DE681980C - Process for the preparation of 4-amino-2-oxyquinolines - Google Patents

Description

Process for the preparation of 4-amino-2-oxyquinolines It has been found that 4-amino-2-oxyquinolines are obtained in a very simple manner if you use 2, q.-diokyquinoline and its derivatives ammonia or primary or secondary amines at elevated temperature can act.

2,4-Dioxyquinolines suitable as starting materials are 2, q.-Dioxyquinoline itself and its monoalkali salts, monoesters and monoethers and its homologues and substitution products, e.g. B. the alkyl-2, q.-dioxyquinolines and amino-2, q.-dioxyquinolines. Examples of the primary or secondary amines which are suitable for the reaction are called mono- and dialkylamines, e.g. B. ethylamine, oxethylamine, cyclohexylamine, diethylamine, Benzylamine, also @ Pxperi, diyne and primary and secondary polyamines, e.g. B. ethylenediamine. The reaction is expediently carried out in such a way that ammonia or the mentioned amines, optionally in the presence of solvents, to the 2, q.-dioxyquinolines act at elevated temperature, expediently at temperatures between 150 and 25o ° leaves. It is advantageous to work in iron pressure vessels with stirring or vigorous shaking. When using ammonia, ammonia emitting substances or Volatile amines are expediently worked in aqueous solution. If you go from Alkali salts of the 2, q.-dioxyquinolines, are used in the reaction mixture slightly acidic salt, e.g. B. sodium bisulfite or ammonium sulfite, to that makes the 2,4-dioxyquinoline free from the alkali salts, but without the ammonia or the amines in mineral salts convict that little for the implementation are suitable. Working up the conversion mixture is very easy, since the 4-amino-2-oxyquinolines formed are mostly already in pure form and precipitate in crystalline form. They are suitable for a wide variety of purposes organic chemistry, for example as intermediates for dyes.

It is known to have 6, 8-dioxyquinoline with a primary aliphatic Implement amine, with both oxy groups replaced by the remainder of the aliphatic amine be replaced (patent specification 486 079). Surprisingly, the implementation is proceeding different if one starts from 2,4-Ddoxyquinolinen; in these only one oxy group wix exchanged. This implementation process is also quite unexpected because in other reactions of the 2, 4-Dioxyquinoline, z. B. with phosphorus pentachloride in the presence of phosphorus oxychloride, both oxy groups are exchanged. . example 1450 parts of 2,4-dioxyquinoline are heated with 600 parts of 2oo / oigerrfw aqueous Ammonia for 10 hours in the pressure vessel at 2200. After cooling and draining the The 4-amino-2-oxyquinoline which has separated out in crystallized form is sucked under pressure off, wash it with water until it reacts neutral and crystallize it from glacial acetic acid around, giving long, white needles with a melting point of 297 °. The yield is 8i o / o of the invoiced amount.

Example 2 2o parts of monoacetyl-2,4-dioxyquinoline (obtainable from Acetylation of 2,4-dioxyquinoline with acetic anhydride in the presence of pyridine; Melting point 213 °) is heated with 20o parts of 2ooroiger aqueous ammonia solution i 5th hours at 220 °. After working up in the process described in Example i 4-Amino-2-oxyquinoline is obtained in a yield of 800% of the calculated yield Lot.

Methoxyoxyquinoline (available in place of acetoxyquinoline by methylation of 2,4-dioxyquinoline in alkaline solution with dimethyl sulfate) react in the same way with ammonia, also using 4-amino-2-oxyquinoline receives.

Example 3 25 parts of 2,4-dioxyquinoline are heated with zoo parts of monoethanolamine 1 for 5 hours in a pressure vessel at 200 °. When cooling down, the 4-ethanolamino-2-oxychino- separates. lin from the formula the end. It is filtered off with suction, washed until neutral and dried. The yield is 85%. For further purification, it can be made from water and organic solvents, e.g. B. glacial acetic acid, formic acid or alcohol, recrystallize, Zoobei you get pure white, shiny crystals with a melting point of 279 °.

Example 4 25 parts of 2, 4-Dioxychinolin 1 are heated for 5 hours with 25o parts of ethylenediamine at 200 °. After cooling, it is filtered off with suction, dried and the separated compound is recrystallized from trichlorobenzene or quinoline. The 4-co-aminoethylamino-2-oxyquinoline of the formula which melts at 27 ° is thus obtained in good yield Example 5 25 parts of 2,4-dioxyquinoline are heated to 220 ° for 20 hours in a pressure vessel with zoo parts of benzylamine. After cooling, the 4-benzylamino-2-oxyquinoline has been found in long, white needles deposited almost in the calculated yield. It is filtered off with suction, washed with water. and recrystallized from alcohol. It is insoluble in water, more easily soluble in glacial acetic acid, alcohol and ethyl acetate.

EXAMPLE 6 15 parts of 2, [-dioxyquinoline] are heated with 125 parts of cyclohexylamine in a pressure vessel to a20 ° for 20 hours. After the end of the reaction, a crystallized body has separated out in good yield. It is filtered off with suction, washed with water and dried, then recrystallized from methanol or ethanol. The compound that crystallizes in rhombohedra is 4-cyclohexylamino-2-oxyquinoline It is insoluble in water and benzene, but easily soluble in methanol, ethanol and glacial acetic acid. EXAMPLE 7 15.8 parts of 6-methyl-2, q-dioxyquinoline (obtained by alkali fusion of 5-methylacetylanthranilic acid) are heated with zoo parts of 25% aqueous ammonia in a pressure vessel at 220 ° for 15 hours. After the reaction has ended, 6-methyl-4-amino-2-oxyquinoline has been found in yellowish crystals in good yield eliminated. It is filtered off with suction, washed with water and dried. It is sparingly soluble in alkalis, alcohol, benzene, more easily in water, from which it can also be dissolved. It is advisable to clean it by dissolving it with glacial acetic acid.

Claims (1)

PATENT CLAIM: Process for the production of q.-amino-2-oxyquinolines, characterized in that on 2, q.-DioXyquinoline, its monoalkali salts, Monoesters or monoethers and their homologues and other substitution products Ammonia or primary or secondary amines can act at elevated temperature.