N-(2-Oxoethyl)phthalimide

78902-09-7

2913-97-5

Example 5: Preparation of N-2-[4-(4-bromo-2-fluorophenylamino)-7-(1-methylpiperidin-4-ylmethoxy)-quinazolin-6-ylamino]-ethyl-propenamide Step 5-1: Synthesis of 1,3-dioxo-1,3-dihydroisoindol-2-yl acetaldehyde Phthalimidoacetaldehyde diethyl acetal (10 g, 0.0379 mol) was dissolved in 100 mL of aqueous 1N HCl, refluxed and stirred for 1 hour. Upon completion of the reaction, the reaction solution was extracted with 200 mL of dichloromethane, followed by washing the organic layer with 100 mL of saturated saline. The solvent was removed by distillation under reduced pressure to give N-(2-acetaldehyde-based) phthalimide 7.16 g (yield: 99%). 1H NMR (CDCl3) δ: 9.66 (s, 1H), 7.90-7.84 (m, 2H), 7.78-7.73 (m, 2H), 4.56 (s, 2H).