159326-71-3

888720-29-4

General procedure for the synthesis of 4-chloropyrrolo[1,2-f][1,2,4]triazine from pyrrolo[2,1-f][1,2,4]triazin-4(3H)-one: Step 3: Synthesis of 4-chloropyrrolo[1,2-f][1,2,4]triazine Diisopropylethylamine (3.5 mL, 20.3 mmol) was added to a solution of pyrrolo[1,2-f][1,2,4]triazin-4(3H)-one (2.5 g, 18.5 mmol) dissolved in toluene (37.5 mL) under nitrogen protection. Subsequently, phosphorus trichloride (5.1 mL, 55.7 mmol) was added and the reaction mixture was heated at 100 °C for 20 hours. Upon completion of the reaction, the mixture was cooled to 0 °C, aqueous sodium bicarbonate was added slowly and stirred at room temperature for 30 min. The aqueous layer was extracted with ethyl acetate and the organic phase was dried with magnesium sulfate and filtered. The filtrate was concentrated in vacuo to give a yellow solid product which could be used in the next reaction without further purification (2.31 g, 15.0 mmol, 81% yield). 1H NMR (400 MHz, CDCl3) δ: 8.22 (s, 1H), 7.87 (dd, J = 2.4 Hz, 1.6 Hz, 1H), 7.00-6.97 (m, 2H).