A NEW EFFICIENT CATALYTIC METHOD OF NAPHTHOLS RING ALKYLATION

The attempts carried out so far concerning catalytic ring alkylation o f naphthols with alcohols have, as a rule, brought about a complex mix ture of products from which the separation of individual compounds wit h the aim of their practical utilization has been proved to be impossi ble. We have found that naphthols and some of their derivatives could be easily alkylated with methanol or higher alcohols in the presence o f iron oxide catalyst by a gas-phase continuous process. As a result o f alkylation the alkyl group enters into the ortho-position to the hyd roxyl group. The yields of alkylnaphthols are approximately about 90%, which simplifies their separation and purification considerably. The advantage of the newly developed method of alkylation is that it leads to high degree of raw materials utilization: it is practically wastel ess, thus it is well suited to the requirements of modern process tech nologies, Its application may contribute to the increase of the demand for naphthol derivatives as potential raw materials for many new synt heses of pharmaceuticals, plant protection agents, dyes, etc. (C) 1998 Elsevier Science B.V.