Medicine intermediate N - ethylethylenediamine ( NEED ) was synthesized from acrylamide and ethylamine by addition reaction and Hofmann rearrangement. 以丙烯酰胺为起始原料,经乙胺加成后,再经Hofmann重排两步反应后合成了药物中间体N - 乙基乙二胺 ( NEED ).
The old letters brought many recollections to my mind.这些以前的信件使我忆起许多往事.Recollections of past troubles flooded back on me.这个别离,把过去一切的苦楚都压过去了.The sight brought back to his mind a rush of childish recollections.眼前的景色猛地又使他想起童...