DE3546925C2 - New 2-amino-thiophene cpds. and derived disperse azo dyes - Google Patents

Abstract

Thienyl cpds. of formula (I) are new. In (I) R = halo; R1 = Cn, 1-6C alkoxycarbonyl, 3-6C alkenyloxycarbonyl, CONH2 (opt. substd. by 1 or 2 1-4C alkyl), 1-4C alkylsulphonyl, PhSO2, 1-4C alkylcarbonyl, PhCO or CONHPh; R2 = HCO, CN, -CH=C(R4)2 or -CH=N-OH; R3 = -N=N-K or NH2; K = residue of a coupler; each R4 = CN, 1-6C alkoxycarbonyl or 3-6C (alkenyl or alkynyl)oxycarbonyl; or one is CN and the other benzoyl, opt. substd. by one 1-4C alkoxycarbonyl, 1-4C alkylsulphonyl, PhSO2 or CONH2 (opt. substd. by 1-4C alkyl or phenyl); or one is H and the other is benzoyl (opt. substd. by one 1-2C alkoxycarbonyl, halo, 1-4C alkyl or NO2), 1-4C alkylcarbonyl or 3-6C alkenylcarbonyl; or one is NO2 and the other H, Me or Et.

Description

It has been found that compounds of the formula II

where Hal is a halogen atom,
R ₁ cyan, optionally having up to two substituents, alkoxycarbonyl, alkenyloxycarbonyl, alkyl- or phenylcarbonyl, aminocarbonyl, phenyl-, alkyl- or dialkyl-aminocarbonyl, alkyl- or phenylsulfonyl,
R ₂ formyl, cyan or a group of the formula

R ₃ and R ₄ independently of one another are cyano, optionally up to twice substituted alkoxycarbonyl, C _3-6 -alkenyloxycarbonyl or alkynyloxycarbonyl, or the one cyan and the other alkylsulfonyl, optionally up to twice substituted phenyl, benzoyl, phenylsulfonyl or aminocarbonyl,
R ₅ alkylcarbonyl, alkenylcarbonyl or optionally benzoyl carrying up to two substituents,
R _{6 is} hydrogen, methyl or ethyl,
can be prepared by using a compound of formula IV

(which can also be in the enol form and apparently reacts in this form)
wherein R _{7 is} a primary, optionally protected amino group, with a Vilsmeier reagent to give a compound of formula V.

implements
the formyl group, if appropriate, is converted into a group corresponding to the meanings of R ₂ by known methods and R _{7 is} saponified to form the free amino group.

The reaction of a compound of formula IV in which R _{1 is} aminocarbonyl results in a compound of formula V in which R _{1 is} cyano; treatment with the Vilsmeier reagent causes water to be split off.

The compounds of formula III are known; some of the compounds of formula IV known, they can be analogous to known methods, e.g. B. J.org.Chem. 38, (20), 3615 ff. (1973), or analogously to the information in Example 2.

When reacting one mole of a compound of formula IV, 2-3 moles of a Vilsmeier reagent are preferably used. In this reaction, a formyl group is introduced in the 5-position, the hydroxyl group (in the 4-position) is replaced by a chlorine atom and the NH ₂ group is converted into a formamidino group, which is easily hydrolyzed to the amino group. The known reaction product of phosphorus oxychloride and dimethylformamide is preferably used as the Vilsmeier reagent, the compound of the formula

arises, which is hydrolyzed in a known manner in an acidic or basic medium to 2-amino-3- (R ₁ ) -4-chloro-5-formylthiophene. In the compounds of the formula II in which R _{2 is} a formyl group, this can be reacted further in a generally known manner. Consider here z. B. condensation with hydroxylamine and optionally acylation on oxygen with nitrile formation; Implementation according to Knoevenagel or Perkin etc. This gives rise to the compounds in which R _{2 has} the meanings given above.

By diazotization of the amines of the formula H and coupling to suitable couplings Components can be made valuable dyes, as in the main application P 35 29 831.6 is described in more detail.

