To a solution of 0.14 g of the product of Example 1 and 0.15 g of phenyl(4,6-dimethoxypyrimidin-2-yl)carbamate in 2 mL of dry acetonitrile was added 0.1 mL of 1,5-diazabicyclo[5.4.0]undec-5-ene. The solution was stirred for 15 minutes at room temperature, diluted with 2 mL of water and acidified with 5% hydrochloric acid to a pH of 4. The precipitated product was collected by filtration, washed thoroughly with water, washed with 1-chlorbutane, and dried in vacuo at 40° C. to afford 0.02 g of the subject compound, m.p. 127°-128° C. (dec).
