1-(Trifluoromethyl)-1,2-benziodoxol-3(1H)-one
[CAS# 887144-94-7]

Identification

• Classification: Organic raw materials >> Organic fluorine compound >> Fluorobenzoic acid series
• Name: 1-(Trifluoromethyl)-1,2-benziodoxol-3(1H)-one
• Molecular Formula: C₈H₄F₃IO₂
• Molecular Weight: 316.02
• CAS Registry Number: 887144-94-7
• EC Number: 688-223-5
• SMILES: C1=CC=C2C(=C1)C(=O)OI2C(F)(F)F

Properties

• Melting point: 150 - 158 °C (Expl.)

Safety Data

• Hazard Symbols: GHS07 Warning
• Risk Statements: H315-H319-H335
• Safety Statements: P261-P264-P264+P265-P271-P280-P302+P352-P304+P340-P305+P351+P338-P319-P321-P332+P317-P337+P317-P362+P364-P403+P233-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Specific target organ toxicity - single exposure	STOT SE	3	H335
Eye irritation	Eye Irrit.	2	H319
Skin irritation	Skin Irrit.	2	H315
Specific target organ toxicity - repeated exposure	STOT RE	2	H373
Flammable solids	Flam. Sol.	2	H228

Discovery and Applications

1-(Trifluoromethyl)-1,2-benziodoxol-3(1H)-one is a hypervalent iodine compound with the molecular formula C₈H₄F₃IO₂. Structurally, it features a five-membered 1,2-benziodoxole ring in which the iodine atom is in a +3 oxidation state, bonded to a carbonyl oxygen at the 3-position and a trifluoromethyl group at the 1-position. The fused benzene ring stabilizes the hypervalent iodine center, and the trifluoromethyl substituent imparts strong electron-withdrawing character. The compound typically appears as a crystalline solid, soluble in polar organic solvents such as acetonitrile, dichloromethane, and dimethylformamide, while being sensitive to moisture and light.

This compound is primarily used as a trifluoromethylation reagent in organic synthesis. Its hypervalent iodine center enables the transfer of the –CF₃ group to nucleophilic carbon centers, facilitating the introduction of trifluoromethyl groups into arenes, alkenes, and heterocycles under mild conditions. Trifluoromethylated products are highly valued in medicinal chemistry and agrochemicals because the –CF₃ group can significantly enhance metabolic stability, lipophilicity, and bioavailability.

1-(Trifluoromethyl)-1,2-benziodoxol-3(1H)-one is also employed in photoredox and transition-metal catalyzed reactions, where it serves as an electrophilic CF₃ source. The reagent allows selective functionalization of complex molecules, making it a versatile tool for late-stage trifluoromethylation in drug discovery and materials chemistry.

The compound is typically synthesized by oxidation of 2-iodobenzoic acid derivatives to the corresponding hypervalent iodine intermediate, followed by introduction of the trifluoromethyl group using suitable CF₃ sources, such as trimethyl(trifluoromethyl)silane in the presence of fluoride activators. Handling requires standard precautions for hypervalent iodine compounds, including avoidance of friction, heat, and moisture, as they can be sensitive and potentially explosive under improper conditions.

Overall, 1-(Trifluoromethyl)-1,2-benziodoxol-3(1H)-one is a highly useful hypervalent iodine reagent that combines a stable benziodoxole framework with an electrophilic trifluoromethyl group. Its ability to transfer –CF₃ efficiently under mild conditions makes it an important tool in modern synthetic organic chemistry, particularly for the preparation of trifluoromethylated arenes, heterocycles, and functional materials.

References

2022. Direct Trifluoromethylation of C(sp3)—H Bonds. Science of Synthesis.
URL: SD-238-00134

2022. Trifluoromethylation of Prefunctionalized Alkanes. Science of Synthesis.
URL: SD-238-00133

2010. Reactivity of a Hypervalent Iodine Trifluoromethylating Reagent toward THF: Ring Opening and Formation of Trifluoromethyl Ethers. The Journal of Organic Chemistry, 75(3).
DOI: 10.1021/jo9025429