DD200740A1 - PROCESS FOR PREPARING SUBSTITUTED 3,4-DIAMINOTHIENO [2,3-B] PYRROLES - Google Patents

Abstract

The title compounds I, which can be used as intermediates, in particular for dyes, are prepared according to the invention by reacting substituted 2,4-diaminothiophene-3-carbonitriles II with acceptor-substituted halomethanes III in one stage in the presence of bases.

Description

23409

Sitel of the invention

Process for the preparation of substituted 3,4-diaminothieno [2,3-b] pyrroles

Field of application of the invention

The invention relates to a process for the preparation of substituted 3,4-diaminothieno [2,3-b] pyrroles. Such compounds can gain importance as intermediates, especially for dyes.

Characteristic of the known technical solutions

Substituted or unsubstituted 3,4-biaminothleno [2,3-b] pyrroles have not yet been described in the literature. Related substituted 4-aminothieno [2,3-b] pyrroles were prepared according to Z. Heterocycl. Chem. 11 , 143 O 974 ·) from 2-aminothiophene-3-carbonitriles and glyoxylic acid esters in several stages, as well as according to Bull. Sog.chim.France 197.5 , 1786 from 2-acylaminothiophene-3-carbonitriles and special oC-halocarbonyl compounds manufactured.

Object of the invention

The aim of the invention is to produce substituted 3,4-diaminothienopyrroles in a simple manner.

Explanation of the essence of the invention

The object of the invention is, hitherto unknown te, substituted 3,4-diaminothieno [2,3-b] pyrroles by a

-a- ZJ4Uyö b

simple procedure accessible. Erfindungsgemäfi the object is achieved in that substituted 3,4-Diaainopyrrole the general formula I.

1 2

in which R is an aryl or allyl radical and H and H, identical or different from each other, may be alkozycarbonyl, acyl, ilitrile or garbamido groups, can be prepared by using substituted 2,4-biaminothiophene-3-carbonitriles of the formula II,

Λ 2

n R and R have the abovementioned meaning,

with acceptor-substituted halomethanes of Porael III,

R ^ III

in which Σ represents a bromine or chlorine atom and R- ^{5 has} the meaning given for I, are reacted. This is done in one stage at temperatures of 60-150 ⁰ G in a solvent, preferably dimethylformamide, and in the presence of bases, preferably by successive addition of potassium carbonate for the alkylation and triethylamine for the cyclization. The Thlophenderivate ^ ^he formula II required as starting materials are in a known manner by cyclization according to Canad.J.Chem. 48, 2709 (1970), 4 pounds, 1372 (1971) and dissertation M.Hentschel, Dresden University of Technology, 1974, available in simple methods.

_ * 3 - f ~ \ Li. I 3 - / WV »?

embodiments

Example 1: Diethyl 3j-4-diamino-6-phenylthleno [2,3-t] -pyrrole-2,5-dicarboxylate

0.02 mol of 4-amino-3 ~ cyano-2-phenylaminotH.ioph.en-5-carboxylic acid ethyl ester, dissolved in 30 ml of absolute dimethylformamide, together with 0.02 mol of bromoacetic acid ethyl ester and 0.04 mol of anhydrous potassium carbonate for 2 hours stirred at 120-130 ⁰ G. Is then added dropwise at 90 ⁰ G 2 ml of triethylamine and stirred for one more hour at this temperature. After, the Sr en cold stirred lüiswasser in the 6-five-fold volume of 2 hours. Allowed to stand, filtered off with suction and washed with water, laughing recrystallization from ethanol, the product melts at 176-178 ⁰ G. Crude yield 69%, pure yield 50 %.

Example 2: 3'-4-diamino-5'-benzoyl-5-phenylthieno [2,3-b. pyrrole-2-carboxylic acid ethyl ester

A mixture consisting of 0.02 mol of 4-amino-3-cyano-2-phenylaminothiopline-5-carboxylic acid eet hy Lester, 0.02 mol of phenacyl bromide, 0.04 mol of anhydrous potassium carbonate and 30 ml of absolute dimethylformamide is added 2 hrs 120-130 ⁰ G stirred. Then added dropwise at 90 ⁰ G 2 ml of triethylamine and stirred for 1 hr. At this temperature. After cooling, it is stirred into the 6-8fache volume of water, filtered off with suction after 2 hours and washed with V / asser. Recrystallized from n-propyl alcohol. M.p. 215-217 ⁰ G, crude yield 82%, pure yield 61%.

