反应详情

温度

80 °C

Into a 2000 mL flask was weighed 35.33 g (223.5 mmol) of 2,4-dioxopentanoic acid ethyl ester, 50 g (234.7 mmol) of 2,6 dichlorophenyl hydrazine, 400 mL of acetic acid and 400 mL of ethanol. The resulting solution was heated at 80° C. for 18 h and was then cooled and was washed into a separatory funnel with 1.0 M aq. NaOH and ethyl acetate. The organic layer was separated, washed with sat. aq. NaHCO3, brine, dried over Na2SO4, and was concentrated in vacuo. The residue was recrystallized from EtOH-heptanes to afford 1-(2,6-dichlorophenyl)-5-methyl-1H-pyrazole-3-carboxylic acid ethyl ester (44.6 g, 60%); 1H NMR (400 MHz, DMSO-d6): δ 7.67 (d J=7.67 Hz, 2H), 7.57 (m, 1H), 4.17 (q, J=7.07 Hz 2H), 1.97 (s, 3H); 1.18 (t, J=7.07 Hz 3H), MS (ES): 321 [M+Na]+.

1. customInto a 2000 mL flask was weighed
2. temperaturewas then cooled
3. washwas washed into a separatory funnel with 1.0 M aq. NaOH and ethyl acetate
4. customThe organic layer was separated
5. washwashed with sat. aq. NaHCO3, brine
6. dry with materialdried over Na2SO4
7. concentrationwas concentrated in vacuo
8. customThe residue was recrystallized from EtOH-heptanes