Water → methyl 3-chloro-1-(pyridin-3-yl)-1H-pyrazole-5-carboxylate

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]+).

1. customwas consumed
2. extractionThe mixture was extracted with ethyl acetate (2×300 mL)
3. customthe organic layers were dried
4. concentrationconcentrated
5. customThe residue was purified by flash column chromatography
6. concentrationThe pure fractions were concentrated

ORD-Eintrag

ord-77082f727af942149a1e08917a13e0e7

Quelldatensatz

uspto-grants-2016_09

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US09434712B2