| 摘要 |
2-Halothiazole carbonyl halide of the aromatic series are prepared by reacting a thiazole carboxylic acid which contains a carboxylic acid group on an aromatic nucleus (fused or substituent) and a mercapto or hydroxy group in the 2-position with an inorganic acid halide in the presence of at least one molecular proportion (based on the thiazole carboxylic acid) of an N-dialkylated formamide or thioformamide or in the presence of an N-alkyl pyrrolidone. Temperatures above 90 DEG C. are preferred. The usual inorganic acid halide is a mixture of PCl5 and POCl3. The invention also comprises as novel compounds 2-halothiazole carbonyl halides of the naphthalene series, 2-halobenzthiazole-6- or 7-carbonyl halides and the 2-chlorobenzthiazole carbonyl chlorides prepared in examples. Examples describe the preparation of: 2-chlorobenzthiazole-5-, 6-, and 7-carbonyl chlorides; 4-(21-chloro-41-thiazolyl) benzoyl chloride; 2-(21-chloro-51-benzthiazolyl)-6-benzthiazole carbonyl chloride and 2-chloronaphtho-[1, 2-d] thiazole-7-carbonyl chloride. Products of examples are converted into the corresponding methyl esters. Bis (5-, 6- and 7-chlorobonyl-2-benzthizolyl) sulphides and disulphides are obtained in a similar reaction but using only half an equivalent of dimethylformamide for the sulphides and none for the disulphides. They are converted to the corresponding methyl esters. 2-Mercaptobenzthiazole-6-carboxylic acid is obtained by the action of CS2 in alcoholic NaOH on 2-amino-5-carboxythiophenol hydrochloride. 2-Mercaptobenzthizole-7-carboxylic acid is obtained by refluxing 2-amino-7-carbethoxy-benzthiazole with KOH, neutralizing and treating with CS2. 2-(21-Mercapto-51-benzthiazolyl)-6-benzthiazole carboxylic acid is prepared by the action of sodium sulphide and sulphur in aqueous NaOH on 2-(41-chloro-31-nitrophenyl)-6-benzthiazole carboxylic acid, itself prepared by condensing 2-amino-5-carboxythiophenol hydrochloride with 4-chloro-3-nitrobenzoyl chloride in pyridine. 2-Mercaptonaphtho-[1, 2-d]thiazole-7-carboxylic acid is prepared by the action of sodium sulphide and sulphur on an aqueous sodium hydroxide solution of 6-chloro-5-nitro-1-naphthoic acid. Specification 310,815 is referred to. |
