Ethyl 3-[(2-chloro-5-nitropyrimidin-4-YL)(cyclopentyl)amino]-2,2-difluoropropanoate → 2-Chloro-9-cyclopentyl-7,7-difluoro-8,9-dihydro-5H-pyrimido[4,5-B][1,4]diazepin-6(7H)-one

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Reaction Steps

To a solution of 6.16 g (0.016 mole) of 3-[(2-chloro-5-nitro-pyrimidin-4-yl)-cyclopentyl-amino]-2,2-difluoro-propanoic acid ethyl ester (IV-20) in 120 mL of acetic acid was added 6.0 g (0.11 g-atom) of iron powder. The mixture was heated to 80 degrees for 2 hours and then filtered while hot. Water and ethyl acetate were added to the filtrate and the mixture was stirred for 10 minutes and then filtered. The layers were separated. The organic layer was washed successively with ammonium hydroxide and water, dried over anhydrous magnesium sulfate, filtered and concentrated under reduced pressure. Recrystallization of the residue with ethyl acetate and hexane gave 2.94 g of 2-chloro-9-cyclopentyl-7,7-difluoro-5,7,8,9-tetrahydro-pyrimido[4,5-b][1,4]diazepin-6-one (VI-20).

Provenance & Evidence