Reactions of Nitrophenols and their Derivatives

The reactions in this group comprise substitution of the nitro or the hydroxyl group, etherification of the latter and condensation reactions in the aromatic ring. 

In the category of hydroxyl replacement, 2-hydroxy-3,5-dinitrobenzoic acid added slowly to phosphorus oxychloride/dimethylformamide (1 1) followed by completion of reaction at ambient temperature during 2 hours produced 2-chloro-3,5-dinitrobenzoic acid in a yield of 90% (ref. 72). 

3-Nitrophenyl trifluoromethyl ether has been derived in 62% yield from a vigorously stirred mixture of 3-nitrophenol, anhydrous carbon tetrachloride and antimony pentafluoride together with a little antimony pentachloride by heating at 150°C for 5.5 hours (ref.73). 

Methoxymethylation of 2-chloro-4-nitrophenol with paraformaldehyde and methanol occurred by the addition of concentrated sulphuric acid over 35mins. followed by reaction at 90-95°C during 4 hours. Dropwise treatment with methanol and continuation of refluxing for 2.5 hours resulted in a 93% yield of 2-chloro-6-methoxymethyl-4-nitrophenol (ref.74). 

2-Alkylation and reduction of the nitro group to the amino has been observed in the methyl ether of 4-hydroxy-nitronaphthalene. Cydohexylmagnesium chloride in tetrahydrofuran added dropwise but rapidly at 0°C to the compound in tetrahydrofuran followed successively by tert-butanol and phosphorus trichloride in tetrahydrofuran with completion of the reactton at ambient temperarure during 3 hours gave after acidification with hydrochloric acid, 

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