Methods and compositions for stimulating osteoblast proliferation or treating malignant cell proliferation and methods for selecting osteoblast proliferation stimulants

A method of stimulating bone growth comprising the step of:

• administering to osteoblast or osteoblast precursor cells an effective amount of a compound of the formula III
• wherein:
• R1 is selected from the group consisting of:
• aryl, naphthyl, cycloalkyl, cycloalkenyl, keto substituted cycloalkyl, and keto substituted cycloalkenyl, where each of the above substituents is substituted by one or more of the groups independently selected from the group consisting of:
• C1-C7 alkyl, C1-C7 alkoxy, benzyloxy, hydroxy, C1-C2 haloalkyl, halo, cyano, —NO2, —CF3, carboxyl, hydrogen, (C1-C4)alkoxycarbonyl, —N(C1-C4 alkyl)2, (C1-C4)alkylcarbonyloxy, aryl, (C1-C4)alkylcarbonylamino, (C1-C4)alkylcarbonyl, (C1-C4)alkyl-aryl and —NH2;
• R2 is selected from the group consisting of:
• H, C1-C4 alkyl, C1-C4 alkenyl, C1-C4 alkynyl, C1-C4 alkoxy and —NH2;
• R3 and R6 are selected from the group consisting of:
• H, hydroxy, halo, (C1-C5)alkylcarbonyloxy, cyano, C1-C4 alkyl, C1-C4 alkenyl and C1-C4 alkoxy;
• R4 and R5 are selected from the group consisting of:
• H, halo, hydroxy, (C1-C4)alkyl-carbonyloxy, cyano, C1-C2 haloalkyl, C1-C4 alkoxy, benzoyl, (C1-C4)alkyl-aryl, (C1-C6)alkylaminocarbonyloxy, phenylaminocarbonyloxy, C1-C4 alkyl, C1-C4 alkenyl, C1-C4 alkynyl, (C1-C4)alkenyl-aryl, (C1-C4)alkynyl-aryl, (C1-C4)alkyl-(C6-C10)cycloalkyl, (C1-C4)alkenyl-(C6-C10)cycloalkyl, (C1-C4)alkynyl-(C6-C10)cycloalkyl, (C1-C4)alkyl-(C6-C10)cycloalkenyl, (C1-C4)alkenyl-(C6-C10)cycloalkenyl, (C1-C4)alkynyl-(C6-C10)cycloalkenyl, carboxy or (C1-C4)alkoxycarbonyl.