The bacterium Rhodococcus erythropolis is employed to hydroxylate the
anxiolytic lesopitron, and this bacterium, together with Agrobacterium
sp. and the fungus Beauveria bassiana, are used to extend the field o
f hydroxylation of heteroaromatic compounds to a series of unexplored
pyrimidines. Of all the substrates investigated, only the carbamate 11
a is regioselectively hydroxylated by B. bassiana at the C-5 position
of the pyrimidine ring; in contrast, the bacteria are able to regiosel
ectively oxidize, when free, the C-2 and/or C-4 positions of the pyrim
idine moiety of all the substrates 1a - 12a, up to a maximum of two ox
idations. (C) 1997 Elsevier Science Ltd.