196597-86-1

To develop a new therapeutic agent for sleep disorders, we synthesized a novel series of tricyclic indan derivatives and evaluated them for their binding affinity to melatonin receptors. In our previous paper, we proposed a conformation of the methoxy group favorable for the binding of the MT1 receptor. To fix the methoxy group in an active conformation, we decided to synthesize conformationally restricted tricyclic indan analogues with the oxygen atom in the 6-position incorporated into a furan, 1,3-dioxane, oxazole, pyran, morpholine, or 1,4-dioxane ring system. Among these compounds, indeno[5,4-b]furan analogues were found to be the most potent and selective MT1 receptor ligands and to have superior metabolic stability. The optimization of substituents led to (S)-(-)-22b, which showed very strong affinity for human MT1 (Ki = 0.014 nM), but no significant affinity for hamster MT3 (Ki = 2600 nM) or other neurotransmitter receptors. The pharmacological effects of (S)-(-)-22b were studied in experimental animals, and it was found that a dose of 0.1 mg/kg, po promoted a sleep in freely moving cats, as demonstrated by a decrease in wakefulness and increases in slow wave sleep and rapid eye movement sleep, which lasted for 6 h after administration. Melatonin (1 mg/kg, po) also had a sleep-promoting effect, though it lasted only 2 h. A new chiral method for the synthesis of (S)-(-)-22b starting from 60, which was prepared from 59 employing asymmetric hydrogenation with the (S)-2,2′-bis(diphenylphosphino)-1,1′-binaphthyl-Ru complex, was developed. (S)-(-)-22b (TAK-375) is currently under clinical trial for the treatment of insomnia and circadian rhythm disorders.

A compound having the following general fomula: wherein R1 is an optionally substituted hydrocarbon, amino or heterocyclic group; R2 is H or an optionally substituted hydrocarbon group; R3 is H or an optionally substituted hydrocarbon or heterocyclic group; X is CHR4, NR4, O or S in which R4 is H or an optionally substituted hydrocarbon group; R5 is H, a halogen atom, C1-6 alkyl group, a C1-6 alkoxy group, a hydroxy group, a nitro group, a cyano group or an amino group wherein the C1-6 alkyl group, the C1-6 alkoxy group and the amino group may be substituted by 1 to 5 substituents, Y is C or N; ring B is an optionally substituted benzene ring; m = 1 to 4 and n = 0 to 2; L represents a leaving group such as a halogen atom, an alkylsulfonyl group, an alkylsulfonlyoxy group and arylsulfonyloxy group; or a salt thereof.

A compound of the formula: STR1 wherein R1 is an optionally substituted hydrocarbon, amino or heterocyclic group; R2 is H or an optionally substituted hydrocarbon group; R3 is H or an optionally substituted hydrocarbon or heterocyclic group; X is CHR4, NR4, O or S in which R4 is H or an optionally substituted hydrocarbon group; Y is C, CH or N; ring A is optionally substituted 5- to 7-membered ring; ring B is an optionally substituted benzene ring; and m is 1 to 4, or a salt thereof, a process for producing it, an intermediate for the production and a pharmaceutical composition comprising it are provided.