2-thiophenecarboxylic acid, 5-iodo-

1. Basic information

English name: 5-Iodo-2-thiophenecarboxylic acid

Molecular formula: C₅H₃IO₂S

Molecular weight: 240.04 g/mol

CAS registration number: None (need to be further accurately queried in the authoritative database to determine)

2. Physical and chemical properties

Appearance: White to off-white crystalline powder under normal conditions, its color is related to purity, and the color of high-purity products is closer to pure white.

Melting point: about 155 - 158℃ (data comes from relevant experimental measurements and some professional literature, there may be slight differences under different experimental conditions). In this temperature range, the substance changes from solid to liquid, which can be accurately measured by melting point instrument and other equipment.

Boiling point: Due to the strong intermolecular force and structural characteristics, the boiling point is relatively high, and it is expected to be above 350℃ (no exact literature report has been seen, based on the boiling point of similar iodine-containing aromatic acid compounds). Distillation under normal pressure is prone to decomposition. If distillation separation is required, it must be carried out under high vacuum conditions.

Density: The density is estimated to be greater than 1 g/cm³, possibly in the range of 1.8 - 2.0 g/cm³ (referring to similar iodine-containing organic carboxylic acids, the iodine atom has a large relative atomic mass and has a significant effect on the density).

Solubility: Slightly soluble in water. This is because although there are carboxyl groups in its molecules that can form hydrogen bonds with water, the presence of thiophene rings and iodine atoms limits its solubility in water. It is soluble in common organic solvents such as dichloromethane, chloroform, ethanol, ether, etc. It can show good solubility in dichloromethane and can be used for solution phase reactions and crystallization operations.

Stability: The properties are relatively stable in a light-proof and dry environment at normal temperature and pressure. However, decomposition reactions may occur under high temperature, high humidity or light conditions. It has a certain sensitivity to acids and alkalis. In a strongly acidic or alkaline environment, the carboxyl group may undergo corresponding reactions, and the iodine atom may also participate in some side reactions.

III. Uses

Pharmaceutical synthesis field: As an important pharmaceutical intermediate, it is used to synthesize drug molecules with specific biological activities. The carboxyl group in its structure can be connected to other compounds containing nitrogen, oxygen and other active groups through esterification, amidation and other reactions, while the iodine atom can participate in nucleophilic substitution reactions, introduce other functional groups, and construct a complex drug molecular skeleton. For example, it can be used to synthesize certain compounds with potential antibacterial, antiviral or antitumor activity. Through reactions such as Suzuki coupling, it can react with specific borate compounds to prepare thiophene derivatives with novel structures, providing new molecular entities for drug research and development.

In terms of pesticide research and development: it is used to synthesize new pesticides, and its unique chemical structure is used to give pesticides specific mechanisms of action and activities. For example, by modifying its structure, pesticide products with high insecticidal, fungicidal or herbicidal activity can be developed. In the design of some pesticide molecules, the introduction of 5-iodo-2-thiophenecarboxylic acid structural fragments can enhance the affinity of pesticide molecules with specific receptors or enzymes in the target organism, thereby improving the efficacy of pesticides.

In the field of materials science: it can be used as a monomer or intermediate for the synthesis of functional materials. By polymerizing with other monomers, its structure is introduced into the main chain or side chain of polymer materials, giving the materials unique properties. For example, when synthesizing organic polymers with photoelectric properties, the introduction of this compound structure is expected to improve the polymer's charge transfer properties, fluorescence properties, etc., so that it can be applied to organic light-emitting diodes (OLEDs), solar cells and other fields.