Phthalic acid, 4-Nitro

The nitration of phthalic anhydride with a mixture of concentrated sulphuric and nitric acids yields a mixture of 3-nitro- and 4 nitro phthalic acids these are readily separated by taking advantage of the greater solubility of the 4 nitro acid in water. Treatment of 3 nitrophtlialic acid with acetic anhydride gives 3 nitrophthahe anhydride. 

Note The exothermic nitration of phthalic acid or phthalic anhydride by a fuming nitric acid-sulfuric acid mixt may give mixts of the potentially expl phthaloyl nitrates or nitrites or their nitro derivatives. Formation of these compds can be avoided if the nitrating mixt is... 

Nitro-o-phthalic Acid. Pale yel prisms or plates from w mp dec 207—230°. Prepn and properties are given in Refs Rpfe- Oil /I a rtoci... 

Nitro-m-phthalic Acid. Crysts, mp 255—60°. Diff sol in cold w, v sol in hot w, ale eth. Forms numerous salts of which the silver salt was reported to be expl Ref Beil 9,839, (373) [610]... 

Phthalaldehyde, 34, 82 Phthalic acid, 32, 67 Phthalic anhydride, 32, 19 Phthalideacetic acid, 34,10 PlITHALIMIDE, N-2-BROMOETHYL-, 32, 18 3-Picoline, 4-nitro-, 1-oxide, 36, 53 3-Picoline-l-oxide, 36, 54... 

Nitrophenyl disulfide, b216 3-Nitro-o-phthalic acid, n31... 

Phthalic acid, 3-nitro-, hazard note, 53, 129 a-Pinene oxide, preparation of, 53, 18... 

The reaction product from the mercuration of 3-nitro-phthalic acid (1 mole) is used. The mercury compound can be used without drying if desired. If this is done, solution takes place much more readily. 

Participation of proton-donors other than hydroxonium ion has been observed, e.g. for phenylglyoxylic (59) and pyruvic (60) acids, for substituted benzaldehydes (61—63), unsaturated acids (49, 64), N-nitros-amines (65), nitrones (66), unsaturated ketones (67), aryl alkyl ketones (68) and various heterocyclic compounds (69, 70). Consecutive dissociation has been observed for maleic and fumaric acids (48), for phthalic acid (50) and for pyridoxal derivatives (71). 

Among the electron acceptors which exhibit the sensitization 133 are various nitro compounds, cyano-compounds, some organic acids such as phthalic acid, carboxylic acid anhydrides, quinones, etc. The most efficient electron accepting sensitizer known to date is 2,4,7-trinitro-9-fluorenone (TNF)134,135. Not surprisingly,... 

The largest group of organic molecular compounds, in which hydrogen bond formation plays no part, are the compounds, usually in the ratio 1 1, between on the one hand aliphatic and aromatic nitro compounds (nitromethane, tetranitro-methane, chloropicrin CC13N02, nitrobenzene, s-trinitrobenzene, picric acid), quinones, anhydrides (phthalic acid-and maleic acid anhydride) and ketones with on the other hand especially aliphatic and aromatic amines (aniline, pyridine), unsaturated aliphatic and aromatic hydrocarbons, ethers etc. 

Nitro-m-phthalic Acid. Prisms from methanol, mp 310-315° (begins to brown ca 287°). SI sol in w, easily sol in ale or eth. Its barium salt, which is very sol in w, is probably expl (Ref 2)... 

Nitro-d-phthalic Acid. Needles from eth, mp 162—64°. Easily sol in w ale sol in hot AcOH diff sol in cold AcOH fairly sol in eth insol in chlf, benz, petr eth C tetrachloride. Prepn and properties are given in Refs Refs 1) Beil 9,828, (370) [606] 2) J.R. 

Nitro-p-phthalic Acid (Nitroterephthalic Acid). Only one isomer is possible. Crysts, mp 268— 70°. Easily sol in ale or eth, sol in hot w. Can be prepd by nitration of terephthalic acid or by other methods given in the Refs. Some of its salts are probably expl... 

In the first case one nucleus remains as a benzene ring in phthalic acid while in the second case it must be the other nucleus which remains as a benzene ring in tetra-chlor phthalic acid. The proof here then is exactly the same as in the case of nitro naphthalene and amino naphthalene, viz., that in naphthalene either nucleus is a benzene ring. 

Nitrophthalic acid has usually been prepared by nitration of phthalic acid or phthalic anhydride,followed by separation from the accompanying 3-nitrophthalic acid. > It has also been prepared from 6-nitro-2-naphthol-4-sulfonic acid (obtained from the technical diazo-anhydride of 6-nitro-i-amino-2-naphthol-4-sulfonic acid). The present procedure is more convenient than any of the earlier methods. 

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