[Study on intermediate products in chloroform formation from L-tyrosine treated with sodium hypochlorite].

Possible intermediates in the formation of chloroform during by the sodium hypochlorite (NaClO) treatment of L-tyrosine were investigated using HPLC and LC/MS. One product showed the same MS characteristics as the substance formed by the NaClO treatment of 4-hydroxybenzyl cyanide (4-HBC), and it was suggested to be m-chloro-4-hydroxybenzyl cyanide (m-C-4-HBC). Since m-C-4-HBC is not commercially available it was synthesized by treating 4-HBC with NaClO, and purified by extraction with ethyl acetate, followed by HPLC on preparative isolation columns, using a column switching method. The product was confirmed to be 3-chloro-4-hydroxybenzyl cyanide (3-C-4-HBC), by means of NMR spectral analysis. When L-tyrosine or 4-HBC was treated with NaClO, 3-C-4-HBC and CHCl3 were generated. When 3-C-4-HBC was treated with NaClO, CHCl3 was generated. Judging from these results, 3-C-4-HBC was confirmed to be an intermediate in the formation of CHCl3 from L-tyrosine. Thus, the reaction pathway of CHCl3 formation from L-tyrosine treated with NaClO is concluded to be: L-tyrosine-->4-HBC-->3-C-4-HBC-->CHCl3.