Laporte Industries Limited

Ian Robert King

Francis Robert Hardy

Anthony MacDonald Hildon

A method of preparing an o-phenyl phenol from a cyclohexanone which comprises the steps of forming an o-cyclohexenyl cyclohexanone from the cyclohexanone by condensing the cyclo-hexanone in the presence of an inherently sulphur-free condensation catalyst, and then dehydrogenating the resulting o-cyclohexenyl cyclohexanone by contacting the o-cyclohexenyl cyclohexanone with a dehydrogenation catalyst in the presence of sufficient sulphur in the form of elemental sulphur or an organo-sulphur compound to improve the selectivity of the dehydrogenation catalyst with respect to the formation of o-phenyl phenol.

Process for the production of o-phenylphenol

A .delta.- or .epsilon.- lactone is heated in the vapour phase and the presence of a cracking catalyst to form a monounsaturated acyclic carboxylic acid. For example .epsilon.-caprolactone gives .delta. - .epsilon. hexenoic acid. This acid is then cyclised by heating with a strong protonating agent. In the example the product is .gamma.-caprolactone or 4-hexanolactone.

Lactones

A feed material containing the group --O--(CR.sub.2).sub.n --CO-- in a macrocyclic ring or acylic chain is heated to between 300.degree.C and 500.degree.C in the absence of a catalyst to give a mono-unsaturated acyclic carboxylic acid. For example polymeric .epsilon.-caprolactone gives .delta.-.epsilon. hexenoic acid. This acid is then cyclised by heating with a strong protonating agent. In the example the product is .gamma.-caprolactone or 4-hexanolactone.

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Luton, United Kingdom

Ian Robert King