Formamidine acetate → HCID 178518023, compound

Participants

Reaction Conditions

Reaction Steps

A mixture of 4,5-difluoroanthranilic acid (20.43 g, 118 mmol) and formamidine acetate (13.55 g, 130 mmol) in reagent EtOH was stirred at 120° C. (oil bath) for 3 hr. The reaction was briefly a homogeneous brown solution, and then became an opaque mixture. The reaction was allowed to cool to rt, and the resulting solid was filtered, washed with denatured EtOH (1×10 mL), and allowed to air dry. Powdering with a mortar and pestle provided 4-hydroxy-6,7-difluoroquinazoline as a beige powder (16.9 g, 79%). 16.6 g of this material (91.1 mmol) was taken up in SOCl2 (66 mL), DCE (66 mL), and DMF (7.05 mL, 91 mmol), and was stirred at 110° C. (oil bath) for 1 hr. The resulting homogeneous amber solution was then concentrated under rotary evaporation, and taken up in toluene (2×100 mL) with repeated rotary evaporation to provide the crude title compound as a beige solid. A portion of this material (8.4 g of 17.7 g total) was taken up in DCM (80 mL) and gently shaken with 2M trisodium citrate (1×40 mL) until a homogeneous clear organic layer resulted. This organic layer was immediately applied (without drying) directly onto a silica flash column (79 mm×6″) pre-equilibrated with 1:1 hexanes/EtOAc. Trivial elution with 1:1 hexanes/EtOAc, followed by repeated rotary evaporation from toluene (2×50 mL) of the combined fractions afforded the title compound as a light yellow solid (6.79 g, 78%). 1H-NMR (400 MHz, CDCl3) δ 9.05 (s, 1H), 8.05 (dd, 1H), 7.86 (dd, 1H).

Provenance & Evidence