| abstract |
Disclosed herein are compounds of formula (I) where R1 is alkyl, trifluoromethyl or pyridinyl; R2 is H, alkyl or substituted arylalkyl, in which the substituents are independently one or two halogens, carboxyl or alkoxycarbonyl groups; R3 and R4 are H, alkyl, halogen or nitro; or a pharmaceutically acceptable salt thereof, which are useful as inhibitors of smooth muscle cell proliferation. |