Ethanol → N-ethyl-N-(beta-benzthiazolylmercaptoethyl)-m-toluidine

Participants

Reaction Steps

73.5 Parts of 2-mercapto-benzthiazole and 79.0 parts of N-ethyl-N-(β-chloroethyl)-m-toluidine are successively added to a solution of 10.15 parts of sodium in 200 parts of absolute ethanol and the mixture is heated to the refluxing temperature for 6 hours. After cooling, the mixture is poured into 1,000 parts of water, the pH is adjusted to 9-10 and the oil which has separated out is taken up in chloroform. The chloroform solution is washed with water in the usual manner, dried over calcium chloride and evaporated. 127.2 Parts of crude N-ethyl-N-(β-benzthiazolylmercaptoethyl)-m-toluidine are obtained as an oily residue. 65.6 Parts of this toluidine base are dissolved in 43.8 parts of dimethylformamide, 34 parts of phosphorus oxychloride are added dropwise over the course of about one hour at below 50°, and the mixture is stirred for a further 15 hours, at 60°-65°. It is then allowed to cool to approx. 40° and a total of 150 parts by volume of methanol is added--initially dropwise, and whilst cooling externally to 40°-50° until the exothermic reaction has subsided--7 parts of emulsifier are introduced and the pH value is now adjusted to 7-8 by dropwise addition of approx. 55 parts by volume of concentrated aqueous ammonia whilst cooling with water. A solution of 13.8 parts of malodinitrile in 15 parts of methanol is then added, the reaction mixture is stirred for 2 hours at 55°-60° and after cooling the dyestuff of the formula ##STR17## which has precipitated is filtered off. The product is washed with 150 parts by volume of methanol and then with 750 parts of warm water, and after drying at 70° in a vacuum drying cabinet 70.6 parts of dyestuff (87.5% of theory) of melting point 190°-192° are obtained.

Provenance & Evidence