| 摘要 |
<p>Phenols are alkylated in the o-position by reacting a phenol (I) where R = H, alkyl, phenyl or alkyl-substituted phenyl, with an alkanol in the vapour phase in the presence of water vapour, using an MgO-based catalyst. The MgO catalyst may contain 2-15% of a binder such as SiO2 or a cellulose derivative. The reaction temp. is pref. at least 440 degrees C. and the amount of water vapour present = 3-15% on phenol + alkanol. In an example a 6 : 1 mixt. of methanol and phenol + 12.4% water was passed over a bed of MgO at 504 degrees C. to give 212 g. 2,6-xylenol/hr. per cm. catalyst. Catalyst life was 80 hrs. Products are useful as disinfectants, wood preservatives, etc. and cpds. such as 2,6-xylenol can be polymerised into useful thermoplastics.</p> |
