Hydroxylamine → HCID 136403314, compound

Participants

Reaction Steps

To 4-(2,6-difluorophenyl)-3-(4-hydroxyphenyl)-1-methyl-1H-pyrazole-5-carbaldehyde oxime (30.0 mg, 0.09 mmol) in acetic anhydride (1 mL) was irradiated in the microwave for 20 min. 1.5 ml water was added and the mixture was stirred at rt for 3 h, extracted with DCM, filtered through a phase separator and concentrated. The raw product was dissolved in DMSO (1 mL) and neutral hydroxylamine solution (50 wt % in water, 0.12 mL, 1.96 mmol) was added. The mixture was stirred in the microwave at 130° C. for 10 min. EtOAc and water were added and the phases were separated. The mixture was purified on preparative HPLC to give (Z)-4-(2,6-difluorophenyl)-N′-hydroxy-3-(4-hydroxyphenyl)-1-methyl-1H-pyrazole-5-carboximidamide (5.2 mg, 0.016 mmol, 18%). 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: 345.11 (M+H), 343.26 (M−H); 1H NMR (MeOD, 500 MHz): 7.37 (m, 1H), 7.15 (m, 2H), 6.96 (m, 2H), 6.65 (m, 2H) and 3.99 (s, 3H).

Provenance & Evidence