CaSR antagonist

1. A compound represented by the following formula (1″):

wherein

R 1′ is a hydroxyl group or a C 1-6 alkoxy group,

R 2′ is a hydroxyl group, a halogen atom, an amino group, a C 1-7 acylamino group, a halo C 1-6 alkyl group, a C 1-6 alkoxy-carbonyl group, a C 1-6 alkoxy group, a halo C 1-6 alkoxy group, a C 1-6 alkyl group, a hydroxy-C 1-6 alkyl group, a di(C 1-6 alkyl)amino group or a nitro group,

R 4′ is a C 1-6 alkyl group or a C 3-6 cycloalkyl group,

R 6′ is a halogen atom, a C 1-6 alkyl group, a C 1-6 alkoxy group or a halo C 1-6 alkyl group, or when R 7′ is adjacent, R 6′ and R 7′ are linked to form —CH═CH—CH═CH—, and

R 7′ is a hydrogen atom, a halogen atom, a C 1-6 alkyl group, a C 1-6 alkoxy group or a halo C 1-6 alkyl group,

an optically active form thereof, a pharmaceutically acceptable salt thereof, or an optically active form of the salt thereof.

2. A compound represented by the following formula (1′ ″ ):

wherein

R 2″ is a C 1-6 alkyl group,

R 4″ is a methyl group or a cyclopropyl group,

R 6″ is a halogen atom or a C 1-6 alkyl group, and

R 7″ is a hydrogen atom, a halogen atom, a C 1-6 alkyl group, a C 1-6 alkoxy group or a halo C 1-6 alkyl group,

an optically active form thereof, a pharmaceutically acceptable salt thereof, or an optically active form of the salt thereof.

3. The compound of claim 1 or 2 , which is selected from the group consisting of

2′-[1-[(2R)-3-[[1-(3-fluoro-4-methylphenyl)-2-methylpropan-2-yl]amino]-2-hydroxypropoxy]ethyl]-3-methylbiphenyl-4-carboxylic acid,

2′-[1-[(2R)-3-[[1-(4-chloro-3-fluorophenyl)-2-methylpropan-2-yl]amino]-2-hydroxypropoxy]ethyl]-3-methylbiphenyl-4-carboxylic acid,

2′-[1-[(2R)-3-[[1-(3-chloro-4-methylphenyl)-2-methylpropan-2-yl]amino]-2-hydroxypropoxy]ethyl]-3-methylbiphenyl-4-carboxylic acid,

2′-[1-[(2R)-3-[[1-(4-chloro-3-methylphenyl)-2-methylpropan-2-yl]amino]-2-hydroxypropoxy]ethyl]-3-methylbiphenyl-4-carboxylic acid,

2′-[1-[(2R)-3-[[1-(4-chloro-2-fluorophenyl)-2-methylpropan-2-yl]amino]-2-hydroxypropoxy]ethyl]-3-methylbiphenyl-4-carboxylic acid,

2′-[1-[(2R)-3-[[1-(2-fluoro-4-methylphenyl)-2-methylpropan-2-yl]amino]-2-hydroxypropoxy]ethyl]-3-methylbiphenyl-4-carboxylic acid,

2′-[1-[(2R)-3-[[1-(4-ethyl-3-fluorophenyl)-2-methylpropan-2-yl]amino]-2-hydroxypropoxy]ethyl]-3-methylbiphenyl-4-carboxylic acid,

2′-[1-[(2R)-3-[[1-(3-fluoro-4-methylphenyl)-2-methylpropan-2-yl]amino]-2-hydroxypropoxy]ethyl]-3-methylbiphenyl-4-carboxylic acid,

2′-[1-[(2R)-3-[[1-(3-fluoro-4-methylphenyl)-2-methylpropan-2-yl]amino]-2-hydroxypropoxy]ethyl]-3-methylbiphenyl-5-carboxylic acid,

2′-[(cyclopropyl)[(2R)-3-[[1-(4-chloro-2-fluorophenyl)-2-methylpropan-2-yl]amino]-2-hydroxypropoxy]methyl]-3-methylbiphenyl-4-carboxylic acid,

2′-[(cyclopropyl)[(2R)-3-[[1-(4-chloro-3-fluorophenyl)-2-methylpropan-2-yl]amino]-2-hydroxypropoxy]methyl]-3-methylbiphenyl-4-carboxylic acid,

3-methyl-2′-[1-[(2R)-3-[[1-(3,4-dimethylphenyl)-2-methylpropan-2-yl]amino]-2-hydroxypropoxy]ethyl]biphenyl-4-carboxylic acid,

2′-[1-[(2R)-3-[[1-(4-methylphenyl)-2-methylpropan-2-yl]amino]-2-hydroxypropoxy]ethyl]-3-methylbiphenyl-4-carboxylic acid,

2′-[1-[(2R)-3-[[1-(4-chloro-3-methoxyphenyl)-2-methylpropan-2-yl]amino]-2-hydroxypropoxy]ethyl]-3-methylbiphenyl-4-carboxylic acid,

2′-[1-[(2R)-3-[[1-(4-ethylphenyl)-2-methylpropan-2-yl]amino]-2-hydroxypropoxy]ethyl]-3-methylbiphenyl-4-carboxylic acid,

3-ethyl-2′-[1-[(2R)-3-[[1-(3-fluoro-4-methylphenyl)-2-methylpropan-2-yl]amino]-2-hydroxypropoxy]ethyl]biphenyl-4-carboxylic acid,

2′-[1-[(2R)-3-[[1-(3-fluoro-4-methylphenyl)-2-methylpropan-2-yl]amino]-2-hydroxypropoxy]ethyl]-3-isopropylbiphenyl-4-carboxylic acid,

2′-[1-[(2R)-3-[[1-(3-fluoro-4-methylphenyl)-2-methylpropan-2-yl]amino]-2-hydroxypropoxy]ethyl]-3-propylbiphenyl-4-carboxylic acid,

2′-[1-[(2R)-3-[[1-(3-fluoro-4-methylphenyl)-2-methylpropan-2-yl]amino]-2-hydroxypropoxy]ethyl]-3-isobutylbiphenyl-4-carboxylic acid,

3-ethyl-2′-[1-[(2R)-3-[[1-(4-chloro-3-fluorophenyl)-2-methylpropan-2-yl]amino]-2-hydroxypropoxy]ethyl]biphenyl-4-carboxylic acid,

2′-[1-[(2R)-3-[[1-(4-chloro-3-fluorophenyl)-2-methylpropan-2-yl]amino]-2-hydroxypropoxy]ethyl]-3-isopropylbiphenyl-4-carboxylic acid,

2′-[1-[(2R)-3-[[1-(3-fluoro-4-methylphenyl)-2-methylpropan-2-yl]amino]-2-hydroxypropoxy]ethyl]-3-(1-methylpropyl)biphenyl-4-carboxylic acid,

2′-[1-[(2R)-3-[[1-(3-chlorophenyl)-2-methylpropan-2-yl]amino]-2-hydroxypropoxy]ethyl]-3-methylbiphenyl-4-carboxylic acid,

2′-[1-[(2R)-3-[[1-(3,4-dichlorophenyl)-2-methylpropan-2-yl]amino]-2-hydroxypropoxy]ethyl]-3-methylbiphenyl-4-carboxylic acid,

2′-[1-[(2R)-3-[[1-(3-methoxy-4-methylphenyl)-2-methylpropan-2-yl]amino]-2-hydroxypropoxy]ethyl]-3-methylbiphenyl-4-carboxylic acid,

2′-[1-[(2R)-3-[[1-(3,5-dichlorophenyl)-2-methylpropan-2-yl]amino]-2-hydroxypropoxy]ethyl]-3-methylbiphenyl-4-carboxylic acid,

2′-[1-[(2R)-3-[[1-(4-chloro-3-trifluoromethylphenyl)-2-methylpropan-2-yl]amino]-2-hydroxypropoxy]ethyl]-3-methylbiphenyl-4-carboxylic acid,

