K. Matsumoto et al., MANNICH REACTIONS OF INDOLES WITH DICHLOROMETHANE AND SECONDARY-AMINES UNDER HIGH-PRESSURE, Heterocycles, 36(10), 1993, pp. 2215-2219
Mannich reactions of indole with dichloromethane and secondary amines
gave the corresponding Mannich bases in moderate to good yields, while
2-methylindole afforded only low yields of the Mannich bases. Some li
mitations were observed in the cases of hindered amines and 2-phenylin
dole.