Benzo-fused heterocycles and carbocycles by intramolecular SNAr and tandem SN2-SNAr reactions

Abstract

(Chemical Equation Presented) Benzo-fused heterocyclic and carbocyclic systems have been synthesized by intramolecular SNAr and tandem SN2-SNAr reactions. Treatment of 3-(2-fluoro-5- nitrophenyl)-1-propanol with sodium hydride in N,N-dimethylformamide gave 6-nitrochroman in 80% yield by an intramolecular SNAr reaction. Treatment of 2-(3-bromopropyl)-1-fluoro-4-nitrobenzene with benzylamine in N,N-dimethylformamide gave 1-benzyl-6-nitrotetrahydroquinoline in 98% yield by a tandem SN2-SNAr reaction. Finally, in a similar process, reaction of this same bromide with dimethyl malonate under basic conditions gave 1,1-bis(methoxycarbonyl)-6-nitro-1,2,3,4-tetrahydronaphthalene in 80% yield. Further studies exploring ring size effects are also presented.