Dichloromethane and some other chlorinated solvents can be used in radical halogenations with NBS or 1,3-dibromo-5,5-dimethylhydantoin. So can
acetonitrile, methyl acetate, t-butyl acetate, 1,2-dichlorobenzene, chlorobenzene, fluorobenzene or benzotrifluoride, with varying efficiency. In some
cases, one can use also ethyl acetate, t-butanol, benzene or acetone, though some of these tend to react more than acetonitrile or methyl acetate, so
you need to compensate with an excess of the reagent. The point is to use solvents that have no easily abstractable hydrogens. |