Tricyclic substituted thiadiazine dioxide compounds as BACE inhibitors, compositions and their use

1. A compound, or a stereoisomer of said compound, or a pharmaceutically acceptable salt of said compound or said stereoisomer, said compound having the structural Formula (I):

or a tautomer thereof having the structural Formula (I′):

or pharmaceutically acceptable salt thereof, wherein:

R 1 is selected from the group consisting of H, lower alkyl, and cyclopropyl;

ring A is selected from the group consisting of aryl, monocyclic heteroaryl, monocyclic cycloalkyl, monocyclic cycloalkenyl, monocyclic heterocycloalkyl, monocyclic heterocycloalkenyl, and a multicyclic group;

each R 2A (when present) is independently selected from the group consisting of: halo, oxo, —OH, —CN, —SF 5 , —OSF 5 , —NO 2 , —Si(R 5 ) 3 , —N(R 6 ) 2 , —OR 6 , —SR 6 , alkyl, haloalkyl, heteroalkyl, alkenyl, alkynyl, cycloalkyl, -alkyl-cycloalkyl, heterocycloalkyl, and -alkyl-heterocycloalkyl,

wherein said alkyl, haloalkyl, heteroalkyl, alkenyl, alkynyl, cycloalkyl, -alkyl-cycloalkyl, heterocycloalkyl, and -alkyl-heterocycloalkyl of R 2A are each optionally unsubstituted or substituted with one or more groups independently selected from R 8 ;

m is 0 or more;

ring B is selected from the group consisting of a 5-membered heteroaryl, a 5-membered heterocycloalkyl, a 5-membered heterocycloalkenyl ring, a 5-membered cycloalkyl ring, and a 5-membered cycloalkenyl ring, wherein each said ring comprises from 1 to 4 ring heteroatoms independently selected from the group consisting of N, N-oxide, O, S, S(O), and S(O) 2 ;

each R 2B (when present) is independently selected from the group consisting of halo, —CN, alkyl, cycloalkyl, -alkyl-cycloalkyl, heterocycloalkyl, -alkyl-heterocycloalkyl, heteroalkyl, haloalkyl —O-alkyl, —O-cycloalkyl, —O-alkyl-cycloalkyl, —O-heteroalkyl, and —O-haloalkyl;

n is 0 or more;

ring C is selected from the group consisting of aryl, monocyclic heteroaryl, monocyclic cycloalkyl, monocyclic cycloalkenyl, monocyclic heterocycloalkyl, monocyclic heterocycloalkenyl, and a multicyclic group;

each R 2C (when present) is independently selected from the group consisting of: halo, oxo, —OH, —CN, —SF 5 , —OSF 5 , —Si(R 5 ) 3 , —N(R 6 ) 2 , —NR 7 C(O)R 6 , —NR 7 S(O) 2 R 12 , —NR 7 S(O) 2 N(R 6 ) 2 , —NR 7 C(O)N(R 6 ) 2 , —NR 7 C(O)OR 6 , —C(O)R 6 , —C(O) 2 R 6 , —C(O)N(R 6 ) 2 , —S(O)R 12 , —S(O) 2 R 12 , —S(O) 2 N(R 6 ) 2 , —OR 6 , —SR 6 , alkyl, haloalkyl, heteroalkyl, alkenyl, alkynyl, cycloalkyl, -alkyl-cycloalkyl, aryl, -alkyl-aryl, heteroaryl, -alkyl-heteroaryl, heterocycloalkyl, and -alkyl-heterocycloalkyl,

wherein said alkyl, haloalkyl, heteroalkyl, alkenyl, alkynyl, cycloalkyl, -alkyl-cycloalkyl, aryl, -alkyl-aryl, heteroaryl, -alkyl-heteroaryl, heterocycloalkyl, and -alkyl-heterocycloalkyl of R 2C are each optionally unsubstituted or substituted with one or more groups independently selected from R 8 ;

p is 0 or more;

