Ethyl 2-oxo-2-(thiophen-2-yl)acetate CAS 4075-58-5

Reflecting their high stabilities, thiophenes arise from many reactions involving sulfur sources and hydrocarbons, especially unsaturated ones. The first synthesis of thiophene by Meyer, reported the same year that he made his discovery, involves acetylene and elemental sulfur. Thiophenes are classically prepared by the reaction of 1,4-diketones, diesters, or dicarboxylates with sulfidizing reagents such as P4S10 such as in the Paal-Knorr thiophene synthesis. Specialized thiophenes can be synthesized similarly using Lawesson's reagent as the sulfidizing agent, or via the Gewald reaction, which involves the condensation of two esters in the presence of elemental sulfur. Another method is the Volhard–Erdmann cyclization.

Thiophene is produced on a modest scale of around 2,000 metric tons per year worldwide. Production involves the vapor phase reaction of a sulfur source, typically carbon disulfide, and a C-4 source, typically butanol. These reagents are contacted with an oxide catalyst at 500–550 °C.

Ethyl thiophene-2-glyoxylate (4075-58-5) also can be called Ethyl-2-thiopheneglyoxylate ; Ethyl alpha-oxothiophen-2-acetate ; Thiophene-2-glyoxylic acid ethyl ester ; Ethyl 2-oxo-2-(2-thienyl)acetate .It is hazardous,so the first aid measures and others should be known.Such as: When on the skin: first,should flush skin with plenty of water immediatelyfor at least 15 minutes while removing contaminated clothing. Secondly,Get shoesmedical aid . Or in the eyes: Flush eyes with plenty of water for at least 15 minutes, occasionally lifting the upper and lower eyelids.Then get medical aid soon.While ,it's Inhaled: Remove from exposure and move to fresh air immediately.Give artificial respiration while not breathing. When breathing is difficult, give oxygen. And as soon as to get medical aid. Then you have the ingesting of the product : Wash mouth out with water,and get medical aid immediately.Notes to physician: Treat supportively and symptomatically.

In addition, Ethyl thiophene-2-glyoxylate (4075-58-5) can be stable under normal temperature and pressure conditions.It is not compatible with strong oxidizing agents, ignition sources, strong acids, strong bases,and you must not take it with incompatible materials.And also prevent it to broken down into hazardous decomposition products: irritating and toxic fumes and gases, carbon dioxide, carbon monoxide.

Phosphonic acid derivatives have received applications in energy storage and catalysis. They have also been used in ion exchange, enantioselective intercalation reactions, and in the self-assembly of thin films exhibiting electroactive properties. Besides, polyelectrolyte membranes based on phosphonic acid derivatives have also been developed and shown to exhibit considerable resistance to temperature and corrosion, as well as to attacks by free radicals.

Phosphonic acid derivatives are also interesting compounds from a more fundamental viewpoint. In fact, the intrinsic conformational flexibility of their hydroxyl groups and also their ability to participate in intra- and/or intermolecular H-bond type interactions, both as acceptors or donors, result usually in interesting molecular and supramolecular architectures. These is reinforced in the cases where the substituent connected to the phosphonic acid moiety has also structural characteristics challenging investigation (e.g., conformational flexibility, π-electron delocalization, H-bond forming capability, among others).

We the synthesis of a new phosponic acid, (2-oxo-2-(thiophen-2-yl)ethyl) phosphonic acid (OTEPA; Scheme 1) is reported, together with its structural and spectroscopic characterization at the molecular level and in the crystalline phase. OTEPA is a simple phosphonic acid derivative that matches the structural characteristics for displaying a considerable number of conformers (it has five different internal rotation degrees that may result in conformational isomers) and different types of intra/inter molecular H-type interactions [it displays five electronegative centres, plus a delocalized ring π-system, which can act as H-bond acceptors (electron donors), and two OH groups that can work as H-bond donors].

The main aim of this article is to shed light on the different importance of the major intra- and intermolecular interactions existing in the isolated molecule of the compound and/or in the crystalline phase. These data are relevant to improve the available knowledge on the structural characteristics and properties of the phosphonic acid moiety. the conformational space of the OTEPA molecule was investigated theoretically, and the most stable conformers were structurally and spectroscopically characterized. The relative stabilities of the conformers are explained based on the structural features of the compound, the intramolecular H-bond established between one of the OH groups of the phosphonic acid fragment and the carbonyl oxygen atom of the substituent being the major intramolecular interaction responsible for the stabilization of the lowest energy conformers of the compound.

Very interestingly, the O⋯S contact between the carbonyl oxygen atom and the sulphur atom of the thiophene ring (which is similar to the N⋯S type contact found previously in other molecular systems) was found to be also an important intramolecular interaction in determining the stability of the two lowest energy conformers of OTEPA. On the other hand, in the crystal, the intramolecular H-bond stabilizing the lowest energy conformers of the isolated OTEPA molecule is replaced by intermolecular H-bonds established with neighbor molecules, so that the selected conformations in the crystalline phase are higher-energy structures while isolated (with energies higher than that of the most stable conformer by more than 13 kJ mol−1). OTEPA is then an interesting example of a compound showing conformational selection upon crystallization that requires considerable structural reorganization.