15 ml of phosphoryl chloride were added to 1.50 g (3.149 mmol) of the compound from Example 82A, and the mixture was stirred overnight. The reaction mixture was then taken up in 222 ml of acetonitrile and, with ice cooling, stirred into 133 ml of concentrated ammonia solution (33% in water). The reaction mixture was stirred at room temperature overnight and then concentrated on a rotary evaporator. Ethanol and water were added to the residue. A precipitate formed, which was filtered off and then washed with diethyl ether. Drying under high vacuum gave 982 mg of the title compound (70% of theory).
