2-aminopyridine compounds useful as β-secretase inhibitors for the treatment of alzheimer's disease

1. A compound of formula (II)

wherein:

R 1a , R 1b , R 1c , R 1d and R 1e are selected from the group consisting of:

(1) hydrogen,

(2) halogen,

(3) cyano,

(4) —C 1-6 alkyl, wherein said alkyl is unsubstituted or substituted with one or more hydroxyl, halogen, or NH 2 ,

(5) —OR 7a ,

(6) —C(═O)—NR 7a R 7b ,

(7) —NH—C(═O)—R 7a ,

(8) —N—R 7a R 7b ,

(9) —S(═O) p —R 8a ,

(10) —NR 7a —S(═O) p —R 8a ,

or R 1c and R 1d are linked together to form the group —OCH 2 CH 2 O— or —OCH 2 CH 2 —;

R 2a , R 2b , R 2c , R 2d and R 2e are selected from the group consisting of:

(1) hydrogen,

(2) halogen,

(3) cyano,

(4) hydroxyl,

(5) —C 0-6 alkyl-C 3-8 cycloalkyl

(6) —C 1-6 alkyl, wherein said alkyl is unsubstituted or substituted with one or more halogen or hydroxyl,

(7) —C 2-6 alkenyl,

(8) —O—R 7a ,

(9) —C(═O)—R 7a

(10) —NO 2 ,

(11) C 6-10 aryl, wherein said aryl can be unsubstituted or substituted with one or more

(a)halogen,

(b) cyano,

(c) —C 1-6 alkyl,

(d) —C 1-6 alkoxy,

(e) —C(═O)—O—R 7a ,

(f) —C(═O)—R 7a ,

(g) —NR 7a R 7b ,

(h) —NR 7a —S(═O) p —R 8a ,

(i) —NR 7a —C(═O)—R 7b ,

(j) —NO 2

(k) heteroaryl selected from the group consisting of furyl,pyranyl, benzofuranyl, isobenzofuranyl, chromenyl, thienyl, benzothiophenyl, pyrrolyl, pyrazolyl, imidazolyl, pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, indolyl, indazolyl, benzimidazolyl, quinolyl and isoquinolyl,

wherein said heteroaryl is unsubstituted or substituted with one or more halogen, —C 1-6 alkyl, —C 1-6 alkoxy, hydroxy or cyano,

or R 2c and R 2d are linked together to form a group —CR 7a R 7b CR 7c R 7d CR 7e R 7f —, —OCH 2 CH 2 O— or —OCH 2 CH 2 —, and

R 3 , R 4 and R 5 are independently selected from the group consisting of:

(1) hydrogen

(2) -(Q 2 ) n —R 9

(3) heteroaryl wherein said heteroaryl is selected from the group consisting of furyl, pyranyl, benzofuranyl, isobenzofuranyl, chromenyl, thienyl, benzothiophenyl, pyrrolyl, pyrazolyl, imidazolyl, pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, indolyl, indazolyl, benzimidazolyl, quinolyl and isoquinolyl,

(4) —C 6-10 aryl

(5) a carbocyclic group having from 3 to 8 ring atoms, optionally having (i) a —C(═O)— ring atom, (ii) from one to three ring heteroatoms selected from the group consisting of S, N and O, and (iii) a single carbon-carbon double bond,

(6) halogen,

(7) cyano,

(8) —N 3 ,

(9) —NO 2 ,

(10) —OR 7a

wherein R 9 is selected from the group consisting of

(a) —C 1-10 alkyl,

(b) —C 0-3 alkyl-C 3-8 cycloalkyl,

(c) —C 2-10 alkenyl,

(d) —C 2-10 alkynyl,

(e) —C 3-10 cycloalkenyl, and

(f) —C 3-10 cycloalkynyl, and

Q 2 is selected from the group consisting of O, S, NR 7a ,—(C═O)—O—, —NR 7a —S(═O) p ——S(═O) p ,—C(═O)—NR 7a , —NR 7a —C(═O)—,

wherein said R 9 alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, cycloalkynyl, carbocyclic, aryl and heteroaryl groups are unsubstituted or substituted with one or more,

