OSERUEME TIMOTHY ILEVBAOJE2023-09-222023-09-222021-10-26https://teras.ng/api/asset/document/3e0aa079-90cb-44ed-980e-c9739da016c7https://teras.ng/catalog-item/9e4d817b-0033-4e88-87ce-506be7edad13http://dspace.teras-network.net:4000/handle/123456789/44336A series of monoazo reactive dyes with quinazolinone moiety were synthesised starting with the synthesis of 6,7-dimethoxy-2-phenyl-4H-benzo[d][1,3]oxazin-4-one from 2-amino-4,5- dimethoxybenzoic acid and fusing with different di-amino compounds to give dye intermediates A, B and C; 3-(4-aminophenyl)-6,7-dimethoxy-2-phenylquinazolin-4(3H)-one (A), 4-amino-4'- (6,7-dimethoxy-4-oxo-2-phenylquinazolin-3(4H)-yl)-[1,1'-biphenyl]-2,2'-disulfonic acid (B), and 3-(4-((4-aminophenyl)sulfonyl)phenyl)-6,7-dimethoxy-2-phenylquinazolin-4(3H)-one (C) which were diazotised at 0-5°C, followed by azo coupling with cyanurated H-acid, gamma acid and J- acid as coupling components. All the reactive dyes and intermediates were characterised by their percentage yield, UV-Visible spectroscopy, FT-IR spectroscopy, and GC-MS techniques. The UV-visible spectrophotometric investigation of the synthesised dyes was carried out in DMF, methanol and water with different dielectric constants to obtain the absorption maxima, molar extinction coefficients and solvatochromic effects of the dyes. The synthesised reactive dyes were applied on cotton fabric 2% shade with a liquor ratio of 50:1 and the percentage exhaustion and fixation of the dyes were found to be reasonably good and acceptable in the range 82 – 91% and 66 – 78%, respectively. The dyeings of all the dyes on cotton fabric gave moderate to good light fastness (3-4), good to very good wash fastness (3-4) and fair to very good fastness to perspiration (2-4). The dyes gave colours ranging from purple, red to pink shades, with a good degree of levelness. This indicates that the dyes were covalently bonded to the fabricResearch Theses