Kawasaki Steel Corporation

Hitoshi Saima

Tadahiro Wakui

Makiko Ijiri

Tokio Iizuka

Toshinobu Suzuki

Akinori Matsuura

The improved process for preparing para-hydroxybenzoic acid comprises reacting potassium phenol with carbon dioxide in an inert reaction medium or without using a reaction medium in the presence of at least one compound selected from the group consisting of the compounds represented by the following general formula I or II: ##STR1## at a reaction temperature of 230.degree.-450.degree. C. and at a carbon dioxide pressure ranging from atmospheric pressure to 6 kg/cm.sup.2 (G). The process may comprise two stages and the first-stage reaction described above is followed by the second stage in which the reaction is further continued with the pressure of carbon dioxide in the system being reduced and/or the reaction temperature being elevated within the range specified above. Also, phenol may be used as the starting material instead of potassium phenolate.

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Chiba, Japan

Hitoshi Saima