| 摘要 |
Condensation products of alcohols and phenols are manufactured by effecting the condensation by means of zinc chloride in the presence of a volatile liquid having a boiling point lower than the appropriate operating temperature, which in the case of primary alcohols is about 180 DEG C. and in the case of secondary and tertiary alcohols (to which the process is particularly applicable) about 130 DEG C. In the former case toluene and in the latter benzene or isohexylene are suitable, the last substance being advantageously used when the alcohol is methyl isobutyl carbinol, since in this case some isohexylene is produced in the reaction. The zinc chloride need not be anhydrous, but may be in the form of an aqueous solution, e.g. obtained by concentrating the solution remaining from a previous operation. The phenol is preferably employed in slight excess over the molecular proportion. The reaction may be effected by adding the volatile liquid, the phenol and the alcohol to the zinc chloride solution, heating, preferably under reflux, separating the upper layer containing the condensation product, removing the volatile liquid, washing the condensation product with water to remove zinc chloride and purifying it, e.g. by vacuum distillation. In examples, phenol is condensed with methyl isobutyl carbinol in the presence of (1) isohexylene, and (2) benzene. |
