Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D333/00—Heterocyclic compounds containing five-membered rings having one sulfur atom as the only ring hetero atom
  • C07D333/02—Heterocyclic compounds containing five-membered rings having one sulfur atom as the only ring hetero atom not condensed with other rings
  • C07D333/04—Heterocyclic compounds containing five-membered rings having one sulfur atom as the only ring hetero atom not condensed with other rings not substituted on the ring sulphur atom
  • C07D333/06—Heterocyclic compounds containing five-membered rings having one sulfur atom as the only ring hetero atom not condensed with other rings not substituted on the ring sulphur atom with only hydrogen atoms, hydrocarbon or substituted hydrocarbon radicals, directly attached to the ring carbon atoms
  • C07D333/08—Hydrogen atoms or radicals containing only hydrogen and carbon atoms

Definitions

• the invention is concerned with a method of preparing 3-substituted thiophene with the following formula (I)
• the derivatives of the thiophene are important raw materials in preparing different plastic products.
• Thiophene is used as an intermediate for preparing such pharmaceuticals, especially antihistamines, that contain a thiophene part. It is also an intermediate in preparing veterinary pharmaceuticals, pesticides, dyes and so on.
• Thiophene is advantageously prepared in laboratories so that anhydrous sodium succinate in powder form is heated together with phosphorus trisulfide to high tempratures in a flow of carbon dioxide.
• the raw thiophene is condensed from the outcoming gas flow, it is steam-distilled and dried.
• succinic acid anhydride is treated with phosphorus trisulfide or pentasulfide.
• Sokony-vacuum (Mobil Oil Corporation) -method was based on a non- catalytic continuous reaction between butane and sulfur in high temperature.
• SUBSTITUTE SHEET phase methods in which C 4 raw materials and sulfur sources are used, especially by means of metal oxide catalysts to avoid reaction speeds, yields and forming of thiophene tars.
• a vapour phase reaction between furan and hydrogen sulfide is carried out by means of a metal oxide catalyst that contains heteropolyacid, as a result of which thiophene and water is achieved in a relatively low temperature (300-400°C).
• the method can also be used to prepare 2-methyl-thiophene from 2-methyl furan and to prepare tetrahydrothiophene from tetrahydrofuran.
• raw material as 1-butene, butadiene, n-butyl alcohol and croton aldehyde reacts continuously with carbon sulfide by means of a metal oxide catalyst that contain alkali in high temperatures (500°C).
• carbon sulfide acts as a sulfur source, that apparently is converted to methane and carbon dioxide.
• This method can also be used to prepare 2- and 3-alkyl substi- tuted thiophenes.
• a continuous high temperature reaction (500-600°C) between butane and sulfur is carried out by means of a mixed metal oxide catalyst, that dehydrates the butane.
• the hydrogen formed reacts quickly with sulfur to prepare hydrogen sulfide in a very exotermic reaction.
• the hydrogen sulfide reacts with the butane rest to form thiophene with good yields.
• 2- and 3-alkyl substituted thiophenes can be prepared from higher hydrogen carbons.
• US Patent 3 939 179 is an example of the last-mentioned method and US Patent 3 822 289 is an example of the foregoing one.
• the first-mentioned method is presented in US Patent 3 197 483.
• thiophene is prepared by heating alkalisalts of succinic- or alkyl succinic acids in the temperature of 280-340°C with phosphorus sulfide (P0S5) by means of a hydrogen carbon with a high boiling point.
• thiophenes are prepared by the reaction between alkyl succinic acid and their derivatives in the presence of phosphorus.
• This invention is concerned with a new method of preparing 3-substituted thiophene by means of the reaction used in the publication mentioned Carpenter, AJ., Chadwick, DJ.; Journal of the Organic Chemistry.
• R 1 and R 2 are alkyls
• the reaction in the method there is first carried out as a first step the reaction known from said article after which the reaction is continued by strong acid to achieve the desired compound.
• the advantages of the invention are that the amino group is removed from the product by using an one step reaction and that the reaction can be carried out preferably by acid and that a high temperature is not necess ⁇ ary. Only carbon oxide and a hydroxide of amine are achieved as by-product from which the amide can be recovered. In addition to that the starting materials are easily available compounds.
• N-t-buthyl-2-thiophene amide 1,8 g (0,01 moles) was dissolved in 40 ml tetra- hydrofuran and cooled to -60°C. Nitrogen was used as protecting gas in the reaction. 0,02 moles of buthyl Utium was added to the hexane solution and the mixing was continued in the same temperature for 20 minutes. The heptyl bromide 1,8 g (0,01 moles) was dissolved in tetrahydrofuran and added to the cold mixture that could slowly warm up to room temperature. The protecting gas was removed and 40 ml of water was added to the mixture. The organic part of the solution was extracted separate with ether (3 x 60 ml).
• N-t-buthyl-3-heptyl-2-thiophene amide was heated in a 20% hydro ⁇ gen chloride solution for ca 65 h to loose the amide group.
• the organic com ⁇ pound was extracted with ether from the cooled solution, the solution was dried and the ether was evaporated.
• the separated compound was 3-heptyl-thiophene with the boiling point of 247°C. Made with 50 mmol the yield received was 50%.

Landscapes

• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Low-Molecular Organic Synthesis Reactions Using Catalysts (AREA)
• Pharmaceuticals Containing Other Organic And Inorganic Compounds (AREA)
• Plural Heterocyclic Compounds (AREA)
• Heterocyclic Carbon Compounds Containing A Hetero Ring Having Oxygen Or Sulfur (AREA)

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Publications (1)

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• 1991
  • 1991-03-28 FI FI911527A patent/FI90540C/fi not_active IP Right Cessation
• 1992
  • 1992-03-26 EP EP19920907531 patent/EP0577683A1/en not_active Withdrawn
  • 1992-03-26 WO PCT/FI1992/000090 patent/WO1992017465A1/en not_active Application Discontinuation

Non-Patent Citations (1)

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