The synthesis of 2,7-substituted octahydro-2H-pyrido[1,2-a]pyrazines, analogues of quinolizidine and piperazine drugs

Article abstract of DOI:10.1016/S0040-4020(01)80853-X

The versatility of amino ketone 2 (2-benzyloctahydro 2H pyrido[ 1,2- a]pyrazin-7-one) was demonstrated by the synthesis of 2,7-substituted derivatives, designed as analogues of both quinolizidine and piperazine drugs. The 7- ketone group was functionalized via Grignard reaction with o- and p-fluorophenylmagnesium bromide, followed by dehydration and hydrogenation. Final substitution of the 2-amino group afforded the 2- pyridyl and p-fluorobenzoyl target compounds 10 and 11.