Synthesis of Vertilecanin C and Two New Derivatives of Vertilecanin A via Nicotinic Acid

Vertilecan in C and 2 new phenyl-su bstituted derivatives of vertilecanin A were synthesized. Lithiat ion of 5-benzoylpicolinamide with BuLi at - 78 °C followed by treatment with methyl brorn oacetate gave vertilec anin C [methyl 2-(3-benzoylpicolinamido)acetate] a natural product. Vertilecanin A type ph enopicolinic acid de rivati ves were synt hesized sta r t ing from nicotinic acid in 4 steps. Chlor ina t ion of nico t inic acid with 80Cb followed by treatment with ani sole in the presence of AICb gave (4-met hoxy phenyl)( pyridin-3-y l)met ha none. The Minisci reac tion of th e keto ne afforded 5-( 4methoxybenzoyl )pi colinamide. Ti Cla-catalyzed acid ic hyd rolysis of th e picolinamide gave 5-( 4-met hoxybenzoyl) picolinic acid, from which 5-(hydroxy(4-methoxyphenyl )methyl)p icolin ic acid was obtained by select ive reducti on wit h NaBH4 . The same reaction sequence performed with toluene inst ead of anisole afforded 5-( hyd roxy( p-- tolyl)met hyl)picolinic acid.