Modulators of 5-HT receptors and methods of use thereof

1. A compound of formula (I):

or a pharmaceutically acceptable salt thereof, wherein

R 1 , R 2 , R 4 , R 5 and R 6 are independently selected from the group consisting of hydrogen, alkenyl, alkyl, haloalkyl, G 1 , and —(CR 4a R 5a ) m —G 1 ;

R 4a and R 5a , at each occurrence, are each independently hydrogen, halogen, alkyl, or haloalkyl;

G 1 , at each occurrence, is independently aryl or heteroaryl, wherein each G 1 is independently unsubstituted or substituted with 1, 2, 3, 4, or 5 substituents selected from the group consisting of alkyl, alkenyl, alkynyl, halogen, cyano, —G 3 , —NO 2 , —OR 1b , —O—(CR 4b R 5b ) m —G 3 , —OC(O)R 1b ,—OC(O)N(R b )(R 3b ), —SR 1b , —S(O)R 2b , —S(O) 2 R 2b , —S(O) 2 N(R b )(R 3b ), —C(O)R 1b , —C(O)OR 1b , —C(O)N(R b )(R 3b ), —C(OH)[(CR 4b R 5b ) m —R 4b ] 2 , —N(R b )(R 3b ), —N(R a )C(O)R 1b , —N(R a )C(O)O(R 1b ), —N(R a )C(O)N(R b )(R 3b ), —(CR 4b R 5b ) m —G 3 , —(CR 4b R 5b ) m —NO 2 , —(CR 4b R 5b ) m —OR 1b , —(CR 4b R 5b ) m OC(O)R 1b , —(CR 4b R 5b ) m —OC(O)N(R b )(R 3b ), —(CR 4b R 5b ) m —SR 1b , —(CR 4b R 5b ) m —S(O) 2 R 2b , —(CR 4b R 5b ) m —S(O) 2 N(R b )(R 3b ), —(CR 4b R 5b ) m —C(O)R 1b , —(CR 4b R 5b ) m —C(O) OR 1b , —(CR 4b R 5b ) m —C(O)N(R b )(R 3b ), —(CR 4b R 5b ) m —N(R b )(R 3b ), —(CR 4b R 5b ) m —N(R a )C(O)R 1b , —(CR 4b R 5b ) m —N(R a )C(O)O(R 1b ), —(CR 4b R 5b ) m —N(R a )C(O)N(R b )(R 3b ), cyanoalkyl, and haloalkyl;

R a and R b , at each occurrence, are each independently hydrogen, alkyl, or haloalkyl;

R 1b and R 3b , at each occurrence, are each independently hydrogen, alkyl, or haloalkyl;

R 2b , at each occurrence, is independently alkyl or haloalkyl;

R 4b and R 5b , at each occurrence, are each independently hydrogen, halogen, alkyl, or haloalkyl;

m, at each occurrence, is independently 1, 2, 3, 4, or 5;

G 3 , at each occurrence, is independently aryl or heteroaryl, wherein each G 3 is independently unsubstituted or substituted with 1, 2, 3, 4, or 5 substituents selected from the group consisting of alkyl, alkenyl, alkynyl, halogen, cyano, —NO 2 , —OR 1b , —OC(O)R 1b ,—OC(O)N(R b )(R 3b ), —SR 1b , —S(O)R 2b , —S(O) 2 R 2b , —S(O) 2 N(R b )(R 3b ), —C(O)R 1b , —C(O) OR 1b , —C(O)N(R b )(R 3b ), —N(R b )(R 3b ), —N(R a )C(O)R 1b , —N(R a )C(O)O(R 1b ), —N(R a )C(O)N(R b )(R 3b ), —(CR 4b R 5b ) m —NO 2 , —(CR 4b R 5b ) m —OR 1b , —(CR 4b R 5b ) m —OC(O)R 1b , —(CR 4b R 5b ) m —OC(O)N(R b )(R 3b ), —(CR 4b R 5b ) m —SR 1b , —(CR 4b R 5b ) m —S(O) 2 R 2b , —(CR 4b R 5b ) m —S(O) 2 N(R b )(R 3b ), —(CR 4b R 5b ) m —C(O)R 1b , —(CR 4b R 5b ) m —C(O)OR 1b , —(CR 4b R 5b ) m —C(O)N (R b )(R 3b ), —(CR 4b R 5b ) m —N(R b )(R 3b )(CR 4b R 5b ) m —N (R a )C(O)R 1b , —(CR 4b R 5b ) m —N(R a )C(O)O(R 1b ), —(CR 4b R 5b ) m —N(R a )C(O)N(R b )(R 3b ), cyanoalkyl, and haloalkyl;

