Hydrochloric acid was found to be an effective catalyst for condensation of leucoquinizarin with aromatic mono-and dialdehydes but ineffective with aliphatic aldehydes; o-dialdehydes gave polycyclic compounds. Piperidinium acetate was found to be effective for both aliphatic and aromatic aldehydes. They are presented in relationship to previously reported alkaline dithionite condensations. A mechanism is proposed in which the dehydration step is ...
![9,10-Anthracenedione,2-[[4-(dimethylamino)phenyl]methyl]-1,4-dihydroxy- Structure](https://image.chemsrc.com/caspic/383/25158-10-5.png)
