Process for the production of 6-hydroxy-2-naphthoic acid
AssigneeAmerican Cyanamid Company
InventorsMichael J. Mueller, Carroll S. Montgomery
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Abstract
The production of 6-hydroxy-2-naphthoic acid from anhydrous potassium 2-naphthoxide and carbon dioxide is improved by forming a mixture of 0.8-1.2 moles of 2-hydroxynaphthalene per equivalent of potassium base, dehydrating the mixture, adding carbon dioxide at about 20 to 90 psi at about 255.degree.-280.degree. C. and agitating and heating it at said pressure and temperature.
Claims7
In a process for preparing 6-hydroxy-2-naphthoic acid by reacting essentially anhydrous potassium 2-naphthoxide with carbon dioxide at an elevated temperature, and recovering 6-hydroxy-2-naphthoic acid therefrom, the improvement which comprises forming a mixture of 2-hydroxynaphthalene and a potassium base, using about 0.8 to 1.2 moles of 2-hydroxynaphthalene per equivalent of potassium base;
- dehydrating said mixture;
- introducing carbon dioxide into said dehydrated mixture at about 20 psi to 90 psi at about 255.degree. C. to 280.degree. C., while agitating said mixture in a pressure reactor;
- and heating said agitated mixture at said temperature and under said pressure until the ratio of 6-hydroxy-2-naphthoic acid to 3-hydroxy-2-naphthoic acid in the reaction mixture is at least 2, before recovering said 6-hydroxy-2-naphthoic acid.
Dependencies are inferred from the claim text.