Patent GB-603616-A (GB)
Title: Improvements in and relating to the manufacture of derivatives of di-substituted methane compounds
IPC: C07F3/10
Filed: 1945-10-30
Abstract: Disubstituted methane (D.S.M.) compounds are manufactured by reacting formaldehyde with a salt formed from certain arylsulphonic acids and an organometallic compound of the general formula R3MA, wherein R3 represents an alkyl radical or an aryl, aralkyl or heterocyclic radical, which may or may not p  be substituted with neutral, acidic or basic substituents, M represents a polyvalent metal (preferably mercury or arsenic) and A represents an acidic radical (such as halide, nitrate or acetate), or hydroxide or oxide, or (where R3 is basic or contains a basic substituent) an atomic grouping forming with M an acidic radical, and of such a nature that the compound will react with the arylsulphonic acid, and irrespective of whether the said group is or is not split off in the process of the formation of the salt.  The arylsulphonic acids which may be employed are phenolsulphonic acids, alkylphenolsulphonic acids, carboxyphenolsulphonic acids, diphenyl- and alkyldiphenyl-mono- and -di-sulphonic acids, benzenesulphonic acids, sulphobenzoic acids, naphthalene- and alkylnaphthalene-mono- and -di-sulphonic acids, naphthol- and alkylnaphthol-sulphonic acid, and nuclear halogen substitution products of any of the foregoing.  The reaction may be carried by reacting formaldehyde with a solution of the preformed arylsulphonic acid salt, or the arylsulphonic acid and the organometallic compound may be added to a solvent (e.g. water), and the formaldehyde (which does not immediately react with the arylsulphonic acid) may be introduced either before or after either or both of the said components, the reaction in each case being brought about by, for example, heating with or without the addition of an acid condensing agent (e.g. sulphuric acid).  The components may be used in equivalent quantities, but usually the formaldehyde is in excess (this excess being eliminated during or after the condensation), whilst (to modify the solubility or pH of the product) excess of either of the other components may be added before, during or after the condensation.  The products have bactericidal, fungicidal and insecticidal properties which make them useful in pharmacy, agriculture, horticulture and the textile industry and in the preservation of timber, for which purposes they are advantageously employed in the form of a solution in a solution of an excess of the D.S.M. compound.  In examples: (1) 10 equivalents of naphthalene-2-sulphonic acid are fused with 1 equivalent of phenyl mercuric acetate and the product is heated with 11.3 equivalents of aqueous formaldehyde; (2) a solution of equimolecular proportions of phenyl mercuric acetate and naphthalene-2-sulphonic acid in aqueous ethyl alcohol or water is treated with excess of formaldehyde, first in the cold and then with gentle warming; (3) 20 equivalents of naphthalene-2 : 7-disulphonic acid are reacted with one of phenyl mercuric acetate and 22.6 of formaldehyde as in (1).  Specifications 547,564, 552,751 and 584,196 are referred to.  A sample has been furnished under Sect. 2 (5) of the product obtained by fusing sulphosalicylic acid with an equimolecular proportion of phenyl mercuric acetate and heating the product with excess of aqueous formaldehyde.