Synthesis
The general procedure for the synthesis of 3-thiophene ethylamine hydrochloride from 3-thiopheneacetonitrile was as follows: thiophen-3-ylacetonitrile (2.0 g, 16.2 mmol) was dissolved in tetrahydrofuran (36 mL), and borane-dimethyl sulfide complex (3.0 mL, 30.4 mmol) was slowly added. The reaction mixture was heated to reflux for 16 hours. Upon completion of the reaction, methanol was added slowly at room temperature to terminate the reaction. Subsequently, saturated HCl/methanol solution (10 mL) was added and stirred at room temperature for 20 minutes. The reaction solution was concentrated to give the initial solid product. The solid was washed with ether (20 mL) to afford the target compound 3-thiophene ethylamine hydrochloride (Compound 41A) as a white solid (2.5 g, yield: 94%).
References
[1] Patent: CN108250128, 2018, A. Location in patent: Paragraph 0698; 0700; 0701; 0702
[2] Patent: WO2007/146759, 2007, A2. Location in patent: Page/Page column 24
[3] Patent: WO2007/146758, 2007, A2. Location in patent: Page/Page column 33
[4] Journal of Medicinal Chemistry, 2014, vol. 57, # 9, p. 3687 - 3706
[5] Patent: WO2012/114252, 2012, A1. Location in patent: Page/Page column 46
