Hydrochloric Acid → HCID 10899987、化合物

A mixture of 5.8 g (26 mmol) of 5-ethoxy-7-fluoro-1,2,4-triazolo[4,3-c]pyrimidine-3(2H)-thione in 50 mL of absolute ethanol was prepared and to this was added at 0° C. with vigorous stirring and cooling 12.2 mL (33 mmol) of 21 weight percent sodium ethoxide in ethanol. A mildly exothermic reaction took place and the mixture changed from a suspension to a plum colored solution. The mixture was stirred at below 10° C. for 2.25 hours to complete the reaction. It was then acidified with 25 mL of 1.25N hydrochloric acid, stirred at -10° C. for 30 min, and filtered to recover the precipitate that formed. The precipitate was washed with 10 mL of cold water and dried to obtain 3.3 g (60 percent of theory) of the title compound of 98 percent purity. A second crop amounting to 1.7 g of 60 percent purity material (19 percent of theory) was obtained from the filtrate. The title compound melts at 83.5° C. to 86.5° C. and is a white solid.