Selective HDAC1 and HDAC2 inhibitors

A compound of Formula II:

• or a pharmaceutically acceptable salt thereof;
• wherein
• R1 and R2 are independently H, mono-, bi-, or tri- cyclic aryl or heteroaryl, wherein the mono-, bi-, or tri-cyclic aryl or heteroaryl is optionally substituted;
• or R1 and R2 are linked together to form a group of Formula:
• R3 and R4 are independently selected from H, C1-6-alkyl, C2-6-alkenyl, C2-6-alkynyl, C3-6-cycloalkyl, C1-6-alkyl-C3-6-cycloalkyl, heterocycloalkyl, C1-6-alkyl-heterocycloalkyl, NR6R6, O—C1-6-alkyl-OR7, aryl, heteroaryl, C(O)N(H)-heteroaryl, C(O)-heteroaryl, C(O)-heterocycloalkyl, C(O)-aryl, C(O)—C1-6-alkyl, CO2—C1-6-alkyl, or C(O)—C1-6-alkyl-heterocycloalkyl, wherein the cycloalkyl, heterocycloalkyl, aryl, or heteroaryl is optionally substituted;
• R5 is H, C1-6-alkyl, CO2R7 or C1-6-alkyl-OR7;
• R6 is H, C1-6-alkyl, CO2R7 or C1-6-alkyl-OR7;
• R7 is H or C1-6-alkyl;
• X1, X2, and X3 are each independently CH, N, or S, wherein at least one of X1 or X2 is N or S;
• a line denotes an optionally double bond;
• p is 0 or 1.