반응 #85390

반응 방정식

Methyl 3-chloro-1-(pyridine-3-yl)-4,5-dihydro-1H-pyrazole-5-carboxylate

water

diammonium cerium (IV) nitrate

→

desired product

수율 57.4%

Methyl 3-chloro-1-(pyridin-3-yl)-1H-pyrazole-5-carboxylate

수율 57.4%

용매

tetrahydrofuran

반응 조건

후처리

1. 1
   기타was consumed
2. 2
   추출The mixture was extracted with ethyl acetate (2×300 mL)
3. 3
   기타the organic layers were dried
4. 4
   농축concentrated
5. 5
   기타The residue was purified by flash column chromatography
6. 6
   농축The pure fractions were concentrated

실험 절차

Methyl 3-chloro-1-(pyridine-3-yl)-4,5-dihydro-1H-pyrazole-5-carboxylate (2.63 g, 11.0 mmol) was stirred in tetrahydrofuran (50 mL) and water (50 mL) at 0° C. diammonium cerium (IV) nitrate (15.0 g, 27.4 mmol) was added in portions and the reaction was stirred at room temperature for 18 hours. thin layer chromatography analysis indicated that the starting material was consumed. The mixture was extracted with ethyl acetate (2×300 mL) and the organic layers were dried and concentrated. The residue was purified by flash column chromatography using 50-100% ethyl acetate/hexanes as eluent. The pure fractions were concentrated to provide the desired product as a yellow solid (1.50 g, 52%): mp 99-102° C.; 1H NMR (400 MHz, DMSO-d6) δ 9.00 (dd, J=2.5, 0.7 Hz, 1H), 8.83 (dd, J=5.2, 1.5 Hz, 1H), 8.35 (ddd, J=8.3, 2.5, 1.4 Hz, 1H), 7.83 (ddd, J=8.3, 5.2, 0.7 Hz, 1H), 7.35 (s, 1H), 3.78 (s, 3H); 13C NMR (101 MHz, CDCl3) δ 158.34, 149.90, 146.89, 141.39, 136.09, 134.77, 133.30, 123.14, 112.01, 52.53; ESIMS m/z 238 ([M+H]+).

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