Abstract: A method in the production of hydrogen peroxide by the anthraquinone process is described, in which method anthraquinone derivatives dissolved in a working solution are subjected alternatingly to hydrogenation and oxidation. To reduce the relative moisture in the working solution to a suitable level of 20-98%, preferably 40-85%, the working solution is dried prior to hydrogenation by contacting it with a gas or a gaseous mixture, the water vapor pressure of which is below that of the working solution. Suitable gases or gas mixtures are air or exhaust gases from the oxidation stage of the anthraquinone process.

Abstract: The present invention provides a process for the preparation of 4-hydroxy-3-(heterocyclocarbamoyl)-2H-1,2-benzothiazine-1,1-dioxides of the general formula: ##STR1## wherein R.sub.1 is a hydrogen atom or a methyl radical, R.sub.2 is a nitrogen-containing heterocyclic radical and R.sub.3 is a hydrogen or halogen atom or a methyl radical, and of the alkali metal, alkaline earth metal and amine salts thereof, by the reaction of an amine-substituted, nitrogen-containing heterocyclic compound with a halo-acetyl halide, reaction of the intermediate thus obtained with sodium benzoic acid sulphimide, ring expansion of the benzoisothiazole ring to give a benzothiazine ring and, in case R.sub.

Abstract: The invention discloses (+)-(3-methyl-4-oxo-5N-piperidinothiazolidin-2-ylidene)acetic acid esters and a process for their preparation. The process provides the dextrorotatory isomers substantially free from the corresponding levorotatory isomers. Antihypertensive pharmaceutical compositions comprising the dextrorotatory esters and methods for using said compositions are also disclosed.

Abstract: A new and chemically unique one-pot process for the preparation of thiazolidin-4-one-acetic acid derivatives of the general formula: ##STR1## wherein R.sub.1 is a lower alkyl radical.