Pyridazinones as parp7 inhibitors

A compound having Formula I:

• or a pharmaceutically acceptable salt thereof, wherein:
• X is halo or CF3;
• Y is NR1 or 0;
• R1 is H or C1-6 alkyl;
• R2 is H or C1-6 alkyl;
• wherein said C1-6 alkyl is optionally substituted with ORa;
• or R1 and R2 together with the atoms to which they are attached form a 4-10 membered heterocycloalkyl group;
• wherein the 4-10 membered heterocycloalkyl group has at least one ring-forming carbon atom and 1, 2, or 3 ring-forming heteroatoms independently selected from N, O, and S;
• wherein a ring-forming carbon atom of the 4-10 membered heterocycloalkyl group is optionally substituted by oxo to form a carbonyl group;
• and wherein the 4-10 membered heterocycloalkyl group is optionally substituted with 1, 2, 3, or 4 substituents each independently selected from halo, D, OH, C1-6 alkyl, C1-6 haloalkyl, C1-6 alkoxy, C1-6 alkylamino, and
• C1-6 dialkylamino;
• R3 is H or C1-6 alkyl;
• each R4 is independently selected from D, C1-6 alkyl, C1-6 haloalkyl, and C1-6 alkoxy;
• CyZ is a 5-10 membered heteroaryl group substituted with Rz;
• RZ is halo, CN, C1-6 alkyl, or C1-3 haloalkyl;
• Ra is selected from H, C1-6 alkyl, and C1-6 haloalkyl;
• and
• n is an integer from 0 to 8.