Phosgene → 2-Isocyanatoethyl methacrylate

Participants

Reaction Conditions

Reaction Steps

A 20 gallon glass-lined jacketed reactor equipped with a recycle line and heat exchanger was charged with 9,979 g of methylene chloride (two gallon) and 11,340 g (3 gallons) of water. The recycle pump was started and the reactor cooled to approximately 0° C. A solution of 2-isopropenyl-2-oxazoline (2,268 g) in 7,598 g of water, a solution of phosgene (2,977 g) in 11,340 g of methylene chloride, and a solution of 35 percent sodium hydroxide (approximately 9,525 g) were added simultaneously to the reactor with stirring and cooling during a time period of approximately 65 minutes. The reaction temperature rose to approximately 16° C. during the course of the addition. Stirring at 116 rpm was continued for an additional 3 minutes. The aqueous and organic layers were allowed to separate and the organic layer recovered. The organic layer was then dried by passing it through 3 angstrom molecular sieves and inhibited with 25 g of phenothiazine and concentrated under reduced pressure. A final vacuum distillation at 46°-47° C./0.4 mm Hg gave 2,681 g of 2-isocyanatoethyl methacrylate for an 84.7 percent yield. In three other duplicate runs, the yields range from 78 percent to the above 84.7 percent yield. This is an average of 82 percent over the 4 runs.

Provenance & Evidence