Reactive dyestuffs containing a free or salified acid group and a halopyridine residue

摘要

The invention comprises dyestuffs of the formula where A is the residue of a dyestuff molecule containing a free or solified acid group, one X is halogen and the others are H, OH, CH3 or halogen, Y is -NRCO-, -NRSO2- or -N = N-, Z is H, alkyl, hydroxyalkyl, -COOR, -CONalkylene, -CONalkanetriyl-OH, -CN, -SO3H, or NO2 R and R1 are H, alkyl or hydroxyalky and n is 1 or 2. The compounds wherein R is -NRCO- or -NRSO2- may be prepared by reacting together and A(NHR)n where W1 is SO2 or CO. The compounds wherein R is -N = N- may be prepared by diazotization and coupling of appropriate components.ALSO:2 - Hydroxy - 5 - nitro - pyridine - 3 -sulphonic acid is prepared from 2 - hydroxy - 5 nitro - pyridine and chlorosulphonic acid; this acid is converted to the Ca salt with CaCO3 and then to the Na salt with Na2CO3; this Na salt is treated with POCl3 to give 2 - chloro - 5 - nitro - pyridine - 3 - sulphonyl chloride; this chloride is converted into the Na salt of 2-chloro - 5 - nitro - pyridine - 3 - sulphonate by Na2CO3 and this nitro compound is reduced to the corresponding amine by the Bechamp method using Fe powder. 2-Aminopyridine is treated with chlorosulphonic acid to give a mixture of 2-aminopyridine 3- and 5-sulphonic acid, the amino groups of which are converted to hydroxy groups via the diazo compounds and the resulting mixture when treated with PCl5 gives a mixture of 2-chloropyridine-3- and 5-sulphonychloride. 2 - Chloropyridine - 5 - sulphonylchloride may also be prepared from N - methyl - 2 - pyridone - 5 - sulphonic acid. 3,5 - Dichlorosulphonyl - 2 - chloropyridine is obtained by treating the mixture of 2-hydroxypyridine 3- and 5-sulphonic acid with chlorosulphonic acid.