| abstract |
A compound having the formula: or a pharmaceutically acceptable salt thereof, where Rp is hydrogen or a protective hydroxy group; X is F, Cl or Br; and R1 is selected from the group consisting of (1) -CH2-CH = CH-Y, wherein Y is selected from the group consisting of (a) H, (b) phenyl, (c) quinolinyl, (d) naphthyridinyl, (e) substituted heteroaryl, where the heteroaryl is pyridinyl, quinolinyl or thiophenyl substituted with carboxamide, alkylamino, dialkylamino, carboxaldehyde, nitro, -CN, -CH (= N-OH), -CH (= N-NH2), -CH (= NN = C (CH3) 2), pyridyl, thiophenyl or pyrimidinyl or N-protected amino, where the N-protecting group is t-butyloxycarbonyl; (f) quinoxalinyl, and (g) (aryl) oyl, where the aryl is phenyl; and (2) -CH2-C = C-Y, in which Y is as defined above. |