C5-C6-carbocyclic fused iminothiadiazine dioxides as BACE inhibitors, compositions, and their use

A compound, or a pharmaceutically acceptable salt thereof, said compound having the structural Formula (I):

• or a tautomer thereof having the structural Formula (I′):
• or pharmaceutically acceptable salt thereof, wherein:
• ring C is a 3-, 4-, 5-, or 6-membered fused cycloalkyl group;
• p is 1, 2, 3, or 4, provided that the value of p does not exceed the number of substitutable hydrogen atoms on ring C;
• each RC is independently selected from the group consisting of H, F, —OH, oxo, lower alkyl, lower cycloalkyl, —O-(lower alkyl) and —O-(lower cycloalkyl),
• wherein each said lower alkyl and lower cycloalkyl are optionally substituted with one or more fluorine, and
• wherein 1 to 2 non-adjacent, non-terminal carbon atoms in each said lower alkyl are optionally independently replaced with —O—, —NH—, —N-(lower alkyl)-, —S—, —S(O)—, or —S(O)2—;
• R1 is selected from the group consisting of H, lower alkyl, lower cycloalkyl, and -(lower alkyl)-(lower cycloalkyl),
• wherein each said lower alkyl and lower cycloalkyl are optionally substituted with one or more fluorine, and
• wherein 1 to 2 non-adjacent, non-terminal carbon atoms in each said lower alkyl are optionally independently replaced with —O—, —NH—, —N-(lower alkyl)-, —S—, —S(O)—, or —S(O)2—;
• ring A is selected from the group consisting of aryl and heteroaryl;
• m is 0, 1, 2, or 3, provided that the value of m does not exceed the number of substitutable hydrogen atoms on ring A;
• each RA (when present) is independently selected from the group consisting of halogen, —CN, —OH, oxo, —NH-(lower alkyl), —NHC(O)-(lower alkyl), lower alkyl, -(lower alkyl)-(lower cycloalkyl), and —O-(lower alkyl),
• wherein each said lower alkyl and lower cycloalkyl are optionally substituted with one or more fluorine, and
• wherein 1 to 2 non-adjacent, non-terminal carbon atoms in each said lower alkyl are optionally independently replaced with —O—, —NH—, —N-(lower alkyl), —S—, —S(O)—, or —S(O)2—;
• q is 0 or 1;
• -L1-, when present, represents a bond or a divalent moiety selected from the group consisting of —C(O)NH—, —CH2C(O)NH—, —NH—, —CH(CH3)NH—, —CH2NH—, —O—, and —CH2O—;
• ring B, when present, is selected from the group consisting of aryl, heteroaryl, cycloalkyl, and heterocycloalkyl;
• n is 0, 1, 2, or 3, provided that the value of n does not exceed the number of substitutable hydrogen atoms on ring B;
• and
• each RB, when present, is independently selected from the group consisting of halogen, —CN, —OH, oxo, lower alkyl, lower cycloalkyl, -(lower alkyl)-(lower cycloalkyl), —O-(lower alkyl), —O-(lower cycloalkyl), —O-(lower alkyl)-(lower cycloalkyl), —C≡CH, —C≡C—CH3, —OCH2—C≡C—H, and —OCH2—C≡C—CH3,
• wherein each said lower alkyl and lower cycloalkyl are optionally substituted with one or more fluorine, and
• wherein 1 to 2 non-adjacent, non-terminal carbon atoms in each said lower alkyl are optionally independently replaced with —O—, —NH—, —N-(lower alkyl)-, —S—, —S(O)—, or —S(O)2—.