R 3 is selected from the group consisting of hydrogen, alkyl, alkylcarbonyl, haloalkyl, (CR 4a R 5a ) m —G 1 , C(O)—G 1 , —S(O) 2 R 7 , and —C(O)NR 8 R 9 ;

R 7 and R 8 are independently selected from the group consisting of alkyl, haloalkyl, G 1 and —(CR 4a R 5a ) m —G 1 ;

R 9 is selected from the group consisting of hydrogen, alkyl, and haloalkyl;

X 1 is CR 10 ;

X 2 is CR 11 ;

X 3 is CR 12 ;

X 4 is CR 13 ;

R 10 , R 11 , R 12 , and R 13 are each independently hydrogen, alkyl, alkenyl, alkynyl, halogen, cyano, —G 1 , —G 2 , —NO 2 , —OR 1 , —O—(CR 4a R 5a ) m —G 1 , —O—(CR 4a R 5a ) m —G 2 , —OC(O)R 1a ,—OC(O)N(R b )(R 3a ), —SR 1a , —S(O)R 2a , —S(O) 2 R 2a , —S(O) 2 N(R b )(R 3a ), —C(O)R 1a , —C(O)OR 1a , —C(O)N(R b )(R 3a ), —N(R b )(R 3a ), —N(R a )C(O)R 1a , —N(R a )C(O)O(R 1a ), —N(R a )C(O)N(R b )(R 3a ), —N(R a )S(O) 2 (R 2a ), —(CR 4a R 5a ) m —NO 2 , —(CR 4a R 5a ) m —OR 1a , —(CR 4a R 5a ) m —OC(O)R 1a , —(CR 4a R 5a ) m —OC(O)N(R b )(R 3a )—(CR 4a R 5a ) m —SR 1a , —(CR 4a R 5a ) m —S(O)R 2a , —(CR 4a R 5a ) m —S(O) 2 R 2a , —(CR 4a R 5a )S(O) 2 N(R b )(R 3a ), —(CR 4a R 5a ) m —C(O)R 1a , —(CR 4a R 5a ) m —C(O)OR 1a , —(CR 4a R 5a ) m —C(O)N(R b )(R 3a ), —(CR 4a R 5a ) m —N(R b )(R 3a ), —(CR 4a R 5a ) m —N(R a )C(O)R 1a , —(CR 4a R 5a ) m —N(R a )C(O)O(R 1a ), —(CR 4a R 5a ) m —N(R a )C(O)N(R b )(R 3a ), —(CR 4a R 5a ) m —G 1 , —CR 4a ═CR 5a —G 1 , cyanoalkyl, or haloalkyl;

wherein R 1a and R 3a , at each occurrence, are each independently hydrogen, alkyl, haloalkyl, G 1 , or —(CR 4a R 5a ) m —G 1 ;

R 2a , at each occurrence, is independently alkyl, haloalkyl, G 1 , or —(CR 4a R 5a ) m —G 1 ;

G 2 , at each occurrence, is independently cycloalkyl, cycloalkenyl or heterocycle, wherein each G 2 is independently unsubstituted or substituted with 1, 2, 3, 4, or 5 substituents selected from the group consisting of alkyl, alkenyl, halogen, cyano, —NO 2 , —OR 1b ,S(O) 2 R 2b , —C(O)OR 1b , haloalkyl, and oxo;

or R 10 and R 11 , or R 11 and R 12 , or R 12 and R 13 taken together with the carbon atoms to which they are attached form a phenyl ring, cycloalkyl, heterocycle, or heteroaryl, wherein each phenyl ring, cycloalkyl, heterocycle and heteroaryl is independently unsubstituted or substituted with 1, 2, 3, 4, or 5 substituents selected from the group consisting of alkyl, alkenyl, alkynyl, halogen, cyano, —G 1 , —G 2 , —NO 2 , —OR 1a , —O—(CR 4a R 5a ) m —G 1 , —O—(CR 4a R 5a ) m —G 2 , —OC(O)R 1a , —OC(O)N(R b )(R 3a ), —SR 1a —S(O)R 2a , —S(O) 2 R 2a , —S(O) 2 N(R b )(R 3a ), —C(O)R 1a , —C(O)OR 1a , —C(O)N(R b )(R 3a ), —N(R b )(R 3a ), —N(R a )C(O)R 1a , —N(R a )C(O)O(R 1a ), —N(R a )C(O)N(R b )(R 3a ), —N(R a )S(O) 2 (R 2a ), —(CR 4a R 5a ) m —NO 2 , —(CR 4a R 5a ) m —OR 1a , —(CR 4a R 5a ) m —OC(O)R 1a , —(CR 4a R 5a ) m —OC(O)N(R b )(R 3a ) m —(CR 4a R 5a ) m —SR 1a —(CR 4a R 5a ) m —S(O)R 2a , —(CR 4a R 5a ) m —S(O) 2 R 2a , —(CR 4a R 5a ) m —S(O) 2 N(R b )(R 3a ), —(CR 4a R 5a ) m —C(O)R 1a , —(CR 4a R 5a ) m —C(O)OR 1a , —(CR 4a R 5a ) m —C(O)N (R b )(R 3a ), —(CR 4a R 5a ) m —N(R b )(R 3a ), —(CR 4 R 5a ) m —N(R a )C(O)R 1a , —(CR 4a R 5a ) m —N(R a )C(O)O(R 1a ), —(CR 4a R 5a ) m —N(R a )C(O)O(R 1a ), —(CR 4a R 5a )m N(R a )C(O)N(R b )(R 3a ), —(CR 4a R 5a ) m —G 1 , —CR 4a ═CR 5a —G 1 , cyanoalkyl, or haloalkyl;

