167145-13-3

Colorless or light red oily liquid

2-[2-(3-Methoxyphenyl)ethyl]phenol is an intermediate used to prepare sarpogrelate (S142300, HCl salt) analogues. Sarpogrelate hydrochloride is a potent and selective 5-HT2A receptor antagonist. It is also an antiplatelet agent.

(1) Check the cooling system and vacuum system of the autoclave reactor to ensure that the equipment is intact. Perform a 0.3 MPa nitrogen pressure test for 1 hour, requiring a pressure drop of less than 0.05 MPa; (2) After confirming the normal state of the autoclave, add 400 g of industrial ethanol and 36 g (0.114 mol) 1-(benzyloxy)-2-(3-methoxystyryl)benzene. Stirring was initiated and 5 g (0.0035 mol) of palladium carbon catalyst was added. Open the hydrogen cylinder valve, control the pipeline pressure below 0.3 MPa, replace the nitrogen with hydrogen and repeat the process three times; (3) Increase the hydrogen pressure in the autoclave to 0.3 MPa and close the hydrogen valve. Start stirring and heating (oil or water bath), when the reaction temperature reaches about 30 °C, a pressure drop is observed, indicating the start of the hydrogenation reaction; (4) Maintain the reaction temperature at about 30 °C and the hydrogen pressure in the range of 0.1-0.3 MPa. Record the pressure and reaction temperature and time before and after each hydrogen charging; (5) After the reaction was carried out for 2 hours, the pressure drop slowed down and the reaction basically stopped. Maintaining 0.3 MPa hydrogen pressure and 30°C reaction conditions for 1 hour, the reaction was considered complete if the pressure drop was less than 0.01 MPa. At the end of the reaction, the reaction mixture was filtered (using a Brinell funnel and rapid characterization filter paper) to remove the palladium-carbon catalyst. The ethanol was concentrated at atmospheric pressure until about 90 mL remained. 26 g of an off-white solid was obtained after natural cooling, with an HPLC purity of 97.79%, a melting point of 50.2-52.4 °C, and a yield of 98.4%.

[1] Patent: CN107324979, 2017, A. Location in patent: Paragraph 0040; 0077; 0090-0096
[2] Chinese Chemical Letters, 2010, vol. 21, # 3, p. 287 - 289
[3] Patent: CN105906486, 2016, A. Location in patent: Paragraph 0008; 0013