Claims
- 1. A process for the production of 2-hydroxynaphthalene-3-carboxylic acid which comprises heating sodium .beta.-naphtholate in a first stage to a temperature of at least 180.degree. C. as a solution or suspension in a liquid araliphatic compound having one of the formulae ##STR7## in which R.sup.1 is phenyl or naphthyl, R.sup.2 is alkyl of one to four carbon atoms or hydrogen, R.sup.3 is alkylene of one to eight carbon atoms, and the phenylene groups of the compounds of formulae III through VII optionally bearing alkyl of one to three carbon atoms as substituents thereof, then reacting sodium naphtholate after heating thereof in said first stage with carbon dioxide in a second stage at a temperature of at least 180.degree. C. to form the sodium salt of 2-hydroxynaphthalene-3-carboxylic acid, and acidifying the latter compound to convert it into 2-hydroxy-naphthalene-3-carboxylic acid.
- 2. A process as set forth in claim 1 where said araliphatic compound is employed in an amount of 20 to 100% by weight based on said naphtholate.
- 3. A process as set forth in claim 1 wherein the reaction in the second stage conducted at a temperature in the range of 200.degree. to 280.degree. C.
- 4. A process as set forth in claim 3 wherein the reaction in the second stage is conducted at a pressure in the range of from 2 to 50 atmospheres and an amount of carbon dioxide in the range of from 0.5 mole to 10 moles, based on said naphtholate.
- 5. A process as set forth in claim 1 wherein said araliphatic compound is 1-methyl-3-phenylindan or 1-phenyl-4-phenylethyltetrahydronaphthalene.
- 6. A process for the production of 2-hydroxynaphthalene-3-carboxylic acid which comprises heating sodium .beta.-naphtholate in a first stage to a temperature of at least 180.degree. C. as a solution or suspension in an aromatic ether having one of the formulae ##STR8## in which R.sup.1 is alkyl of one to four carbon atoms, cyclopentyl, cyclohexyl, --R.sup.5 --(OR.sup.5).sub.n --CH.sub.3, ##STR9## individual radicals R.sup.2 and R.sup.3 may be identical or different and each is alkyl or alkoxy in each case of one to four carbon atoms, cycloalkyl or cycloalkoxy of five or six carbon atoms, hydrogen or --(OR.sup.5).sub.n --CH.sub.3, one radical R.sup.2 may also be: ##STR10## fused with the benzene nucleus at the side a in which R.sup.3 has the above meanings, R.sup.4 is alkylene of two to four carbon atoms or ##STR11## in which R.sup.3 has the above meaning, R.sup.5 is alkylene of two to four carbon atoms, R.sup.6 is alkyl of one to four carbon atoms and n is zero, 1, 2 or 3 and the said radicals may bear groups which are inert under the reaction conditions for example alkoxy or alkyl of one to three carbon atoms in each case as substituents, reacting the sodium naphtholate from said first stage with carbon dioxide in a second stage at a temperature of at least 180.degree. C., and acidifying the sodium salts of 2-hydroxynaphthalene-3-carboxylic acid to convert it to 2-hydroxynaphthalene-3-carboxylic acid.
- 7. A process as set forth in claim 6 wherein the amount of the aromatic ether employed is in the range of 20 to 100% by weight based on said naphtholate.
- 8. A process as set forth in claim 6 wherein the carboxylation in the second stage is conducted at a pressure in the range of from 2 to 50 atmospheres and with an amount of carbon dioxide in the range of from 0.5 mole to 10 moles, based on said naphtholate.
- 9. A process as set forth in claim 6 wherein said aromatic ether is .beta.-naphthol methyl ether.
