Patent GB-667049-A (GB)
Title: Process for the preparation of capillary-active substances
IPC: C07D277/74
Filed: 1949-09-14
Abstract: Capillary active substances are prepared by condensing in neutral or weakly alkaline solution 2-mercaptoarylene-thiazole sulphonic acid or 2-mercaptoarylene-thiazole carboxylic acids with aliphatic or aralkylic halogen compounds, the aliphatic hydrocarbon chains of which consist of at least 5 C-atoms, or with hydroaromatic halogen compounds having at least 5 C-atoms in their ring or rings.  In a modification of the process, instead of using 2-mercaptoarylene thiazole sulphonic acids for the condensation, the 2-mercaptoarylene thiazoles themselves may be used and the product sulphonated.  In examples: (1) disodium-2-mercaptobenzothiazole - 6 - sulphonate is condensed with 1-chloro-octane in aqueous alcohol; if 2-chloro-octane is used a more soluble product is obtained; (2) disodium-2-mercaptobenz-thiazole-5-sulphonic acid is condensed with 1-chloro-octane; (3) the 2-mercaptobenzothiazole-5-sulphonate of example (2) is replaced by the corresponding 5-carboxylic acid; (4) the acid zinc salt of 2-mercaptobenzothiazole-6-sulphonic acid is treated with soda lye to form the zincate and the product condensed with 2-chloro-octane.  The product is 2-(2-octyl)-mercapto-benzothiazole-6-sulphonic acid; (5) the 1-chloro-octane used in example (1) is replaced by bornyl chloride; (6) 2-octyl-mercaptobenzothiazole is prepared by condensing the sodium salt of 2-mercaptobenzothiazole with chlorooctane and then sulphonated by treatment with oleum; (7) the disodium-2-mercaptobenzothiazole-6-sulphonate is condensed with pinene hydrochloride to give 2-bornyl mercaptobenzothiazole-6-sulphonic acid.ALSO:Capillary active substances comprise the condensation product of a 2-mercaptoarylenethiazole sulphonic- or carboxylic acid with an aliphatic or aralkylic halogen compound, the aliphatic hydrocarbon chain of which consists of at least 5 C-atoms, or with a hydroaromatic halogen compound having at least 5 carbon atoms in the ring.  In examples the preparation is described of (1) 2-n-octylmercaptobenzothiazole-6-sulphonic acid 2-n-octylmercaptobenzothiazole-5-sulphonic acid; (3) the corresponding 5-carboxylic acid to example (2); (4) 2 - bornyl - mercaptobenzothiazole - 6-sulphonic acid.  The products are stated to possess resistance to water-hardening agents and to acids and to retain their surface active properties both in the alkaline and in the acid zone.  They are stable in strongly acid solution and are useful as auxiliary agents in the carbonization process of wooden fabrics.  The compounds are also suitable for pickling metals and in derusting process where the addition of 0.05 per cent of the products of the invention resulted in the de-rusting with very little amount of loss of metal.ALSO:Capillary active substances which have the effect of rendering metal surfaces remarkably passive to acids and are useful as additions to pickling solutions comprise 2-alkyl- or 2-arakyl-mercaptobenzothiazole sulphonic or carboxylic acids. Compounds benzothiazole 5- or 6-sulphonic acid and the corresponding 5-carboxylic acid, and 2-bornyl - mercaptobenzothiazole - 6 - naphthonic acid.  The addition of 0.05 per cent of the above agents to a derusting solution effected a considerable diminution in the amount of metal dissolved in the process.