Collins Russian Dictionary 2nd Edition © HarperCollins Publishers 2000, 1997:
unsympathetic [ˈʌnsɪmpəˈθɛtɪk] adj равноду́шный*равноду́шен (unlikeable) несимпати́чный*несимпати́чен
unsympathetic to or towards равноду́шный*+dat
* is used to mark translations which have irregular inflections. The Russian-English side of the dictionary gives inflectional information.
Русский: