8-hydroxycymene preparation by dehydrogenation
AssigneeUnilever Patent Holdings B.V.
InventorChristopher P. Newman
Life of this patent
Estimating the term…
Abstract
The invention relates to a process for the conversion of 8-hydroxymenthenes into 8-hydroxycymenes by treating the 8-hydroxymenthenes in the vapour phase with an alkaline dehydrogenation catalyst, e.g. palladium on an alkaline support. The process is carried out above 145.degree. C. The hydroxymenthene vapour is preferably passed through the catalyst system at a pressure below 8 kPa and/or with the aid of an inert gas or vapour. Oxygen may be present as a hydrogen acceptor. The process is particularly suitable for converting 8-hydroxy-p-menth-1-ene into 8-hydroxy-p-cymene. The reaction products are of value as intermediates in the preparation of musk fragrance chemicals.
Claims17
Process for the vapour phase catalytic conversion of an 8-hydroxymenthene to an 8-hydroxycymene which comprises treating an 8-hydroxymenthene with an alkaline dehydrogenation catalyst at a temperature above 145.degree. C.
Use of the product mixture, obtained by vapour phase catalytic conversion of an 8-hydroxymenthene to an 8-hydroxycymene using an alkaline dehydrogenation catalyst at a temperature above 145.degree. C., for the preparation of indane or tetralin precursors for musk fragrances.
8-Hydroxymenthene-rich feedstock for vapor phase catalytic dehydrogenation, which has been treated to free it from catalyst-poisoning contaminants.
Dependencies are inferred from the claim text.