By this series of transformations it is possible to pass from one anilid to the other, the steps being:
CO.NH.C₆H₅C=N.C₆H₅C[NH.C₆H₅]₂
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//N.C₆H₅ /O
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C₆H₃—SO₂NH.C₆H₅ ➡ C₆H₃—SO₂ ➡ C₆H₃—SO₂
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NO₂NO₂NO₂
This is of special interest as affording a means of passing from a derivative of one of the chlorides, to a substance derived from the other, by steps that can be clearly followed.
Conclusions.
In the course of this investigation several facts have been established.
1. By the methods described, the symmetrical chloride of paranitroorthosulphobenzoic acid can be obtained in fine crystalline form, perfectly free from its isomer, with an average yield of forty percent.
2. By treatment of the chloride with benzene and aluminium chloride, only one chlorine atom can be replaced by a phenyl group.
3. The barium salt of paranitroorthobenzoyl benzenesulphonic acid, when perfectly pure, crystallizes constantly with seven molecules of water of crystallization.
4. With alcohols, the symmetrical chloride yields directly the acid etherial salt of paranitroorthosulphobenzoic acid, no evidence having been obtained of an intermediate chloro-etherial salt. The unsymmetrical chloride on the other hand yields the intermediate product.
5. With phenols, two series of derivatives are obtained.