R 4 is selected from the group consisting of lower alkyl and lower haloalkyl;

each R 5 (when present) is independently selected from the group consisting of alkyl, heteroalkyl, haloalkyl, cycloalkyl, and -alkyl-cycloalkyl;

each R 6 (when present) is independently selected from the group consisting of H, alkyl, alkenyl, alkynyl, heteroalkyl, haloalkyl, cycloalkyl, -alkyl-cycloalkyl, heterocycloalkyl, -alkyl-heterocycloalkyl, aryl, -alkyl-aryl, heteroaryl, and -alkyl-heteroaryl,

wherein each said alkyl, alkenyl, alkynyl, heteroalkyl, haloalkyl, cycloalkyl, -alkyl-cycloalkyl, heterocycloalkyl, -alkyl-heterocycloalkyl, aryl, -alkyl-aryl, heteroaryl, and -alkyl-heteroaryl of R 6 is unsubstituted or substituted with one or more groups independently selected from halo, —CN, —OH, lower alkyl, cycloalkyl, lower heteroalkyl, lower haloalkyl, lower —O-alkyl, lower —O-heteroalkyl, and lower —O-haloalkyl;

each R 7 (when present) is independently selected from the group consisting of H, alkyl, heteroalkyl, haloalkyl, cycloalkyl, -alkyl-cycloalkyl, aryl, -alkyl-aryl, heteroaryl, and -alkyl-heteroaryl,

wherein each said cycloalkyl, -alkyl-cycloalkyl, aryl, -alkyl-aryl, heteroaryl, and -alkyl-heteroaryl of R 7 is unsubstituted or substituted with one or more groups independently selected from halo, —CN, lower alkyl, cycloalkyl, lower heteroalkyl, lower haloalkyl, lower —O-alkyl, lower —O-heteroalkyl, and lower —O-haloalkyl;

each R 8 (when present) is independently selected from the group consisting of halo, oxo, —OH, —CN, —SF 5 , —OSF 5 , alkyl, —O-alkyl, haloalkyl, haloalkoxy, —C(O)OR 11 , cycloalkyl, -alkyl-cycloalkyl, —O-cycloalkyl, —O-alkyl-cycloalkyl, —O-benzyl, heteroalkyl, —O-heteroalkyl, and -alkyl-OH;

R 9 is selected from the group consisting of H, halo, alkyl, cycloalkyl, haloalkyl, and heteroalkyl;

R 10 is selected from the group consisting of H, halo, alkyl, cycloalkyl, haloalkyl, and heteroalkyl;

R 11 (when present) is selected from the group consisting of H, lower alkyl, lower heteroalkyl, cycloalkyl, and -alkyl-cycloalkyl; and

each R 12 (when present) is independently selected from the group consisting of alkyl, alkenyl, alkynyl, heteroalkyl, haloalkyl, cycloalkyl, -alkyl-cycloalkyl, heterocycloalkyl, -alkyl-heterocycloalkyl, aryl, -alkyl-aryl, heteroaryl, and -alkyl-heteroaryl,

wherein each said alkyl, alkenyl, alkynyl, heteroalkyl, haloalkyl, cycloalkyl, -alkyl-cycloalkyl, heterocycloalkyl, -alkyl-heterocycloalkyl, aryl, -alkyl-aryl, heteroaryl, and -alkyl-heteroaryl of R 12 is unsubstituted or substituted with one or more groups independently selected from halo, —CN, —OH, lower alkyl, cycloalkyl, lower heteroalkyl, lower haloalkyl, lower —O-alkyl, lower —O-heteroalkyl, and lower —O-haloalkyl.

2. A compound of claim 1 , or a tautomer thereof, or a stereoisomer of said compound or said tautomer, or a pharmaceutically acceptable salt of said compound, said tautomer, or said stereoisomer, wherein:

R 4 is selected from the group consisting of —CH 3 and —CHF 2 ; and

one of R 9 and R 10 is H and the other is selected from the group consisting of H, halo, lower alkyl, cycloalkyl, lower haloalkyl, and lower heteroalkyl.

3. A compound of claim 2 , or a tautomer thereof, or a stereoisomer of said compound or said tautomer, or a pharmaceutically acceptable salt of said compound, said tautomer, or said stereoisomer, wherein:

ring B is selected from the group consisting of pyrrolyl, imidazolyl, oxadiazolyl, triazolyl, isoxazolyl, oxazolyl, thienyl, pyrazolyl, furanyl, tetrazolyl, thiazolyl, and isothiazolyl.

