Nitronaphthalenes structure

The core scaffold of three of the previously identified inhibitors, VI, SI, and S5 (31), is 4,5-dihydroxynaphthalene-2,7-disulfonate—structure A in Durrant et al. (47). Similarity searches were performed using three structures similar to this core scaffold naphthalene-2-sulfonic acid, 2-naphthoic acid, and 2-nitronaphthalene—structures B, C, and D in Fig. 1 of Durrant et al. (47), respectively. 

Davies and Warren" found that when 1,4-dimethylnaphthalene was treated with nitric acid in acetic anhydride, and the mixture was quenched after 34 hr, a pale yellow solid with an ultraviolet spectrum similar to that of a-nitro-naphthalene was produced. However, if the mixture was allowed to stand for 5 days, the product was i-methyl-4 nitromethylnaphthalene, in agreement with earlier findings. Davies and Warren suggested that the intermediate was 1,4-dimethyl-5 nitronaphthalene, which underwent acid catalysed rearrangement to the final product. Robinson pointed out that this is improbable, and suggested an alternative structure (iv) for the intermediate, together with a scheme for its formation from an adduct (ill) (analogous to l above) and its subsequent decomposition to the observed product. 

Condensation of the dianion of 1,2-dimercaptobenzene (380) with 1-chloro-8-nitronaphthalene (483) in DMF provided 45% of benzo[2,3]naphthalene [5,6,7-/j][l,4]dithiepin (484) and a small amount of its 5-oxide 485 (Eq. 44) (89JHC667). Though the structure of 485 was adequately determined (NMR studies, X-ray crystallography), its formation was not definitely explained. 

Figure 1.4 Low- and high-resolution STM images of a decanter of 1-nitronaphthalene, together with the minimum structure optimized from a force model, showing individual enantiomers in a 6 4 ratio. (Reprinted with permission from Ref. [7]. Copyright 1999, American Physical Society.)...

The potassium salt of pcrfluoro-1-naphthol is oxidized similarly but to a mixture of quinoidal structures which are difficult to separate.170 In contrast, quinone structures are obtained in preparative yields by the oxidation of perfluoro-2-naphthol with concentrated nitric acid. The isolable l-nitronaphthalen-2(l //)-one 10 is easily transformed to 1,2-naphthoquinone 11 in high yield.120... 

The most extensive work on the subject so far has been carried out by Brink and Shrieve [44]. The highest yield of 2-methyl-1-nitronaphthalene they obtained was 57% of the theoretical. This was produced by nitrating 2-methylnaphthalene at low temperatures (0-30°C) with a 70% excess of 70% nitric acid The other isomers appeared as a by-product oil. When using a 15% excess of a nitrating mixture composed of 25% HNOs, 55% H2S04 and 20% H20 the yield of 1-nitro-2-methylnaphthalene was also 57%. Dinitration took place when acetic anhydride was used. The product was in the form of a solid with m. p. 209-213°C. No determination of the structure of the dinitroproducts was carried out. 

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