Yield:22302-58-5 91%

Reaction Conditions:

with potassium carbonate in acetone at 0 - 20; for 4 h;

Steps:

5.1.1. General method for preparation of intermediates 9e11 and54-68

General procedure: 15.0 mmol (1 eq) of aniline (or a series of amines), and potassiumcarbonate (30 mmol, 2 eq) was dissolved in 60 mL acetone,and stirred in an ice bath to 0° C. 2-chloropropionyl chloride (2-bromobutyryl bromide or 2-bromoisobutyryl bromide 18.0 mmol,1.2 eq)was slowly added dropwise and stirred at room temperaturefor 4 h. The reaction mixture was quenched with water andextracted with ethyl acetate. The organic layer was washed withwater and brine successively, dried over anhydrous sodium sulfate,and concentrated in vacuum. The resulting residue was purified bysilica gel chromatography (petroleum ether/EtOAc 10/1) to givethe desired intermediates 9-11 and 54-68.

References:

Xiong, Jiaying;Zhuang, Tao;Ma, Yurong;Xu, Junyi;Ye, Jiaqi;Ma, Ru;Zhang, Shuang;Liu, Xin;Liu, Bi-Feng;Hao, Chao;Zhang, Guisen;Chen, Yin [European Journal of Medicinal Chemistry,2021,vol. 226,art. no. 113879]