4. A compound of claim 3 , or a tautomer thereof, or a stereoisomer of said compound or said tautomer, or a pharmaceutically acceptable salt of said compound, said tautomer, or said stereoisomer, wherein:

n is 0 or more; and

each R 2B (when present) is independently selected from the group consisting of halo, —CN, methyl, ethyl, propyl, cyclopropyl, —CH 2 -cyclopropyl, —OCH 3 , —CH 2 OCH 3 , —CHF 2 , —CH 2 F, —CF 3 , —OCF 3 , and —OCHF 2 .

5. A compound of claim 4 , or a tautomer thereof, or a stereoisomer of said compound or said tautomer, or a pharmaceutically acceptable salt of said compound, said tautomer, or said stereoisomer, wherein:

ring A is selected from the group consisting of phenyl, pyridyl, pyrazinyl, furanyl, thienyl, pyrimidinyl, pyridazinyl, thiazolyl, thiadiazolyl, isothiazolyl, oxazolyl, oxadiazolyl, isoxazolyl, imidazolyl, pyrazolyl, pyrrolyl, quinazolinyl, benzofuranyl, benzimidazolyl, benzoxazolyl, benzoisoxazolyl, benzothiazolyl, benzoisothiazolyl, benzothienyl, naphthyl, quinolyl, isoquinolyl, indazolyl, indolyl, thienylpyridinyl, and thienylpyrazolyl.

6. A compound of claim 5 , or a tautomer thereof, or a stereoisomer of said compound or said tautomer, or a pharmaceutically acceptable salt of said compound, said tautomer, or said stereoisomer, wherein:

m is 0 or more; and

each R 2A group (when present) is independently selected from the group consisting of halo, oxo, —CN, —SF 5 , —NHCH 3 , —N(CH 3 ) 2 , —OCH 3 , —OCH 2 CH 3 , —O-cyclopropyl, —O—CH 2 -cyclopropyl, —CH 2 OCH 3 , —S(CH 3 ), methyl, ethyl, propyl, cyclopropyl, —CH 2 -cyclopropyl, —C≡C—CH 3 , —CF 3 , —CHF 2 , —OCF 3 , and —OCHF 2 .

7. A compound according to claim 6 , or a tautomer thereof, or a stereoisomer of said compound or said tautomer, or a pharmaceutically acceptable salt of said compound, said tautomer, or said stereoisomer, wherein:

ring C is selected from the group consisting of benzimidazolyl, benzothiazolyl, cyclopropyl, dihydroindenyl, dihydrooxazolyl, furanyl, indenyl, indolyl, isothiazolyl, isoxazolyl, oxadiazolyl, oxazolyl, phenyl, pyrazinyl, pyrazolyl, pyridazinyl, pyridyl, pyrimidinyl, pyrazolopyridinyl, pyrrolopyridinyl, pyrrolopyrimidinyl, thiazolyl, and thienyl.

8. A compound according to claim 7 , or a tautomer thereof, or a stereoisomer of said compound or said tautomer, or a pharmaceutically acceptable salt of said compound, said tautomer, or said stereoisomer, wherein:

p is 0 or more; and

each R 2C group (when present) is independently selected from the group consisting of halo, oxo, —CN, —SF 5 , —OSF 5 , —N(R 6 ) 2 , —NR 7 C(O)R 6 , —NR 7 S(O) 2 R 12 , —NR 7 C(O)N(R 6 ) 2 , —NR 7 C(O)OR 6 , —C(O)R 6 , —C(O) 2 R 6 , —C(O)N(R 6 ) 2 , —S(O)R 12 , —S(O) 2 R 12 , —S(O) 2 N(R 6 ) 2 , —OR 6 , —SR 6 , lower alkyl, lower haloalkyl, lower heteroalkyl, lower alkynyl, aryl, -alkyl-aryl-, cycloalkyl, heteroaryl, -alkyl-heteroaryl, heterocycloalkyl, and heterocycloalkenyl,

wherein each said lower alkyl, lower haloalkyl, lower heteroalkyl, lower alkynyl, aryl, -alkyl-aryl-, cycloalkyl, heteroaryl, -alkyl-heteroaryl, heterocycloalkyl, and heterocycloalkenyl of R 2 (when present) is independently unsubstituted or substituted with one or more groups independently selected from the group consisting of R 8 .

