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hexaethylguanidinium chloride; at 100℃; for 3h;Product distribution / selectivity;
COMPARATIVE EXAMPLES 1, 2, AND 4; EXAMPLES 3 AND 5-9; Comparative Example 1; This example was conducted without the use of polymerization inhibitors. To a 100 ml 4-neck round bottom flask fitted with a reflux condenser, thermocouple and magnetic stirrer was charged 4.98 grams (46 mmoles) of sodium methacrylate, 32.3 grams (163 mmoles) of chloropropyltrimethoxysilane and 0.10 grams (0.38 mmole) of hexaethylguanidinium chloride. The mixture was heated to 100 C. and held at that temperature for 3 hours. After this time the reaction mixture was cooled to room temperature and analyzed by gas chromatography. The crude reaction mixture was found to contain 29.2% methacryloxytrimethoxysilane. This represents an 88% yield based on the theoretical amount of contained product.
94%Chromat.
With 4,4'-Methylenebis(2,6-di-tert-butylphenol);hexaethylguanidinium chloride; In chlorobenzene; xylene; at 100℃; for 5h;Product distribution / selectivity;
Comparative Example 4; This example illustrates the alternate preparation of methacryloxypropyltrimethoxysilane using a diluent solvent and water wash (extraction) to remove by-product sodium chloride salt from the crude product. To a 1000 ml 4-neck round bottom flask fitted with a reflux condenser, thermocouple, and mechanical stirrer was charged 153.21 grams (1.42 moles) of sodium methacrylate, 0.59 grams (1.4 mmoles) Ethanox 702, 253.24 grams (1.27 moles) chloropropyltrimethoxysilane, and 112.33 grams of xylene. The mixture was heated to 100 C. At this temperature 38.66 grams of a 14.5% solution of hexaethylgaunidinium chloride in chlorobenzene was added. The reaction mixture was held at 100 C. for 5 hours. The resultant dark purple solution was then cooled to 50 C. and 257.5 grams of de-ionized water was added to the reaction vessel and stirred until the salt dissolved. The flask contents were poured into a 1-liter separatory funnel and the water layer removed. The organic portion was analyzed by gas chromatography and found to contain 63.7 weight percent methacryloxypropyltrimethoxysilane (94% of theory).
98%Chromat.
With 4,4'-Methylenebis(2,6-di-tert-butylphenol);hexaethylguanidinium chloride; at 100℃; for 5.5h;Product distribution / selectivity;
C. Use of Co-Dried Sodium Methacrylate and Hexaethylguanidinium Chloride; To a 500 ml 4-neck round bottom flask fitted with a reflux condenser, thermocouple, and mechanical stirrer was charged 45.29 grams of the sodium methacrylate/hexaethylgaunidinium chloride prepared in the above preparation. This mixture contains 0.797 grams (3.02 mmoles) of hexaethylgaunidinium chloride and 44.49 grams (412 mmole) of sodium methacrylate. Also charged to the reaction vessel was 122.89 grams (618 mmole) of chloropropyltrimethoxysilane and 0.16 (0.37 mmole) of Ethanox 702. This mixture was heated to 100 C. and held at that temperature for 5.5 hours. A sample of the crude reaction mixture contained 69.9 weight percent (98% of theory) methacryloxypropyltrimethoxysilane as determined by gas chromatography.
98%Chromat.
With 2,6-di-tert-butyl-4-methyl-phenol; 4,4'-Methylenebis(2,6-di-tert-butylphenol);hexaethylguanidinium chloride; In 1,2-dichloro-benzene; at 100℃; for 4h;Product distribution / selectivity;
Comparative Example 2; This example was conducted with the use of polymerization inhibitors. To a 250 ml 4-neck round bottom flask fitted with a reflux condenser, thermocouple, and mechanical stirrer was charged 31.34 grams (290 mmole) of sodium methacrylate, 83.22 g (419 mmoles) chloropropyltrimethoxysilane, 0.04 grams of 2,6-di-t-butyl-4-methylphenol (BHT, 0.18 mmole), 0.12 grams of Ethanox 702, and 6.0 grams of a 20% solution of hexaethylguanidinium chloride in o-dichlorobenzene (1.2 grams hexaethylguanidinium chloride, (4.5 mmole). This mixture was heated to 100 C. for 4 hours. After this time the resultant dark purple solution was analyzed by gas chromatography and found to contain 68.0% of methacryloxypropyltrimethoxysilane (98% of theory).
72.3%Chromat.
With 2,6-di-tert-butyl-4-methyl-phenol; 4,4'-Methylenebis(2,6-di-tert-butylphenol);hexaethylguanidinium chloride; at 110℃; for 3h;Product distribution / selectivity;
Example 5; This example illustrates the use of sodium methoxide as the neutralizing base. To a 500 ml 4-neck round bottom flask equipped with a reflux condenser, addition funnel, thermocouple and magnetic stirrer was charged 38.67 grams (0.45 moles) of methacrylic acid and 52.12 grams of methanol. To the addition funnel was charged 95.89 grams of a 25% solution of sodium methoxide in methanol (23.97 grams of contained sodium methoxide, 0.44 moles, 98.6% of theoretical). The sodium methoxide solution was slowly added to the methacrylic acid over a 1.3 hour period with vigorous stirring. Near the end of the addition the amount of formed solids made stirring difficult. After all of the sodium methoxide solution was charged, the addition funnel was rinsed with 17.53 grams of methanol. To the resulting thick slurry was added 3.21 grams of a 34% aqueous solution of hexaethylguanidinium chloride solution (1.09 grams of contained hexaethylguanidinium chloride, 4.1 mmoles). This material was rinsed into the reaction flask with 7.58 grams of methanol. The methanol was removed by mildly heating the reaction slurry under vacuum. The remaining paste was further dried by heating in a vacuum oven at 90 C. and 125 mmHg overnight. The resulting dry solids were broken up with a spatula and the reaction flask fitted with a reflux condenser, thermocouple and mechanical stirrer. To the solids were added 0.192 grams (0.45 mmoles) of 4,4'-methylenebis(2,6-di-t-butylphenol), 0.081 grams (0.36mmoles) of butylated hydroxytoluene (BHT) and 131.58 grams (0.66 moles) of chloropropyltrimethoxysilane. The mixture was then heated to 110 C. for 3 hours. During this time the color of the reaction mixture changes from purple to yellow. Analysis of the final product by gas chromatograpy indicated that the crude reaction mixture contained 72.3% of the desired gamma-methacryloxypropyltrimethoxysilane.
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