Dihydropyrido[4,3-b]pyrazine-3-ones as modulators of toll-like receptors

A compound of Formula I:

• or a pharmaceutically acceptable salt thereof, wherein:
• L1 is —NR8—, —O—, —S—, —N(R8)C(O)—, —S(O)2—, —S(O)—, or a covalent bond;
• R1 is H, alkyl of 1-8 carbon atoms, alkenyl of 2-8 carbon atoms, or alkynyl of 2-8 carbon atoms, all of which are optionally substituted by alkyl of 1-6 carbon atoms, alkoxy of 1-4 carbon atoms, carbocyclyl of 3-8 carbon atoms, or halo;
• Z is H, halogen, or alkyl, in which alkyl is optionally substituted by halo;
• X1 is alkylene of 1-6 carbon atoms optionally substituted by alkyl of 1-4 carbon atoms, —O—, —C(O)—, —S(O)—, —S(O)2—, or a covalent bond;
• D is carbocyclyl, heterocyclyl, aryl, or heteroaryl;
• L2 is alkylene of 1-6 carbon atoms optionally substituted by alkyl of 1-4 carbon atoms , or a covalent bond;
• R2 is —NR6R7;
• m is 1 or 2;
• R3 is alkyl of 1-6 carbon atoms or halogen;
• n is 0, 1, 2, 3, 4 or 5;
• R4 and R5 are each independently H or alkyl of 1-6 carbon atoms, or R4 and R5, taken together with the carbon to which they are attached, form —C(═O);
• R6 and R7 are each independently H or alkyl of 1-6 carbon atoms, or
• R6 and R7, taken together with the nitrogen to which they are both attached, form a 3 to 8 membered heterocycle;
• and
• R8 is H or alkyl of 1-6 carbon atoms.