Sulfamides as gamma-secretase inhibitors

1. A compound of formula I(D):

wherein:

R 2a represents H or C 2-6 acyl which is optionally substituted with a carboxylic acid group or with an amino group;

R 4 represents R 9 , halogen, CN, NO 2 , —OR 9 , —SR 9 , —S(O) t R 10 where t is 1 or 2, —N(R 9 ) 2 , —COR 9 , —CO 2 R 9 , —OCOR 10 , —CH═N—OR 11 , —CON(R 9 ) 2 , —SO 2 N(R 9 ) 2 , —NR 9 COR 10 , —NR 9 CO 2 R 10 , —NR 9 SO 2 R 10 , —CH═CHCH 2 N(R 16 ) 2 , —CH 2 N(R 16 ) 2 , —NHCOCH 2 OR 10 or —NHCOCH 2 N(R 16 ) 2 ;

R 7 represents H or R 8 ; or two R 7 groups together with a nitrogen atom to which they are mutually attached may complete a pyrrolidine, piperidine, piperazine or morpholine ring;

R 8 represents C 1-10 alkyl, perfluoroC 1-6 alkyl, C 3-10 cycloalkyl, C 3-6 cycloalkylC 1-6 alkyl, C 2-10 alkenyl, C 2-10 alkynyl, Ar or —C 1-6 alkylAr;

R 9 H or R 10 ; or two R 9 groups together with a nitrogen atom to which they are mutually attached may complete a pyrrolidine, piperidine, piperazine or morpholine ring which is optionally substituted by R 12 , —COR 12 or —SO 2 R 12 ;

R 10 represents C 1-10 alkyl, perfluoroC 1-6 alkyl, C 3-10 cycloalkyl, C 3-6 cycloalkylC 1-6 alkyl, C 2-10 alkenyl, C 2-10 alkynyl, C 6-10 aryl, heteroaryl, heterocyclyl, C 6-10 arylC 1-6 alkyl, heteroarylC 1-6 alkyl, heterocyclylC 1-6 alkyl, C 1-6 arylC 2-6 alkenyl, or heteroarylC 2-6 alkenyl, wherein the alkyl, cycloalkyl, alkenyl and alkynyl groups optionally bear one substituent selected from halogen, CF 3 , NO 2 , CN, —OR 11 , —SR 11 , —SO 2 R 12 , —COR 11 , —CO 2 R 11 , —CON(R 11 ) 2 , —OCOR 12 , —N(R 11 ) 2 and —NR 11 COR 12 ; and the aryl, heteroaryl and heterocyclic groups optionally bear up to 3 substituents independently selected from halogen, NO 2 , CN, R 12 , —OR 11 , —SR 11 , —SO 2 R 12 , —COR 11 , —CO 2 R 11 , —CON(R 11 ) 2 , —OCOR 12 , —N(R 11 ) 2 and —NR 11 COR 12 ;

R 11 represents H or R 12 ; or two R 11 groups together with a nitrogen atom to which they are mutually attached may complete a heterocyclic ring system of 3–10 atoms, 0–2 of which (in addition to said nitrogen atom) are selected from O, N and S, said ring system bearing 0–2 substituents selected from halogen, CN, NO 2 , oxo, R 12 , OH, OR 12 , NH 2 , NHR 12 , CHO, CO 2 H, COR 12 and CO 2 R 12 ;

R 12 represents C 1-6 alkyl which is optionally substituted with halogen, CN, OH, C 1-4 alkoxy or C 1-4 alkoxycarbonyl; perfluoroC 1-6 alkyl, C 3-7 cycloalkyl, C 2-6 alkenyl, C 2-6 alkynyl, Ar, —C 1-6 alkylAr, ArOC 1-6 alkyl or C-heterocyclyl which is optionally substituted with halogen, CN, C 1-6 alkyl, OH, perfluoroC 1-6 alkyl, C 2-6 acyl, C 1-4 alkoxy or C 1-4 alkoxycarbonyl;

