反应详情

温度

100 °C

The β-(methacryloyloxy)-ethyl thioxanthone-1-carboxylate used in the above Examples 1-3 is prepared as follows: Dry sodium thiophenolate prepared from 7.5 g (0.33 gram equivalent) of sodium, 300 ml of methanol and 36 ml (0.33 mol) of thiophenol is dissolved in 300 ml of dimethylsulfoxide, and 80.4 g (0.3 mol) of 3-nitrophthalic acid N-phenylimide are added. The reaction mixture is heated at 50° C. for 90 minutes and then poured into a mixture of 300 ml of water and 300 ml of anhydrous acetic acid. The resulting suspension is filtered with suction and the product is dried at 80° C./13,000 Pa. 100 g (100% of theory) of 3-phenylthiophthalic acid N-phenylimide are obtained. 99.4 g (0.3 mol) of 3-phenylthiophthalic acid N-phenylimide are suspended in 1,326 ml of a 20% sodium hydroxide solution and the suspension is heated at 100° C. for 30 minutes, with stirring. After cooling, the alkaline suspension is acidified with 672 ml of 37% hydrochloric acid, with stirring. After one hour, the fine suspension is filtered with suction, the material on the suction filter is suspended, whilst still wet, in 882 ml of 37% hydrochloric acid and the suspension is refluxed for one hour. The reaction mixture is cooled, the resulting fine suspension is filtered with suction and the product is dried at 80° C./13,000 Pa. 69.4 g (85% of theory) of 3-phenylthiophthalic acid are obtained. 69 g (0.25 mol) of 3-phenylthiophthalic acid and 700 ml of polyphosphoric acid are heated at 200° C. for 90 minutes, with stirring, then cooled and stirred into 3,000 ml of water. After one hour the resulting suspension is filtered with suction and the material on the suction filter is washed with water and dried at 80° C. The resulting crude product is dissolved in 350 ml of hot N,N-dimethylformamide, animal charcoal is added and the mixture is filtered. The filtrate is diluted with five times the amount of water, the resulting suspension is filtered and the product is washed with water and dried. 63 g (98% of theory) of thioxanthone-1-carboxylic acid are obtained; melting point 259° C. The acid obtained in this way can be further used direct. 82 g (0.32 mol) of thioxanthone-1-carboxylic acid in 460 ml of thionyl chloride are refluxed for 5 hours. The resulting dark, clear solution is evaporated to dryness. 87.5 g (100% of theory) thioxanthone-1-carboxylic acid chloride are obtained. 11 g (0.04 mol) of thioxanthone-1-carboxylic acid chloride and 10.4 g (0.08 mol) of 2-hydroxyethyl methacrylate in 170 ml of dioxane are heated at 80° C. for 3 hours and the mixture is then evaporated to dryness. The solid residue is stirred with 100 ml of water and the pH of the resulting suspension is adjusted to 8 with a 3% sodium bicarbonate solution. The crude product is then extracted with 200 ml of methylene chloride, the extract is dried over solid sodium sulfate and the methylene chloride is evaporated. The residue is dissolved in 100 ml of methanol and the solution is filtered with 4 g of animal charcoal. The product which has crystallised out is dissolved in 1,200 ml of diethyl ether and extracted with 50 ml of 1% sodium hydroxide solution. The ether phase is washed with water and dried over sodium sulfate. The ethereal solution is then stabilised with 0.05% by weight of 2,6-di-tert.-butyl cresol and concentrated. 7.7 g (52% of theory) of β-(methacryloyloxy)-ethyl thioxanthone-1-carboxylate are obtained; melting point 112°-113° C. IR spectrum (chloroform): 1740 cm-1 (--COOR); 1660 cm-1 (--CO--).

1. temperatureAfter cooling
2. stirringwith stirring
3. filtrationthe fine suspension is filtered with suction
4. filtrationthe material on the suction filter
5. temperaturewhilst still wet, in 882 ml of 37% hydrochloric acid and the suspension is refluxed for one hour
6. temperatureThe reaction mixture is cooled
7. filtrationthe resulting fine suspension is filtered with suction
8. customthe product is dried at 80° C./13,000 Pa