GB623428A - Manufacture of new substituted ethylenes - Google Patents

Abstract

Substituted ethylenes are manufactured by treating an ethane compound containing the atomic grouping <FORM:0623428/IV (b)/1> (wherein the symbols x represent -NH-, oxygen or sulphur, at least one being oxygen or sulphur), or a substitution product or salt (e.g. hydrochloride or sulphate) thereof, with a dehydrogenating agent at a raised temperature (e.g. 80-150 DEG C.). Suitable dehydrogenating agents and reaction media are those enumerated in the parent Specification, except that ferric salts (of which ferric chloride is the only example given) are specified for the dehydrogenation of thiazoles only. The preferred agent is mercuric acetate in glacial acetic acid, which generally produces a mercury complex compound of the dehydrogenation product, from which the mercury may be eliminated by treatment with acid or alkali (the latter being used in the case of products, such as oxazoles, which are sensitive to acids). The products may be used for marking fibrous materials, especially cellulosic fibres, in order that they may be identified by fluorescence. Examples describe the dehydrogenation of a : b -di-(4-methylthiazolyl-2)-ethane, a : b -di-(benzthiazolyl-2)-ethane, a : b -di-(4 : 5-diphenylthiazolyl - 2) - ethane, a : b - di - (benzaoazolyl-2)-ethane, a -(benzimidazyl-2)-b -(benzoxazolyl-2)-ethane and a -(benzthiazolyl-2)-b -(benzimidazyl-2)-ethane. Additional starting materials specified are: a : b -di-(thiazolyl-2)-ethane, a : b - di - 4 - ethylthiazolyl - 2) - ethane, a : b - di - (oxazolyl - 2) - ethane, and a : b - di - (benzthiazolyl - 2 or benzoxazolyl - 2) - ethanes containing a halogen, nitro or methoxy substituent in the benzene nucleus. a : b -Di-(benzoxazolyl-2)-ethanes are obtainable by heating an o-aminophenol with succinic acid or a functional derivative thereof at 170-180 DEG C. with exclusion of air. a : b -Di-(benzthiazolyl-2)-ethane is obtainable by heating o-aminothiophenol with succinic acid at 170-175 DEG C. with exclusion of air. a : b -Di-(4 : 5-diphenylthiazolyl-2)-ethane is obtainable from the thioamide of succinic acid and a -chlorobenzoin in absolute alcohol. a -(Benzimidazyl- 2)-b -(benzoxazolyl- 2)-ethane and a - benzthiazolyl - 2) - b - (benzimidazyl - 2) - ethane are obtainable by heating b -(benzimidazyl-2)-propionic acid to 170-180 DEG C. with o-aminophenol and o-aminothiophenol respectively.