Mercaptoquinazoline Dyes. Synthesis of 2-Mercapto3-(2'4'-dichloro-4-stilbenyl)-6-arylazo-4-oxoquinazoline Dyes and their Application

Department of Chemistry, South Gujarat University, Surat-895 007 Manuscript received 14 January 1988, revised 29 August 1988, accepted 4 October 1988 The azo dyes of the type 2-mercapto-3-(2',4'-dichloro-4-stilbenyl)-6-arylazo-4- oxoquinazoline have been synthesised by reaction of 5-nitro-N-acetylanthranilic acid with p-tolylthiourea, condensation of the product with 2,4-dlchlorobenzaldehyde, reduc­tion with sodium sulphide to the amine, diazotisation and finally coupling with various components. Dyeing properties of these dyes on silk, wool and viscose rayon were assessed. The percentage exhaustion of dye-bath on silk and wool was good to excellent and on viscose rayon it was poor to moderate. A study of the fastness of dyed patterns showed that the dyes were good to very good on silk and wool, and fair to good for viscose rayon