AT211814B - Process for the preparation of new, unsaturated 2-acyl-4-aminophenol ethers - Google Patents

Description

  

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  Process for the preparation of new, unsaturated 2-acyl-4-aminophenol ethers
The present invention relates to the preparation of new 2-acyl-4-aminophenol ethers of the general formula:
 EMI1.1
 In this formula, X denotes a carbon double bond or a carbon three
 EMI1.2
 branched alkylene radical with 3-10 carbon atoms; R. i is hydrogen or an aliphatic acyl or 2-oxyacyl radical having 1-4 carbon atoms; R2 is hydrogen, a straight-chain or branched alkyl radical with 1-11 carbon atoms or an optionally substituted aryl radical;

   Ra is hydrogen, halogen, an alkyl, preferably a methyl group, an alkoxy, preferably a methoxy group, or an acylamino, preferably an acetamino group; R4 is hydrogen, halogen, an alkoxy group with 1-4 carbon atoms, an acyloxy group, preferably an acetoxy group, a hydroxyl group, an amino, alkylamino or dialkylamino group, the alkyl radicals of which each contain 1-4 carbon atoms and optionally one together with the nitrogen atom can form another heteroatom-containing ring, or a radical of the general formula:
 EMI1.3
 in which R "R, and R3 have the meaning given above.



   According to the invention, these compounds are obtained in the following way:
Reduction of nitro compounds of the general formula:
 EMI1.4
 in which R2, R3, R4 and X have the meaning given, according to processes known per se to give the corresponding amino compounds and optionally acylation thereof with suitable derivatives of aliphatic carboxylic acids or 2-oxycarboxylic acids having 1-4 carbon atoms.



   The 2-acyl-4aminophenol ethers obtainable according to the invention can be converted into the corresponding carbonyl derivatives, e.g. B. oximes, hydrazones, substituted hydrazones, semicarbazones, thiosemicarbazones, open and cyclic ketals and acetals can be converted.



   Some representatives from the class of the 2-acyl-4aminophenols or their simple, saturated ethers are known from the work of Kunckell, Ber. d. German Chemical Society, Volume 34, 1901, page 124 ff. and Mathiesen, Chem. Soc. (London), 1949, pp. 1133-1137 and Marc Julia, Bull. Soc. Chim. France, 1952, pages 639-642. The literature has not yet found any information on the effects of these products.



   It has now been found that the compounds prepared according to the invention have a good antipyretic and anti-inflammatory effect and produce a considerably lower formation of methaemoglobin in the organism than, for example,. B. the well-known p-ethoxy-acetanilide. The pharmacological effect of the new unsaturated ethers also exceeds that of the 2-acyl-4-aminophenol derivatives known from the literature.



   The following examples illustrate the invention.



   Example l: a) 2-Acetyl-4-amino-5-methoxyphenyl-allyl ether:

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 10.0 g of 2-acetyl-4-nitro-5-methoxyphenyl-allyl ether are heated to the boil in 100 cm3 of methanol with 5 cm3 of concentrated hydrochloric acid and 6.0 g of iron filings are added with stirring. After the strong evolution of hydrogen has subsided, the mixture is refluxed for a further 4 hours, neutralized with alcoholic sodium hydroxide solution, the hydroxide sludge is filtered off while hot and the filter residue is digested three times with boiling methanol.



  The filtrate and the rewashes are combined and concentrated. After adding water, a brown precipitate is obtained, which is recrystallized from water. Crystals with a melting point of 93 ° C. are obtained. b) 2-Acetyl-4-acetamino-5-methoxy-phenyl-allyl ether:
After drying, the crystals obtained according to a) are refluxed in acetic anhydride together with a little sodium acetate for 15 minutes. After cooling, it is poured into water, filtered off with suction and crystallized
 EMI2.1
 Allyl ethers are left with 24.0 g of syrupy, anhydrous lactic acid in a drying cabinet at 50 ° C. for 48 hours. The initially undissolved crystals go into solution.



  It is taken up in dilute sodium hydroxide solution, filtered off with suction and the precipitate is washed neutral.



  After drying, it is recrystallized three times from benzene. Yellowish crystals, insoluble in dilute acids and alkalis, with a temperature of 122-123 C; Yield: 2.8 g.

 

Claims (1)

PATENT CLAIM: Process for the preparation of new, unsaturated 2-acyl-4-aminophenol ethers of the general formula: EMI2.2 wherein: X denotes a straight-chain or branched alkylene radical containing a carbon double bond or a carbon triple bond and having 3-10 carbon atoms, Ri is hydrogen or an aliphatic acyl or. 2-oxyacyl radical with 1-4 carbon atoms, R2 hydrogen, a straight-chain or branched alkyl radical with 1-11 carbon atoms or an optionally substituted aryl radical, Rg hydrogen, halogen, an alkyl, preferably a methyl group, an alkoxy, preferably a methoxy group, or an acylamino, preferably an acetamino group, R4 is hydrogen, halogen, an alkoxy group with 1-4 carbon atoms, an acyloxy, preferably an acetoxy group, a hydroxyl group, an amino, alkylamino or dialkylamino group, the alkyl radicals of which have 1-4 carbon atoms each contain and together with the nitrogen atom can also form a ring which may have a further heteroatom, or a radical of the general formula: EMI2.3 in which Rl> R2 and R3 have the meaning given above, characterized in that nitro compounds of the general formula: EMI2.4 where Ru, Ru, ruz and X have the meaning given, reduced to the corresponding amino compounds and these optionally acylated with suitable derivatives of aliphatic carboxylic acids or oc-oxycarboxylic acids with 1-4 carbon atoms.