DE2304201C2 - 2-aminothiophenes - Google Patents

Description

2. Compounds according to claim 1, characterized by Z as the nitro group.

3. Compounds according to claim 1 or 2, characterized by

X as Ci - C ₇ alkoxycarbonyl,

Y as hydrogen or Ci - C ₄ - alkyl and
Z as a nitro group.

The invention relates to new 2-aminothiophenes according to claim 1 above.

The 2-aminothiophenes according to the invention are suitable as diazo components in the preparation of Azo dyes, especially disperse azo dyes. Those with the 2-aminothiophenes according to the invention Azo dyes produced show an improved one compared to those known from US Pat. No. 2,8 05,218 Etching behavior with an etching pressure.

Those compounds according to the invention in which Z stands for a nitro group can be obtained by nitration of the corresponding N-acylamino compounds of the above formula, in which Z stands for hydrogen, and subsequent hydrolysis of the N-acylamino compound. The nitration may in a sulfuric acid medium, preferably at temperatures ranging from - are carried out 5 to 10 ° C, or in a mixture of acetic acid and acetic anhydride at 35 to 40 ⁰ C. Subsequent hydrolysis is then carried out by heating in a dilute aqueous solution of an acid, e.g. B. sulfuric acid performed. When compounds in which Y is phenyl are used in the nitration, the nitration often results in the introduction of a second nitro group into the phenyl radical, especially when the nitration is carried out in sulfuric acid.

However, if X is a carboxylic acid group, then the nitration must be carried out under such conditions be carried out that only one nitro group is introduced into the thiophene ring, otherwise the tendency consists that the carboxylic acid group by a second

Nitro group is replaced.

The compounds in which X is an aminocarbonyl, N- (Ci -d-alkylj-aminocarbonyl- or N ₁ N-di (Ci -Gt-alkyl) aminocarbonyl group and / or Z is an aminocarbonyl group can be obtained in this way that the corresponding N-acylamino compounds of the above formula, in which X and / or Z is a carboxylic acid group, by treatment with thionyl chloride in an inert

ίο solvents, e.g. B. toluene, converted into the corresponding acid chloride, the resulting acid chloride with ammonia or an N- (Ci - CpAlky!) - amine or N ₁ N-Di (Ci-C ₄ -alkyl) -amine and then the N- Hydrolyzed acylamino group

If the alkoxycarbonyl group represented by X is something other than a Ci - C ₄ alkoxycarbonyl group, then such compounds can conveniently be obtained by ester exchange, one of the compounds mentioned in which X is a Ci - C ₄ -Alkoxycarbonylgruppe, or the corresponding N-acyl derivative with the corresponding alcohol, e.g. B. jS-methoxyethanol, in the presence of a catalyst, e.g. B. tetra-n-butyl titanate, is implemented, whereupon, if an N-acyl derivative is assumed, then the acyl group is removed by hydrolysis.

The compounds in which Z stands for a cyano group can be selected from the corresponding N-acyl compounds, in which Z stands for a hydrogen atom, by reaction with phosphoryl chloride and N-methylformanilide be prepared to give the corresponding N-acyl compound in which Z for formyl stands, which on conversion to the oxime and subsequent treatment with acetic anhydride, the cyano compound results, which is then deacylated in the usual way.

The compounds in which X is something other than an aminocarbonyl or carboxylic acid group, Y is a Ci-C ₄ alkyl group and Z is an aminocarbonyl or phenylaminocarbonyl group, can be obtained by reacting a cyano compound of the formula XOOC · CH ₂ CN in which X is other than an aminocarbonyl or carboxy group, with an amide of the formula (Ci-C ₄ alkyl) COCH ₂ CONH ₂ or (C, - C ₄ - alkyl) COCH ₂ CONH-Phetiyl and sulfur in ethanol as a medium containing a base, e.g. B. diethylamine contains.

