Trichloroisocyanuric Acid1

[87-90-1]  · C3Cl3N3O3  · Trichloroisocyanuric Acid  · (MW 232.41)

(powerful chlorinating agent for sulfides,3,4 amides and imides,5 aromatic compounds,6 ketones,7 and ethers;8 oxidizing agent for secondary alcohols,9 ethers,10 alkenes,11 and oximes12)

Alternate Names: TCICA; 1,3,5-trichloro-1,3,5-triazine-2,4,6(1H,3H,5H)-trione; trichloro-s-triazinetrione; isocyanuric chloride.

Physical Data: mp 249-251 °C.

Solubility: 0.2% in H2O; very sol acetonitrile; sol acetone, acetic acid, ethyl acetate; sl sol benzene, chloroform, methylene chloride.

Form Supplied in: white granular solid; widely available for swimming pool use; purity 97-99%; available chlorine 88-91% as measured by iodometric titration.2

Analysis of Reagent Purity: mp or iodometric titration.

Purification: can be recrystallized from 1,2-dichloroethane or benzene.

Handling, Storage, and Precautions: moisture sensitive, but may be stored under nitrogen at rt for over a year. The dust is extremely destructive to mucous membranes and upper respiratory tract, eyes, and skin. This reagent has been reported to explode after a delay period when in contact with alcohols, amines, or dialkyl sulfoxides, or when contaminated with organic compounds. As with other strong oxidizing agents, it should be added to a solvent.

Chlorination Reactions.

Trichloroisocyanuric acid is an inexpensive, convenient, and effective chlorinating and oxidizing agent. It is more reactive than other N-chloro compounds and can often be used in place of chlorine. The cyanuric acid formed as a byproduct is easily removed by filtration.

Allyl phenyl sulfides are converted to 1-(phenylthio)-3-chloro-1-alkenes, which are acrolein synthons (eq 1).3 Alkyl phenyl sulfides are dichlorinated to 1,1-dichloroalkyl phenyl sulfides.4 In acetonitrile at rt, amides and imides are chlorinated at nitrogen.5 Aromatic compounds are chlorinated on the ring or benzylic position.6 Ketones are converted to a-chloro ketones7 (see also Chlorine, N-Chlorosuccinimide, and Sulfuryl Chloride). Dry cyclic ethers give 2,3-dichloro cyclic ethers.8

Oxidation Reactions.

Secondary alcohols are rapidly oxidized to ketones in acetone containing pyridine9 (see also N-Bromosuccinimide, N-Chlorosuccinimide, Potassium Dichromate, Potassium Permanganate, Pyridinium Chlorochromate, Sodium Dichromate, and Sodium Hypochlorite). Esters are formed by oxidation of ethers in the presence of water.10 Alkenes react to form chlorohydrins in acetone containing acetic acid and water.11 Oximes are converted to gem-chloronitro compounds (eq 2).12

Other Applications.

N,N-Disubstituted carbodiimides are produced on treatment of N,N-disubstituted thioureas with trichloroisocyanuric acid in the presence of pyridine or aqueous NaOH.13 Dithioacetals are converted to ketones by the action of trichloroisocyanuric acid and Silver(I) Nitrate in aqueous acetonitrile.14


1. Filler, R. CRV 1963, 63, 21.
2. Eaton, E. Manuf. Chem. Aerosol News 1964, 35, 45 (CA 1965, 62, 9285f).
3. Mura, A. J., Jr.; Bennett, D. A.; Cohen, T. TL 1975, 4433.
4. Cohen, T.; Kosarych, Z.; Suzuki, K.; Yu, L. JOC 1985, 50, 2965.
5. (a) Nagao, Y.; Katagiri, S. Sci. Rep. Hirosaki Univ. 1991, 38, 20 (CA 1992, 116, 128 875v). (b) Back, T. G.; Chau, J. H.-L.; Dyck, B. P.; Gladstone, P. L. CJC 1991, 69, 1482.
6. (a) Jeromin, G. E.; Orth, W.; Rapp, B.; Weiss, W. CB 1987, 120, 649 (CA 1987, 106, 156 429q). (b) Juenge, E. C.; Beal, D. A.; Duncan, W. P. JOC 1970, 35, 719.
7. Hiegel, G. A.; Peyton, K. B. SC 1985, 15, 385.
8. (a) Duncan W. P.; Strate, G. D.; Adcock, B. G. OPP 1971, 3, 149. (b) Juenge, E. C.; Spangler, P. L.; Duncan, W. P. JOC 1966, 31, 3836.
9. (a) Hiegel, G. A.; Nalbandy, M. SC 1992, 22, 1589. (b) Mukawa, F. Nippon Kagaku Zasshi 1957, 78, 450 (CA 1959, 53, 5338a).
10. (a) Juenge, E. C.; Corey, M. D.; Beal, D. A. T 1971, 27, 2671. (b) Juenge, E. C.; Beal, D. A. TL 1968, 5819.
11. (a) Mukawa, F. Nippon Kagaku Zasshi 1957, 78, 452 (CA 1959, 53, 5338e). (b) Mukawa, F. BCJ 1960, 33, 25. (c) Sendo, Y.; Konoike, T.; Murakami, M.; Yoshioka, M. H 1981, 16, 599. (d) Aoki, T.; Yoshioka, M.; Kamata, S.; Konoike, T.; Haga, N.; Nagata, W. H 1981, 15, 409.
12. Walters, T. R.; Zajac, W. W., Jr.; Woods, J. M. JOC 1991, 56, 316.
13. Furumoto, S. Yuki Gosei Kagaku Kyokai Shi 1974, 32, 727 (CA 1975, 82, 125 361t).
14. Olah, G. A.; Narang, S. C.; Salem, G. F. S 1980, 659.

Gene A. Hiegel

California State University, Fullerton, CA, USA



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