On April 11, 2002, Moeller, Hinrich; Oberkobusch, Doris; Hoeffkes, Horst published a patent.Synthetic Route of 2510-01-2 The title of the patent was Oxidative hair dyes containing acridine aldehydes and acridine ketones. And the patent contained the following:
The invention concerns the synthesis of acridine aldehyde and acridine ketone derivatives and their application in oxidative hair dyes. Compounds of the general formula (I) are defined, where R1 = hydrogen atom, C1-4-Alkyl or group of aryls; R2, R3, R4 and a R5, same or different = a hydrogen atom, halogen atom, a C1-C4-Alkyl, C1-C4-Hydroxyalkyl, C1-C4-Alkoxy, C1-C4-Hydroxyalkoxy, hydroxy group, nitro group, sulfo group, amino group, which can be substituted by C1-C4-Alkyl, or a C1-C4-Acyl, whereby two of the groups can form a condensed aromatic ring, whereby the groups of COR1, R2, R3, R4 and R5 to any ring of the cyclic system; X- an anion, in particular halide, sulfonate, like benzene sulfonate, p-Toluene sulfonate, methanesulfonate or trifluoro methanesulfonate, Me sulfate, Et sulfate, perchlorate, sulfate, hydrogensulfate, tetrafluoroborate or tetrachlorozincate, alkanoate, whereby X- is absent if R6 is neg. charged; R6 = hydrogen atom, C1-4-Alkyl, C1-C4-Hydroxyalkyl, C1-C6 carboxyalkyl, C1-C6 sulfoalkyl, C1-4-aralkyl, heteroalkyl, neg. charged oxygen. Thus 9-formyl-10-methylacridinium-p-toluene sulfonate was synthesized from acridine-9-carboxaldehyde and p-toluene sulfonic acid Me ester. The product was used in combination with 3-methyl-p-aminophenol to yield a light brown hair color. The experimental process involved the reaction of 2-(2,3-Dihydro-1H-inden-1-ylidene)malononitrile(cas: 2510-01-2).Synthetic Route of 2510-01-2
The Article related to oxidative hair dye acridine aldehyde ketone, Essential Oils and Cosmetics: Hair Preparations and other aspects.Synthetic Route of 2510-01-2
Referemce:
Nitrile – Wikipedia,
Nitriles – Chemistry LibreTexts