R 14 represents H, C 1-10 alkyl, perfluoroC 1-6 alkyl, C 3-10 cycloalkyl, C 3-6 cycloalkylC 1-6 alkyl, C 2-10 alkenyl, C 2-10 alkynyl, C 1-6 aryl, heteroaryl, C 6-10 arylC 1-6 alkyl, or heteroarylC 1-6 alkyl, wherein the alkyl, cycloalkyl, alkenyl and alkynyl groups optionally bear one substituent selected from halogen, CN, NO 2 , —OR 7 , —SR 7 , —S(O) t R 8 where t is 1 or 2, —N(R 7 ) 2 , —COR 7 , —CO 2 R 7 , —OCOR 8 , —CON(R 7 ) 2 , —NR 7 COR 8 , —C 1-6 alkylNR 7 COR 8 , —NR 7 CO 2 R 8 and —NR 7 SO 2 R 8 , and the aryl and heteroaryl groups optionally bear up to 3 substituents selected from R 8 , halogen, CN, NO 2 , —OR 7 , —SR 7 , —S(O) t R 8 where t is 1 or 2, —(R 7 ) 2 , —COR 7 , —CO 2 R 7 , —OCOR 8 , —CON(R 7 ) 2 , —NR 7 COR 8 , —C 1-6 alkylNR 7 COR 8 , —NR 7 CO 2 R 8 and —NR 7 SO 2 R 8 ;

each R 16 independently represents H or R 10 , or two R 16 groups together with the nitrogen to which they are mutually attached complete a mono- or bicyclic heterocyclic ring system of 5–10 ring atoms selected from C, N, O and S, said ring system optionally having an additional aryl or heteroaryl ring fused thereto, said heterocyclic system and optional fused ring bearing 0–3 substituents independently selected from halogen, oxo, NO 2 , CN, R 12 , —OR 11 , —SR 11 , —SO 2 R 12 , —COR 11 , —CO 2 R 11 , —CON(R 11 ) 2 , —OCOR 12 , —N(R 11 ) 2 and —NR 11 COR 12 ;

Ar represents phenyl or heteroaryl either of which optionally bears up to 3 substituents independently selected from halogen, CF 3 , NO 2 , CN, OCF 3 , C 1-6 alkyl and C 1-6 alkoxy;

“heterocycly” at every occurrence thereof means a cyclic or polycyclic system of up to 10 ring atoms selected from C, N, O and S, wherein none of the constituent rings is aromatic and wherein at least one ring atom is other than C; and

“heteroaryl” at every occurrence thereof means a cyclic or polycyclic system of up to 10 ring atoms selected from C, N, O and S, wherein at least one of the constituent rings is aromatic and wherein at least one ring atom is other than C;

w is 1 or 2;

or a pharmaceutically acceptable salt thereof.

2. A compound according to claim 1 wherein R 2a is H.

3. A compound according to claim 1 which is

and pharmaceutically acceptable salts thereof.

4. A pharmaceutical composition comprising one or more compounds according to claim 1 and a pharmaceutically acceptable carrier.

5. A method of treatment of a subject suffering from or prone to Alzheimer's disease which comprises administering to that subject an effective amount of a compound according to claim 1 .

6. A compound according to claim 3 wherein:

R 2a is H, R 14 is n-propyl, and R 4 is selected from 3-pyridyl, (pyridin-3-yl)methoxy, —CO 2 Me, 2-(pyridin-2-yl)ethoxy, 3-(morpholin-4-yl)propyl, —CH 2 OH, —CHO, —CH=CHCO 2 Me, 3-[(4-methyl-1,2,4-triazol-3-yl) thio]prop-1-enyl, —CN, 5-(4-fluorophenyl)oxazol-2-yl, 5-(4-fluorophenyl)-1,3,4-oxadiazol-2-yl, 3-(pyridin-2-yl) -1,2,4-oxadiazol-5-yl, 3-pyrazinyl-1,2,4-oxadiazol-5-yl, —CH=CHCH 2 OH and 5-(4-fluorophenyl)pyrazol-3-yl; or

