Preparation of phthalides
AssigneeBASF SE
InventorsJochem Henkelmann, Thomas Ruehl, Horst Zimmermann
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Abstract
A process for the preparation of phthalides of the formula I ##STR1## where R.sup.1, R.sup.2, R.sup.3 and R.sup.4 independently of one another, are hydrogen, C.sub.1 - to C.sub.4 -alkyl or C.sub.1 - to C.sub.4 -alkoxy, by reacting phthalic anhydrides of the formula II ##STR2## where R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are as defined as above, on hydrogenation catalysts at from 50.degree. to 400.degree. C. and at from 1 to 400 bar, wherein the hydrogenation catalysts employed are essentially free from Lewis acids.
Claims16
A process for the preparation of phthalides of the formula ##STR5## where R1, R2, R3 and R4, independently of one another, are hydrogen C1-C4 alkyl or C1-C3 alkoxy, which comprises:
- reacting a phthalic anhydride of the formula ##STR6## where R1, R2, R3 and R4 are as defined above with hydrogen in the presence of a hydrogenation catalyst at from 50.degree. to 400.degree. C. and at from 1 to 400 bar, wherein the hydrogenation catalyst employed is a fixed-bed catalyst essentially free from Lewis acids and is selected form the group consisting of:
- a) oxides of the elements of main groups one to four of the Periodic Table of Elements, oxides of the elements of sub-groups one to eight of the Periodic Table of Elements, oxides of the elements of the lanthanide group, or mixtures of said oxides;
- and
- b) metallic catalysts wherein the metal is selected from the group consisting of ruthenium, rhenium, palladium, platinum, boron, tin and mixtures thereof on support materials.
Dependencies are inferred from the claim text.