3-Cyano-4-fluorophenylhydrazine hydrochloride → tert-butyl 1-(3-cyano-4-fluorophenyl)-5-(2-furyl)-1H-pyrazole-3-carboxylate

HRID 639574Notes

Reaction equation

HRID 639574 reaction equation
[C:1]([O:5][C:6](=[O:17])[C:7]([O-])=[CH:8][C:9]([C:11]1[O:12][CH:13]=[CH:14][CH:15]=1)=O)([CH3:4])([CH3:3])[CH3:2].[Li+].Cl.[F:20][C:21]1[CH:28]=[CH:27][C:26]([NH:29][NH2:30])=[CH:25][C:22]=1[C:23]#[N:24]>C(O)(=O)C>[C:23]([C:22]1[CH:25]=[C:26]([N:29]2[C:9]([C:11]3[O:12][CH:13]=[CH:14][CH:15]=3)=[CH:8][C:7]([C:6]([O:5][C:1]([CH3:4])([CH3:3])[CH3:2])=[O:17])=[N:30]2)[CH:27]=[CH:28][C:21]=1[F:20])#[N:24]

Participants

4

Reactant 2

HCID 219368473-Cyano-4-fluorophenylhydrazine hydrochlorideHCID 67241625Lithium 1-tert-butoxy-4-(2-furyl)-1,4-dioxo-2-buten-2-olate

Product 1

HCID 21936867tert-butyl 1-(3-cyano-4-fluorophenyl)-5-(2-furyl)-1H-pyrazole-3-carboxylateYield 95%

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Procedure

Part A. To lithium 1-tert-butoxy-4-(2-furyl)-1,4-dioxo-2-buten-2-olate (13 g, 54 mmol; Example 74, Part A) was added 2-fluoro-5-hydrazinobenzonitrile hydrochloride (10 g, 54 mmol) and 250 mL of glacial acetic acid. The resulting orange mixture was maintained at rt for 20 h and then concentrated to dryness. The resulting residue was taken up in 30% chloroform in hexanes and filtered to afford tert-butyl 1-(3-cyano-4-fluorophenyl)-5-(2-furyl)-1H-pyrazole-3-carboxylate (18 g, 95%) as a light brown solid. LC/MS (ESI+): 354.2 (M+H)+. 1H NMR (CDCl3) δ 7.64-7.78 (m, 3H), 7.42 (s, 1H), 7.05 (s, 1H), 6.45 (s, 1H), 6.30 (s, 1H), 1.61 (s, 9H).

Workup

  1. concentrationconcentrated to dryness
  2. filtrationfiltered

Sources & evidence

ORD record
ord-ea921c6b084d4100815ed707f98484a9
Source dataset
uspto-grants-2010_04
Patent number
US07691846B2

Reaction notes

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