(2-Methoxyphenyl)hydrazine monohydrochloride → 5-Isopropyl-1-(2-methoxy-phenyl)-1H-pyrazole-3-carboxylic acid ethyl ester

HRID 869061Notes

Reaction equation

[CH3:1][O:2][C:3]1[CH:8]=[CH:7][CH:6]=[CH:5][C:4]=1[NH:9][NH2:10].[CH2:11]([O:13][C:14](=[O:23])[C:15](=O)[CH2:16][C:17](=O)[CH:18]([CH3:20])[CH3:19])[CH3:12]>CCO.C1(C)C=CC=CC=1>[CH2:11]([O:13][C:14]([C:15]1[CH:16]=[C:17]([CH:18]([CH3:19])[CH3:20])[N:9]([C:4]2[CH:5]=[CH:6][CH:7]=[CH:8][C:3]=2[O:2][CH3:1])[N:10]=1)=[O:23])[CH3:12]

Participants

Conditions

Temperature: 100 °C

Procedure

2-Methoxyphenylhydrazine (14.07 g, 81 mmol) in EtOH (100 mL) was added dropwise to a refluxing solution of 5-methyl-2,4-dioxo-hexanoic acid ethyl ester (10 g, 53.7 mmol) in toluene (100 mL), under an argon atmosphere. The reaction mixture was stirred for 18 h at 100° C., allowed to cool to rt, concentrated, diluted with a saturated aqueous solution of sodium bicarbonate (250 mL), and extracted with EtOAc. The organic extracts were washed with a saturated aqueous solution of sodium bicarbonate, dried (Na2SO4), filtered, and concentrated. The residue was purified by silica gel column chromatography (hexane/EtOAc, 95:5→7:3) to provide 10.1 g of the title compound. tR: 1.11 min (LC-MS 4);

Workup

temperatureto cool to rt
concentrationconcentrated
additiondiluted with a saturated aqueous solution of sodium bicarbonate (250 mL)
extractionextracted with EtOAc
washThe organic extracts were washed with a saturated aqueous solution of sodium bicarbonate
dry with materialdried (Na2SO4)
filtrationfiltered
concentrationconcentrated
customThe residue was purified by silica gel column chromatography (hexane/EtOAc, 95:5→7:3)

Sources & evidence

ORD record: ord-8c1c7992b79340ebaa94a51d9afde95c
Source dataset: uspto-grants-2015_03
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08969341B2

Reaction notes

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