Synthesis and Physical Characterization of Monofunctional Azo Reactive Dyes Derived from 2-Methyl-3-(2’-Methylphenyl)-6-Arylazo-4- Oxoquinazoline

Abstract

A series of quinazoline based mono azo reactive dyes (D1-6) was prepared by
coupling 2-methyl-3-(2’-methylphenyl)-6-arylazo-4-oxoquinazoline diazonium
solution with six (6) cyanurated coupling components. The intermediates were
white solids except IM4 which was yellow; IM 1 and IM 4 were powdery, IM 2
crystalline and IM 3 needle-like, also all the intermediates were insoluble in water.
This may be due to the fact that they lack solubilizing group in their structure, they
may however, be soluble in organic solvent. Their melting points range 82 – 124 0C
and percentage yield above 50 %. The synthesized dyes gave bright colours of red,
yellow, brown, reddish brown and dark blue. Percentage yield of the dyes is also
above 50 % and their melting points well above 300 0C which is consistent with
literatures. Their molar masses were calculated from molecular formulas of the
dyes, all the synthesized dyes are soluble in water because of the presence of
sulphonic, hydroxyl, and amine groups in their structure.