Hydrazine hydrate (1:1) → 4-[1-(3-Cyclopentyloxy-4-methoxy-phenyl)ethyl]-5-methylpyrazol-3-one

HRID 1871533Notes

Reaction equation

[C:1]([CH:4]([CH:9]([C:11]1[CH:16]=[CH:15][C:14]([O:17][CH3:18])=[C:13]([O:19][CH:20]2[CH2:24][CH2:23][CH2:22][CH2:21]2)[CH:12]=1)[CH3:10])[C:5](OC)=[O:6])(=O)[CH3:2].O.[NH2:26][NH2:27]>C(O)C>[CH:20]1([O:19][C:13]2[CH:12]=[C:11]([CH:9]([C:4]3[C:5](=[O:6])[N:26]=[N:27][C:1]=3[CH3:2])[CH3:10])[CH:16]=[CH:15][C:14]=2[O:17][CH3:18])[CH2:24][CH2:23][CH2:22][CH2:21]1

Participants

Conditions

Temperature: 0 °C

Procedure

To a stirred solution of methyl 2-acetyl-3-(3-cyclopentyloxy-4-methoxyphenyl)-butanoate (362 mg, 1.08 mmol) in absolute ethanol (10 ml) at 0° C. was added hydrazine monohydrate (54 mg, 1.08 mmol) in one portion. The resulting solution was stirred at 0° C. for 45 minutes and then refluxed at 80° C. for 3 hours. Further hydrazine monohydrate (15.6 mg, 3.1×10-4 mol) was added and refluxing continued for a further 3 hours. After cooling to room temperature, the reaction mixture was concentrated in vacuo and purified by flash chromatography (SiO2 ; methylene chloride/ethanol/ammonia (97.5:2.5:0.25)) to afford the title compound as a white solid (76 mg).

Workup

temperaturerefluxed at 80° C. for 3 hours
temperaturerefluxing
waitcontinued for a further 3 hours
temperatureAfter cooling to room temperature
concentrationthe reaction mixture was concentrated in vacuo
custompurified by flash chromatography (SiO2 ; methylene chloride/ethanol/ammonia (97.5:2.5:0.25))

Sources & evidence

ORD record: ord-83fdc4f3a8ba43a691f52a4c624a1c41
Source dataset: uspto-grants-2000_08
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06103749

Reaction notes

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