反应详情

A suspension of 8 g of the product of Example 7 and 0.4 g of DABCO in 90 ml of xylenes was heated under N2 at 130°-135° C. while 1.8 ml of phosgene was added portionwise at a rate to maintain a reflux temperature of about 130°-135° C. The mixture was refluxed an additional two hours, cooled under N2 to room temperature, filtered, and the filtrate was concentrated in vacuo to yield 6.9 g of the subject compound as a crude oil.

1. additionwas added portionwise at a rate
2. temperatureto maintain a reflux temperature of about 130°-135° C
3. temperatureThe mixture was refluxed an additional two hours
4. filtrationfiltered
5. concentrationthe filtrate was concentrated in vacuo