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

HRID 2392080Notes

Reaction equation

HRID 2392080 reaction equation
[CH2:1]([C:3]1[S:7][C:6]([C:8]([O:10][CH3:11])=[O:9])=[CH:5][C:4]=1[C:12]1[N:16]([CH3:17])[N:15]=[CH:14][CH:13]=1)[CH3:2].[Br:18]N1C(=O)CCC1=O>O1CCCC1>[Br:18][C:13]1[CH:14]=[N:15][N:16]([CH3:17])[C:12]=1[C:4]1[CH:5]=[C:6]([C:8]([O:10][CH3:11])=[O:9])[S:7][C:3]=1[CH2:1][CH3:2]

Participants

4

Reactant 2

HCID 67184N-bromobutanimideHCID 57826625methyl 5-ethyl-4-(1-methyl-1H-pyrazol-5-yl)-2-thiophenecarboxylate

Product 1

HCID 57826735methyl 4-(4-bromo-1-methyl-1H-pyrazol-5-yl)-5-ethyl-2-thiophenecarboxylateYield 85.2%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

A solution of methyl 5-ethyl-4-(1-methyl-1H-pyrazol-5-yl)-2-thiophenecarboxylate (980 mg, 3.92 mmol)[prepared in Example 98] and N-bromosuccinimide (697 mg, 3.92 mmol) in tetrahydrofuran (19.6 ml) was stirred in a sealed tube for 1 h at 70° C. The reaction mixture 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, 10-40% EtOAC in hexanes) yielding methyl 4-(4-bromo-1-methyl-1H-pyrazol-5-yl)-5-ethyl-2-thiophenecarboxylate (1.1 g, 3.34 mmol, 85% yield) as a yellow oil: LCMS (ES) m/e 329, 331 (M, M+2)+.

Workup

  1. customThe reaction mixture 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, 10-40% EtOAC in hexanes)

Sources & evidence

ORD record
ord-12a65c37ee7c40fab862cc28d6932264
Source dataset
uspto-grants-2012_09
Patent number
US08273782B2

Reaction notes

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