Example 3: 3j 4-Diamino-5-cyano-6-phenylthieno [2,3-b] pyrrole-2-carboxylic acid ethyl ester

0.02 mol of 4-amino-2-phenylaminothioph. -En-3-cyano-5-carboxylic acid ethyl ester are reacted with 0.02 mol of chloroacetonitrile as described in Example 1 and worked up. Recrystallized from dimethylformamide, the product melts at 295-293 ⁰ G. Pure yield 54 %.

Example 4: Diethyl 6-allyl-3,4-diaminothieno [2,3-V] pyrrole-2,5-dicarboxylate

0.02 mol of 2-AlIyIlLLOO acid ethyl ester were stirred in 3ö ml Dime-uhy! Formamide together with 0.02 mol of ethyl bromoacetate and 0.04 mol of potassium carbonate for 2 hrs. At 120-130 ⁰ C stirred. Were then added at 90 ⁰ G 2 ml of triethylamine to the reaction mixture and stirred at this temperature for a further hour. Cooling compartment was stirred into the vial "volume of water, filtered off with suction and washed with water

After recrystallization from ethanol, the product melted at 67-69 ⁰ O. Crude yield 88 % _t pure yield 66%.

Example 5 ^: 3,4-Diamino-carbamido-e-phenylthieno [2,3-b] pyrrole-5-carboxylic acid ethyl ester

As described in the example, 0.02 mol of 4-amino-3-C3 ⁷ -n-2-phen7la.minothiophene-5-carbons amide reacted with 0.02 mol of 3romessigsäureethylester and worked up. Ucrystallized mainly from dimethylforaamide / water. Schflip. 2 ^ 2-2 ^ 5 ⁰ G. Yield 52 %. ,

Example 6: 3, ² J- diamino-6-ph.enylthieno [2,3-b] thiophene-2, 5-öicarbonsäuredinitril

solution of 0.02 mol of 4-amino-2-phen; 7-aryl-linotiliophene ~ 3,5-ö-etharbodinitrile in 30 ml of abs. Dimethylformamide is admixed with 0.02 mol of chloroacetonitrile and 0.04 mol of anhydrous potassium carbonate, and the mixture is stirred at 125 for 3 hours. Then it is added dropwise at 90 ⁰ G 2 ml of triethyl amine au and stirred for 1 hr. At this temperature

 Bach cooling is stirred into the 6-fold volume of siswasser and after einstdg. Stand sucked off. The crude product is dissolved in n-propyl alcohol, filtered, diluted with water and filtered with suction. Thereafter, it is recrystallized from n-propyl alcohol / water (2: 1)

M.p. 257-259 ⁰ G, yield 54%.

Example 7: Ethyl 3,4-diamino-5-carbainido-1-phenylthieno [2,3-c] p-proline-2-carboxylate

A mixture of 20 mmol 4-Aaino-3-oyan ~ 2-pn.enylai3.Lnothiophen - 5 - carboxylic acid ethyl ester, 20 mmol Ghloracetamid, 40 mmol KoCO- & 30 ml abs. Dimethylformamide are stirred at 120 ^° C. for 2 hours. At 90 ° is placed 2 ml of triethylamine and stirred for 0.5 h. After cooling, water is stirred into 200 ml of ice and filtered with suction after 1 hr. The dry crude product is 30 min. In a solution of 0.3 S Na in 15 - & 1 abs. Ethanol heated. Then it is stirred in water and filtered off with suction. M.p. 191-193 ⁰ G (ethanol). Yield 55 %.

Claims (1)

3rfindungsansprueh Process for the preparation of substituted 3-minothieno [2,3-b] pyrroles of general formula I ₅ • S 1 . ο wherein R is a üryl- or - ^ HyIr est and R * "and R may be the same or different from each other illkozycarbonyl-, acyl, nitrile or Garbaaiidogruppen, characterized in that substituted 2,4-Siaminothiophen-O-carbonitriles of the formula II II R and R have the abovementioned meaning, with acceptor-substituted halomethanes of the formula III X-GH ₂ -R III in which X is a chlorine or bromine atom and R ^ has the meaning indicated above, are reacted in a solvent, preferably dimethylformamide, at 60-150 ⁰ G in the presence of bases and thereby successively added as bases potassium carbonate and triethylamine be set.