TH61785A - Preparation of diary-carbonate replaced in structure by ester in the non-solvent state. - Google Patents

Abstract

DC60 (09/10/45) High yields of esterified diaryl carbonates, such as bis-methyl salicylic carbonate, can be achieved by the condensation of esterified phenol with phosgene under phase transfer catalysis (PTC) and possibly with the selection of a tertiaryamine catalyst in a solvent-free reaction system incorporating an aqueous phase with a pH controlled at 8.3 or higher. Optimal conditions for this fabrication utilize an excess of esterified phenol relative to phosgene, resulting in a high conversion rate of phosgene to esterified diaryl carbonates. The esterified diaryl carbonates as a product can be easily separated as a solid by filtration or as a liquid with an excess of esterified phenol as a solvent. In general, this approach is an attractive prospect for... The production of bis-methyl salicylate carbonate and esterified diaryl carbonate is possible by the condensation of esterified phenol with phosgene under phase transfer catalysis (PTC) conditions, or possibly with the selection of a tertiaryamine catalyst, in a solvent-free reaction system incorporating an aqueous phase with a pH controlled at 8.3 or higher. Optimal conditions for this fabrication utilize an excess of esterified phenol relative to phosgene, resulting in a high conversion rate of phosgene to esterified diaryl carbonate. The esterified diaryl carbonate product can be easily separated as a solid by filtration or as a liquid using an excess of esterified phenol as a solvent. In general, this approach presents an attractive prospect for... Produce bis-methylsalicylic carbonate and diaryl carbonate which are replaced in the structure by esters.

Claims (28)

