Patent GB-667621-A (GB)
Title: 2-tertiaryamino-6-dialkylaminoalkoxy-benzthiazoles and process for the manufacture thereof
Filed: 1950-02-24
Abstract: The invention comprises benzthiazoles of the general formula <FORM:0667621/IV (b)/1> wherein R1 and R2 are the same or different groups and may each be a lower alkyl, aryl or aralkyl group or together with the nitrogen atom may represent a heterocyclic group, n is an integer from 2 to 5 and the group CnH2n includes straight and branched chain radicals.  The invention also comprises the addition salts of the above compounds with organic or inorganic acids, and the preparation of the above compounds by reacting an alkali metal derivative of a compound of the formula <FORM:0667621/IV (b)/2> with a dialkylaminoalkyl halide of the formula <FORM:0667621/IV (b)/3> In examples: (1) 6-ethoxy-2-dimethylaminobenzthiazole is heated with HBr and the 6-hydroxy - 2 - dimethylamino - benzthiazole so obtained is converted to its sodium salt and reacted with 1-diethylamino-2-chloro-ethane in the presence of chloroform; the 2-dimethylamino - 6 - (b  - diethylaminoethoxy) - benzthiazole forms salts with propionic, caprylic and undecylenic acids; (2) the dry sodium salt obtained by distilling a mixture containing 2-dimethylamino - 6 - hydroxy - benzthiazole, chloroform, sodium hydroxide and water is reacted by heating with 1-dimethylamino-2-chloroethane to give 2-dimethylamino-6-(b -dimethylamino - ethoxy) - benzthiazole; (3) the sodium salt of 2-dimethylamino-6-hydroxybenzthiazole is reacted with 2-chloro-1-dimethylamino - propane to yield 2 - dimethylamino - 6 - (b  - dimethylamino - isopropoxy)-benzthiazole; (4) the sodium salt of 2-dimethylamino - 6 - hydroxy - benzthiazole is reacted with 2-dimethyl-3-diethylamino-propane to give 2-dimethylamino-6-(31-diethylamino - 21,21-dimethylpropoxy) - benzthiazole; (5) 6 - ethoxy - 2 - dibutylamino - benzthiazole is converted by means of aluminium chloride in chlorobenzene to 6-hydroxy-2-dibutylaminobenzthiazole which in the form of its sodium salt is reacted with 1-diethylamino-2-chloroethane to yield 2-butylamino-6-(b -diethylaminoethoxy) - benzthiazole; (6) 6 - ethoxy - 2 - morpholyl-benzthiazole is converted to 2-(41-morpholyl) - 6 - (b  - diethylaminoethoxy) - benzthiazole as in (5); (7) 6-ethoxy-2-piperidylbenzthiazole is converted to 2-(11-piperidyl)-6-(b -diethylaminoethoxy)-benzthiazole as in (5); (8) p-ethoxyphenyl isothiocyanate is condensed with 1,2,3,4-tetrahydroquinoline to give 1-(p-ethoxyphenyl - thiocarbamyl) - 1,2,3,4 - tetrahydroquinolylthiourea which is brominated to give 6 - ethoxy - 2 - (11, 21, 31, 41 - tetrahydroquinolyl)-benzthiazole which is then converted as in (5) to 2-tetrahydroquinolyl-6-(b -diethylaminoethoxy) - benzthiazole; (9) p - ethoxyphenyl isothiocyanate is condensed with methyl aniline to p - ethoxyphenyl - methylphenylthiourea which is converted as in (8) to 2-methylphenylamino - 6 - (a  - diethylaminoethoxy) - benzthiazole; and (10) 6-ethoxybenzthiazole-2-sodium sulphonate is condensed with methylbenzylamine to give 6-ethoxy-2-methylbenzylamino - benzthiazole which is converted to 2-methylbenzylamino-6-(b -diethylaminoethoxy)-benzthiazole as in (1).