反应详情

NaHB(OAc)3 (0.423 g, 1.996 mmol, 1.4 eq.) was added in three equal portions in 10 minutes to a cloudy solution of compound 19 (1.0 g, 1.43 mmol), N-hydroxyethylpiperazine (0.192 mL, 1.57 mmol, 1.1 eq.) and acetic acid (0.179 mL, 3.14 mmol, 2.2 eq.) in dry chloroform (20 mL) under N2 in an ice bath. The reaction was stirred in ice bath for 30 minutes and at room temperature overnight to give a white suspension. The reaction was worked up as above to give compound 20d as a white foam (0.804 g, 69%).

1. customat room temperature overnight to give a white suspension