Production of alkoxynaphthyl-substituted ketones from naphthaldehydes
AssigneeAlbemarle Corporation
InventorKevin J. Theriot
Life of this patent
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Abstract
A mixture formed from an alkoxy-2-naphthaldehyde (e.g., 6-methoxy-2-naphthaldehyde), acetone, and aqueous NaOH and/or KOH is heated at about 20.degree. to about 56.degree. C. for about 0.25 to about 2 hours such that the conversion of monoalkoxy-substituted 2-naphthaldehyde is at least 97% and the yield of (alkoxy-substituted 2-naphthyl)-3-buten-2-one is at least 95% based on the monoalkoxy-substituted 2-naphthaldehyde used in forming the mixture. The (alkoxy-substituted 2-naphthyl)-3-buten-2-one can be hydrogenated using, for example, a Pd/C catalyst to form the corresponding saturated ketone. The process enables efficient production of precursors of nabumetone and related pharmaceuticals by a clean, highly efficient reaction.
Claims10
A process for the preparation of an (alkoxy-substituted 2-naphthyl)-3-buten-2-one which comprises:
- a) mixing (i) a monoalkoxy-substituted 2-naphthaldehyde, (ii) acetone and (iii) alkali metal hydroxide solution wherein the alkali metal cation is sodium or potassium or both of them, in proportions in the range of about 5 to about 20 moles of acetone and in the range of about 0.1 to about 5 moles of alkali metal hydroxide per mole of monoalkoxy-substituted 2-naphthaldehyde;
- and
- b) heating the mixture at one or more temperatures in the range of about 20.degree. to about 56.degree. C. for a period in the range of about 0.25 to about 3 hours such that the conversion of monoalkoxy-substituted 2-naphthaldehyde is at least 97% and the yield of (alkoxy-substituted 2-naphthyl)-3-buten-2-one is at least 95% based on the monoalkoxy-substituted 2-naphthaldehyde used in a).
Dependencies are inferred from the claim text.