Hydrochloric Acid → N-ethyl-3-(3-ethoxy-4-nitrophenyloxy)-5-methylpyrazole-1-carboxamide

Participants

Reaction Steps

Triethylamine (0.07 g, 0.7 mmol) and ethyl isocyanate (0.12 g, 0.7 mmol) were added to a solution of 3-(3-ethoxy-4-nitrophenyloxy)-5-methylpyrazole (0.16 g, 0.6 mmol) in ethyl acetate (5 ml) at 0° C., and the mixture was allowed to have room temperature gradually and stirred for 5 hours. After completion of the reaction, the reaction mixture was poured into 1N hydrochloric acid (10 ml) and extracted with ethyl acetate (10 ml×2). An organic layer was washed with water (10 ml×2), dried over anhydrous magnesium sulfate and filtered to remove a desiccant, and the solvent was distilled off from the filtrate under reduced pressure. The resultant crude product was purified with a silica gel column (ethyl acetate/hexane=1/15), to give a yellow solid of N-ethyl-3-(3-ethoxy-4-nitrophenyloxy)-5-methylpyrazole-1-carboxamide (0.13 g, yield: 61.8%). mp: 110-112° C.; 1H-NMR (CDCl3, TMS, ppm): δ 1.24 (t, J=7.3 Hz, 3H), 1.49 (t, J=7.0 Hz, 3H), 2.63 (d, J=0.5 Hz, 3H), 3.40 (dq, J=6.0 and 7.3 Hz, 2H), 4.14 (q, J=7.0 Hz, 2H), 5.80 (q, J=0.5 Hz, 1H), 6.73 (dd, J=2.4 and 9.0 Hz, 1H), 6.82 (d, J=2.4 Hz, 1H), 6.92 (br s, 1H), 7.92 (d, J=9.0 Hz, 1H).

Provenance & Evidence