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

Participants

Reaction Conditions

Reaction Steps

Hydroxylamine (50 wt % solution in water, 0.8 mL, 13.5 mmol) was added to 5-(2,5-dimethyl-1H-pyrrol-1-yl)-1-(2-fluoro-4-hydroxyphenyl)-3-methyl-1H-pyrazole-4-carbonitrile (28 mg, 0.09 mmol) dissolved in MeOH (1.6 mL). The reaction was heated at 150° C. in the microwave for 15 min. Purification using preparative HPLC gave 5-(2,5-dimethyl-1H-pyrrol-1-yl)-1-(2-fluoro-4-hydroxyphenyl)-N′-hydroxy-3-methyl-1H-pyrazole-4-carboximidamide (8.68 mg, 28%). 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: 344.14 (M+H), 342.25 (M−H); 1H NMR (acetone-d6, 500 MHz): 7.13 (t, 1H, J=8.5 Hz), 6.68 (m, 2H), 5.76 (s, 2H), 2.40 (s, 3H) and 1.95 (s, 6H).

Provenance & Evidence