Sodium hydride → 3-Amino-7-chloro-1-cyclopropyl-6-fluoro-1H-pyrido[2,3-d]pyrimidine-2,4-dione

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Reaction Steps

A solution of 3.83 g (15 mmol) of 7-chloro-1-cyclopropyl-6-fluoro-1H-pyrido[2,3-d]pyrimidine-2,4-dione (Example 23i) in 50 mL of dimethylformamide-dioxane (1:1) is cooled to 0° C. and treated portionwise with 0.8 g (20 mmol) of 60% sodium hydride/mineral oil. The reaction is stirred to room temperature for 30 minutes, re-cooled to 0° C. and 3.2 g (16 mmol) of 2,4-dinitrophenylhydroxylamine is added all at once. After stirring at room temperature overnight, the dioxane is removed in vacuo and the residue is diluted to 300 mL with ice and water and stirred at 5° C. for 1 hour. The precipitate is removed by filtration, washed with water, ether and dried in vacuo to give 2.65 g of the title compound, mp 192–194° C. A second crop, (0.6 g) could be isolated by evaporating the filtrate and triturating the residue with petroleum ether.

Provenance & Evidence