Reaction Steps
To a solution of sodium ethoxide, prepared by reacting sodium (0.28 g, 12 mmol) with ethanol(6 ml), was added guanidine hydrochloride (1.2 g, 12 mmol) and the mixture was briefly stirred at reflux. A solution of methyl 5-(N-(4-cyanophenyl)-2,2,2-trifluoroacetamido)-3,4-dihydro-2-hydroxy-1-naphthalene carboxylate (0.63 g, 1.5 mmol) in ethanol (6 ml) was added and the reaction mixture was stirred at reflux under nitrogen for 18 hours. The solution was diluted with water (50 ml), neutralized with acetic acid, and the resulting precipitate filtered and dried at 110° C. under reduced pressure. A solution of the solid in pivalic anhydride (10 ml) was refluxed for 5 minutes and then concentrated under high vacuum. The residue was eluted on silica gel (30 g) with ethyl acetate:methylene chloride (1:9) and the resulting solid recrystallized from diethyl ether, the slurry diluted with hexane, filtered, and the solid dried at 100° C. under reduced pressure to give N-(7-(4-cyanoanilino)-1,2,5,6-tetrahydro-1-oxobenzo[f]quinazolin-3-yl)pivalamide (0.48 g). 1H NMR (DMSO-d6, 200 MHz) δ: 1.23 (s, 9H, t-butyl), 2.67 (s, 4H, ArCH2's), 6.68 (d, J=9 Hz, 2H, Ar), 7.10 (d, J=8 Hz, 1H, Ar), 7.26 (t, J=8 Hz, 1H, Ar), 7.50 (d, J=9 Hz, 2H, Ar), 8.38 (d, J=8 Hz, 1H, Ar), 8.53 (s, 1H, C7—NH), 11.28 (br s, 1H, N2H), 12.16 (br s, 1H, C3—NH). A solution of the pivalamide (0.15 g) and 10% palladium on carbon (70 mg) in diglyme (5 ml) was stirred at reflux under nitrogen for 10 hours. Pivalic anhydride (2×0.5 ml, 4.9 mmol) was added at 5 and 9 hours. The solution was diluted with diglyme (15 ml), filtered hot through celite, and concentrated under high vacuum. The residue was purified by chromatography on silica gel (15 g) eluting with ethyl acetate:methylene chloride (1:9) and then recrystallization from methanol. The solid was filtered and dried at 90° C. under reduced pressure to give N-(7-(4-cyanoanilino)-1,2-dihydro-1-oxobenzo[f]quinazolin-3-yl)pivalamide (86 mg). 1H NMR (DMSO-d6, 200 MHz) δ: 1.26 (s, 9H, t-butyl), 6.85 (d, J=9 Hz, 2H, Ar), 7.49-7.60 (m, 4H, Ar), 7.72 (t, J=8 Hz, 1H, Ar); 8.29 (d, J=9 Hz, 1H, Ar); 9.07 (s, 1H, C7—NH), 9.61 (d, J=9 Hz, 1H, Ar), 11.25 (br s, 1H, N2H), 12.32 (br s, 1H, C3—NH). Mass spectrum (CI—CH4) 412 (M+1, 100%). Anal. Calculated for C24H21N5O2.17/100H2O: C, 69.54; H, 5.19; N, 16.89. Found: C, 69.56; H, 5.23; N, 16.88.
