2,5-Thiophenedicarbonyl dichloride

Basic information

Chinese name: 2,5-thiophene dicarbonyl chloride

CAS number: 1939-77-3

Molecular formula: C₆H₂Cl₂O₂S

Molecular weight: 213.05 g/mol

Alias: Thiophene-2,5-diacyl chloride; 2,5-thiophene dicarboxylic acid chloride

Structural characteristics: With thiophene ring as the core, acyl chloride groups (-COCl) are connected to the 2nd and 5th positions respectively. It belongs to sulfur-containing heterocyclic acyl chloride compounds with high chemical activity.

Physical and chemical properties

Appearance and properties: Usually colorless to light yellow crystalline solid or liquid, may be dark yellow when the purity is low; easy to absorb moisture when exposed to humid air, the surface may be sticky or turbid.

Melting point: 48-50℃ (pure product)

Boiling point: 145-148℃ (2 mmHg, under reduced pressure), easy to decompose when heated under normal pressure.

Solubility: Soluble in polar organic solvents (such as dichloromethane, chloroform, tetrahydrofuran, acetonitrile), insoluble in water, but reacts violently with water to generate thiophene-2,5-dicarboxylic acid and hydrogen chloride (HCl) gas.

Chemical properties: The acyl chloride group (-COCl) has strong electrophilic activity and can undergo acylation reactions with nucleophilic reagents such as amines (generating amides), alcohols (generating esters), and phenols (generating phenolic esters). It is a key intermediate in the construction of thiophene derivatives.