Process for the preparation of 9-formyl-9,10-dihydro-9,10-methanoanthracene

摘要

9-Formyl-9,10-dihydro-9,10-methanoanthracene of the formula is prepared from 9-amino-12-hydroxy-9,10-dihydro-9,10-ethanoanthracene of the formula by treatment with nitrous acid or with a metal nitrite in an acidic medium. As an intermediate, the compound is of prime importance in the synthesis of therapeutically valuable 9-aminoalkyl derivatives of 9,10-dihydro-9,10-methanoanthracene. The starting material A is prepared from a 9-carboxy-12-(hydroxy or R'O)-9,10-dihydro-9,10-ethanoanthracene, where R' denotes a protective group, by Curtius or Hoffmann degradation and, in the case of R'O, hydrolytic elimination of the protective group.