Mercuration of nitrohydroxybenzaldehydes / by T.A. Henry and T.M. Sharp.

  • Henry, Thomas Anderson, 1873-1958
Date:
[1924.]
Catalogue details

Licence: Public Domain Mark

Credit: Mercuration of nitrohydroxybenzaldehydes / by T.A. Henry and T.M. Sharp. Source: Wellcome Collection.

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    can be separated by fractional crystallisation from appropriate fatty acids; if the mercuric acetate is increased to two molecular proportions the product consists almost entirely in each case of the corresponding dimercuri-derivative, very little of the rnono- compound being formed. In such compounds, the mercury can usually be replaced by a nitro-group or by a halogen, and it has been assumed generally that the group thus introduced occupies the same position in the molecule as the mercury it replaces, and it is on this basis that constitutional formulae have been assigned to many of the organic derivatives of mercury already described. The results obtained in apjfiying such processes to the dimercurinitro-m-hydroxy- benzaldehydes show that the assumption is not always justified. Thus the dimercuri-compounds formed from the 6-nitro-, 4-nitro-, and 2-nitro-derivatives of m-hydroxybenzaldehyde all yield on treatment with bromine, 2 : 4-dibromo-6-nitro-3-hydroxybenz- aldehyde. This substance should be produced from the 6-nitro- derivative (I)*, whereas the 4-nitro-isomeride (II) should yield 2 : 6-dibromo-4-nitro-3-hydroxybenzaldehyde and the 2-nitro- isomeride (III) ought to furnish 4 : 6-dibromo-2-nitro-3-hydroxy- benzaldehyde. (I.) CHO NO/bHg- \>H Hg- CHO no2 (II.) CHO (III.) The stej^s taken to ensure the purity and identity of the initial materials, proof that the three dimercuri-compounds are different, and evidence of the identity and constitution of the single dibromo- nitro-m-hydroxybenzaldehyde yielded by the three are detailed in the experimental portion and need not be summarised here. The authors are of opinion that the data given leave no room for doubt that in the action of bromine on the two dimercuri-compounds formed from the 2-nitro- and 4-nitro-m-hydroxybenzaldehydes each nitro-group changes position with the bromine atom, which replaces the mercury atom in position 6. This anomalous behaviour with bromine made it difficult to determine the position of the mercury residues in the 4-nitro- and 2-nitro-derivatives and it has not been found possible to replace mercury in these substances by nitro-groups. Fortunately, they behave normally with iodine and with the assistance of the results * In these formulae, Hg- represents a mercuri-residue -HgOH, -HgOAc,