The literature records but few investigations of the preparation and properties or guaiacol coupled with diazotized amines. This would seem rather odd in view of the The literature records but few investigations of the preparation and properties or guaiacol coupled with diazot1zed amines. This would seem rather odd in view of the decided value that the azo derivatives of a number of closely related phenols have proved to possess, not only as dyes, but also as antiseptics and bactericides. The preparation of the free bases of benzene-azo-guaiacol and guaiacol dis-azo benzene have been reported, and a number of acetyl derivatives of azo guaiacol compounds have been investigated, but the guaiacol compounds analagous to such dyes as methyl orange, Congo red, and Orange-II are not described in the literature. In this investigation a number of dyes have been prepared by coupling guaiacol with various diazotized amines Some of the physical properties of these compounds have been noted . In all oases the sodium salt of the dye has been prepared, and in a few instances the free base has been satisfactorily isolated, although in the majority of instances the free base was precipitated as a viscous, tarry substance Which resisted attempts at recrystallization. In an attempt to secure an easily recrystallizable modification of the dyes the aoetyl derivatives of a few were prepared, but these only assumed crystalline form in the case of the acetyl derivatives of benzidine azo guaiacol and p- toluidine azo guaiaool.