Process for the preparation of 2-hydroxy-naphthalene-6-carboxylic acid
AssigneeHoechst Aktiengesellschaft
InventorsVolker Hautzel, Siegbert Rittner
Life of this patent
Estimating the term…
Abstract
2-Hydroxy-naphthalene-6-carboxylic acid or its dipotassium salt is obtained in a good yield and purity without substantial formation of the isomeric compound 2-naphthol-3-carboxylic acid by reacting potassium .beta.-naphtholate with potassium carbonate in the presence of carbon monoxide at a temperature above 260.degree. C. in potassium formate as the solvent.
Claims7
A process for the preparation of 2-hydroxy-naphthalene-6-carboxylic acid or its dipotassium salt, which comprises reacting potassium .beta.-naphtholate with potassium carbonate and carbon monoxide at a temperature above 260.degree. C. and under a carbon monoxide pressure above 10 bar in 2,5- to 18-times the amount by weight, calculated with respect to the amount of the potassium .beta.-naphtholate, of potassium formate as the solvent or siluent, and optionally converting the dipotassium salt thus formed into 2-hydroxy-naphthalene-6-carboxylic acid.
Dependencies are inferred from the claim text.