Protoporphyrinogen oxidase inhibitors

A compound of formula (I):

• or salt thereof, wherein:
• R1 is C1-6alkyl, C3-4alkenyl, C3-4alkynyl, cyclopropyl, CH2C3-6cycloalkyl, phenyl or C1-2alkyl-phenyl, each substituted with C(O)Ria or CH2C(O)R1a and each optionally substituted with up to 3 F or Cl atoms, wherein each C1-6alkyl is also optionally substituted with —OR1b;
• R1a is OR1b, CH2OC(O)C1-4alkyl, C(O)OR1b, N(R1b)(R1c), ON(R1b)(R1c), NHN(R1b)(R1c), NHS(O)2N(R1b)2, NHS(O)2C1-4alkyl, or NHOR1b;
• each R1b is, independently, H, C3-6cycloalkyl, CH2phenyl, or C1-4alkyl optionally substituted with up to 3 F or Cl atoms;
• R1c is H or C1-4alkyl optionally substituted with C(O)OR1b or R1b and R1c together with an intervening nitrogen atom form a 4 to 6 membered heterocyclic ring, optionally containing an additional atom or group selected from N, O, S, S(O)2 and optionally substituted with one or more groups selected from —C(O)OR1b and —C(O)R1b;
• each of R2 and R3 is H, F, or R2 and R3 together with the intervening carbon is cyclopropyl;
• R4 is H, F, CH3, or Cl;
• R5 is H or F;
• each of R6 and R7 is, independently, F, H, CH3, CF3, or OCH3;
• R8 is H or F;
• and
• wherein Ring A contains at least 4 F atom substituents.