Toluene → benzyl(5-bromo-4-nitro-2-propyl-2H-pyrazol-3-yl)amine

HRID 2262324Notes

Reaction equation

HRID 2262324 reaction equation
[Br:1][C:2]1[C:6]([N+:7]([O-:9])=[O:8])=[C:5](Br)[N:4]([CH2:11][CH2:12][CH3:13])[N:3]=1.C[Si]([N-:18][Si](C)(C)C)(C)C.[Li+].P(C(C)(C)C)(C(C)(C)C)C(C)(C)C.[C:37]1([CH3:43])[CH:42]=[CH:41][CH:40]=[CH:39][CH:38]=1>>[CH2:43]([NH:18][C:5]1[N:4]([CH2:11][CH2:12][CH3:13])[N:3]=[C:2]([Br:1])[C:6]=1[N+:7]([O-:9])=[O:8])[C:37]1[CH:42]=[CH:41][CH:40]=[CH:39][CH:38]=1

Participants

5

Reactant 4

HCID 1140TolueneHCID 83681Tris(1,1-dimethylethyl)phosphineHCID 2733832Lithium HexamethyldisilazideHCID 130072253,5-dibromo-1-propyl-4-nitro-1H-pyrazole

Product 1

HCID 13007229benzyl(5-bromo-4-nitro-2-propyl-2H-pyrazol-3-yl)amine

Procedure

Treatment of 3,5-dibromo-4-nitro-1H-pyrazole 1 with 2-bromoethanol and NaH in DMF affords 2-(3,5-dibromo-4-nitro-1H-pyrazol-1-yl)ethanol 2. Reaction of the compound 2 with lithium bis(trimethylsilyl)amide in the presence of bis(dibenzylidene)palladium (0) and P(t-Bu)3 in toluene affords the bis-silylamine 3, which is readily converted to 2-(5-amino-3-bromo-4-nitro-1H-pyrazol-1-yl)ethanol 4 by addition of aqueous HCl and neutralization (Org. Lett. 2001, 3, 2729). Reduction of the compound 4 with Fe in acetic acid provides 2-(4,5-diamino-3-bromo-1H-pyrazol-1-yl)ethanol 5.

Sources & evidence

ORD record
ord-12de18b9da484373bcdd6bcabaf7e65b
Source dataset
uspto-grants-2010_12
Patent number
US07850742B2

Reaction notes

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