| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing the subject compound useful, e.g. as an intermediate for synthesizing fluorescent brighteners, in a short time, in high yield and economically advantageously without producing a sulfur compound as the by-product, by a reaction at normal or elevated pressure in the presence of a specific fatty acid derivative. SOLUTION: This method is to react, in the presence of (A) zinc chloride, (B) biphenyl with (C) a polymer of formaldehyde (e.g. at least 75 wt.% pure para-formaldehyde) and (D) hydrogen chloride, wherein the reaction process is effected in the presence of (E) an anhydride of a fatty acid (e.g. acetic anhydride) or chloride of a fatty acid (e.g. acetyl chloride) at normal or elevated pressure (e.g. 0.5 to 5.0 kg/cm<2> ). It is preferable to use 0.05 to 1.5 mols of the component E per mol of the component B. |
