Abstract: The application is concerned with new pyrazolone compounds having the structure: ##STR1## wherein R is hydrogen or halogen (especially fluorine, bromine and chlorine) and R.sub.1 and R.sub.2 independently of one another are hydrogen or halogen (especially bromine and chlorine) and R.sub.3 is lower alkyl (especially methyl, ethyl, propyl and butyl). The compounds are useful in heat transfer printing of polyester fabrics and impart yellow shades thereto. The application discloses a method of making the new compounds and discusses the utilization of the compounds in the heat transfer printing of polyester fabrics, in the preparation of ink formulations, and in making transfer sheets for heat transfer printing.

Abstract: New yellow azo pyrazolone compounds having the structure ##STR1## wherein R is halogen and R.sub.1 and R.sub.2 are hydrogen, lower alkyl or halogen. The compounds are useful as yellow dyes in heat transfer printing of synthetic fabrics.

Abstract: The invention is directed to transfer sheets for heat transfer printing polyester textiles in yellow hues, to inks that are useful in making such transfer sheets, to an improved process for heat transfer printing polyester textiles and to the printed or dyed fabrics thereby produced; the yellow hue being imparted by the use of at least one compound having the structure: ##STR1## wherein R.sub.1 is lower alkyl.