The compounds in which X and / or Z is a group of the formula -CONH ₂ can be obtained by mild hydrolysis of the corresponding compounds in which X and / or Z is a cyano group, for example by adding the cyano compounds 0 ° C subjected to the action of 95% sulfuric acid.

The above-mentioned N-acyl compounds can be obtained by treating the appropriately substituted 2-aminothiophene with an acylating agent, e.g. B. an acid anhydride or an acid chloride, for example acetic anhydride or acetyl chloride, in which case the N-acetyl derivative is obtained, or with a mixture of formic acid and acetic anhydride, in which case the N-formyl derivative is obtained. The correspondingly substituted 2-aminothiophenes, which are used as starting materials used to prepare the compounds according to the invention are themselves known Compounds and are obtained by the usual methods for the preparation of thiophene derivatives.

Specific examples of compounds of the invention are

2-amino-3- (methylsulfonyl- or
phenyIsulfonyl) -5-nitrothiophene,
2-Amino-5-nitrothiophene-3-carboxylic acid and the
Esters thereof with methanol, ethanol,
n-butanol and 0-methoxyethanol,
2-Amiπo-3-cyano-4-methyl-5-aminocarbonyl-

thiophene and
2-Amino-3-carbethoxy-4- (nitrophenyl) -

5-nitrothiophene.

A preferred class of compounds according to the invention are the compounds of the general formula

Y X

O ₁ N

-NH ₂

in which X and Y have the meanings given above and Y is preferably hydrogen or a Ci - C-t-alkyl group and X preferably represents a carboxylic acid ester group.

The invention is illustrated by the following examples, in which the parts and percentages are expressed in weight.

example 1

213 parts of 2-acetylamino-ethoxycarbonyl-3 are dissolved in 2000 parts of sulfuric acid at 0 to 10 ⁰ C and then a mixture of 67 parts of nitric acid (SG 1.50) and 200 parts of sulfuric acid was slowly added, maintaining the temperature by external cooling between 0 and held at 5 ° C. The mixture is then poured onto ice and water and the precipitated 2-acetylamino-3-ethoxycarbonyl-5-nitrothiophene (mp 144 ° C.) is filtered off. The solid is stirred for 24 hours in a mixture of 200 parts of ethanol and 90 parts of sulfuric acid at 8O ⁰ C, the solution was cooled, the precipitated 2-amino-3-ethoxycarbonyl-5-nitrothiophene filtrated, washed first with ethanol and then washed with water and dried. The product melts at 240 to 242 ° C.

The 2-acetylamino-3-ethoxycarbonylthiophene itself was obtained by heating 2-amino-3-ethoxycarbonylthiophene with acetic anhydride.

Instead of the 2-acetylamino-3-ethoxycarbonylthiopheris used in Example 1 an equivalent amount of 2-formylamino-3-ethoxycarbonylthiophene (obtained by treating 2-amino-3-ethoxycarbonylthiophene with a mixture of formic acid and acetic anhydride) is used, whereby 2-amino-3-ethoxycarbonyl-S-nitrothiophene is obtained.

2-amino-3-methoxycarbonyl-5-nitrothiophene
(Bp 227 ° C),

2-amino-3-ethoxycarbonyl-4-methyl-5-nitrothiophene (Bp. 204 ° C) and

2-amino-3-isobutoxycarbonyl-5-nitrothiophene

(Bp 138 ° C)

are obtained in a similar manner by nitration of

2-acetylamino-3-methoxycarbonylthiophene,

2-acetylamino-3-ethoxycarbonyl-4-methyithiophene respectively.

2-acetylamino-3-isobutoxycarbonylthiophene.

Example 2

2-Amino-3-cyano-5-nitrothiophene is prepared by deacylation of 2-Formy! Amino-3-cyano-5-nitrothiophene by heating in an 8 ° / o solution of sulfuric acid in ethanol at 80 ⁰ C.

