3-(4-Hydroxyanilino)-9-ethylcarbazole in Butanol sodium polysulfide solution heating, methods and C.I. Vat Blue 43 (C.I. 53630) similarity. This indophenol is by N – ethylcarbazole and 4-Nitrosophenol in concentrated sulfuric acid, in – 23 ℃ condensation and have to (BIOS 983,65-70) o note: use with C.I. leuco sulfur dye similar method, some the structure of the dyes can be converted into the leuco compound.
