On April 24, 2002, Moeller, Hinrich; Meinigke, Bernd published a patent.Application of 2510-01-2 The title of the patent was Hair dye containing nitroxanthene derivatives. And the patent contained the following:
The invention concerns hair dyes that contain nitroxanthene derivatives of the general formula (I); where R1 = H, carboxy-, carboxylato-;, sulfo-, sulfonato-, hydroxy group; R2, R3 = H, halogen, hydroxyl; M = H, alkali, alkali earth atom. The nitroxanthene derivative is preferably C.I. Acid Red 91. The compositions further contain other dyes, surfactants and amino acids. Thus a pinkish red color was achieved by using 5 mmol Acid red 91 and 5 mmol 2,4,5,6-tetraamidopyrimidine x H2SO4 in a pH 6 aqueous medium that further contained 5 mmol sodium acetate, one drop of 20% fatty alkyl ether sulfonate. The experimental process involved the reaction of 2-(2,3-Dihydro-1H-inden-1-ylidene)malononitrile(cas: 2510-01-2).Application of 2510-01-2
The Article related to hair dye nitroxanthen derivative acid red, Essential Oils and Cosmetics: Hair Preparations and other aspects.Application of 2510-01-2
Referemce:
Nitrile – Wikipedia,
Nitriles – Chemistry LibreTexts