PARP inhibitors for treating cancer and asthma

A compound of Formula I, or a pharmaceutically acceptable salt thereof:

• wherein R1 is selected from C1-C3 alkyl, C2-C3 alkenyl, and C2-C3 alkynyl;
• and
• R2 is selected from a phenyl ring and a 3-membered to 10-membered aromatic, partially unsaturated, or unsaturated heterocycle containing 1, 2, 3, or 4 ring nitrogen atoms, with the phenyl ring and the 5- to 10-membered aromatic, partially unsaturated, or unsaturated heterocycle being substituted by 0, 1, 2 or 3 substituents selected from the group of Cl, F, Br, I, OH, C1-C6 alkyl, —O-C1-C6 alkyl, —NH2, —NH(C1-C6 alkyl), —N(C1-C6 alkyl)2, —CO2H, —CO2(C1-C6 alkyl), —CO2-phenyl, and —CO2-benzyl;
• wherein the phenyl and benzyl rings of the R2 —CO2-phenyl, —CO2-benzyl groups are substituted by 0, 1, 2, or 3 substituents selected from the group of Cl, F, Br, I, OH, C1-C6 alkyl, —O-C1-C6 alkyl, —NH2, —NH(C1-C6 alkyl), and —N(C1-C6 alkyl)2.