70158-52-0

Upstream product

• 7783-06-4 hydrogen sulfide 
• 6964-21-2 thiophen-3-yl-acetic acid 
• 58414-52-1 thiophen-3-yl-acetic acid methyl ester 
• 616-38-6 carbonic acid dimethyl ester 
• 67-56-1 methanol 
• 21080-92-2 2-(thiophen-3-yl)malonic acid 
• 79-22-1 methyl chloroformate 

Relevant academic research and scientific papers

3-Dithiolthione-substituted polythiophene and its redox activities

We synthesized 3-dithiolthione-substituted polythiophene, poly[3-(1′,2′-dithiol-3′-thione-4′-yl)thiophene], by cyclization reaction of poly[3-bis(methoxycaronyl)methyl thiophene]. Its redox behavior and electronic states showed that the oxidation of the p

Poly(2-thiophen-3-yl-malonic acid), a polythiophene with two carboxylic acids per repeating unit

A new substituted polythiophene derivative bearing malonic acid, poly(2-thiophen-3-yl-malonic acid), has been prepared and characterized using a strategy that combines both experimental and theoretical methodologies. The chemical structure of this material has been investigated using FTIR and 1H NMR, and its molecular conformation has been determined using quantum mechanical calculations. Interestingly, the arrangement of the inter-ring dihedral angles was found to depend on the ionization degree of the material, that is, on the pH, which has been found completely soluble in aqueous base solution. Thus, the preferred anti-gauche conformation changes to syn-gauche when the negatively charged carboxylate groups transforms into neutral carboxylic acid. UV-vis experiments and quantum mechanical calculations on model systems with a head-to-tail regiochemistry showed that the lowest ??-??* transition energy is 2.25 and 2.39 eV for the negatively charged and the neutral polymer, respectively. These values are slightly larger than those previously reported for other polythiophenes with bulky polar side groups. The polymer presents a good thermal stability with a decomposition temperature above 215 ?°C and an electrical conductivity of 10-5 S/cm, which is characteristic of semiconductor materials. Scanning electron microscopy micrographs showed that, after doping, the surface of this material displays regular distribution pores with irregular sizes. This surface suggests that poly(2-thiophen-3-yl-malonic acid) is a candidate for potential applications such as selective membranes for electrodialysis, wastewater treatment, or ion-selective membranes for biomedical uses. ? 2010 American Chemical Society.

γ-methylidene-δ-valerolactones as a coupling partner for cycloaddition: Palladium-catalyzed [4 + 3] cycloaddition with nitrones

A new type of reagent, γ-methylidene-δ-valerolactones, has been devised, which acts as a four-carbon unit in a palladium-catalyzed cycloaddition reaction through the formation of a 1,4-zwitterionic species. The utility has been demonstrated in the context of stereoselective [4 + 3] cycloaddition with nitrones to provide highly functionalized 1,2-oxazepines, including the asymmetric variant with high enantioselectivity. Copyright

Thiophene Systems. 10. The Synthesis and Chemistry of some Thienopyridinols

Substituted thieno-, thieno- and thienopyridinols have not been described despite the fact that a few descriptions of the parent ring systems have appeared in the literature.As a part of our ongoing program to investigate the synthesis of thiophene derivatives with potential biological activity, we became interested in the preparation of the various thienopyridinols.Syntheses of the title compounds 2a, 3 and 25 were achieved starting from thiophene-3-acetic acid and 3-acetylthiophene.The two isomeric systems 2a and 3 were reacted with electrophiles to give products substituted at the position α to the hydroxy group on the pyridine ring (the 4- and 6- positions, respectively).Lack of stability of 25 precluded studies on this system.Compound 2a, 3 and 25 reacted with acetic anhydride to give O-acetyl derivatives while reaction of the anion of 2a and 3 with methyl iodide gave mixtures of O- and N-methylation.The N-methylated products are the novel thienopyridones 45 and 47.

Chemical process

An improved process for the preparation of 3-substituted thiophenes. The thiophenes are useful for the preparation of penicillins and cephalosporins. The process is for the preparation of a thiophene of formula (I): STR1 where R1 represents a carboxylic acid group, or an ester or amide thereof or a nitrile group; R2 represents a group suitable for use as an α-substituent in the side-chain of a penicillin or cephalosporin; which comprises treating under basic conditions a compound of formula (II): STR2 wherein X represents halogen or optionally functionalized hydroxyl, Y represents halogen, hydroxyl, or alkoxy; with a source of nucleophilic sulphur ionically bound to a polymeric support.

Process for the preparation of thiophenes

A process for the preparation of 3-substituted thiophenes which involves cyclization of a novel intermediate, avoids the use of previously employed expensive starting materials. The thiophenes are useful for the preparation of penicillins and cephalosporins. The process is for the preparation of a thiophene of formula (I): STR1 where R1 represents a carboxylic acid group, or an ester or amide thereof or a nitrile group; R2 represents a group suitable for use as an α-substituent in the side-chain of a penicillin or cephalosporin; which comprises treating a compound of formula (II): STR2 wherein X represents halogen or optionally functionalized hydroxyl, Y represents halogen, hydroxyl, or alkoxy; with a source of nucleophilic sulphur under basic conditions.

Preparation of a 3-thienylmalonic acid and the corresponding diesters

Preparation of a 3-thienylmalonic acid or a diester thereof comprising reacting in a polar solvent in the presence of a copper (I) halide a thiophene compound of formula: STR1 wherein X=I or Br, R1 =H or a C1-4 alkyl group, R2 =H or a C1-2 alkyl group and R3 =H or a C1-2 alkyl group, with the proviso that R2 and R3 cannot be an alkyl group simultaneously, with a mono-deprotonated methylene compound of formula: STR2 wherein a cation is present and Z'=Z" is CN or COOR in which R is a C1-4 alkyl group, or Z'=CN and Z"=COOR' in which R' is a C1-2 alkyl group, followed by hydrolysis by methods known per se to get the corresponding free acid.