In the following examples, the parts mean parts by weight; the temperatures are in Celsius degrees indicated.  

example 1

37.5 parts of 2-amino-3-ethoxycarbonyl-4-oxo-4,5-dihydrothiophene (J.org.Chem.38, (20), 3615 ff (1973), J.L. Isidor et al) are described in 152 Parts of dimethylformamide dissolved, cooled to -10 °, with good stirring slowly mixed with 90 parts of phosphorus oxychloride, heated to 70 °, allowed to cool again and discharged onto 500 parts of ice water, whereby the temperature of the mixture rises to about 40 °. You stir half Hour while cooling to about 5 °, then filter the precipitate and wash it off with a little ice water. The compound thus obtained ent speaks the formula 2-dimethylaminomethylimino-3-ethoxycarbonyl-4-chloro 5-formyl-thiophene and has a melting point of 197 °. she will suspended in 500 parts of water and 25 parts of 85% phosphoric acid, with 395 parts of ethyl alcohol and 60 parts of 30 percent sodium hydroxide solution transferred. It is heated to 65 to 70 ° with stirring for two hours, where at pH kept at about 9 by adding sodium carbonate becomes. Then dilute with 300 parts of ice water, slowly add as much 30 percent hydrochloric acid (about 23 parts), that a pH of 6.5 sets. The precipitate, 2-amino-3-ethoxycarbonyl-4-chloro-5- Formylthiophene, with a melting point of 176-178 °, is filtered off and washed with a little ice water. From an ethanol / water mixture mixed recrystallized, the pure compound melts at 180 °. By reacting the 5-formyl group with methylene-active compounds, analogous to known work regulations, derivatives of these Obtained thiophene compound.  

Example 2

• a) 122 parts of 1,1-dicyano-2-methoxy-propene are dissolved (suspended) together with 32 parts of sulfur powder in approx. 300 parts of N, N-dimethylformamide, cooled to approx. 10 °, and then stirred with approx. 52 parts of triethylamine are added dropwise over 30 minutes. The temperature of the reaction mixture is allowed to rise to room temperature (25 °) and the solution of the 2-amino-3-cyano-4-methoxy-thiophene formed is poured into a mixture of approx. 500 parts of ice and approx. 150 parts conc. Hydrochloric acid. The mixture is stirred for 1-2 hours, the hydrolysis product, 2-amino-3-cyano-thienin-4-one, 2-amino-3-cyan-4-hydroxy-thiophen-4-one is filtered off and washed with a little ice water after. The product is dried in vacuo.
  70 parts of the intermediate product thus obtained are dissolved in 400 parts of N, N-dimethylformamide, at about 5 °, 230 parts of phosphorus oxychloride are added dropwise within about 15 minutes. The reaction temperature is then allowed to rise with stirring, heated to 70 ° and poured onto about 1000 parts of ice after 3-4 hours. The mixture is then neutralized to about pH 6 with about 450 parts of 25% ammonia and the product 2- (N, N-dimethylformamidino) -3-cyano-4-chloro-5-formylthiophene with a melting point of 183- Filtered at 88 °. The compound recrystallized from acetonitrile melts at 191.5-93 °.
• b) 24.15 parts of 2- (N, N-dimethylformamidino) -3-cyano-4-chloro-5-formyl thiophene are suspended in 100 parts of 50% formic acid, 1 Part of ammonium sulfate added, and while stirring for about 5 hours the cooked under reflux. Allow to cool and filter that Hydrolysis product, 2-amino-3-cyano-4-chloro-5-formylthiophene.

The amine can be diazotized according to Example 16 without further purification and be coupled. The pure connection - from ethanol / water recrystallized - melts at 267-9 ° C.  

By condensation on the 5-formyl group, analogous to known ones Work regulations (e.g. according to Knoevenagl, oxime formation / dehydration etc.) derivatives of this compound are obtained. These derivatizations but can also on the corresponding azo dyes - production according to Example 17 - be made.

The following Table 1 shows further ones that can be produced according to the invention 2-Amino-4-halothiophene of the formula II indicated, where Hal always Chlorine means.  

Table 1

Claims (2)

Process for the preparation of thiophene compounds of the formula II
where Hal is a halogen atom,
R ₁ cyan, optionally having up to two substituents, alkoxycarbonyl, alkenyloxycarbonyl, alkyl- or phenylcarbonyl, aminocarbonyl, phenyl-, alkyl- or dialkyl-aminocarbonyl, alkyl- or phenylsulfonyl,
R ₂ formyl, cyan or a group of the formula
R ₃ and R ₄ independently of one another are cyano, optionally up to twice substituted alkoxycarbonyl, C _3-6 -alkenyloxycarbonyl or alkynyloxycarbonyl, or the one cyan and the other alkylsulfonyl, optionally up to twice substituted phenyl, benzoyl, phenylsulfonyl or aminocarbonyl,
R ₅ alkylcarbonyl, alkenylcarbonyl or optionally benzoyl carrying up to two substituents,
R _{6 is} hydrogen, methyl or ethyl,
characterized in that a compound of formula IV
(which can also be in the enol form). wherein R _{7 is} a primary, optionally protected amino group, with a Vilsmeier reagent to give a compound of formula V.
converts the formyl group, if necessary, using known methods, converts it into a group corresponding to the meanings of R ₂ and saponifies R ₇ to form the free amino group.