Substituted pyrrolo, -furano, and cyclopentylpyrimidines having antimitotic and/or antitumor activity and methods of use thereof

A compound of Formula IV, and pharmaceutically acceptable salts thereof:

• wherein R1 is a substituted aryl, R2 is CH3, R3 is CH3, Y is N, X is NR4 wherein R4 is one of (a) a hydrogen (H), or (b) an alkyl having from one to ten carbon atoms and having a straight or branched configuration, and wherein the alkyl is partially or completely saturated, or a substituted alkyl having from one to ten carbon atoms, R5 is H, and R6 is an alkylaryl group, wherein each substituent of any said substituted group is the same or different and is selected from the group consisting of a straight or branched alkyl, alkenyl, or alkynyl, a cyclic or alicyclic group having from one to six carbon atoms, a heterocyclic group having from one to six carbon atoms, an alkoxy group, an aryloxy group, an alkyloxyaryloxy group, an aryl group, an amine, a halogen, a phenol, a piperidine, a pyrrole, a ketone, a methylalkyl ketone, and a trifluoromethyl ketone.