3- Nitroquinoline, reaction with potassium

Trifluoromethylquinoline-N-oxide under similar conditions gave 4-cyano-3-trifluoromethylquinoline in 48% yield [91], while 4-nitroquinoline-N-oxide gave (31) on reaction with potassium cyanide and ethyl cyanoacetate [92]. 

Isoxazole rings were annelated onto 5-nitroquinoline and isoquinoline-based o-nitrobenzyl-p-tolylsulfones by treatment with potassium phenoxide, which acted as both base and reductant (Equation (42)) <95H(40)187>. In the cases of quinolines as starting materials, product benzisoxazoles (75) both with and without phenoxy substitution were obtained, but in the case of an isoquinoline starting material no phenoxy-substituted product was generated. The reaction is thought to proceed via a nitrosobenzylsulfone carbanion intermediate, and can be applied to nitronaphthalenes but not to less active nitrobenzenes. 

In the series of azaaromatics pyridine appears to possess the least electron deficiency and cannot be aminated under these conditirms. In contrast, diazines, triazines, tetrazines, quinolines, quinoxalines, quinazolines, naphthiridines, polyazaaromatic compounds, and their nitro derivatives are able to undergo oxidative amination. Moreover, amination of highly Jt-deficient triazines, tetrazines, 3-nitropyridine, 3-nitroquinoline, etc. is possible to perform without KNH2, since ammonia itself serves as nucleophile in such cases (Scheme 6). However, the more electron deficiency of an azine substrate, the less regioselectivity of the reaction. Oxidative amination of 3-nitrop3ridine in Uquid ammonia with potassium permanganate affords a mixture of 2-amino-3-nitro- (33%), 4-amino-3-nitro- (24%), and... 

Ried and his group have continued their work with benzo[6]thiophen derivatives, and have shown that they may be converted to a number of heterocycles [e.g. (267) and (268)] upon reaction with dicyclohexyl carbodi-imide and cyanamides. Some Japanese workers have followed up an earlier report concerning nitroquinolines with an interesting reaction in the naphthalene series. The potassium salt (269), which is formed from 2-nitronaphthalene cyclizes on treatment with HCl to give naphtho-l,3-oxazines (270), and these in turn can be further modified. 

Various reactions of nitroquinolines with hydroxylamine in potassium hydroxide alkalinity afforded oxadiazoloquinolines besides the known aminonitroquinolines. l,2,5-Oxadiazolo[3,4-/]quinolines were obtained from the 5- or 6-nitroquinolines. The 7- and 8-nitroquinolines gave the appropriate l,2,5-oxadiazolo[3,4-/i]quino-lines. 

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