1-Naphthols, 1,4-dihydro- from derivs

Pyrolysis of the Mannich base (109) derived from 2-naphthol leads to generation of a quinone methide which when trapped with an aromatic amine leads to benz[a]acridines (0. Bilgic and D.W. Young, J. chem. Soc. Perkin I, 1980, 1233). Thus, aniline yields the parent compound together with 7,12-dihydrobenz[a]acridine. Formation of the dihydro compound appears to be variable for whereas /7-metlylaniline and o-anisidine yield only... 

These include the SSA-catalyzed synthesis of heterocyclic compounds such as xanthenes, coumarins, oxazoles, and so on. Xanthenes are of great therapeutic and biological interest on account of their many biological activities such as anti-inflanunatory, antiviral, antibacterial properties, and so on. Seyyed Hamzeh et al. (2008) carried out the SSA-catalyzed synthesis of aryl-14 f-dibenzo[fl,y]xanthenes from aldehydes and P-naphthol and 1,8-dioxo-octahydro-xanthenes from aldehydes and 1,3-dicarbonyl componnd such as dimedone under solvent-free conditions (Schemes 5.25, 5.26). Reactions were carried out at 80°C. Nazeruddin et al. (2011) documented an effective method for 9,10-dihydro-12-aryl-8 f-benzo[a]xanthenes-ll(12 f)-one derivatives in excellent yield and short reaction time using SSA under solvent-free conditions (Scheme 5.27). 

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