Water → Trifluoroacetic acid

Participants

Reaction Conditions

Reaction Steps

To a suspension of commercially available ethyl 6-chloroimidazo[1,2-b]pyridazine-2-carboxylate (II Farmaco, 1997, 52, 4, 213) (66 mg, 0.255 mmol) in NMP (2.5 mL) was added 4-((8-azabicyclo[3.2.1]octan-3-yloxy)methyl)-5-cyclopropyl-3-(2-(trifluoromethoxy)phenyl)isoxazole (I-1) (120 mg, 0.29 mmol) and potassium fluoride (51 mg, 0.88 mmol). The mixture was heated at 200° C. for 30 minutes under microwave irradiation. The mixture was poured into water and extracted with ethyl acetate twice. The combined organic layers were washed with brine, dried over sodium sulfate, filtered and concentrated. The crude product was purified using mass-triggered reverse phase HPLC using gradient of 40 to 60% acetonitrile/water with 0.05% TFA as modifier to yield ethyl 6-(3-((5-cyclopropyl-3-(2-(trifluoromethoxy)phenyl)isoxazol-4-yl)methoxy)-8-azabicyclo[3.2.1]octan-8-yl)imidazo[1,2-b]pyridazine-2-carboxylate as TFA salt. 1H NMR (400 MHz, CDCl3) δ 8.17 (s, 1H), 7.67 (d, J=10.0 Hz, 1H), 7.54 (dd, J=7.6 and 2.0 Hz, 1H), 7.51 (dd, J=7.6 and 0.8 Hz, 1H), 7.40-7.37 (m, 2H), 6.72 (d, J=10.0 Hz, 1H), 4.43 (q, J=7.2 Hz, 4H), 4.32 (bs, 2H), 4.28 (bs, 2H), 3.48 (m, 1H), 2.14-2.07 (m, 1H), 2.05-1.86 (m, 6H), 1.69 (bs, 1H), 1.65 (bs, 1H), 1.42 (t, J=7.2 Hz, 3H), 1.25-1.20 (m, 2H), 1.13-1.08 (m, 2H). MS m/z 598.2 (M+1).

Provenance & Evidence