compositions.
摘要:
A process for preparing substituted 4-methylidenecinnamic acid derivatives of Formula (I). ##STR1## The variables are defined herein. The compounds of Formula (I) can be used, for example, as UV absorbers.
摘要:
The invention relates to a photostable liquid-crystalline medium comprising at least one compound of the formula I and at least one compound of the formula II and to the use thereof for electro-optical purposes, and to displays containing this medium.
摘要:
The invention relates to a photostable liquid-crystalline medium comprising at least one compound of the formula I and at least one compound of the formula II and to the use thereof for electro-optical purposes, and to displays containing this medium.
摘要:
The invention relates to a process for the preparation of cinnamic acid derivatives which involves reacting chlorinated aromatic compounds and acrylic acid derivatives in the presence of palladium catalysts.
摘要:
The invention relates to ketotricyclo�5.2.1.0!decane derivatives of the formula I ##STR1## wherein Phe is a phenylene group which is unsubstituted or substituted by 1 to 4 hydroxyl, alkyl or alkoxy groups having 1 to 10 C atoms, and their preparation and use as UV filters, in particular in cosmetic or pharmaceutical preparations.
摘要:
The invention relates to a photostable liquid-crystalline medium comprising at least one compound of the formula I and at least one compound of the formula II and to the use thereof for electro-optical purposes, and to displays containing this medium.
摘要:
The invention relates to an improved process for the preparation of thioglycolic acid alkyl esters by heating a reaction mixture which essentially comprises thioglycolic acid, an alcohol and an acid catalyst, the water formed being removed by distillation using a water separator, in which the resulting product mixture is passed over a basic ion exchanger, if appropriate after removal of the acid catalyst.
摘要:
The invention relates to bis(methylidene)phenylene derivatives of the formula A.sup.1 -Phe-A.sup.2 I wherein Phe is an unsubstituted or substituted phenylene group, A.sup.1 is a group selected from the formulae 1, 2 and 3 and A.sup.2 is a group other than A.sup.1 selected from the formulae 1, 2 and 3 ##STR1## wherein R.sup.1 and R.sup.2 are independently H or CH.sub.3 and their preparation and use as UV filters, in particular cosmetic and pharmaceutical preparations.
摘要:
The invention relates to a process for the preparation of N-protected dialkyl (2S,3S)-3-ethylaspartates or their salts from unpurified (2S,3S)-3-ethylaspartic acid obtainable by enzymatic amination of ethylfumaric acid.