- 10. A process for the production of 2-hydroxynaphthalene-3-carboxylic acid which comprises heating sodium .beta.-naphtholate in a first stage to a temperature of at least 180.degree. C. as a solution or suspension in an aromatic ether having one of the formulae ##STR12## wherein the individual radical R.sup.3 may be identical or different and each is alkyl or alkoxy in each case of one to four carbon atoms cycloalkyl or cycloalkoxy of five or six carbon atoms, hydrogen or --(OR.sup.5).sub.n --CH.sub.3, R.sup.4 is alkylene of two to four carbon atoms or ##STR13## in which R.sup.3 has the above meanings, R.sup.5 is alkylene of two to four carbon atoms, R.sup.6 is alkyl of one to four carbon aoms and n is zero, 1, 2 or 3 and the said radicals may bear groups which are inert under the reaction conditions for example alkoxy or alkyl of one to three carbon atoms in each case as substituents, reacting the sodium naphtholate from said first stage with carbon dioxide in a second stage at a temperature of at least 180.degree. C., and acidifying the sodium salts of 2-hydroxynaphthalene-3-carboxylic acid to convert it to 2-hydroxynaphthalene-3-carboxylic acid.
- 11. A process as set forth in claim 10 wherein the amount of the aromatic ether employed is in the range of 20 to 100% by weight based on said naphtholate.
- 12. A process as set forth in claim 10 wherein the carboxylation in the second stage is conducted at a pressure in the range of from 2 to 50 atmospheres and with an amount of carbon dioxide in the range of from 0.5 mole to 10 moles, based on said naphtholate.
- 13. A process as set forth in claim 10 wherein said aromatic ether is 1,2-dinaphthoxyethane.
- 14. A process for the production of 2-hydroxynaphthalene-3-carboxylic acid which comprises heating sodium .beta.-naphtholate in a first stage to a temperature of at least 180.degree. C. as a solution or suspension in an aromatic ether having one of the formulae ##STR14## wherein the individual radical R.sup.3 may be identical or different and each is alkyl or alkoxy in each case of one to four carbon atoms, cycloalkyl or cycloalkoxy of five or six carbon atoms, hydrogen or --(OR.sup.5).sub.n --CH.sub.3, R.sup.4 is alkylene of two to four carbon atoms or ##STR15## in which R.sup.3 has the above meanings, R.sup.5 is alkylene of two to four carbon atoms, R.sup.6 is alkyl of one to four carbon atoms and n is zero, 1, 2 or 3 and the said radicals may bear groups which are inert under the reaction conditions for example alkoxy or alkyl of one to three carbon atoms in each case as substituents, reacting the sodium naphtholate from said first stage with carbon dioxide in a second stage at a temperature of at least 180.degree. C., and acidifying the sodium salts of 2-hydroxynaphthalene-3-carboxylic acid to convert it to 2-hydroxynaphthalene-3-carboxylic acid.
- 15. A process as set forth in claim 14 wherein the amount of the aromatic ether employed is in the range of 20 to 100% by weight based on said naphtholate.
- 16. A process as set forth in claim 14 wherein the carboxylation in the second stage is conducted at a pressure in the range of from 2 to 50 atmospheres and with an amount of carbon dioxide in the range of from 0.5 mole to 10 moles, based on said naphtholate.
- 17. A process as set forth in claim 14 wherein said aromatic ether is 1,4-diphenoxybutane, 1,2-diphenoxyethane, 1,2-di-(3'-methyl)-phenoxyethane, or 4,4'-dimethoxydiphenylethane.
- 18. A process as set forth in claim 14 wherein said aromatic ether is .omega.,.omega.'-diphenoxy-1,4-diethylenebenzene.
Priority Claims (1)
Number |
Date |
Country |
Kind |
2260637 |
Feb 1972 |
DT |
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RELATED APPLICATION
This application is a division of our copending application Ser. No. 422,547, filed Dec. 6, 1973 now abandoned.
US Referenced Citations (15)
Non-Patent Literature Citations (2)
Entry |
Lecher et al., "J. Prakt. Chem.," 4th Ser., 3, 232(1956). |
Serdel et al., "J. Prakt Chem.," 4th Ser., 2, 53(1955). |
Divisions (1)
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Number |
Date |
Country |
Parent |
422547 |
Dec 1973 |
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