Reaktion #64258

Reaktionsgleichung

2-hydroxypropyl carbamate

methacrylic anhydride

→

2-hydroxypropyl carbamate methacrylate

Ausbeute 67.2%

Lösungsmittel

pyridine

Reaktionsbedingungen

Aufarbeitung

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

Vorschrift

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.

Quelle