| 摘要 |
1,201,545. Preparation of hexachlorophene. E. B. MICHAELS. 10 June, 1968 [8 June, 1967; 6 Feb., 1968], No. 275l4/68. Heading C2C. The invention relates to a method for preparing bis-(3,5,6-trichloro-2-hydroxyphenyl) methane (hexachlorophene) which comprises the steps of admixing 1 part, by weight, of 2,4,5- trichlorophenol in from 0À25 to less than 1 part, by weight, of an organic medium selected from formic acid, acetic acid, acetic anhydride, propionic acid and mixtures of the same, condensing the latter, 2,4,5-trichlorophenol mixture with from 0À08 to 0À09 parts, by weight, of a formaldehyde-yielding material or formaldehyde in the presence of from 1 to 2 parts of an acid-condensing agent at a temperature ranging from about 80‹ to 120‹ C., and recovering hexachlorophene. In an example, 2,4,5-trichlorophenol in acetic acid is heated to 95‹ C. and 98% sulphuric acid added to which paraformaldehyde is gradually added whilst maintaining the temperature at 90‹ to 100‹ C. and hexachlorophene subsequently recovered. The di-sodium salt may be obtained by heating with sodium carbonate and sodium hydroxide and a mono-sodium salt by adding sulphuric acid to reduce the pH to 10.
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