| 摘要 |
<p>Dihydroxy compounds of general formula HO-(CH2-CH2-CH2-CH2-O)n-H in which n = 1 to 10 are prepared by heating a diacetyl compound of general formula CH3COO(CH2-CH2-CH2-CH2-O) n-COCH3 with water in the presence of not more than 4% (calculated on the weight of the diacetyl compound) of an acidic catalyst at a temperature not exceeding 120 DEG C. The preferred amount of catalyst is from 0.5 to 1.0% and the temperature is preferably substantially 100 DEG C. Suitable diacetyl compounds are 1,4-butylene glycol diacetate, 1, 4-dibutylene glycol diacetate, 1, 4-tributylene glycol diacetate and 1, 4-tetra-butylene glycol diacetate. Mixtures of 1, 4-buty-lene glycol diacetate and 1, 4-polybutylene glycol diacetate are also suitable. Suitable acid catalysts are sulphuric acid, phosphoric acid, potassium hydrogen sulphate, p-toluene sulphonic acid or mixtures of these. Examples describe the preparation of 1, 4-dibutylene glycol and 1, 4-tributylene glycol.</p> |
