54879-78-6Relevant academic research and scientific papers
Synthesis of 1,2-Dihydroisoquinolines by a Modified Pomeranz-Fritsch Cyclization
Ji, Xiang,Huang, Zheng,Lumb, Jean-Philip
, p. 1062 - 1072 (2020/01/31)
Isoquinolines (IQs) and their derivatives are present in many natural products and biologically active small molecules. Herein, we report a modified procedure for the classical Pomeranz-Fritsch protocol, which expands the scope of 1,2-dihydroisoquinoline (DHIQ) products. 1,2-DHIQs are an attractive branch point for the synthesis of IQs, but because of their innate reactivity, they have remained difficult to prepare. We demonstrate that the Fujioka/Kita conditions, combining trimethylsiyltriflate (TMSOTf) and an amine base, activate dimethylacetals required for Pomeranz-Fritsch cyclization under sufficiently mild conditions to prepare a broad range of 1,2-DHIQ products. We also demonstrate the synthetic value of these DHIQs by further functionalization to either reduced tetrahydroisoquinoline (THIQ) or fully aromatized IQ natural products.
Gastric-mucous membrane protection activity of coptisine derivatives
Hirano,Osawa,Yamaoka,Yokoi
, p. 1277 - 1281 (2007/10/03)
Coptisine and 8-oxocoptisine were isolated as principles of the gastric-mucous membrane protection from Coptidis rhizoma. The two compounds showed stronger activity than cimetidine and sucralfate. We prepared several derivatives having a partial structure of coptisine from commercially available starting materials. The compounds obtained were tested for gastric-mucous membrane protective activity and a correlation between activity and structure was studied. Our results suggest that the partial charge of the catechol skeleton is related to activity.
Preparation of N-benzylsulfonamido-1,2-dihydroisoquinolines and their reaction with Raney nickel. A mild, new synthesis of isoquinolines
Larghi, Enrique L.,Kaufman, Teodoro S.
, p. 3159 - 3162 (2007/10/03)
N-benzylsulfonamido-1,2-dihydroisoquinolines react with Raney nickel to provide isoquinotines in excellent yields and under mild, neutral conditions.
