The Synthesis of 9,10‐Dihydro‐9,10‐(Methaniminomethano)Anthracene and N‐Protected Derivatives Via Double Reductive Amination

Abstract

An efficient synthesis of 9,10‐dihydro‐9,10‐(methaniminomethano)anthracene and several N‐protected derivatives is described via the double reductive amination of cis‐9,10‐dihydro‐9,10‐dicarboxaldehyde.

Keywords:

• Anthracene
• Bicyclic amine
• Double reductive amination
• Heterocycle

Acknowledgments

We thank Bristol‐Myers Squibb for a fellowship for P. Stoy, the National Science Foundation for a REU undergraduate fellowship (CHE 0097585) for J. Rush, and the National Institutes of Health for funding (GM 52491).

Notes

^aProcedure for deactivating silica gel: Silica gel (60 Å) was dispersed in a 4:1 mixture of hexanes and hexamethyldisilazane (HMDS) and the resulting slurry added to a chromatography column. The column was washed thoroughly with 4:1 hexanes/ethyl acetate, then again washed thoroughly with hexanes prior to loading the sample onto the column.

^bThe ¹H NMR spectra for compounds 6 and 7 in CDCl₃ have recently been reported (see Refs. 9 and 25), but without ¹H‐¹H coupling constants or mention of the spectrometer field strength.