Preparation of polyfunctional aryl azides from aryl triazenes. A new synthesis of ellipticine, 9-methoxyellipticine, isoellipticine, and 7-carbethoxyisoellipticine.
The preparation of polyfunctional aryl azides by the reaction of aryl triazenes with NaN3 in the presence of KHSO4 or BF3.OEt2/TFA (trifluoroacetic acid) has been described. A variety of functional groups (halides, esters, ketones, nitriles, aldehydes, and boronic esters) are tolerated under the Lewis acidic conditions. By using this methodology, the potent antitumor agents, ellipticine and 9-methoxyellipticine, have been synthesized. In addition, isoellipticine and a related derivative, 7-carbethoxyisoellipticine, were also prepared.
Liu
Ching-Yuan
CY
Department Chemie und Biochemie, Ludwig-Maximilians-Universität München, Butenandtstrasse 5-13, Haus F, 81377 Munich, Germany.
Knochel
Paul
P