(a) halogen,

(b) cyano,

(c) —C 1-6 alkyl,

(d) —C 2-6 alkenyl,

(e) —C 2-6 alkynyl,

(f) —OR 7a

(g) —C(═O)—O—R 7a ,

(h) —C(═O)—R 7a ,

(i) —C(═O)—NR 7a R 7b ,

(j) —NR 7a R 7b ,

(k) —NR 7a —S(═O) p —R 7b ,

(l) —NR 7a —C(═O)—R 7b ,

(m) —NO 2 ,

(n) —CH 2 —C 6-10 aryl,

(o) —C 6-10 aryl,

(p) heteroaryl,

(q) —C 3-8 cycloalkyl

(r) —C(═O)—N—SO 2 R 8a ,

and said R 9 alkyl, alkenyl and alkynyl groups are optionally interrupted with one or more Q 2 groups,

R 7a , R 7b , R 7c , R 7d , R 7e and R 7f are selected from the group consisting of:

(1) hydrogen,

(2) —C 1-6 alkyl,

(3) —C 3-8 cycloalkyl

(4) —C 6-10 aryl, and

(5) —CH 2 —C 6-10 aryl;

provided that when R 7a and R 7b are bound to the same N atom, then R 7a and R 7b may form a four to five hydrocarbon chain with the N atom to which they are attached to form a carbocyclic ring having a single N atom;

wherein said R 7a —R 7f alkyl, cycloalkyl or aryl groups are unsubstituted or substituted with one or more halogen, —C 1-6 alkyl,—C 1-6 alkoxy, hydroxyl, cyano or a carbocyclic group having from 3 to 8 ring atoms, optionally having (i) a —C(═O)— ring atom, (ii) from one to three ring heteroatoms selected from the group consisting of S, N and O, and (iii) a single carbon-carbon double bond;

R 8a is selected from the group consisting of

(1) —C 1-6 alkyl,

(2) —C 6-10 aryl, and

(3) —CH 2 —C 6-10 aryl;

wherein said R 8a alkyl or aryl groups are unsubstituted or substituted with one or more halogen, —C 1-6 alkyl, —C 1-6 alkoxy, hydroxyl or cyano;

n is 0 or 1;

p is 0, 1 or 2;

and pharmaceutically acceptable salts thereof, and individual enantiomers and diastereomers thereof.

2. The compound of claim 1 , wherein R 1a , R 1b , R 1c , R 1d and R 1e are selected from the group consisting of:

(a) hydrogen,

(b) halogen,

(c) —OR 8a wherein R 8a is C 1-6 alkyl, and

(d) —CH 2 OH.

3. The compound of claim 2 , wherein R 1a , R 1d and R 1e are hydrogen, and R 1b and R 1c are independently selected from the group consisting of:

(a) hydrogen,

(b) halogen,

(c) —OR 8a wherein R 8a is C 1-6 alkyl, and

(d) —CH 2 OH.

4. The compound of claim 1 , wherein R 2a , R 2b , R 2c , R 2d and R 2e are selected from the group consisting of:

(1) hydrogen,

(2) —C 1-6 alkyl, wherein said alkyl is unsubstituted or substituted with one or more halogen,

(3) —O—R 7a , wherein R 7a is C 1-6 alkyl,

(4) —NO 2 ,

(5) —C 2-6 alkenyl,

(6) —C 1-6 alkyl—C 3-6 cycloalkyl.

5. The compound of claim 1 wherein R 2a , R 2b , R 2c , R 2d and R 2e are each hydrogen.

6. The compound of claim 1 wherein R 3 , R 4 and R 5 are independently selected from the group consisting of:

(1) hydrogen

(2) C 1-10 alkyl

(3) C 6-10 aryl, and

(4) halogen.

7. The compound of claim 1 wherein R 3 , R 4 and R 5 are each hydrogen.

8. A compound of claim 1 which is selected from the group consisting of

and pharmaceutically acceptable salts thereof.

9. The pharmaceutical composition comprising a therapeutically effective amount of a compound of claim 1 or a pharmaceutically acceptable salt thereof and a pharmaceutically acceptable carrier.

10. The method for inhibition of β-secretase activity in a mammal in need thereof which comprises administering to the mammal a therapeutically effective amount of a compound of claim 1 or a pharmaceutically acceptable salt thereof.

11. A method for treating Alzheimer's disease in a patient in need thereof comprising administering to the patient a therapeutically effective amount of a compound of claim 1 or a pharmaceutically acceptable salt thereof.