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

HRID 1961081Notes

Reaction equation

HRID 1961081 reaction equation
[CH3:1][C:2]1[S:6][C:5]([C:7]([O:9][CH3:10])=[O:8])=[CH:4][C:3]=1[C:11]1[N:15]([CH3:16])[N:14]=[CH:13][CH:12]=1.C1C(=O)N([Br:24])C(=O)C1>O1CCCC1>[Br:24][C:12]1[CH:13]=[N:14][N:15]([CH3:16])[C:11]=1[C:3]1[CH:4]=[C:5]([C:7]([O:9][CH3:10])=[O:8])[S:6][C:2]=1[CH3:1]

Participants

4

Reactant 2

HCID 67184N-bromobutanimideHCID 57826485methyl 5-methyl-4-(1-methyl-1H-pyrazol-5-yl)-2-thiophenecarboxylate

Product 1

HCID 57826393methyl 4-(4-bromo-1-methyl-1H-pyrazol-5-yl)-5-methyl-2-thiophenecarboxylateYield 78%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

A solution of methyl 5-methyl-4-(1-methyl-1H-pyrazol-5-yl)-2-thiophenecarboxylate (580 mg, 2.45 mmol) and n-bromosuccinimide (437 mg, 2.45 mmol) in tetrahydrofuran (12.300 ml) was stirred in a sealed tube for 1 h at 70° C. The solution was then partitioned between H2O-DCM and the aqueous phase was washed several times with DCM. The combined organic fractions were dried over Na2SO4, concentrated then purified via column chromatography (silica, 20% EtOAc in hexanes) yielding methyl 4-(4-bromo-1-methyl-1H-pyrazol-5-yl)-5-methyl-2-thiophenecarboxylate (600 mg, 1.90 mmol, 78% yield) as a yellow oil: LCMS (ES) m/e 314, 316 (M, M+H)+.

Workup

  1. customThe solution was then partitioned between H2O-DCM
  2. washthe aqueous phase was washed several times with DCM
  3. dry with materialThe combined organic fractions were dried over Na2SO4
  4. concentrationconcentrated
  5. customthen purified via column chromatography (silica, 20% EtOAc in hexanes)

Sources & evidence

ORD record
ord-36cbe021fbb4487fb05f3207e9b77c4d
Source dataset
uspto-grants-2013_04
Patent number
US08410158B2

Reaction notes

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