1. A method for preparing esterified diaryl carbonate, involving a contact time, is used. This preparation involves the contact of the esterified phenol with phosgene and a catalyst and aqueous phase in a solvent-free mixture, where the pH of the aqueous phase is kept at least approximately 8.3 throughout the contact time. The phosgene is used in a relative amount of between approximately 0.10 and 1.20 mol of phosgene per mol of esterified phenol. 2. Method according to claim 1, where diaricarbonate is replaced in the structure by... The ester has structure I (chemical formula) (l), where the independently occurring R1 is C1-C20 alkyl radicals, C4-C20 cycloalkyl radicals or C4-C20 aromatic radicals, R2 which occurs independently of the halogen atom, cyano group, nitro group, C1-C20 alkyl radicals, C4-C20 cycloalkyl radicals, C4-C20 aromatic radicals, C1-C20 alkoxy radicals, C4-C20 cycloalkoxy radicals, C4-C20 aryloxy radicals, C1-C20 alkylthior radicals, C4-C20 cycloalkylthior radicals or C4-C20 arylthior radicals, C1-C20 alkylsulfinyl radicals, C4-C20 Cycloalkylsulfonyl radicals, C4-C20 Arylsulfonyl radicals, C1-C20 Alkylsulfonyl radicals, C4-C20 Cycloalkylsulfonyl radicals, C4-C20 Arylsulfonyl radicals, C1-C20 Alxoxycarbonyl radicals, C4-C20 Cycloalkylsulfonyl radicals, C4-C20 Aryloxycarbonyl radicals, C2-C60 Alkylamino radicals, C6-C60 Cycloalkylamino radicals, C5-C60 Arylamino radicals, C1-C40 Alkylaminocarbonyl radicals, C4-C40 Cycloalkylamino Carbonyl radicals, C4-C40 arylaminocarbonyl radicals and C1-C20 acylamino radicals, and bR1, which occur independently of each other, are represented by the numbers 0-4. 3. Method according to claim 2, where diaryl carbonate is replaced in the structure by the ester bis-methyl salicylate carbonate. 4. Method according to claim 2, where the phenol substituted in structure by such ester has structure II (chemical formula) (ll), where R1 which occurs independently of each other is C1-C20 alkylradical, C4-C20 cycloalkylradical or C4-C20 aromatic radical, R2 which occurs independently of the halogen atom, cyano group, nitro group, C1-C20 alkylradical, C4-C20 cycloalkylradical, C4-C20 aromatic radical, C1-C20 alkoxyradical, C4-C20 cycloalkoxyradical, C4-C20 aryloxyradical, C1-C20 alkylthioradical, C4-C20 cycloalkylthioradical or C4-C20 arylthioradical, C1-C20 Alkylsulfonyl radicals, C4-C20 Cycloalkylsulfonyl radicals, C4-C20 Arylsulfonyl radicals, C1-C20 Alkylsulfonyl radicals, C4-C20 Cycloalkylsiphonyl radicals, C4-C20 Arylsulfonyl radicals, C1-C20 Alxoxycarbonyl radicals, C4-C20 Cycloalkylamino radicals, C4-C20 Aryloxycarbonyl radicals, C2-C60 Alkylamino radicals, C6-C60 Cycloalkylamino radicals, C5-C60 Arylamino radicals, C1-C40 Alkylaminocarbonyl radicals, C4-C40 Cycloalkylamino Carbonyl radicals, C4-C40 arylaminocarbonyl radicals and C1-C20 acylamino radicals, and bR1, which occur independently of each other, are represented by the numbers 0-4. 5. Method according to claim 4, where the phenols whose structures are replaced by the aforementioned esters are selected from groups containing methyl salicylate, ethyl salicylate, propyl salicylate, isopropyl salicylate, and benzyl salicylate. 6. Method according to Claim 1, where the phase transfer catalyst is selected from groups containing quaternary ammonium salts of aliphatic amines, quaternary ammonium salts of aromatic amines, quaternary phosphonium salts, and sulfonium salts. 7. Method according to claim 6, where the catalyst is selected from groups containing quaternary ammonium compounds of structure III (chemical formula) (lll), where independent R3-R6 are C1-C20 alkyl radicals, C4-C20 cycloalkyl radicals, or C4-C20 aryl radicals, and X is at least one organic or inorganic anion. Suitable anion X includes hydroxide, halide, carboxylate, sulfonate, sulfate, carbon, and bicarbonate. 8. The method under claim 7, where the catalyst is selected from groups containing methyltributylammonium chloride, tetramethylammonium chloride, and dexyltrimethylammonium chloride. 9. Method according to claim 6, where the said quaternary ammonium compound is a hexaalkylguanidinium compound. 10. The method under claim 9, whereby the said hexaalkylguanidinium compound is hexaethylguanidinium chloride. 11. Method under Claim 1, where the aqueous phase is controlled at a pH range of approximately 8.3 to approximately 12. 12. Method under claim 11 where the aqueous phase's pH is controlled to a range between approximately 8.3 and approximately 12 by the addition of alkali metal hydroxide aqueous. 13. The method under claim 12, where the alkali metal hydroxide is sodium hydroxide. 14. Method according to claim 1, where the catalyst is tertiaryamine. 15. The method under claim 14, where the said tertiaryamines are selected from groups containing triethylamine, diisopropylethylamine, tributylamine, 4-N,N-dimethylaminopyridine, and 1,4-diazabiclooctane. 16. The method under claim 15, whereby the said tertiaryamine is triethylamine. 17. Method according to claim 1, where the catalyst is present in the range of approximately 0.1 mol to approximately 2 mol by percentage, which is relative to the total amount of phenol replaced in the structure by the ester used. 18. Preparation method for bis-methyl salicylate carbonate, a contact time method, which involves the contact of the esterified phenol with phosgene, a phase transfer catalyst, and a tertiary amine in an aqueous phase in a solvent-free mixture, where the aqueous phase maintains a pH of at least approximately 8.3 throughout the contact time. The phosgene is used in an amount corresponding to approximately 0.10 to approximately 1.20 molar equivalent of the esterified phenol. 19. The method under claim 18, where the phase transfer catalyst is selected from a group of quaternary ammonium compounds with structure III (chemical formula) (lll), where the independent R3-R6 are C1-C20 alkyl radicals, C4-C20 cycloalkyl radicals, or C4-C20 aryl radicals, and X is at least one organic or inorganic anion. Suitable anion X includes hydroxide, halide, carboxylate, sulfonate, sulfate, carbon, and bicarbonate. 20. The method under claim 19, where the said tertiary amines are selected from groups containing triethylamine, diisopropylethylamine, tributylamine, 4-N,N-dimethylaminopyridine, and 1,4-diazabiclooctane. 21. The method under claim 20, where the said tertiaryamine is triethylamine. 22. Preparation method of bis-methyl salicylate carbonate, such method involving contact time and contact temperature, which includes contact of methyl salicylate and an aqueous phase of approximately 0.10 to approximately 1.20 molar equivalent of phosgene and approximately 0.1 to approximately 2 molar percentages of at least one quaternary ammonium compound in a solvent-free mixture, such molar equivalent of phosgene and the molar percentage of the quaternary ammonium compound relative to the number of moles of methyl salicylate, the aqueous phase is maintained at a pH between approximately 8.3 and approximately 12 by adding an aqueous sodium hydroxide solution. 23. Method according to claim 22, where a quaternary ammonium compound has the structure (chemical formula) (III) where independent R3-R6 are C1-C20 alkyl radicals, C4-C20 cycloalkyl radicals or C4-C20 aryl radicals and X is at least one organic or inorganic anion. Suitable anions X include hydroxide, halide, carboxylate, sulfonate, sulfate, carbon and bicarbonate. 24. Method according to claim 23, where structure III is methyl tributyl ammonium chloride. 25. The method under claim 22, where the contact temperature is between approximately 5 and approximately 15°C. 26. The method under claim 22, where the contact time is between approximately 5 and approximately 60 minutes. 27. The method under claim 22, whereby bis-methyl salicylate carbonate, a product, is separated by filtration from the reaction mixture. 28. The method under claim 22, whereby bis-methyl salicylate carbonate, the product, is separated by a process step which includes the dissolution of the bis-methyl salicylate carbonate, the product, in methylene chloride.