Phosphorus oxychloride → 4-Chloropyrrolo(2,1-f)(1,2,4)triazine

Participants

Reaction Conditions

Reaction Steps

To a solution of pyrrolo[2,1-f][1,2,4]triazin-4-ol (3.70 g, 27.4 mmol, see generally, PCT Appi. WO 2000/071129 the disclosure of which is herein incorporated by reference in its entirety) in 40 mL of toluene at room temperature was added 4.77 mL (27.4 mmol) of diisopropylethylamine followed by 7.70 mL (82.6 mmol) of phosphorus oxychloride. The reaction mixture was heated at 100° C. for 18 h. After cooling to room temperature, the reaction was slowly added to a solution of 5% aq NaHCO3 solution (100 mL) at 0° C. Upon completion of the addition, the biphasic mixture was allowed to stir at room temperature for 30 min. The aqueous layer was extracted with EtOAc (3×100 mL) and the pooled organic extracts were washed with brine (100 mL), dried over anhydrous MgSO4, and concentrated in vacuo to give the crude product (4.10 g, 97%) as a yellow solid. 1H NMR (CDCl3) δ 8.14 (s, 1H), 7.80 (dd, 1H, J=2.4, 1.5 Hz), 6.91 (m, 2H).

Provenance & Evidence