Alkylation of 3-Trifluoromethyl-1,2-dihydroquinoxalin-2-one.

O and N centers of 3-trifluoromethyl-1,2-dihydroquinoxalin-2-one anion shows in reactions with haloalkanes an ambident nucleophilic character. The chemoselectivity of the reaction depends on the alkylating agent: the methylation of 3-trifluoromethyl-1,2-dihydroquinoxalin-2-one in acetonitrile in the presence of K2CO3 yields only an N-methyl isomer whereas under the same conditions in the reaction with (4-bromobutyl)-acetate О- and N-alkylations are competing. [ABSTRACT FROM AUTHOR]