2′-[1-[(2R)-3-[[1-(3-fluoro-4-methylphenyl)-2-methylpropan-2-yl]amino]-2-hydroxypropoxy]ethyl]-3-t-butylbiphenyl-4-carboxylic acid,

2′-[1-[(2R)-3-[[1-(4-chloro-2-fluorophenyl)-2-methylpropan-2-yl]amino]-2-hydroxypropoxy]ethyl]-3-t-butylbiphenyl-4-carboxylic acid,

2′-[1-[(2R)-3-[[1-(4-chloro-3-fluorophenyl)-2-methylpropan-2-yl]amino]-2-hydroxypropoxy]ethyl]-3-t-butylbiphenyl-4-carboxylic acid and

2′-[1-[(2R)-3-[[1-(3-trifluoromethyl-4-methylphenyl)-2-methylpropan-2-yl]amino]-2-hydroxypropoxy]ethyl]-3-methylbiphenyl-4-carboxylic acid

an optically active form thereof, a pharmaceutically acceptable salt thereof or an optically active form of the salt thereof.

4. 2′-[1-[(2R)-3-[[1-(3-Fluoro-4-methylphenyl)-2-methylpropan-2-yl]amino]-2-hydroxypropoxy]ethyl]-3-methylbiphenyl-4-carboxylic acid, an optically active form thereof, a pharmaceutically acceptable salt thereof or an optically active form of the salt thereof.

5. 2′-[1-[(2R)-3-[[1-(4-Chloro-3-fluorophenyl)-2-methylpropan-2-yl]amino]-2-hydroxypropoxy]ethyl]-3-methylbiphenyl-4-carboxylic acid, an optically active form thereof, a pharmaceutically acceptable salt thereof or an optically active form of the salt thereof.

6. 2′-[1-[(2R)-3-[[1-(3-Chloro-4-methylphenyl)-2-methylpropan-2-yl]amino]-2-hydroxypropoxy]ethyl]-3-methylbiphenyl-4-carboxylic acid, an optically active form thereof, a pharmaceutically acceptable salt thereof or an optically active form of the salt thereof.

7. 2′-[1-[(2R)-3-[[1-(4-Chloro-2-fluorophenyl)-2-methylpropan-2-yl]amino]-2-hydroxypropoxy]ethyl]-3-methylbiphenyl-4-carboxylic acid, an optically active form thereof, a pharmaceutically acceptable salt thereof or an optically active form of the salt thereof.

8. A pharmaceutical composition comprising a pharmaceutically acceptable carrier, and a compound of any of claims 1 - 2 or 4 - 7 , an optically active form thereof, a pharmaceutically acceptable salt thereof or an optically active form of the salt thereof as an active ingredient.

9. A method for treating osteoporosis, which comprises administering an effective amount of a composition comprising a pharmaceutically acceptable carrier, and a compound of any one of claims 1 - 2 and 4 - 7 , an optically active form thereof, a pharmaceutically acceptable salt thereof or an optically active form of the salt thereof, as an active ingredient.

10. The method of claim 9 , further comprising concomitant administration of said composition with a different therapeutic drug for osteoporosis.

11. The method of claim 10 , wherein the different therapeutic drug for osteoporosis is selected from the group consisting of a calcium agent, a vitamin D preparation, a vitamin K preparation, a female hormone preparation, an estrogen antagonist preparation, an anabolic steroid preparation, a parathyroid hormone preparation, a calcitonin preparation, a bisphosphonate preparation and an ipriflavone preparation.

12. A calcium receptor antagonist comprising a pharmaceutically acceptable carrier, and a compound of any one of claims 1 - 2 and 4 - 7 , an optically active form thereof, a pharmaceutically acceptable salt thereof or an optically active form of the salt thereof as an active ingredient.

13. A PTH secretagogue comprising a pharmaceutical acceptable carrier and a compound of any one of claims 1 - 2 and 4 - 7 , an optically active form thereof, a pharmaceutically acceptable salt thereof or an optically active form of the salt thereof as an active ingredient.