SYNTHESIS OF AJZEN-SPILON BLACK TRH AND ITS DERIVATIVES

A series of new azoic coupling components, derivatives of Naphthol AS, have heen synthesized by reacting phenyl 3-hydroxy-2-naphthoate with para-substituted anilines. The coupling of Naphthol AS or its derivative with diazotized picramic acid was initially carried out in alkaline aqueous solutions following an original patent procedure. However, all the reactions were incomplete and the azo products were contaminated with the corresponding couplers. This may be due to the low solubility of the couplers in aqueous NaOH solution. Successful coupling reactions were finally achieved, giving pure azo dyes in about 90% yields, by carrying out the reaction in D M F in the presence of sodium acetate. Metallization of the azo dyes with sodium chromium salicylate gave TRH and its derivatives in 60-100% yield. © 1990.