Synthesis of Aminoisoquinolines and Related Compounds. X. A Modified Synthesis of dl-Cularine

Abstract

The Bischler-Napieralski reaction of the phenethylamides (VIIa and VIIb) gave respectively the 6-ethoxycarbamido-3, 4-dihydroisoquinolines, formed by the cyclization at the position para to the ethoxycarbamido group, and both 3, 4-dihydroisoquinolines were converted to the 6-aminoisoquinolines (Xa and Xb). Each 7, 8-disubstituted isoquinolines (XIIa and XIIb), prepared by deamination reaction of Xa and Xb, were submitted to the Ullmann reaction to give respectively 6-methoxy-1-methyl-1, 2, 3, 12, 12a-pentahydrobenzoxepino [2, 3, 4-i, j] isoquinoline (XIII) and dl-cularine (Ia).