The 2-formyl-3-cyano-5-nitrothiophene required for this reaction is prepared as follows: A mixture from 1.5 parts of nitric acid (S.G. 1.50), 2 parts

ίο acetic acid and 2 parts acetic anhydride will within 30 min to a suspension of 5 parts of 2-formylamino-3-cyanothiophene (produced by treatment of 2-amino-3-cyanothiophene with a mixture of formic acid and acetic anhydride) in 20 parts of acetic acid prepared, the temperature of the mixture between 35 and 40 ° C is maintained. That Mixture is poured into ice and water and sodium acetate added to add mineral acidity remove. The mixture is then stirred until no acetic anhydride remains. The received 2-Formyiamino-3-cyano-5-nitrothiophene has a temperature of 216-2i8 ° C.

Example 3

Instead of the 2-acetylamino-3-ethoxycarbonylthiophene from Example 1, an equivalent amount 2-Formylaminothiophene-3-carboxylic acid used, with 2-amino-5-nitrothiophene-3-carboxylic acid with a F. above 310 ° C.

Example 4

28.9 parts of 2-acetylamino-3-ethoxycarbonyl-4-phenylthiophene are gradually added to a mixture of 130 parts of sulfuric acid and 13.5 parts of nitric acid 3 (SG 1.50) at -5.degree. The mixture is stirred for 1 hour at -5 to 0 ^° C. and then poured into 1700 parts of ice and water. The precipitated solid is filtered off and heated ^{to 80 °} C. in an 8% strength solution of sulfuric acid in ethanol for 1 hour. The solution is cooled and the solid is filtered off, washed and dried. The solid consists of a mixture of

2-amino-3-ethoxycarbonyl-4- (o-nitrophenyl) -5-nitrothiophene and 2-amino-3-ethoxycarbonyl-4- (p-nitrophenyl) -5-nitrothiophene.

If nitration is performed in acetic anhydride instead of sulfuric acid, then the result is 2-amino-3-ethoxycarbonyl-4-phenyl-5-nitrothiophene.

Example 5

2-Amino-3- (j3-methoxyethoxycarbonyl) -5-nitrothiophene is prepared by deacylating 2-acetylamino-3- (j3-methoxyethoxycarbonyl) -5-nitrothiophene by hydrolysis in hot 4.5% sulfuric acid solution in ethanol. This compound has a F. of 139 ° C.
The starting compound required for this reaction is prepared as follows: 10 parts of 2-acetylamino-3-ethoxycarbonyl-5-nitrothiophene (prepared as in Example 1) are dissolved in 50 parts of 0-methoxyethanol containing 1 part of tetra-n-butyl titanate and the mixture is heated to boiling for 10 hours. The mixture is cooled, 50 parts of water was added, and the precipitated 2-acetylamino-3 - (/ -? Methocyethoxycarbonyl) -5-nitrothiophene (F. 112-113 ⁰ C) filtered and dried.

Example 6

A mixture of 10 parts of 2-amino-3-ethoxycarbonyl-5-nitrothiophene, 100 parts of n-butanol and 1 part of tetra-n-butyl titanate is 18 hours at the boiling point The mixture is cooled, the precipitated 2-amino-3-n-butyloxycarbonyl-5-nitrothiophene (F. 126 up to 139 "C) filtered off, washed with methanol and dried The corresponding n-heptyl ester, which is produced in a similar manner from n-heptanol, · ο melts at 86 to 89 ° C.

