Iodine-Copper(I) Chloride-Copper(II) Chloride

I2-CuCl-CuCl2
(I2)

[7553-56-2]  · I2  · Iodine-Copper(I) Chloride-Copper(II) Chloride  · (MW 253.80) (CuCl)

[7758-89-6]  · ClCu  · Iodine-Copper(I) Chloride-Copper(II) Chloride  · (MW 99.00) (CuCl2)

[7447-39-4]  · Cl2Cu  · Iodine-Copper(I) Chloride-Copper(II) Chloride  · (MW 134.45)

(iodination of carboxylic acids)

Physical Data: CuCl: mp 430 °C; bp 1490 °C; d 4.14 g cm-3. CuCl2: mp 498 °C; d 3.054 g cm-3.

Solubility: CuCl: sparingly sol H2O; practically insol ether, acetone. CuCl2: sol H2O, ethanol, acetone.

Form Supplied in: CuCl: white crystals. CuCl2: yellow to brown, deliquescent, microcrystalline powder.

Handling, Storage, and Precautions: CuCl: stable in dry air; becomes green on exposure to air and brown on exposure to light. CuCl2: irritating to skin and mucous membranes; forms dihydrate in moist air. Iodination reactions using this combination of reagents should be performed in a fume hood.

Iodination.

Direct a-iodination of acetic acid, propionic acid, butyric acid, or valeric acid using a slight excess of Iodine and 0.5 equiv each of Copper(I) Chloride and Copper(II) Chloride gives the corresponding a-iodo carboxylic acid in high yield (eq 1).1 This synthetic method affords several advantages over classical a-iodo carboxylic acid procedures.


1. Horiuchi, C. A.; Satoh, J. Y. CL 1984, 1509.

C. Akira Horiuchi

Rikkyo (St. Paul's) University, Tokyo, Japan



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