Abstract: Hydroxy aryl carboxylic acids are formed by reacting a hydroxy aryl compound, such as phenol, with a ketone, such as acetone and carbon monoxide in the presence of a strong acid. The preferred embodiment is the one step formation of 2-methyl-2-(p-hydroxyphenyl) propionic acid from phenol, acetone and carbon monoxide in the presence of hydrofluoric acid. When this reaction is conducted in the presence of methanol the corresponding methyl ester is formed.

Abstract: In the preparation of a carboxylic acid by the carbonylation of an olefin in the presence of hydrofluoric acid catalyst, the hydrofluoric acid is isolated from the carboxylic acid by means of an ion-permeable membrane and the thus-isolated hydrofluoric acid can be recycled to again catalyze the carbonylation reaction.

Abstract: Tantalum (TaF.sub.5) or antimony pentafluoride (SbF.sub.5) is separated from a product mixture comprised of HF, isobutyryl fluoride and TaF.sub.5 or SbF.sub.5 by distillation below 760 mm of mercury.

Abstract: A process for the production of isobutyryl fluoride by reacting isopropyl fluoride and carbon monoxide in the presence of anhydrous hydrofluoric acid is described.

Abstract: A process for the production of isobutyric acid anhydride in which propylene is initially carbonylated in the presence of a substantial molar excess of liquid anhydrous hydrogen fluoride to provide a reaction mixture of isobutyroyl fluoride and unreacted hydrogen fluoride. Following distillation of the reaction mixture to recover a recycle stream of hydrogen fluoride, the isobutyroyl fluoride residue is partially hydrolyzed in the presence of a hydrogen fluoride acceptor resulting in a hydrolysis product consisting essentially of isobutyroyl fluoride, isobutyric acid anhydride and a hydrogen fluoride complex of said acceptor. Following removal of the solid complex, the hydrolysis product is fractionally distilled to yield an overhead fraction of isobutyroyl fluoride for reuse in the hydrolysis reaction.

Abstract: A method for recovering isobutyric acid from a solution thereof in concentrated aqueous hydrogen fluoride, the latter having served as the reaction medium for effecting the carbonylation of propylene. The method features the partial removal of anhydrous hydrogen fluoride from said solution to provide an aqueous phase of reduced hydrogen fluoride content from whence the isobutyric acid is extracted with optimum efficiency with an immiscible organic solvent.

Abstract: Urea is reacted with at least a onefold molar excess of dimethylamine in a substantially anhydrous system under pressure and temperature conditions adapted to produce unsymmetrical dimethylurea in essentially quantitative yields.