N-bromobutanimide → methyl 4-(4-bromo-1-ethyl-1H-pyrazol-5-yl)-2-thiophenecarboxylate

HRID 1845429Notes

Reaction equation

HRID 1845429 reaction equation
[CH2:1]([N:3]1[C:7]([C:8]2[CH:9]=[C:10]([C:13]([O:15][CH3:16])=[O:14])[S:11][CH:12]=2)=[CH:6][CH:5]=[N:4]1)[CH3:2].C1C(=O)N([Br:24])C(=O)C1>C1COCC1>[Br:24][C:6]1[CH:5]=[N:4][N:3]([CH2:1][CH3:2])[C:7]=1[C:8]1[CH:9]=[C:10]([C:13]([O:15][CH3:16])=[O:14])[S:11][CH:12]=1

Participants

4

Reactant 2

HCID 67184N-bromobutanimideHCID 67066137methyl 4-(1-ethyl-1H-pyrazol-5-yl)-2-thiophenecarboxylate

Product 1

HCID 57826836methyl 4-(4-bromo-1-ethyl-1H-pyrazol-5-yl)-2-thiophenecarboxylateYield 78.5%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Conditions

Temperature
70 °C

Procedure

To a solution of methyl 4-(1-ethyl-1H-pyrazol-5-yl)-2-thiophenecarboxylate (0.45 g, 1.9 mmol) [see example 92(a)] in THF (5 mL) was added NBS (0.33 g, 2.5 mmol). The reaction mixture was heated to 70° C. under nitrogen. After 2 h, the reaction mixture was concentrated under vacuum and purified on silica (EtOAc/hexanes, 10-30%) to afford the title compound (0.47 g, 78%). LC-MS (ES) m/z=316 (M+H)+.

Workup

  1. concentrationthe reaction mixture was concentrated under vacuum
  2. custompurified on silica (EtOAc/hexanes, 10-30%)

Sources & evidence

ORD record
ord-7d9e44f0d1604fc7bf9c97e0666dcfa9
Source dataset
uspto-grants-2015_02
Patent number
US08946278B2

Reaction notes

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