| abstract |
The present invention relates to processes for the synthesis of morphinanes. In particular, a process of coupling a carboxylic acid compound with an amine compound to obtain an amide product that can be isolated or the crude amide product can be cycled to obtain a 3,4-dihydroisoquinoli na. In one embodiment, the carboxylic acid contains a phenol moiety protected with a labile protecting group. Protected phenol reduces reaction times, simplifies the treatment of the product and reduces the amount of cyclising agent, POCl3, that is needed to obtain 3,4-dihydroisoquinoline. |