Part 9

Am. Ch. Journ. XVIII-810.

A convenient amount of phosphorus oxychloride (50 c.c.) was placed in the retort and the anilid (5 gr.) added through the tubulus. On boiling, with the condenser inverted, the anilid soon dissolved, with evolution of hydrochloric acid gas, and the solution became bright yellow in color, sometimes inclining to orange. The boiling was continued as long as hydrochloric acid was given off. The oxychloride was then distilled off under diminished pressure, care being taken to shake the retort constantly during the distillation as violent bumping is almost sure to occur especially towards the end of the operation. The product remaining, spattered over the walls of the retort, was a greenish yellow solid.

Water was then added, and the whole allowed to stand for an hour or so to thoroughly dissolve the phosphoric acid formed in the reaction.

In case the anilid is not perfectly dry, a much more energetic reaction occurs, and on distilling off the oxychloride, the product remains as a dark, gummy mass. This should be spread out on the sides of the retort while still liquid. On cooling and adding water, this gum gradually disappears, and in its place is found the yellow solid product just described. The gum appears to be a solution of this substance in phosphoric acid.

After the substance is filtered off and dried, it can be crystallized from acetone, benzene, glacial acetic acid or alcohol. From these solvents it crystallizes in small yellow needles resembling quinone in appearance.

The crystals obtained form acetone are rather larger than those from the other solvents, and are more nearly orange in color, apparently because of their greater compactness. When glacial acetic acid is used, care must be taken to avoid any unnecessary heating, as continued heating produces a change that will presently be described. The substance melts at 208°.

Analysis of the substance resulted as follows:

I. 0.3822 gram gave 0.8334 gram CO₂ and 0.1272 gram H₂O.

II. 0.2645 gram gave 0.5812 gram CO₂ and 0.0910 gram H₂O.

III. 0.2023 gram gave 0.1283 gram BaSO₄.

IV. 0.2061 gram gave 0.1280 gram BaSO₄.

V. 0.1853 gram gave 16.73 C.C.N (Standard).

C=N.C₆H₅ / \ / .N.C₆H₅ / / Cal. for C₆H₃——SO₂ \ NO₂ Found. I II III IV V C = 60.11 59.47 59.93 —— —— —— H = 3.44 3.69 3.82 —— —— —— S = 8.45 —— —— 8.70 8.52 —— N = 11.08 —— —— —— —— 11.35

For analyses I & II I am indebted to Mr. Nakaseko, who kindly made them for me.

X. The Action of Reagents upon the Dianil of Paranitroorthosulphobenzoic Acid.

1. The Action of Hydrochloric Acid on the Dianil

When the dianil is boiled for some time with concentrated hydrochloric acid, the yellow color of the substance disappears, and the dianil is converted into a colorless substance without, however, passing into solution. The substance so obtained was filtered off, and crystallized from alcohol. It crystallized in small colorless needles, which melted at 183°, and possessed all the properties of the anil, which, in fact, it proved to be. The reaction was therefore

C=N.C₆H₅ CO / \ / \ / N.C₆H₅ / N.C₆H₅ / / / / C₆H₃——SO₂ + HCl + H₂O = C₆H₃——SO₂ + C₆H₅NH₃Cl \ \ NO₂ NO₂

This reaction also explains the fact that some anil was always obtained in making the dianil from the anilid. Hydrochloric acid is formed in the reaction, and in turn acts on the dianil in the sense of the equation just given.

2. The Action of Alcoholic Potash on the Dianil.

On boiling the dianil with alcoholic potash for a time, the solution turned red, and nothing but tarry products were obtained. In this respect the dianil differs from the dianil of orthosulphobenzoic acid, which under similar conditions, is transformed into infusible anilid. This observation is, however, in keeping with the fact that the nitro derivative, is in general much less stable in the presence of alkali.

3. The Action of Glacial Acetic Acid on the Dianil.

When the dianil is boiled with glacial acetic acid for some time, the color of the solution changes to a much lighter shade of yellow, or becomes colorless. On evaporating the solution to small volume, and allowing it to cool, a colorless substance separates. This is infusible anilid. It could not be obtained in crystals from any solvent, but always separated in flakes. It does not melt or undergo change at 340°.

Like the fusible anilid it dissolves in dilute alkali, but on acidifying the solution it does not immediately reappear. After standing for some time, however, it gradually separates in perfectly pure form. In this particular my observation differs from that of Gray, who states that this anilid is decomposed by solution in alkali.

Inaug. Diss. J. H. Unis. 1895.

A specimen that had been repeatedly precipitated gave the following results on analysis.

I. 0.1607 gram gave 13.88 C.C.N. (standard).

II. 0.2195 gram gave 0.1285 gram BaSO₄.