Blonanserin

Description

Blonanserin, a dual antagonist of dopamine D2 and serotonin 5-HT2 receptors, was launched past year in Japan for the oral treatment of psychosis and schizophrenia. It is the latest entry in the class of atypical antipsychotic agents to reach the market. Blonanserin exhibits high affinity for D2 and 5-HT2 receptors (IC50 23.6 and 9.85 nM, respectively). Its affinity for D2 receptors is very close to that of haloperidol and risperidone, whereas the affinity for 5-HT2 receptors is about 7 times higher than that of haloperidol and 10 times lower than that of risperidone.Blonanserin is chemically derived in three steps starting with a polyphosphoric acid mediated condensation reaction of cyclooctanone with 4-fluorobenzoylacetonitrile. The resultant 4-fluorophenylcycloocta[b]pyridin-2-one intermediate is converted to the corresponding 2-chloro derivative by treatment with phosphoryl chloride and subsequently condensed with 1-ethylpiperazine to afford blonanserin.

Chemical properties

Pale Yellow Solid

Originator

Sumitomo (Japan)

The Uses of Blonanserin

Blonanserin is a novel atypical antipsychotic agent with potent dopamine D2 (Ki, 14.8 nM) and serotonin 5-HT2(Ki, 3.98 nM) receptors antagonist properties.

The Uses of Blonanserin

A 5-HT2 Serotonin receptor and D2 Dopamine receptor antagonist, used as an antipsychotic.

Definition

ChEBI: Blonanserin is an organic molecular entity.

Manufacturing Process

Preparation of 2-(4-ethyl-1-piperazinyl)-4-(4-fluorophenyl)-5,6,7,8,9,10- hexahydrocyclooc ta[b]pyridine:
A mixture of 2-chloro-4-(4-fluorophenyl)-5,6,7,8,9,10-hexahydrocycloocta [b]pyridine (2.0 g), N-ethylpiperazine (2.4 g), and potassium iodide (1.1 g) is stirred at 170°C for 5 hours. After cooling, the reaction mixture is dissolved in ethyl acetate and water. The organic layer is washed with water and extracted with 5% hydrochloric acid. The extract is made alkaline with potassium carbonate, and extracted with ethyl acetate. The extract is washed with water, dried over anhydrous sodium sulfate, and concentrated under reduced pressure.
(a) The residue is recrystallized from acetonitrile to give the desired product (1.2 g), MP: 123°-124°C.
This product obtained in the above (a) is converted to the following salt thereof by treating the product with various acids.

brand name

Lonasen

Therapeutic Function

Antipsychotic

Synthesis

The synthesis of blonanserin III has been described in both the primary and patent literature in the following scheme. Condensation of cyclooctanone (21) with 4-fluorobenzoyl acetonitrile (20) in 75% polyphosphoric acid at 110 ??C provided the fused cyclooctapyridone 22 in 64% yield. Reaction of 22 with phenyldichlorophosphinic acid (23) at 170 ??C gave chloride 24 in 76% yield, which was then reacted with potassium idodide and 4-ethyl piperidine (25) at 170 ??C to give blonanserin (III) in 47% yield after crystallization from acetonitrile.