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
Silicasupportedsodiumhydrogensulfate (NaHSO4·SiO2) or amberlyst-15 acts as an efficient heterogeneous catalyst for the preparation of 14-alkyl and aryl-14-H-dibenzo[a,j]xanthenes with various aldehydes and β-naphthol in dichloroethane solvent in excellent yields. Synthesis of three new compounds are reported using this methodology. Recyclable nature of the amberlyst-15catalyst was also studied