反应详情

温度

65 °C

A four-necked, five-liter round-bottomed reaction flask equipped with a thermometer, condenser, mechanical stirrer, and air sparger is charged with 1,920 g (16.1 moles) of 2-hydroxypropyl carbamate, 2,236 g (14.5 moles) of distilled methacrylic anhydride, 83 g of anhydrous pyridine, and 4.2 g (1,000 parts per million) methoxyhydroquinone. The reaction mass is stirred and slowly heated to 65° C. with a hot-water bath. During this heating period and during the course of the reaction, the reaction mass is sparged with air. The reaction mass is held at 65° C. until the concentration of methacrylic anhydride decreased to less than 1.5 percent by weight. The resulting product is then washed with a saturated solution of sodium carbonate, and the aqueous layer removed from the solids by decantation. This washing procedure is repeated two more times to neutralize all of the methacrylic acid. The resulting solid product is then washed twice with a total of two gallons of distilled water. For each wash, the solids are melted by heating the wash water to 50° C. During the washing procedure, the melted solids are well stirred and the aqueous material is allowed to separate from the molten organic material and decanted before the desired product resolidifies. The wet product is dried overnight in a hood to yield 2,000 g of anhydrous 2-hydroxypropyl carbamate methacrylate that analysis indicates has a 97% purity.

1. customA four-necked, five-liter round-bottomed reaction flask equipped with a thermometer, condenser, mechanical stirrer, and air sparger
2. waitDuring this heating period
3. customduring the course of the reaction
4. customthe reaction mass is sparged with air
5. customis held at 65° C. until the concentration of methacrylic anhydride
6. washThe resulting product is then washed with a saturated solution of sodium carbonate
7. customthe aqueous layer removed from the solids by decantation
8. washThe resulting solid product is then washed twice with a total of two gallons of distilled water
9. temperatureby heating the wash water to 50° C
10. stirringDuring the washing procedure, the melted solids are well stirred
11. customto separate from the molten organic material
12. customdecanted before the desired product
13. customThe wet product is dried overnight in a hood