Mitotic kinesin inhibtors and methods of use thereof

A compound of the Formula I:

• and tautomers, and salts thereof, wherein:
• W is S(O)m;
• m is 0, 1 or 2;
• R1 is (CH2)3NH2;
• Ar1 and Ar2 are independently phenyl or a 5 or 6 membered heteroaryl ring having 1 to 3 heteroatoms independently selected from N, O and S, wherein said heteroaryl is a carbon radical and said phenyl and heteroaryl are optionally substituted with one or more groups independently selected from halogen, cyano, nitro, azido, —OR10, —NR10R11, —NR10SO2R13, SO2NR10R11, —C(═O)R10, —C(═O)OR10, —OC(═O)R10, —NR10C(═O)OR13, —NR10C(═O)R11, —C(═O)NR10R11, —SR10, —S(O)R13, SO2R13, —SO2NHC(═O)R1, —NR10C(═O)NR11R12, —NR10C(NCN)NR11R12, —NR10C(H)NR11R12, —NR10C(R13)NR11R12, —OP(═O)(OR10)2, alkyl, cycloalkyl, alkenyl, alkynyl, aryl, heteroaryl, arylalkyl, heteroarylalkyl, heterocyclyl and heterocyclylalkyl;
• R4 is selected from:
• R10, R11 and R12 independently are selected from hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl, aryl, heteroaryl, heterocyclyl and arylalkyl, wherein said alkyl, alkenyl, alkynyl, cycloalkyl, aryl, heteroaryl, heterocyclyl and arylalkyl are optionally substituted with one or more groups independently selected from oxo (with the proviso that it is not on said aryl or heteroaryl portions), halogen, cyano, nitro, OR14, —NR14R15, trifluoromethyl, difluoromethoxy, trifluoromethoxy, azido, alkyl, cycloalkyl, aryl, heteroaryl, arylalkyl, heteroarylalkyl, heterocyclyl, and heterocyclylalkyl;
• R13 is alkyl, alkenyl, cycloalkyl, aryl, heteroaryl, heterocyclyl or arylalkyl, wherein said alkyl, alkenyl, cycloalkyl, aryl, heteroaryl, heterocyclyl and arylalkyl are optionally substituted with one to three groups independently selected from oxo (with the proviso that it is not on said aryl or heteroaryl portions), halogen, cyano, nitro, OR14, NR14R15, trifluoromethyl, difluoromethoxy, trifluoromethoxy, azido, alkyl, cycloalkyl, aryl, heteroaryl, arylalkyl, heteroarylalkyl, heterocyclyl, and heterocyclylalkyl,
• or any two of R10, R11, R12 and R13 together with the atoms to which they are attached form a 4 to 10 membered heteroaryl or heterocyclic ring, wherein said heteroaryl and heterocyclic rings are optionally substituted with one to three groups independently selected from oxo (with the proviso that it is not on said heteroaryl ring), halogen, cyano, nitro, OR14, —NR14R15, trifluoromethyl, difluoromethoxy, trifluoromethoxy, azido, alkyl, cycloalkyl, aryl, heteroaryl, arylalkyl, heteroarylalkyl, heterocyclyl, and heterocyclylalkyl;
• R14 and R15 are independently selected from hydrogen, alkyl, alkenyl, lower alkynyl, cycloalkyl, aryl, heteroaryl, heterocyclyl and arylalkyl,
• or R14 and R15 together with the atoms to which they are attached form a saturated, partially unsaturated or fully unsaturated 5-6 membered heterocyclyl.