# US 4,394,521 A · Process for the production of the Schiff's bases of 2,6-dichloro-5-hydroxy-aniline > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 4,394,521 A - Document ID: US4394521A - Status: Granted - Kind: A - Application number: 06/258,522 - Filed: 1981-04-28 - Granted: 1983-07-19 - Earliest claimed: 1981-04-28 - Assignees: Lonza-Werke G.m.b.H. - Inventors: Reinhard Sappelt - Web page: https://patentgrep.com/patent/US4394521A ## CPC - A61K 8/40: containing nitrogen (quinones containing nitrogen A61K8/355) - A61Q 5/10: Preparations for permanently dyeing the hair - A61K: PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES (devices or methods specially adapted for bringing pharmaceutical products into particular physical or administering forms A61J3/00; chemical aspects of, or use of materials for deodorisation of air, for disinfection or sterilisation, or for bandages, dressings, absorbent pads or surgical articles A61L; soap compositions C11D) - A61Q: SPECIFIC USE OF COSMETICS OR SIMILAR TOILETRY PREPARATIONS ## Abstract Process for the production of 2,6-dichloro-5-hydroxy-anils having the formula: ##STR1## wherein R.sup.1 and R.sup.2 are the same or different and each is an alkyl radical having 1 to 4 carbon atoms, by the conversion of 2,4-dichloro-3-aminophenol with a ketone. The reaction is conducted at a temperature of 0.degree. to 50.degree. C. ## Claims ### Claim 1 Process for the production of 2,6-dichloro-5-hydroxy-anils having the formula: ##STR4## wherein R.sup.1 and R.sup.2 are the same or different and each is an alkyl radical having 1 to 4 C atoms, comprising reacting 2,4-dichloro-3-aminophenol with a ketone having the formula: R.sup.1 --CO--R.sup.2 wherein R.sup.1 and R.sup.2 have the same meaning as above. ### Claim 2 (depends on 1) Process for the production of 2,6-dichloro-5-hydroxy-anils as claimed in claim 1 wherein said 2,4-dichloro-3-aminophenol is used in the form of a component in a mixture of chlorinated aminophenols. ### Claim 3 (depends on 2) Process for the production of 2,6-dichloro-5-hydroxy-anils as claimed in claim 2 wherein the reaction is carried out at temperatures from 0.degree. to 50.degree. C. ### Claim 4 (depends on 2) Process for the production of 2,6-dichloro-5-hydroxy-anils as claimed in claim 2 wherein the reaction is conducted at a temperature from 6.degree. to 12.degree. C. ### Claim 5 (depends on 2) Process for the production of 2,6-dichloro-5-hydroxy-anils as claimed in claim 2 wherein a catalyst is present. ### Claim 6 (depends on 5) Process for the production of 2,6-dichloro-5-hydroxy-anils as claimed in claim 5 wherein said catalyst is a mineral acid. ### Claim 7 (depends on 5) Process for the production of 2,6-dichloro-5-hydroxy-anils as claimed in claim 5 wherein said catalyst is HCl. ### Claim 8 (depends on 2) Process for the production of 2,6-dichloro-5-hydroxy-anils as claimed in claim 2 wherein a solvent is present. ### Claim 9 (depends on 8) Process for the production of 2,6-dichloro-5-hydroxy-anils as claimed in claim 8 wherein the product is recovered from the solvent as precipitated crystals. ### Claim 10 (depends on 8) Process for the production of 2,6-dichloro-5-hydroxy-anils as claimed in claim 8 wherein the solvent is methanol, ethanol, butanol, isopropanol, propanol, isobutanol, carbon tetrachloride, 1,2-dichloroethane, 1-chlorobutane, 2-chlorobutane, 1,1-dichloroethane, 1,1,2,2-tetrachloroethane, 1,1,1,2-tetrachloroethane, 1,4-dichlorobutane, 2,2-dichlorobutane, 2,3-dichlorobutane, 1-chloropropane, pentachloroethane, 1,1,1-trichloroethane, 1-chloropentane, 1,1,2-trichloroethane, 1,1-dichlorobutane, 1,2-dichlorobutane, 1,3-dichlorobutane, 1,1,1,2-tetrachlorobutane, 1,2-dichloropropane, 1,3-dichloropropane, 2,2-dichloropropane, 1,1,3-trichloropropane, 1,1,1,2-tetrachloropropane or 2-chloropentane. ### Claim 11 (depends on 10) Process for the production of 2,6-dichloro-5-hydroxy-anils as claimed in claim 10 wherein up to 20 moles of said ketone is used per mole of 2,4-dichloro-3-aminophenol. ### Claim 12 (depends on 8) Process for the production of 2,6-dichloro-5-hydroxy-anils as claimed in claim 8 wherein said solvent is an alcohol or a chlorinated hydrocarbon. ### Claim 13 (depends on 2) Process for the production of 2,6-dichloro-5-hydroxy-anils as claimed in claim 2 wherein said mixture of chlorinated aminophenols comprises 2,4-dichloro-3-aminophenol, 4,6-dichloro-3-aminophenol and 2,4,6-trichloro-3-aminophenol. ### Claim 14 (depends on 2) Process for the production of 2,6-dichloro-5-hydroxy-anils as claimed in claim 2 wherein the compound having the formula R.sup.1 --CO--R.sup.2 is acetone. ### Claim 15 (depends on 2) Process for the production of 2,6-dichloro-5-hydroxy-anils as claimed in claim 2 wherein the mixture of chlorinated aminophenols was prepared by chlorinating 3-nitrophenol with elemental chlorine in a melt at a temperature of 60.degree. to 100.degree. C. or in a halogenated solvent, such as chloroform carbon tetrachloride, tetrachloroethane, 1,1,2-trichlorofluorethane and o-dichlorobenzol, at the boiling temperature of the solvent, or in water in the presence of an emulsifier or in the presence of acetic acid at a temperature of 40.degree. to 90.degree. C., and then reducing the nitro group of the chlorinated nitrophenol. ### Claim 16 (depends on 2) Process for the production of 2,6-dichloro-5-hydroxy-anils as claimed in claim 2 wherein the compound having the formula R.sup.1 --CO--R.sup.2 is methyl ethyl ketone. ### Claim 17 (depends on 1) Process for the production of 2,6-dichloro-5-hydroxy-anils as claimed in claim 1 wherein the ketone having the formula R.sup.1 --CO--R.sup.2 is acetone, methyl ethyl ketone, isobutyl ketone, 2-pentanone, 3-methyl-2-butanone, 3-pentanone, 2-hexanone, 3-hexanone, methyl isobutyl ketone, 2-methyl-3-pentanone, 3-methyl-2-pentanone, methyl t-butyl ketone, dipropyl ketone, diisopropyl ketone, diisobutyl ketone or hexamethylacetone. ### Claim 18 (depends on 1, 2, 3, 4, 5, 6, 7, 13, 14, 15, 16) Process for the production of 2,6-dichloro-5-hydroxy-anils as claimed in any of claims 1 to 7 and 13 to 16 wherein an excess of said ketone is used. ### Claim 19 Composition comprising a mixture of 2,4-dichloro-3-aminophenol and a ketone having the formula: R.sup.1 --CO--R.sup.2 wherein R.sup.1 and R.sup.2 are the same or different and each is an alkyl radical having 1 to 4 C atoms. ### Claim 20 (depends on 19) Composition as claimed in claim 19 wherein the ketone having the formula R.sup.1 --CO--R.sup.2 is acetone, methyl ethyl ketone, isobutyl ketone, 2-pentanone, 3-methyl-2-butanone, 3-pentanone, 2-hexanone, 3-hexanone, methyl isobutyl ketone, 2-methyl-3-pentanone, 3-methyl-2-pentanone, methyl t-butyl ketone, dipropyl ketone, diisopropyl ketone, diisobutyl ketone or hexamethylacetone. ### Claim 21 (depends on 19) Composition as claimed in claim 19 wherein an acid catalyst, a solvent, 4,6-dichloro-3-aminophenol and 2,4,6-trichloro-3-aminophenol are also present. ### Claim 22 (depends on 21) Composition as claimed in claim 21 wherein the solvent is methanol, ethanol, butanol, isopropanol, propanol, isobutanol, carbon tetrachloride, 1,2-dichloroethane, 1-chlorobutane, 1,1-dichloroethane, 1,1,2,2-tetrachloroethane, 1,1,1,2-tetrachloroethane, 1,4-dichlorobutane, 2,2-dichlorobutane, 2,3-dichlorobutane, 1-chloropropane, pentachloroethane, 1,1,1-trichloroethane, 1-chloropentane, 1,1,2-trichloroethane, 1,1-dichlorbutane, 1,2-dichlorobutane, 1,3-dichlorobutane, 1,1,1,2-tetrachlorobutane, 1,2-dichloropropane, 1,3-dichloropropane, 2,2-dichloropropane, 1,1,3-trichloropropane, 1,1,1,2-tetrachloropropane or 2-chloropentane. ### Claim 23 (depends on 21) Composition as claimed in claim 21 wherein said acid catalyst is a mineral acid. ### Claim 24 (depends on 23) Composition as claimed in claim 23 wherein said catalyst is HCl or H.sub.2 SO.sub.4. ### Claim 25 (depends on 21) Composition as claimed in claim 21 wherein said solvent is an alcohol or a chlorinated hydrocarbon.