Antiparasitic agents

A compound of the formula

• or a pharmaceutically acceptable salt of said compound, wherein:
• X is O or S;
• R1, R2, R3 and R4 are each independently selected from H, halo, CN, (C1-C4)alkyl (C1-C4)haloalkyl, O—(C1-C4)alkyl, and O—(C1-C4) haloalkyl;
• R5, R6, R7, R8 and R9 are each independently selected from H, halo, (C1-C4)alkyl, (C3-C6)cycloalkyl, (C1-C4)haloalkyl, O—(C1-C4)alkyl, O—(C3-C6)cycloalkyl, O—(C1-C4)haloalkyl, SF5, S(O)m—(C1-C4)alkyl, S(O)m—(C3-C6)cycloalkyl and S(O)m—(C1-C4)haloalkyl;
• R10 is H or (C1-C4)alkyl;
• R11 is H or (C1-C4)alkyl;
• and m is 0, 1 or 2.