9. A compound of claim 1 , or a tautomer thereof, or a stereoisomer of said compound or said tautomer, or a pharmaceutically acceptable salt of said compound, said tautomer, or said stereoisomer, said compound selected from the group consisting of:

10. A pharmaceutical composition comprising a compound according to claim 1 , or a tautomer thereof, or a stereoisomer of said compound or said tautomer, or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable carrier or diluent.

11. A pharmaceutical composition of claim 10 , wherein said at least one additional therapeutic agent is at least one agent selected from:

m 1 agonists; m 2 antagonists; cholinesterase inhibitors; galantamine; rivastigimine; N-methyl-D-aspartate receptor antagonists; combinations of cholinesterase inhibitors and N-methyl-D-aspartate receptor antagonists; gamma secretase modulators; gamma secretase inhibitors; non-steroidal anti-inflammatory agents; anti-inflammatory agents that can reduce neuroinflammation; anti-amyloid antibodies; vitamin E; nicotinic acetylcholine receptor agonists; CB1 receptor inverse agonists; CB1 receptor antagonists; antibiotics; growth hormone secretagogues; histamine H3 antagonists; AMPA agonists; PDE4 inhibitors; GABA A inverse agonists; inhibitors of amyloid aggregation; glycogen synthase kinase beta inhibitors; promoters of alpha secretase activity; PDE-10 inhibitors; Tau kinase inhibitors; Tau aggregation inhibitors; RAGE inhibitors; anti-Abeta vaccine; APP ligands; agents that upregulate insulin, cholesterol lowering agents; cholesterol absorption inhibitors; combinations of HMG-CoA reductase inhibitors and cholesterol absorption inhibitors; fibrates; combinations of fibrates and cholesterol lowering agents and/or cholesterol absorption inhibitors; nicotinic receptor agonists; niacin; combinations of niacin and cholesterol absorption inhibitors and/or cholesterol lowering agents; LXR agonists; LRP mimics; H3 receptor antagonists; histone deacetylase inhibitors; hsp90 inhibitors; 5-HT4 agonists; 5-HT6 receptor antagonists; mGluR1 receptor modulators or antagonists; mGluR5 receptor modulators or antagonists; mGluR2/3 antagonists; Prostaglandin EP2 receptor antagonists; PAI-1 inhibitors; agents that can induce Abeta efflux; Metal-protein attenuating compound; GPR3 modulators; and antihistamines.

12. A method of treating and/or delaying the onset of a disease or pathology, wherein said disease or pathology is selected from Alzheimer's disease, Down's syndrome, Parkinson's disease, memory loss, memory loss associated with Alzheimer's disease, memory loss associated with Parkinson's disease, attention deficit symptoms, attention deficit symptoms associated with Alzheimer's disease, Parkinson's disease, and/or Down's syndrome, dementia, stroke, microgliosis and brain inflammation, pre-senile dementia, senile dementia, dementia associated with Alzheimer's disease, Parkinson's disease, and/or Down's syndrome, progressive supranuclear palsy, cortical basal degeneration, olfactory impairment, olfactory impairment associated with Alzheimer's disease, Parkinson's disease, and/or Down's syndrome, β-amyloid angiopathy, cerebral amyloid angiopathy, hereditary cerebral hemorrhage, mild cognitive impairment (“MCI”), glaucoma, amyloidosis, type II diabetes, diabetes-associated amyloidogenesis, hemodialysis complications (from β 2 microglobulins and complications arising therefrom in hemodialysis patients), scrapie, bovine spongiform encephalitis, traumatic brain injury (“TBI”), Creutzfeld-Jakob disease, and traumatic brain injury, said method comprising administering a compound according to claim 1 , or a tautomer or stereoisomer thereof, or a pharmaceutically acceptable salt thereof, to a patient in need thereof in an amount effective to treat said disease or pathology.

13. A method of claim 12 , wherein said Aβ pathology is Alzheimer's disease.