Categories: Synthesis of N-Heterocycles >
Synthesis of 3,4-dihydroisoquinolines
Name Reactions
Recent Literature
The direct conversion of various amides to isoquinoline and β-carboline
derivatives via mild electrophilic amide activation, with
trifluoromethanesulfonic anhydride in the presence of 2-chloropyridine followed
by cyclodehydration upon warming provides the desired products with short
overall reaction times.
M. Movassaghi, M. D. Hill, Org. Lett., 2008,
10, 3485-3488.
Elimination of the amide group as the nitrile via retro-Ritter reaction is
avoided in a modified Bischler-Napieralski procedure by its conversion to an
N-acyliminium intermediate with oxalyl chloride-FeCl3. Removal of
the oxalyl group in refluxing MeOH-sulfuric acid provides
3,4-dihydroisoquinolines in good yields.
R. D. Larsen, R. A. Reamer, E. G. Corley, P. Davis, E. J. J. Grabowski, P. J.
Reider, I. Shinkai, J. Org. Chem., 1991,
56, 6034-6038.
