Abstract: This invention relates to a process for the purification of waste waters containing organic and, should the situation arise, inorganic sulphur compounds, which waste waters contain a proportion of mercaptobenzothiazole and/or derivatives thereof and, should the situation arise, a proportion of benzothiazole and/or derivatives thereof and/or mercaptobenzimidazole and/or derivatives thereof and, should the situation arise, thiosulphate, whereby the waste waters are treated with an extracting agent comprising salts of aliphatic amines and aliphatic and/or aromatic hydrocarbons.

Abstract: In a process for the preparation of 2-mercaptobenzothiazole from aniline, sulfur and carbon disulfide under pressure and for separation of the 2-mercaptobenzothiazole from the crude reaction product by cooling and recycling the desirable intermediates and by-products into the reactor together with aniline, sulfur and carbon disulfide, the reaction is carried out using a residence time in the reactor of at least one hour to a time before the 2-mercaptobenzothiazole product thus-formed begins to decompose into undesirable intermediate products. A maximum hydrogen sulfide pressure is maintained on quenching to a temperature ranging between 220 and 280.degree. C. by mixing the crude reaction product with carbon disulfide at a temperature sufficient to obtain a homogeneous quenched mixture. The hydrogen sulfide is removed completely only after crystallization of the 2-mercaptobenzothiazole.

Abstract: Crude 2-mercaptobenzothiazole is purified by a process in which the crude 2-mercaptobenzothiazole is dissolved in relatively high-boiling aliphatic or cycloaliphatic alcohols or in mixtures of the alcohols mentioned or azeotropes thereof with water at temperatures of 60.degree. to 200.degree. C., optionally under elevated pressure, or is suspended in relatively high-boiling aliphatic or cycloaliphatic alcohols, aliphatic or cycloaliphatic ethers, organic acids or esters thereof at temperatures of 10.degree. to 100.degree. C., the solution or suspension is subsequently cooled and the product precipitating is filtered off and optionally washed.

Abstract: Tar-like residues from the preparation of 2-mercaptobenzothiazole can be used by heating them at temperatures above 200.degree. C. for at least 1 hour and separating off the aniline and benzothiazole thereby formed.

Abstract: A process for purifying crude synthetic mercaptobenzothiazole according to the invention, which comprises treating the crude mercaptobenzothiazole with aniline, filtering and washing the crystallized mercaptobenzothiazole with aniline and, if desired, recycling the liquid organic phases of the purification medium, wherein the crystallization of mercaptobenzothiazole, the filtration and the washing are carried out at a temperature of from 40.degree. to 120.degree. C.

Abstract: A class of bicyclic nitrogen heterocyclic ether and thioether compounds exhibiting pharmacological activity including cytoprotective, H.sub.2 -antagonist, anti-secretory and anti-ulcerogenic activity, pharmaceutical compositions comprising these compounds, and methods for the treatment of gastrointestinal hyperacidity and ulcerogenic disorders in mammals using said compositions are disclosed.

Abstract: Crude MBT is purified and substantially decolorized by treating same with an alkaline solution to form an MBT salt solution, measuring pH of the salt solution when adding the alkaline solution until an abrupt rise in pH is observed and stopping addition of the alkaline solution in response thereto, treating the salt solution with a solvent to extract solvent-soluble impurities, oxidizing the salt solution by introducing oxygen into an enclosed vessel containing the salt solution and vigorously agitating the solution until oxygen uptake essentially stops, diluting the salt solution with water, filtering the salt solution to remove precipitated impurities, and concentrating the solution.

Abstract: Process for the purification of mercaptobenzothiazole in which the crude product resulting from the reaction of aniline, sulfur and carbon disulfide according to the known process is treated with aniline.

Abstract: A process for the purification of crude 2-mercaptobenzothiazole, prepared by reacting aniline, carbon disulfide and sulfur at elevated temperature and pressure is described. The process comprises the reaction of crude 2-mercaptobenzothiazole with 5-20%, preferably 10-12%, molar excess aqueous alkali metal hydroxide having a concentration of 3 to 20% by weight alkali metal hydroxide at 70.degree. to 90.degree. C. for 0.5-4 hours, with vigorous agitation, followed by filtration of the insoluble impurities and acidification of the filtrate with a non-oxidizing mineral acid, such as hydrochloric and sulfuric acids. The precipitated, filtered product is washed with water and collected in 98-100% yield and 95-98.5% purity.

Abstract: Process for the purification of mercaptobenzothiazole prepared according to known processes, characterized in that the crude product is treated with carbon tetrachloride or with 1,1,2,2-tetrachloroethylene.