Abstract: A process is described for preparing trifluoromethyl ketones of the formula I ##STR1## where R has the given meanings, wherein an alcohol of the formula II ##STR2## is reacted with a compound of the formula IVYO.sub.n H (IV)where n has the given meaning.

Abstract: The present invention relates to compounds of the formula ##STR1## in which R.sup.1 and R.sup.2 are identical or different and are hydrogen or an alkyl radical having 1 to 18 carbon atoms and optionally containing oxygen, nitrogen or halogen, the radicals X, Y and Z are identical and are a fluorine, bromine or iodine atom or if two of the radicals X, Y or Z are identical or all of the radicals X, Y, Z are different from each other, X, Y and Z are a fluorine, chlorine, bromine or iodine atom. The invention further relates to a process for the preparation of the compounds, by reacting an aryldiazonium salt of the formula ##STR2## in which the radicals X, Y and Z are identical and are a fluorine, bromine or iodine atom or, if two of the radicals X, Y and Z are identical or all of the radicals X, Y, Z are different from each other, X, Y and Z are a fluorine, chlorine, bromine or iodine atom and A.sup.(-) is an anion of an acid having a pK.sub.a <7, with a compound of the formula ##STR3## in which R.sup.

Abstract: Process for preparing hydroxybenzaldehydes of the formula (1) ##STR1## in which R.sup.1 -R.sup.4 are hydrogen, fluorine, chlorine, bromine, alkyl, alkoxy, phenyl, naphthyl, phenylalkyl, naphthylalkyl, phenoxy or saturated or unsaturated cyclopentane or cyclohexane radicals, and R.sup.1 -R.sup.4 may with the hydroxybenzene ring carbon atoms on which they are located form 1 or 2 saturated or unsaturated isocyclic or heterocyclic rings, by admixing 1 mol of a phenol of the formula (2) ##STR2## in which R.sup.1 -R.sup.4 have the stated meanings, in a pressure vessel with from 5 to 100 mol of hydrogen fluoride and from 0.5+x to 1.5+x mol of boron trifluoride, where x is the number of oxygen atoms contained in the starting compound (formula (2)), setting the mixture to from -10.sup..degree. to 100.degree. C. and then passing carbon monoxide into this mixture until a pressure of from 10 to 150 bar is reached and allowing the mixture to react at the desired pressure reached.

Abstract: The present invention relates to a process for the preparation of aromatic polyhydroxy compounds, by reacting an aromatic hydroxyaldehyde with hydrogen peroxide, with or without the addition of a base, in the presence of a nitrile R--CN, in which R is an alkyl radical having 1 to 4 carbon atoms or a phenyl radical, which is unsubstituted or substituted by one or more alkyl groups.

Abstract: 1-Indanones of the formula IV or IVa ##STR1## in which R.sup.1 to R.sup.7 are preferably hydrogen or alkyl, or adjacent radicals R.sup.1 to R.sup.4 form a ring, are obtained in a one-step reaction by reacting a compound I ##STR2## with a compound of the formula II ##STR3## or with a compound of the formula (III) ##STR4## in anhydrous hydrogen fluoride and with boron trifluoride.

Abstract: 1-Indanones of the formula III or IIIa ##STR1## in which R.sup.1 to R.sup.7 are preferably hydrogen or alkyl, or adjacent radicals R.sup.1 to R.sup.4 form a ring, are obtained in a one-step reaction by reacting a compound I ##STR2## with a compound of the formula II ##STR3## in liquid hydrogen fluoride.

Abstract: 1-Indanones of the formula IV or IVa ##STR1## in which R.sup.1 and R.sup.7 are preferably hydrogen or alkyl, or adjacent radicals R.sup.1 to R.sup.4 form a ring, are obtained in a one-step reaction by reacting a compound I ##STR2## with a compound of the formula II or a compound III ##STR3## in liquid hydrogen fluoride.