Aluminium lithium hydride → 1-(2,4-difluorophenyl)-N-ethyl-1H-pyrazol-5-amine

HRID 383567Notes

Reaction equation

[F:1][C:2]1[CH:7]=[C:6]([F:8])[CH:5]=[CH:4][C:3]=1[N:9]1[C:13]([NH:14][C:15](=O)[CH3:16])=[CH:12][CH:11]=[N:10]1.[H-].[Al+3].[Li+].[H-].[H-].[H-]>C1COCC1>[F:1][C:2]1[CH:7]=[C:6]([F:8])[CH:5]=[CH:4][C:3]=1[N:9]1[C:13]([NH:14][CH2:15][CH3:16])=[CH:12][CH:11]=[N:10]1

Participants

Conditions

Temperature: 0 °C

Procedure

At 0° C., a solution of N-(1-(2,4-difluorophenyl)-1H-pyrazol-5-yl)acetamide (2.58 g, 10.88 mmol) in 35 mL of THF was treated with lithium aluminum hydride (22 mL of the 1.0 M solution in THF, 22 mmol). The reaction mixture was stirred at 0° C. for 90 min then quenched with Rochelle's salt. It was extracted with EtOAc (3×100 mL) followed by DCM (2×50 mL). The combined organic solution was dried over MgSO4, filtered and concentrated. Purification of the crude material on an ISCO 80 g column (30-80% EtOAc in hexanes) afforded 1-(2,4-difluorophenyl)-N-ethyl-1H-pyrazol-5-amine (1.21 g, 50% yield) as a light yellow viscous oil. MS (ES+): 224.1 (M+H)+.

Workup

customthen quenched with Rochelle's salt
extractionIt was extracted with EtOAc (3×100 mL)
dry with materialThe combined organic solution was dried over MgSO4
filtrationfiltered
concentrationconcentrated
customPurification of the crude material on an ISCO 80 g column (30-80% EtOAc in hexanes)

Sources & evidence

ORD record: ord-fecb52eb9fd64b91bf27c6c66c43498f
Source dataset: uspto-grants-2013_02
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08367671B2

Reaction notes

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