or carboxylate group the monoazo compound of the present invention represented by the above formula i can be prepared by reacting sec butylaniline diazotized by a conventional method with a coupler for forming the coupling component residue cp selected from the group consisting of the coupling component residues represented by the formulas a b c and d hereinafter also referred to as h cp the kind and position of the substituent in the coupling component h cp and the presence or absence of the substituent has substantially no influence on the effect of the present invention the diazo component sec butylaniline may be of any one with respect to the position of the substituent sec butyl group whether 34 ortho 34 34 meta 34 or 34 para 34 this is because the position of the substituent sec butyl group has substantially no influence on the solubility of the monoazo compound of the present invention in organic solvents tone or any other property for this reason when using this monoazo compound for various coloring purposes the monoazo compound of the present invention may be a mixture of such compounds of different positions of the substituent sec butyl group the sec butylaniline used to produce the monoazo compound may therefore be a mixture of o butylaniline.