A NOVEL PROCESS FOR THE PREPARATION OF NOVEL GREEN REACTIVE DYES

摘要

A novel process for the preparation of novel green, reactive dyes of the formula Iwherein R1, R3 and R2 each stands for hydrogen, methyl or methoxy, R4 stands for hydrogen or methoxy, and R5 stands for hydrogen, methyl or methoxy said process comprising(i) diazotising an aniline of the formula IIwherein R4 and R5 are as defined above, with hydrochloric acid and sodium nitrite in the presence of water and at a temperature between 0degree C to 5degrees C to obtain a benzene diazonium chloride of the formula IIIwherein R4 and R5 are as defined above;(ii) coupling the benzene diazonium chloride of the formula IIIwith 1-Naphthol-8-amino-3, 6-di-sulfonic acid in the presence of water and at a temperature between 0degrees C to 5 degrees Celsius to obtain a disulfonic acid of the formula IVwherein R4 and R5 are as defined above.(iii) coupling the disulfonic acid of the formula IV with a tetrazonium chloride of the formula Vwherein R1 and R2 are as defined above in the presence of water and at a temperature between 0 degree Celsius to 5degrees Celsius to obtain a disulfonic acid of the formula VIwherein R1, R2, R4 and R5 are as defined above;(iv) coupling the disulfonic acid of the formula VI with a phenol of the formula VIIwherein R3 is as defined above at a temperature between 0 degree Celsius to 5degrees Celsius and in the presence of an aqueous solution of sodium hydroxide to obtain the green reactive dye of the formula I, and(v) recovering the green reactive dye of the formula I from the reaction mixture.