Hydrazine hydrate (1:1) → HCID 178468931, compound

HRID 2046181Notes

Reaction equation

O.[NH2:2][NH2:3].[CH2:4]([O:6][C:7](=[O:22])[C:8](=O)[CH2:9][C:10](=O)[CH:11]([O:13][C:14]1[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=1)[CH3:12])[CH3:5]>CCO>[CH2:4]([O:6][C:7]([C:8]1[NH:2][N:3]=[C:10]([CH:11]([O:13][C:14]2[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=2)[CH3:12])[CH:9]=1)=[O:22])[CH3:5]

Participants

Conditions

Temperature: 80 °C

Procedure

Hydrazine hydrate (41.7 μL, 0.4 mmol) was added to a stirred solution of 2,4-dioxo-5-phenoxy-hexanoic acid ethyl ester (566 mg, 2.14 mmol) in EtOH (4.5 mL). The mixture was stirred at 80° C. for 1 hour. Then, the mixture was stirred at room temperature for 16 hours. Hydrazine hydrate (20 μL, 0.2 mmol) was added and the mixture was stirred at 80° C. for 2 hours. More hydrazine hydrate (41.7 μL, 0.4 mmol) was added and the mixture was stirred at 80° C. for 2 hours. The solvent was evaporated in vacuo. The crude product was purified by flash column chromatography (silica, AcOEt in DCM 0/100 to 20/80). The desired fractions were collected and solvents evaporated in vacuo to yield (rac)-5-(1-phenoxy-ethyl)-2H-pyrazole-3-carboxylic acid ethyl ester (467 mg, 78% yield) as a colourless oil.

Workup

stirringThen, the mixture was stirred at room temperature for 16 hours
stirringthe mixture was stirred at 80° C. for 2 hours
stirringthe mixture was stirred at 80° C. for 2 hours
customThe solvent was evaporated in vacuo
customThe crude product was purified by flash column chromatography (silica, AcOEt in DCM 0/100 to 20/80)
customThe desired fractions were collected
customsolvents evaporated in vacuo

Sources & evidence

ORD record: ord-15078b5e6d064558885b886a8990e518
Source dataset: uspto-grants-2013_11
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08592422B2

Reaction notes

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