4‐Aminochinazoline durch intramolekulare Friedel‐Crafts‐Reaktion

Polycyclic N‐heterocyclic compounds, part 67: Reaction of 6,7‐substituted N‐(quinazolin‐4‐yl)amidine derivatives with hydroxylamine hydrochloride: Formation of in vitro inhibitors of pentosidine

“…To a solution of 2‐amino‐4‐methylbenzonitrile (500 mg, 3.78 mmol) in dry 2‐ethoxyethanol (5.0 mL) was added formamidine acetate (2.00 g, 19.2 mmol) and the reaction mixture was refluxed for 1 h. After cooling to room temperature, water was added. The precipitate was filtered, washed with 10% aqueous sodium chloride solution, water, and then recrystallized from methanol to give 3d (473 mg, 79%) as colorless feathers, mp 288–289°C (lit [13] 286–289°C); IR (potassium bromide): 3240, 3330 (NH 2 ) cm −1 ; 1 H NMR (DMSO‐ d 6 ): δ 2.46 (s, 3H, 7‐Me), 7.32 (d, 1H, J = 8.4 Hz, H6), 7.46 (s, 1H, H8), 7.65 (br s, 2H, deuterium oxide exchangeable, NH 2 ), 8.09 (d, 1H, J = 8.4 Hz, H5), 8.34 (s, 1H, H2); FAB‐ms: m/z 160 (MH + ).…”