658 Ethyl 1 , 4 - Dihydro - 4 - oxo - 1 , 8 - n aphthyridine - 3 - carboxylates by a Tandem SNAr - Addition - Elimination Reaction Vol 49
نویسندگان
چکیده
A series of N-substituted 1,4-dihydro-4-oxo-1,8-naphthyridine-3-carboxylate esters has been prepared in two steps from ethyl 2-(2-chloronicotinoyl)acetate. Treatment of the b-ketoester with N,N-dimethylformamide dimethyl acetal in N,N-dimethylformamide (DMF) gave a 95% yield of the 2-dimethylaminomethylene derivative. Subsequent reaction of this b-enaminone with primary amines in DMF at 120C for 24 h then afforded the target compounds in 47–82% yields by a tandem SNAr-addition-elimination reaction. Synthetic and procedural details as well as a mechanistic rationale are presented.
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