Camphor-10-sulfonic acid catalyzed condensation of 2-naphthol with aromatic/aliphatic aldehydes to 14-aryl/alkyl-14H-dibenzo[a,j]xanthenes
作者:Kshama Kundu、Sandip Nayak
DOI:10.2298/jsc130805021k
日期:——
(±)-Camphor-10-sulfonic acid (CSA) catalyzed condensation of 2-naphthol with both aliphatic/aromatic aldehydes at 80°C yielded 14-alkyl/aryl-dibenzoxanthenes as the sole product in high yields. However, the same condensation with benzaldehyde at 25°C afforded a mixture of intermediate 1,1-bis-(2-hydroxynaphthyl)phenylmethane and 14-phenyl-dibenzoxanthene while the condensation with aliphaticaldehydes at 25°C furnished
Libraries of benzoxanthenes, as well as of benzochromenes, were efficiently synthesized via one-pot, three-componentreactions of 2-naphthol, aldehydes, and cyclic 1,3-diketones/malononitrile/ethyl cyanoacetate in the presence of catalytic amount of ceric ammonium nitrate (CAN) under solvent free conditions. The protocol offers rapid synthesis of structurally diverse benzoxanthenes and benzochromenes
Perchloric Acid–Silica (HClO4⋅SiO2)-Catalyzed Synthesis of 14-Alkyl- or 14-Aryl-14H-dibenzo[a,j]xanthenes andN-[(2-Hydroxynaphthalen-1-yl)methyl]amides
The synthesis of 14-aryl- or 14-alkyl-14H-dibenzo[a,j]xanthenes 3 involving the treatment of naphthalen-2-ol (1) with arenecarboxaldehydes or alkanals 2 in the presence of HClO4⋅SiO2 as a heterogeneous catalyst was achieved (Table 1), and this reaction was extended to the preparation of N-[(2-hydroxynaphthalen-1-yl)methyl]amides 5 by a three-component reaction with urea (4a) or an amide 4b–d as a third
Heterogeneous catalyst: Amberlyst-15 catalyzes the synthesis of 14-substituted-14H-dibenzo[a,j]xanthenes under solvent-free conditions
作者:Shengkai Ko、Ching-Fa Yao
DOI:10.1016/j.tetlet.2006.10.072
日期:2006.12
A one-pot condensation of β-naphthol with aldehydes in the presence of Amberlyst-15 to give 14-substituted-14H-dibenzo[a,j]xanthenesundersolvent-free condition is described.