76143-79-8Relevant articles and documents
A ONE-POT ISOQUINOLINE SYNTHESIS BY CYCLODEHYDROGENATION OF BENZYLAMINOACETALS WITH CHLOROSULFONIC ACID
Kido, Kazuko,Watanabe, Yasuo
, p. 1151 - 1154 (2007/10/02)
A direct preparation of the fully aromatized isoquinolines (3a-l) by the cyclodehydrogenation of benzylamnoacetals (2a-l) with chlorosulfonic acid is described.Comparing the behavior of chlorosulfonic acid with that of sulfuric acid toward 1,2-dihydroisoquinoline, it is able to be suggested that benzylaminoacetals were cyclized first to 1,2-dihydroisoquinolines, subsequently, dehydrogenated to the fully aromatized isoquinolines by the hydride abstraction with ClSO3H.Subtitution by a larger R3 group than isopropyl in the acetal ArCH(R3)NHCH2CH(OEt)2, interfered this second step, so the corresponding isoquinolines could not be obtained.