Synthesis of indole and pyrrolo(2,3-b)pyridine compounds, used for coloring keratinous fibers, e.g. human hair, involves conversion of tryptophan derivative with tryptophanase enzyme in presence of pyridoxal phosphate

摘要

Synthesis of indole and pyrrolo(2,3-b)pyridine compounds (I) comprises converting a tryptophan derivative (II) in an aqueous solution to (I) with a tryptophanase enzyme in the presence of pyridoxal phosphate (III). Synthesis of indole and pyrrolo(2,3-b)pyridine compounds of formula (I) comprises converting a tryptophan derivative of formula (II) in an aqueous solution to (I) with a tryptophanase enzyme in the presence of pyridoxal phosphate (III); X = nitrogen (N) or a methin group, CR4; R = hydrogen (H) or 1-4 carbon (C) alkyl; R1-4 = H, linear or branched 1-6C alkyl, aryl, difluoromethyl, trifluoromethyl, halogen, especially chlorine (Cl), bromine (Br) or iodine (I), amino, 1-6C alkylamino, arylamino, hydroxyl, 1-4C alkoxy, aryloxy, carboxy, carboxamido, carboalkoxy, carboaryloxy or heterocyclyl.