ChemInform Abstract: Fused Azahetareno(1,6)‐ and (1,7)naphthyridines with Nodal Nitrogen Atom.

Abstract

Condensation of the hetaryl substituted acetonitriles (I) with bromo isonicotinoyl chloride (II) yields the enol compounds (III) which cyclize upon heating to the naphthyridines (IV).

Naphthyridines. Structure, physicochemical properties and general methods of synthesis

“…Fused azahetareno-1,7-naphthyridines 154a ± 158a, containing a nitrogen atom in the bridgehead position, were obtained by the reaction of 3-bromoisonicotinic acid chloride 159 with 2-cyanomethyl derivatives of pyridine, 1-methylbenzoimidazole, benzo-1,3-thiazole, quinoline or 4-methyl-1,3-thiazole followed by cyclisation of the resulting C-acylated derivatives on heating to the melting point or on refluxing in N-methyl-2-pyrrolidone (as shown for compound 154a taken as an example). 173 A similar reaction of 2-cyanomethyl derivatives of hetarenes with 4-chloronicotinoyl chloride yielded annelated azahetareno-1,6-naphthyridines 154b ± 158b. 173 In this case, the intermediate C-acylated derivatives were not isolated because they easily cyclised to give 154b ± 158b.…”

“…173 A similar reaction of 2-cyanomethyl derivatives of hetarenes with 4-chloronicotinoyl chloride yielded annelated azahetareno-1,6-naphthyridines 154b ± 158b. 173 In this case, the intermediate C-acylated derivatives were not isolated because they easily cyclised to give 154b ± 158b. 4,6-Dichloronicotinoyl chloride was used as the initial compound in this synthesis.…”

“…174 The product of interaction of 2-cyanomethylbenzo-1,3-thiazole with 2-chloronicotinoyl chloride cyclises on refluxing in DMF to give benzothiazolo[3,2-a]-1,8-naphthyridin-4-one derivative 156c. 173…”