132813-14-0

2-Chloro-4-(4-fluorophenyl)-5,6,7,8,9,10-hexahydrocycloocta[b]pyridine is an intermediate in the synthesis of Blonanserin (B595850), a 5-HT2 serotonin receptor and D2 dopamine receptor antagonist, used as an antipsychotic.

General procedure for the synthesis of 2-chloro-4-(4-fluorophenyl)-5,6,7,8,9,10-hexahydrocycloocta[b]pyridine from 4-(4-fluorophenyl)-5,6,7,8,9,10-hexahydrocycloocta[b]pyridine as 4-(4-fluorophenyl)-5,6,7,8,9,10-hexahydrocycloocta[b]pyridine: 80.0 g of 4-(4-fluorophenyl)-5,6,7,8,9,10-hexahydrocycloocta[b] Pyridin-2(1H)-one was dissolved in 520 mL of dimethylformamide and cooled to 5 °C. Under stirring, 36.84 g of phosphorus pentachloride was added in 10 portions. After addition, the temperature of the reaction system was raised to 15 °C and the reaction was continued for 3 hours. Upon completion of the reaction, 520 mL of purified water was added to the reaction mixture and stirred at 10 °C for 1 hour. The reaction solution was filtered using a Brinell funnel (Coors), the precipitated crystals were collected and the filter cake was washed with 300 mL of purified water. The resulting crystals were dried at 70 °C to afford 80.0 g of off-white 2-chloro-4-(4-fluorophenyl)-5,6,7,8,9,10-hexahydrocycloocta[b]pyridine in 93.6% yield.

[1] Bioorganic and Medicinal Chemistry Letters, 2005, vol. 15, # 4, p. 1055 - 1059
[2] Patent: KR2015/117123, 2015, A. Location in patent: Paragraph 0046; 0047; 0048
[3] Patent: , 2016, . Location in patent: Paragraph 0026; 0027; 0028; 0029
[4] Asian Journal of Chemistry, 2014, vol. 26, # 18, p. 5928 - 5930
[5] Patent: JP2018/43989, 2018, A. Location in patent: Paragraph 0136-0138