Synthesis of 2-(9,10-Dihydro-9,10-propanoanthracen-9-yl)-N-methylethanamine via a [4+2] Cycloaddition

The synthesis of the tetracyclic molecule 2-(9,10-dihydro-9,10-propano-anthracen-9-yl)-N-methylethanamine(2)as a homologue of the antidepressant 1-(9,10-dihydro-9,10-ethanoanthracen-9-yl)-N-methylmethaneamine (1) was described. The key intermediate 9-(prop-2-en-1-yl)-9,10-dihydro-9,10-propanoanthracen-12-one (7)was successfully synthesized via a [4+2] cycloaddition of α-bromoacrolein and 9-allyl-anthracene, followed by ring expansion and samarium diiodide deoxygenation.