Single azo based pyridine ketone dye and preparation method and application thereof

The invention discloses a single azo based pyridine ketone dye and a preparation method and application thereof. The structural formula of the single azo based pyridine ketone dye is as shown in formula (I). A pyridine ring of a coupled component of the single azo based pyridine ketone dye is provided with a substituent group (the formula can be found in the description), the ether group and polyester fibers in the substituent group have good appetency, the attached dye is not prone to transference from the interior of the fibers to the surface of the fibers even at a high temperature, color change does not happen easily, other fabrics are not stained easily in the ironing process, and thermal migration fastness and sublimation fastness of the dye are greatly improved through the large molecular weight and the ether group so that fabrics can maintain good dyefastness; besides, electron withdrawing substituents such as a methoxy group, nitryl and chlorine elements are introduced to the para-position of a diazo group of the diazo component of the single azo based pyridine ketone dye, or the nitryl is introduced to the meta-position of the diazo group, so that the color of the single azo based pyridine ketone dye is deepened; meanwhile, the nitryl or the chlorine elements is/are introduced to the ortho-position of the diazo group, and the hyperchromic effect is further improved.