Y 1 is N;

Y 2 is O;

Y 3 is CR 15 R 16 ; and

R 15 and R 16 are independently selected from the group consisting of hydrogen, alkyl, and haloalkyl.

2. The compound according to claim 1 of formula (Ie):

or a pharmaceutically acceptable salt thereof, wherein

R 3 is hydrogen, alkyl, alkylcarbonyl, haloalkyl, —(CR 4a R 5a ) m —G 1 , —C(O)—G 1 , —S(O) 2 R 7 , or —C(O)NR 8 R 9 .

3. The compound according to claim 2 wherein R 3 is hydrogen.

4. The compound according to claim 2 , wherein the compound is selected from the group consisting of:

(4aS)-3-methyl-2,3,4,4a,5,6-hexahydro-1H-pyrazino[2,1-d][1,5]benzoxazepine;

(4aS)-10-methyl-2,3,4,4a,5,6-hexahydro-1H-pyrazino[2,1-d][1,5]benzoxazepine;

(4aS)-10-methoxy-2,3,4,4a,5,6-hexahydro-1H-pyrazino[2,1-d][1,5]benzoxazepine;

(4aS)-2,3,4,4a,5,6-hexahydro-1H-pyrazino[2,1-d][1,5]benzoxazepin-10amine;

(4aS)-10-fluoro-2,3,4,4a,5,6-hexahydro-1H-pyrazino[2,1-d][1,5]benzoxazepine;

(4aS)-9-methyl-2,3,4,4a,5,6-hexahydro-1H-pyrazino[2,1-d][1,5]benzoxazepine;

(4aS)-11-chloro-2,3,4,4a,5,6-hexahydro-1H-pyrazino [2,1-d][1,5]benzoxazepine;

(4aS)-11-fluoro-2,3,4,4a,5,6-hexahydro-1H-pyrazino [2,1-d][1,5]benzoxazepine;

(4aS)-9-chloro-2,3,4,4a,5,6-hexahydro-1H-pyrazino[2,1-d][1,5]benzoxazepine;

(4aS)-3-benzyl-2,3,4,4a,5,6-hexahydro-1H-pyrazino[2,1-d][1,5]benzoxazepine;

(4aS)-2,3,4,4a,5,6-hexahydro-1H-pyrazino[2,1-d][1,5]benzoxazepine;

(4aS)-10-chloro-2,3,4,4a,5,6-hexahydro-1H-pyrazino[2,1-d][1,5]benzoxazepine;

(4aS)-3-benzyl-9-chloro-2,3,4,4a,5,6-hexahydro-1H-pyrazino[2,1-d][1,5]benzoxazepine;

(4aS)-9-phenyl-2,3,4,4a,5,6-hexahydro-1H-pyrazino[2,1-d][1,5]benzoxazepine;

(4aS)-9-chloro-3-methyl-2,3,4,4a,5,6-hexahydro-1H-pyrazino[2,1-d][1,5]benzoxazepine;

(4aS)-9-(2-methylphenyl)-2,3,4,4a,5,6-hexahydro-1H-pyrazino [2,1-d][1,5]benzoxazepine;

(4aS)-9-(3-methylphenyl)-2,3,4,4a,5,6-hexahydro-1H-pyrazino [2,1-d][1,5]benzoxazepine;

(4aS)-9-(4-methylphenyl)-2,3,4,4a,5,6-hexahydro-1H-pyrazino [2,1-d][1,5]benzoxazepine;

(4aS)-9-(2-methoxyphenyl)-2,3,4,4a,5,6-hexahydro-1H-pyrazino [2,1-d][1,5]benzoxazepine;

(4aS)-9-(3-methoxyphenyl)-2,3,4,4a,5,6-hexahydro-1H-pyrazino [2,1-d][1,5]benzoxazepine;

