Haptens of risperidone and paliperidone

The compound of Formula I

• wherein:
• R1 is H, or OH;
• R2 is O(CH2)rNH2,
• O(CH2)rNHC(O)(CH2)mCO2H, or Z—(Y)p-G;
• wherein:
• Z is selected from the group consisting of:
• —N(R4)—, —O—, —S—, -heteroalkyl-;
• R4 is H, an alkyl group, cycloalkyl group, aralkyl group or substituted or unsubstituted aryl group;
• Y is an organic spacer group;
• G is a functional linking group capable of binding to a carrier;
• p is 0, or 1;
• r is 1, 2, 3, 4, or 5;
• m is 1, 2, 3, 4, or 5;
• n is 1, 2, 3, 4, or 5.