Trichloroisocyanuric Acid (TCCA)

Biographical Sketches

José C. Barros was born in Rio de Janeiro (Brazil) in 1978 and studied chemical engineering at Instituto Militar de Engenharia (IME). After spending a year in France at Ecole Nationale Supérieure de Chimie de Clermont-Ferrand (ENSCCF), he decided to continue his studies of organic chemistry. He is currently working toward his M.Sc. at Universidade Federal do Rio de Janeiro (UFRJ) under supervision of O.A.C. Antunes and J.F.M. da Silva on the synthesis of HIV-protease inhibitors.

Introduction

Trichloroisocyanuric acid (TCCA) is a stable and inexpensive industrial chemical usually used as bleaching agent and bactericide.

It has found applications in organic chemistry as a ­chlorinating agent or oxidant, [1] allowing thioacetalization of carbonyl compounds, conversion of alcohols to halides, carboxylic acids to acid chlorides, alkenes to chloroethers, N-nitrosation of N,N-dialkylamines, selective mono­nitration of phenols, oxidation of alcohols to carbonyl compounds, aldehydes to methyl esters, aldoximes to ­nitrile oxides, thiols to disulfides, selenols to diselenides, and sulfides to sulfoxides.

Preparation

TCCA (1) is prepared by chlorination of cyanuric acid (2) with chlorine gas (Scheme 1). [2] It is readily soluble in ­organic solvents.

Scheme 1

Abstracts

(A) Amides, lactams and carbamates of a-amino acids can be easy transformed into the corresponding N-chlorinated compounds through reaction with TCCA, under mild reaction conditions. [3]
(B) Primary alcohols are oxidized to acids using stoichiometric TCCA and catalytic RuCl3 in the presence of n-Bu4NBr and K2CO3 in MeCN/H2O. Secondary alcohols are oxidized to ketones in the same set using MeCN/H2O or EtOAc/H2O. Effects of pH, solvent and base were also studied. [4]
(C) Oxidation of 1,3,5-trisubstituted pyrazolines to the corresponding pyrazoles is achieved using TCCA under both hetero­geneous and solvent-free conditions. [5]
(D) Combination of TCCA and catalytic TEMPO in CH2Cl2 leads to the conversion of primary alcohols into aldehydes. [6] In the ­presence of acetone, NaBr and NaHCO3, acids are obtained. [7] ­Secondary alcohols are oxidized to ketones.
(E) Dinitrophenols are obtained upon reaction of phenols with ­TCCA, NaNO2 and wet SiO2 under solid-phase reaction via in situ generation of HNO2. [8]
(F) Epoxides can be produced in mild conditions by reaction of alkenes with trichloroisocyanuric acid in aqueous acetone followed by treatment of resulting chlorohydrin with aqueous KOH in Et2O/pentane. [9]
(G) Primary amines are successfully converted into nitriles by means of TCCA and catalytic TEMPO under mild conditions. ­Other functional groups remain unaffected. [10]
(H) Amino acids are cleanly and efficiently converted into nitriles by means of a decarboxylation reaction carried out with TCCA in water or methanol in the presence of pyridine. Using TCCA, (S)-(+)-2-methylbutyronitrile is obtained at the highest optical ­purity. [11]
(I) Aldoximes derived from an o-protected vanillin, when treated with TCCA in the presence of olefins as dipolarophiles, afford ­nitrile oxides. Subsequent 1,3-dipolar cycloaddition generates the corresponding isoxazolines. [12]

References

• 1 For a review, see: Tilstam U. Weinmann H. Org. Process Res. Dev.   2002.  6:  p.384 
• 2 Chattaway FD. Wadmore J. J. Chem. Soc.  1902,  81:  191 
• 3 De Luca L. Giacomelli G. Nieddu G. Synlett  2005,  223 
• 4 Yamaoka H. Moriya N. Ikunaka M. Org. Process Res. Dev.  2004,  8:  931 
• 5 Zolfigol MA. Azarifar D. Maleki B. Tetrahedron Lett.  2004,  45:  2181 
• 6 De Luca L. Giacomelli G. Nieddu G. Org. Lett.  2001,  3:  3041 
• 7 De Luca L. Giacomelli G. Nieddu G. J. Org. Chem.  2003,  68:  4999 
• 8 Zolfigol MA. Madrakian E. Ghaemi E. Synlett  2003,  2222 
• 9 Wengert M. Sanseverino AM. Mattos MCS. J. Braz. Chem. Soc.  2002,  13:  700 
• 10 Chen F.-E. Kuang Y.-Y. Daí H.-F. Lu L. Huo M. Synthesis  2003,  2629 
• 11 Hiegel GA. Lewis JC. Bae JW. Synth. Commun.  2004,  34:  3449 
• 12 Rodrigues RC. Aguiar AP. Synth. Commun.  2001,  31:  3075