From a Pyridine Substrate with Two or More Synthons

FROM A PYRIDINE SUBSTRATE WITH TWO OR MORE SYNTHONS 

Only a few such syntheses have been reported, as illustrated in the following examples. 

4-Piperidinedione with methyl 3-aminocrotonate and p-nitrobenzaldehyde (128) gave methyl 2-methyl-5-oxo-4-p-nitrophenyl-1,4,5,6,7,8-hexahydro-l,6-naphthyridine-3-carboxylate (129) (reactants, MeOH, reflux, 7h 65%) analogs likewise.869 

Dimethyl l,2,6-trimethyl-4-phenylpiperidine-3,5-dicarboxylate (130) with paraformaldehyde and methylamine hydrochloride gave dimethyl 2,6,7-trimethyl-4-phenyl-l,4,4a,5,6,7-hexahydro-l,6-naphthyridine-2,4a-dicarboxylate (131) (reactants, CHC13, reflux, 26 h 30%) 1210 also analogous condensations532,1210 

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From a Pyridine Substrate with Two or More Synthons... 

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