R 2a is H, R 14 is n-propyl, and R 4 is —CH=CHCH 2 N(R 16 ) 2 where —N(R 16 ) 2 is selected from morpholin-4-yl, 4-trifluoromethylpiperidin-1-yl, 4,4-difluoropiperidin-1-yl, 4-carbamoylpiperidin-1-yl, 4-ethoxycarbonylpiperidin-1-yl, 4-carboxypiperidin-1-yl, 4-hydroxypiperidin-1-yl, 1,2,3,6-tetrahydropyridinyl, 5-aza-2-oxabicyclo[2.2.1]hept-1-yl, N-[(furan-2-yl)methyl]amino, N,N-bis(2-methoxyethyl)amino, N-(indan-1-yl)amino and N-[(pyridin-2-yl)methyl]amino; or

R 2a is H, R 14 is n-propyl, and R 4 is—OCH 2 CH 2 N(R 11 ) 2 where -N(R 11 ) 2 is selected from morpholin-4-yl and 2-oxo-imidazolin-1-yl; or

R 2a is H, R 14 is 2,2,2-trifluoroethyl and R 4 is selected from —OH, —CO 2 Me, —CH 2 OH, —CHO, —CO 2 H, —CH=CHCO 2 Me, —CH=CHCO 2 H, —CH=CHCH 2 OH, —CH=N-OH, —CH=N—OEt, —CH 2 CH 2 CO 2 Me, —CH 2 CH 2 CO 2 H, (morpholin-4-yl)methyl, 2-(imidazol-1-yl)ethoxy, 3-(4-trifluoromethylpiperidin-1-yl)propyl, —CH=N—OCH 2 Ph, —CH=N—OCH 2 (4-F-C 6 H 4 ), —CH=N—OCH 2 (4-CF 3 —C 6 H 4 ), 3-pyrazinyl-1,2,4-oxadiazol-5-yl, 3-(4-fluorophenyl)-1,2,4-oxadiazol-5-yl, 3-(pyridin-2-yl)-1,2,4-oxadiazol-5-yl, —CH=N—OCH 2 (2-F-C 6 H 4 ), —CH=N—OCH 2 CH=CH 2 , —CH=N—OCH 2 (3-F-C 6 H 4 ) and —CH=N—OCH 2 (2,4-di-C1-C 6 H 3 ); or

R 2a is H, R 14 is 2,2,2-trifluoroethyl and R 4 is —CH=CHCH 2 N(R 16 ) 2 where —N(R 16 ) 2 is selected from morpholin-4-yl, 4-trifluoromethylpiperidin-1-yl, 5-aza-2-oxabicyclo[2.2.1]hept-1-yl, 4,4-difluoropiperidin-1-yl, 4-hydroxy-4-trifluoromethylpiperidin-1-yl, 4-methylpiperidin-1-yl, 3-oxo-4-phenylpiperazin-1-yl, 3-oxo-4-cyclohexylpiperazin-1-yl, 3-oxo-piperazin-1-yl, N-(tetrahydrofuran-3-yl)amino, N-methyl-N-(tetrahydrofuran-3-yl) amino, N-(tetrahydropyran-4-yl)amino, N-methyl-N-(tetrahydropyran-4-yl)amino, N-(dioxanylmethyl)amino, N-[(tetrahydropyran-2-yl)methyl]amino, 3-hydroxypiperidin-1-yl, 5-aza-2- oxabicyclo[5.4.0]undeca-7,9,11-trien-5-yl, 2-(phenoxymethyl)morpholin-4-yl, N-[(4-phenylmorpholin-2- yl)methyl]amino, 3,3-difluoropyrrolidin- 1- yl, N-(2,2,2-trifluoroethyl)amino and 3-(pyridin-3-yl)pyrrolidin-1-yl; or

R 2a is H, R 14 is 2,2,2-trifluoroethyl and R 4 is —OCH 2 CH 2 N(R 11 ) 2 where N(R 11 ) 2 is selected from morpholin-1-yl, 4-acetylpiperazin-1-yl, N-(2-methoxyethyl)amino, N-[(thiophen-2-yl)methyl]amino, N-[(pyridin-3-yl)methyl]amino, N-(methoxycarbonylmethyl)amino, 3-oxo-4-phenylpiperazin-1-yl and 4-trifluoromethypiperidin-1-yl.