Abstract
Some interesting observations have been observed in the synthetic studies of chrysen-6-ol and benzo[c]phenanthren-5-ol derivatives by intramolecular cyclization of (2-phenylnaphthalen-1-yl)acetic acid derivatives (4) and (1-phenylnaphthalen-2-yl)acetic acid derivatives (13) with PPA or trifluoroacetic acid (TFA) - trifluoroacetic anhydride (TFAA) mixture. Though chrysen-6-ol derivatives were obtained in very good yields (usual observation) under identical condition attempted cyclization of (1-phenylnaphthalen-2-yl)-acetic acid derivatives (13) produced no benzo[c]phenanthrene-5-ol derivatives (17). On the contrary dimeric intermolecular condensation product (18) (unusual observation) was formed in general in very good to excellent yields. The required precursors (4) were obtained from (2-bromonaphthalen-1-yl)acetonitrile derivative and suitable phenyl boronic acid in two steps although the precursors (13) were prepared from suitable 1-bromo-2-naphthyladehyde and phenyl boronic acid derivatives in six steps.
Acknowledgments
Financial help from CSIR and DST acknowledged gratefully. We are thankful to CSIR for providing NET fellowship to one of the authors (KS).