To a mixture of 0.4997 g (1.578 mmole) of 2-chloro-9-cyclopentyl-7,7-difluoro-5-methyl-5,7,8,9-tetrahydro-pyrimido[4,5-b][1,4]diazepin-6-one (VII-20), 0.3539 g (1.891 mmole) of 4-amino-2,3-difluorobenzoic acid, and 25 mL of dioxane, was added 1.028 g (3.152 mmole) of cesium carbonate and 0.0367 g (0.163 mmole) of palladium acetate. The mixture was deoxygenated with argon, 0.2044 g (0.318 mmole) of 1,1′-[1,1′-binaphthalene]-2,2′-diylbis[1,1-diphenyl phosphine was added and the reaction mixture was heated at 100 degrees for 4 hrs. The cooled mixture was concentrated under reduced pressure, dissolved in ethyl acetate, made slightly acidic by the addition of 1M hydrochloric acid, washed with water, brine, filtered and concentrated under reduced pressure. Purification by silica gel chromatography, eluting with dichloromethane-methanol (gradient, 95:5-80:20) gave 0.565 g of 4-(9-cyclopentyl-7,7-difluoro-5-methyl-6-oxo-6,7,8,9-tetrahydro-5H-pyrimido[4,5-b][1,4]diazepin-2-ylamino)-2,3-difluoro-benzoic acid methyl ester (I-242) as off-white solid.
