Hydroxylamine → 4-(2,4-dimethylthiophen-3-yl)-3-(2-fluoro-4-hydroxyphenyl)-N'-hydroxy-1-methyl-1H-pyrazole-5-carboximidamide

Participants

Reaction Conditions

Reaction Steps

To a solution of 4-(2,4-dimethylthiophen-3-yl)-3-(2-fluoro-4-hydroxyphenyl)-1-methyl-1H-pyrazole-5-carbonitrile (7 mg, 0.02 mmol) in DMSO (0.6 mL) was added neutral hydroxylamine solution (16 M in water, 0.33 mL, 5.35 mmol) The reaction was heated at 150° C. in the microwave for 15 min. EtOAc and water were added and the phases were separated. The crude product was purified on preparative HPLC to give 4-(2,4-dimethylthiophen-3-yl)-3-(2-fluoro-4-hydroxyphenyl)-N′-hydroxy-1-methyl-1H-pyrazole-5-carboximidamide (3.62 mg, 47%). Identification of the title compound by 1H-NMR showed that the oxime product was a single isomer, but did not confirm whether the (E) or (Z) oxime isomer had been obtained. ES/MS m/z: 361.06 (M+H), 359.14 (M−H); 1H NMR (acetone-d6, 500 MHz): 7.05 (t, 1H, J=8.6 Hz), 6.77 (q, 1H, J=0.9 Hz), 6.59 (dd, 1H, J=8.6, 2.5 Hz), 6.51 (dd, 1H, J=11.7, 2.5 Hz), 4.01 (s, 3H), 2.07 (s, 3H) and 1.88 (d, 3H, J=0.9 Hz).

Provenance & Evidence