NOVELTY - Forming substituted para-aminophenol (I) involves: converting substituted 5-fluoro-2-nitro-benzoic acid (II) to substituted 5-hydroxy-2-nitro-benzoic acid (III) by reacting (II) with potassium trimethylsilanolate (TMSOK) in presence of solvent to form compound (III) by isolation; converting (III) to substituted 4-nitrophenol (IV) by reacting (III) with oxalyl chloride in presence of solvent to form acid chloride intermediate; and reacting intermediate with alcohol to form (IV) by isolation; and converting (IV) to compound (I) by hydrogenating (IV) in presence of catalyst and solvent.    USE - For the preparation of substituted para-aminophenol compound (claimed) used in pharmaceutical and dyestuff sectors. In the pharmaceutical sector, compound is used in the production of para-acetaminophenol and also in the synthesis of alpha-para-chlorophenoxyisobutyrate (CPIB), vitamin B1, phenacetin, composite nicotinamide and inhibitors of the hepatitis C Virus polymerase. In the dyestuff sector, compound is used in the production of azo dyes, direct dyes, sulfur dyes and acid dyes. The para-aminophenol is also used to synthesize many important intermediates such as para-phenyl-phenol.    ADVANTAGE - The method is suitable for large scale manufacture; provides alternative process of preparation of substituted para-aminophenol with fewer synthetic steps, improved scalability, more efficient isolation and purification of the product, easier handling, better yields, less reaction time, less consumption of starting materials, enhanced safety, reduced contamination to the environment, and reduced costs associated with the process. The process has both technical and economical advantages over the prior art processes, such as, e.g. less expensive, commercially available starting materials; fewer synthetic steps; better yields; improved scalability; easier handling; enhanced safety; reduced contamination of the environment; and more efficient isolation and purification of the product. The yield is about 85%.    DETAILED DESCRIPTION - Preparation of substituted para-aminophenol compound of formula 4-amino-phenol (substituted on 2-position by R 2, on 3-position by -C(O)-OR 1, on 5-position by R 4 and on 6-position by R 3) (I) or its salt involves: step A) converting a compound of formula 5-fluoro-2-nitro-benzoic acid (substituted on 3-position by R 4, on 4-position by R 3, on 6-position by R 2) (II) to a compound of formula 5-hydroxy-2-nitro-benzoic acid (substituted on 3-position by R 4, on 4-position by R 3, on 6-position by R 2) (III), where the compound (II) is reacted with potassium trimethylsilanolate (TMSOK) in the presence of a solvent at a reaction temperature for reaction time to provide the compound (III), where the compound (III) is obtained via isolation procedure; step B) converting the compound (III) to a compound of formula 4-nitrophenol (substituted on 2-position by R 2, on 3-position by COOR 1, on 5-position by R 4, and on 6-position by R 3) (IV), where the compound (III) is reacted with oxalyl chloride in the presence of a solvent and at a reaction temperature for a reaction time to form an acid chloride intermediate; and then the acid chloride intermediate is reacted with alcohol at a reaction temperature for a reaction time to provide the compound (IV), where the compound (IV) is obtained via isolation procedure; and step C) converting the compound (IV) to compound (I), where the compound (IV) is hydrogenated in the presence of catalyst, a solvent and at a reaction temperature to provide a compound (I), where the compound (I) is obtained via isolation procedure.    R 1=1-6C alkyl or 3-12C cycloalkyl (optionally substituted by at least one substituent selected from H, F, Cl, CF 3, oxo, CF 3, CN, 1-6C alkyl, 3-12C cycloalkyl, -OH, -SH, -O-1-6C alkyl, -S-1-6C alkyl, -NH 2, -NH-1-6C alkyl, aryl or heteroaryl);    R 2, R 3, and R 4=H, F, Cl, CF 3, CN, -OH, -NH 2, 1-6C alkyl, 3-12C cycloalkyl, -O-1-6C alkyl, -NH-1-6C alkyl, -NH-3-12C cycloalkyl, -N(1-6C alkyl-3-12C cycloalkyl) or -N(1-6C alkyl) 2 (optionally substituted by at least one substituent selected from H, F, Cl, CF 3, oxo, CF 3, CN, 1-6C alkyl, 3-12C cycloalkyl, -OH, -SH, -O-1-6C alkyl, -S-1-6C alkyl, -NH 2, -NH-1-6C alkyl, aryl or heteroaryl).    An INDEPENDENT CLAIM is included for a process (P1) of preparing a compound (I) or its salt involving converting a compound (II) to a compound (III), where the compound (II) is reacted with KOH or NaOH in the presence of a solvent at a reaction temperature for a reaction time to provide the compound (III), where the compound (III) is obtained via a isolation procedure; converting the compound (III) to a compound (IV), where the compound (III) is reacted with H 2SO 4 in the presence of a solvent and at a reaction temperature for a reaction time to form a compound (IV), where the compound (IV) is obtained via isolation procedure; and converting the compound (IV) to a compound (I), where the compound (IV) is hydrogenated in the presence of a catalyst, a solvent and at a reaction temperature to provide a compound (I), where the compound (I) is obtained via isolation procedure.