Example 7

A mixture of 18.7 parts of acetoacetanilide, 90 parts of ethanol, 3.2 parts of sulfur, 13.5 parts Ethyl cyanoacetate and 7 parts of diethylamine are stirred for 6 hours at the boiling point. The mixture is cooled the precipitated 2-amino-3-carbethoxy-4-methyl-5-N-phenylcarbamoyl-thiophene (F. 174 to 176 ° C), filtered off, washed with ethanol and dried

Example 8

Instead of the 2-acetylamino-3-ethoxycarbonylthiophene used in Example 1, an equivalent amount of 2-formylamino-3-carbonamidothiophene is used and the nitration is carried out at -10 to -5.degree. 2-Amino-3-carbonamido-5-nitrothiophene (melting point 266 to 268 ° C.) is obtained. _in

Example 9

A mixture of 21.6 parts of 2-formylamino-5-nitrothiophene-3-carboxylic acid, 11.9 parts of thionyl chloride and 500 parts of toluene is stirred at the boiling point for 2 hours. The mixture is filtered, the filtrate is ^{cooled to 5 °} C. and 14.6 parts of diethylamine are then added. The mixture is stirred for 1 hour and the precipitated 2-formylamino-3-N, N-diethylcarbonamido-5-nitrothiophene is filtered off. When treated in a 5% hot sulfuric acid solution in ethanol, this gives 2-amino-3-N, N-diethylcarbonamido-5-ni-

tro-thiophene.

Example 10

A mixture of 22.7 parts of 2-acetylamino-3-ethoxycarbonyl-4-methylthiophene, 261 parts of N-methylformanilide and 28.4 parts of phosphoryl chloride become 90 Stirred for minutes at 90 to 95 ° C. 300 parts of 4N aqueous sodium acetate solution are added, and that The mixture was then stirred at 90 ° C. for 10 minutes. The oily solid was separated off from the liquid and removed Ethanol crystallizes with 2-acetylamino-3-ethoxycarbonyM-methyl-S-formylthiophene (M.p. 174 to 176 ° C) is obtained.

A mixture of 12.7 parts of this thiophene compound, 6.95 parts of hydroxylamine hydrochloride, 10.1 Parts of sodium bicarbonate, 300 parts of ethanol and 50 parts of water are at the boiling point for 90 minutes stirred and filtered, the filtrate was cooled and the oxime which separated out (mp 214 ° C.) was isolated. A mixture of 8.5 parts of the oxime and 30 parts of acetic anhydride are stirred for 30 minutes at the boiling point, then to 200 Parts of water are added and the 2-acetylamino-3-ethoxycarbonyM-methyl-S-cyanithiophene isolated. Subsequent hydrolysis in an aqueous alkaline medium gives 2-amino-3-ethoxycarbonyl-4-methyl-5-cyanothiophene (Mp 196 ° C).

Example 11

Instead of the 2-acetylamino-S-ethoxycarbonyl ^ -phenylthiophens used in Example 4, an equivalent amount of ^ -acetylamino-S-phenylsulfonylthiophene (which was obtained by condensation of phenylsulfonylacetonitrile with 2,5-dihydroxy-1,4-dithiane in piperidine containing Ethanol and subsequent acetylation) used, whereby 2-amino-3-phenylsulfonyl-5-nitrothiophene (mp 155 to 157 ⁰ C) is obtained.

Example 12

A solution of 1 part 2-amino-3-ethoxycarbonyl-4-methyl-5-cyanothiophene in 10 parts of sulfuric acid is kept at 0 ° C. for 24 hours. The solution is poured into water, the precipitated 2-amino-3-ethoxycarbonyl ^ -methyl-S-carbonamidothiophene filtered off and dried.

Claims (1)

Patent claims:
1,2-aminothiophenes of the general formula Y X in the X for Ci-Gt-alkylsulfonyl, phenylsulfonyl, cyano, aminocarbonyl, N- (Ci- C ₄ -alkyl) -aminocarbonyl, N ₁ N-di- (Ci - C ₄ -alkyI) -aminocarbonyl, carboxy, (Ci - C ?) - Alkoxycarbonyl or (Ci - C ₄ -AIkOXy-Ci - C4-alkoxy) carbonyl, Y represents hydrogen, Ci -C ₄ -alkyl, phenyl or nitrophenyl and Z for nitro, cyano, aminocarbonyl or phenylaminocarbonyl stands.