Tetrahydrofuran → HCID 178520647, Verbindung

Temperatur

5 °C

A 250-mL 3-neck flask was charged with 3-chloro-1H-pyrazol-4-amine•hydrochloride (10.0 g, 64.9 mmol), tetrahydrofuran (50 mL), and water (50 mL). The resulting suspension was cooled to 5° C. and sodium bicarbonate (17.6 g, 210 mmol) was added, followed by dropwise addition of 3-chloropropanoyl chloride (7.33 g, 57.7 mmol) at <5° C. The reaction was stirred at <10° C. for 1 hour, at which point thin layer chromatography (TLC) [Eluent: 1:1 ethyl acetate (EtOAc)/hexane] analysis indicated the starting material was consumed and the desired product was formed. It was diluted with water (50 mL) and ethyl acetate (50 mL) and the layers separated. The aqueous layer was extracted with ethyl acetate (20 mL) and the combined organic layers were concentrated to dryness to afford a pale brown solid, which was purified by flash column chromatography using ethyl acetate as eluent. The pure fractions were concentrated to afford a white solid (9.20 g, 77%): mp: 138-140° C.; 1H NMR (400 MHz, DMSO-d6) δ 12.91 (s, 1H), 9.68 (s, 1H), 8.03 (d, J=1.7 Hz, 1H), 3.85 (t, J=6.3 Hz, 2H), 2.85 (t, J=6.3 Hz, 2H); 13C NMR (101 MHz, DMSO-d6) δ 167.52, 130.05, 123.59, 116.48, 40.75, 37.91; EIMS m/z 207 (m+).

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ORD-Eintrag

ord-8cdc94bb6ce1435fa4135eab835ea47a

Quelldatensatz

uspto-grants-2016_09

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US09433215B2