4-CHLORO-5-METHYL-IMIDAZO[5,1-F][1,2,4]TRIAZINE synthesis

Yield:865444-79-7 61%

Reaction Conditions:

with trichlorophosphate in N,N-dimethyl-aniline at 20 - 140; for 1 h;Heating / reflux;

Steps:

28.c

To an oven-dried one-neck reaction flask charged with a magnetic stir bar at rt under argon with a reflux condenser was added 5-methyl-3//-imidazo[5,l-/][l,2,4]triazin-4-one (0.170 g, 1.13 mmol), distilled phosphorous oxychloride (2.34 mL, 25.2 mmol) and NJV-dimethylaniline (0.505 mL, 3.95 mmol). The yellow suspension was refluxed for 1 h at 14O⁰C. The resulting black solution was cooled to rt and concentrated to a black residue. The residue was quenched over ice (5 mL) and then extracted with EtOAc (3 x 40 mL). The organic extracts were combined and dried over Na₂SO₄, filtered and concentrated to yield the crude product as a brown solid. It was purified by flash column chromatography (silica gel 12 g pre-packed column, elution with EtOAc:Hexanes, 1 :1) to give 0.1 16 g (61 %) of the title compound as a yellow solid. ¹ H NMR (CDCl₃) 8.42 (s, IH), 8.10 (s, IH), 2.79 (s, 3H).

References:

WO2008/57402,2008,A2 Location in patent:Page/Page column 67