M. Franssen, H. Boven, H. C. Plas
Sep 1, 1987
Citations
0
Influential Citations
19
Citations
Journal
Journal of Heterocyclic Chemistry
Abstract
Pyrazole, 1-methylpyrazole and 3-methylpyrazole are chlorinated by the enzyme chloroperoxidase from Caldariomyces fumago, in the presence of potassium chloride and hydrogen peroxide at pH 2.7, yielding the corresponding 4-chloro derivatives in good yields. A 4H-pyrazole is proposed as an intermediate in this reaction. 2-Aminopyridine was converted regiospecifically by the same enzyme into 2-amino-3-chloropyridine, and 8-hydroxyquinoline gave its 5,7-dibromo-derivative in very good yield when bromide ion was used as the halide substrate.