(4aS)-9-(4-methoxyphenyl)-2,3,4,4a,5,6-hexahydro-1H-pyrazino [2,1-d][1,5]benzoxazepine;

(4aS)-9-[2-(methylsulfonyl)phenyl]-2,3,4,4a,5,6-hexahydro-1H-pyrazino [2,1-d][1,5]benzoxazepine;

(4aS)-9-[3-(methylsulfonyl)phenyl]-2,3,4,4a,5,6-hexahydro-1H-pyrazino [2,1-d][1,5]benzoxazepine;

1-{2-[(4aS)-2,3,4,4a,5,6-hexahydro-1H-pyrazino [2,1-d][1,5]benzoxazepin-9-yl]phenyl}ethanone;

1-{3-[(4aS)-2,3,4,4a,5,6-hexahydro-1H-pyrazino [2,1-d][1,5]benzoxazepin-9-yl]phenyl}ethanone;

1-{4-[(4aS)-2,3,4,4a,5,6-hexahydro-1H-pyrazino [2,1-d][1,5]benzoxazepin-9-yl]phenyl}ethanone;

2-[(4aS)-2,3,4,4a,5,6-hexahydro-1H-pyrazino[2,1-d][1,5]benzoxazepin-9-yl]phenol;

3-[(4aS)-2,3,4,4a,5,6-hexahydro-1H-pyrazino[2,1-d][1,5]benzoxazepin-9-yl]phenol;

4-[(4aS)-2,3,4,4a,5,6-hexahydro-1H-pyrazino[2,1-d][1,5]benzoxazepin-9-yl]phenol;

(4aS)-9-(2-fluorophenyl)-2,3,4,4a,5,6-hexahydro-1H-pyrazino [2,1-d][1,5]benzoxazepine;

(4aS)-9-(3-fluorophenyl)-2,3,4,4a,5,6-hexahydro-1H-pyrazino [2,1-d][1,5]benzoxazepine;

(4aS)-9-(4-fluorophenyl)-2,3,4,4a,5,6-hexahydro-1H-pyrazino [2,1-d][1,5]benzoxazepine;

(4aS)-9-(pyridin-3-yl)-2,3,4,4a,5,6-hexahydro-1H-pyrazino [2,1-d][1,5]benzoxazepine; and

(4aS)-9-(pyridin-4-yl)-2,3,4,4a,5,6-hexahydro-1H-pyrazino [2,1-d][1,5]benzoxazepine.

5. A method for treating conditions, disorders or deficits modulated by a 5-HT 2C receptor, a 5-HT 6 receptor or both 5-HT 2C and 5-HT 6 receptors wherein the condition, disorder or deficit is selected from the group consisting of a cognitive dysfunction, attention deficit/hyperactivity syndrome, personality disorders, affective disorders, motion or motor disorders, migraine, feeding disorders, gastrointestinal disorders, obesity, diabetes, psoriasis, or ocular hypertension comprising administration of a therapeutically effective amount of the compound of claim 1 , or a pharmaceutically acceptable salt thereof.

6. A method for treating a disorder or condition modulated by the 5-HT 2c , receptor selected from the group consisting of bipolar disorder, depression, anxiety, schizophrenia, cognitive deficits of schizophrenia, obsessive compulsive disorder, migraine, epilepsy, eating disorders, obesity, diabetes, sexual dysfunction/erectile dysfunction, psoriasis, pain and spinal cord injury, pain, bladder dysfunction/urinary incontinence, smoking cessation, ocular hypertension and said method comprising the step of administering to a subject in need thereof the compound of claim 1 , or a pharmaceutically acceptable salt, thereof.

7. The method according to claim 6 wherein the disorder modulated by the 5-HT 2c receptor is schizophrenia or cognitive deficits of schizophrenia, said method comprising the step of administering to a subject in need thereof the compound of claim 1 , or a pharmaceutically acceptable salt, thereof.

8. A method for treating a disorder modulated by the 5-HT 6 receptor selected form the group consisting of deficits in memory and cognition and learning, age-related cognitive decline, mild cognitive impairment, attention deficit/hyperactivity syndrome, schizophrenia, cognitive deficits of schizophrenia, depression, anxiety, obsessive compulsive disorders, epilepsy, migraine, anorexia, bulimia, irritable bowel syndrome, stroke, spinal or head trauma and head injuries, and obesity, said method comprising the step of administering to a subject in need thereof the compound of claim 1 , or a pharmaceutically acceptable salt thereof.

9. A pharmaceutical composition comprising a therapeutically effective amount of the compound of claim 1 , or a pharmaceutically acceptable salt thereof, in combination with one or more pharmaceutically acceptable carriers.