About Us

Trichloroisocyanuric Acid (TCCA)/NaNO2: a New Reagent for Mononitration

It is worthwhile to consider an alternative highly selective nitration process scheme by using a mild nitrating agent such as a combination of Trichloroisocyanuric Acid (TCCA) and sodium nitrite. Very recently, Mattos et al. have reported a new methodology for the preparation of TCCA by the reaction of an aqueous solution of oxone® with sodium cyanurate in the presence of KBr (Equation1). This methodology proved to be simpler and considerably less expensive than the preparation proposed by Gottardi et al. Nitration of aromatic compounds is an industrially prominent reaction, as the nitrated products are important intermediates for fine chemicals and pharmaceuticals. Usually nitration reactions are not selective and are the cause of environmental concerns regarding the disposal of the large excess of mixed acids employed in these processes. Thus, implementation of these processes is generally rare. Besides mixed acids, several other nitrating agents, including concentrated nitric acid, acid anhydrides or triflates, peroxy nitrites, metal nitrates and nitrogen oxides have been utilized bymanyinvestigators.
There are a few reports on the application of Trichloroisocyanuric Acid (TCCA) in organic transformations, and recently, Mattos and co-workers have reported the use of Trichloroisocyanuric Acid (TCCA) for the deprotection of silyl ethers, and regioselective bromination of activated aromatic rings, and bromination of alkenes. Here,wewish to report an alternative procedure for the selective nitration of phenols with Trichloroisocyanuric Acid (TCCA)/ NaNO2 in the presence of wet SiO2. The results which were obtained by the described system compared well with our previous reports on nitration of phenols with sodium nitrite and wet SiO2 in the presence of trichloroisocyanuric acid (TCCA).
In the presence of Trichloroisocyanuric Acid (TCCA), 1,3-dichloro-5,5-dimethylhydantoin, and 1,3-dibromo-5,5-dimethylhydantoin. The reaction times are slightly longer, but in most cases the yields are higher. In conclusion, safe, ecofriendly, inexpensive and readily available reagents, easy and clean work-up and good yieldsmake this method attractive for organic chemists. Trichloroisocyanuric acid (TCCA),9d 1,3-dibromo-5,5-dimethylhydantoin  and 1,3-dichloro-5,5-dimethylhydantoin  in the nitration reaction of phenols with NaNO2 (II) and wet SiO2 (50% m/m) in dichloromethane at room temperature.