反应详情

A total of 128 g of potassium cyanate and 144 g of hydrogen chloride are metered into 700 g of sulfolane at 15-20° C. over a period of 5 hours. For this, 14.4 g of hydrogen chloride are first passed in and 12.8 g of potassium cyanate are then added; this operation is repeated 10 times, until the entire amount of hydrogen chloride and potassium cyanate has been added. 117 g of 4-chloro-N-(ethoxycarbonylmethyl)anthranilic acid are then added at 45-50° C. in the course of 2 hours. The mixture is subsequently stirred for 15 minutes. The suspension is filtered and the residue is washed free from sulfolane and salt with water. After drying, 121 g (95%) of ethyl 1,2,3,4-tetrahydro-7-chloro-2,4-dioxoquinazolin-1-ylacetate are obtained.

1. additionare then added
2. filtrationThe suspension is filtered
3. washthe residue is washed free from sulfolane and salt with water
4. customAfter drying