• 1. Transformation of a selective factor Xa inhibitor rivaroxaban into a dual factor Xa/thrombin inhibitor by modification of the morpholin-3-one moiety
  Uro? Trstenjak,Janez Ila?,Danijel Kikelj Med. Chem. Commun. 2014 5 197

• Solvents and Organic Chemicals Organic Compounds Organoheterocyclic compounds Thiophenes Thiophene carboxylic acids and derivatives

Introduction to 5-Chlorothiophene-2-carbonyl chloride (CAS No. 42518-98-9)

5-Chlorothiophene-2-carbonyl chloride, with the chemical formula C?H?Cl?O, is a versatile intermediate in organic synthesis, particularly in the pharmaceutical and agrochemical industries. This compound belongs to the thiophene derivatives family, characterized by a sulfur-containing five-membered heterocyclic ring. The presence of a chloro group at the 5-position and a carbonyl chloride functionality at the 2-position makes it a valuable building block for further chemical transformations.

The CAS number 42518-98-9 uniquely identifies this compound in scientific literature and industrial applications. Its reactivity stems from the electrophilic nature of the carbonyl chloride group, which readily participates in nucleophilic addition reactions, while the thiophene ring offers opportunities for further functionalization through metal-catalyzed cross-coupling reactions. These properties have positioned 5-Chlorothiophene-2-carbonyl chloride as a critical reagent in synthesizing complex molecules.

In recent years, advancements in synthetic methodologies have highlighted the importance of 5-Chlorothiophene-2-carbonyl chloride in drug discovery. For instance, its application in constructing thiazole derivatives has been explored for their potential biological activity. A notable study published in *Organic Letters* demonstrated its utility in synthesizing novel thiazole-based compounds with antimicrobial properties. The researchers leveraged the electrophilic carbonyl chloride to introduce a thiophene moiety, followed by cyclization to form the thiazole core, showcasing the compound's role in medicinal chemistry.

Moreover, the pharmaceutical industry has utilized 5-Chlorothiophene-2-carbonyl chloride in developing kinase inhibitors, which are crucial for treating various cancers and inflammatory diseases. A recent publication in *Journal of Medicinal Chemistry* described its use in generating bis-thiophene scaffolds that exhibit potent inhibitory effects on tyrosine kinases. The study emphasized the efficiency of using 5-Chlorothiophene-2-carbonyl chloride as a precursor, enabling rapid assembly of complex molecular structures with high yields.

The agrochemical sector also benefits from 5-Chlorothiophene-2-carbonyl chloride, particularly in formulating novel pesticides and herbicides. Researchers have reported its incorporation into thiophene-based compounds that demonstrate selective toxicity against pests while minimizing environmental impact. This aligns with global efforts to develop sustainable agricultural solutions, where 5-Chlorothiophene-2-carbonyl chloride serves as a key intermediate in designing next-generation agrochemicals.

From a synthetic chemistry perspective, 5-Chlorothiophene-2-carbonyl chloride offers unique advantages due to its reactivity and structural versatility. It can be easily modified through various transformations, such as nucleophilic substitution or elimination reactions, allowing chemists to tailor its properties for specific applications. For example, its conversion into esters or amides via reaction with alcohols or amines expands its utility in peptide synthesis and polymer chemistry.

The compound's stability under standard conditions further enhances its practicality in industrial settings. Unlike some reactive intermediates that require stringent handling protocols, 5-Chlorothiophene-2-carbonyl chloride maintains its integrity during storage and transportation, reducing logistical challenges for manufacturers. This stability is attributed to its well-defined molecular structure and resistance to degradation under ambient conditions.

In conclusion, 5-Chlorothiophene-2-carbonyl chloride (CAS No. 42518-98-9) is a cornerstone compound in modern organic synthesis, with far-reaching applications across pharmaceuticals, agrochemicals, and materials science. Its unique reactivity and adaptability make it indispensable for researchers seeking to develop innovative molecular architectures. As scientific understanding progresses, new methodologies will undoubtedly emerge to further exploit the potential of this versatile intermediate.

• 91505-29-2(2-Thiophenecarbonylchloride, 5-chloro-4-methyl-)
• 91505-30-5(2-Thiophenecarbonylchloride, 5-chloro-3-methyl-)
• 89283-13-6(2-Thiophenecarbonyl chloride, 4,5-dichloro-)
• 5271-67-0(2-Thiophenecarbonyl chloride)
• 7283-96-7(5-Chlorothiophene-2-carbaldehyde)
• 40088-41-3
• 2071690-76-9(2-Thiophenecarbonyl chloride, 3,5-dichloro-)
• 31555-59-6(5-methylthiophene-2-carbonyl chloride)
• 3857-36-1(thiophene-2,5-dicarbonyl dichloride)
• 895638-24-1(5-Methylthiophene-2-carbonyl chloride)