SYNTHESIS OF INTERMEDIATES USEFUL IN PREPARING BROMO-SUBSTITUTED TRICYCLIC COMPOUNDS

摘要

The invention relates to a process for preparing a compound of formula (I), comprising: (a) reacting 2,5-dibromo-3-methylpyridine with an amine of the formula NHR5R6 to obtain an amide; (b) reacting the amide with a compound of formula (3) in the presence of a strong base to obtain a compound of formula (4); (c) converting a compound of formula (4) to the corresponding cyano compound or aldehyde; (d) reacting the cyano compound or aldehyde with a piperidine derivative to obtain an aldehyde or alcohol of formula (7a) or (7b), respectively; (e) cyclizing a compound of formula (7a) or (7b); wherein R1-R7 are as defined in the specification.