N-bromobutanimide → 4-(4-bromo-1-methyl-1H-pyrazol-5-yl)-5-chloro-2-thiophenecarboxylic acid

HRID 1961101Notes

Reaction equation

HRID 1961101 reaction equation
[Cl:1][C:2]1[S:6][C:5]([C:7]([OH:9])=[O:8])=[CH:4][C:3]=1[C:10]1[N:14]([CH3:15])[N:13]=[CH:12][CH:11]=1.C1C(=O)N([Br:23])C(=O)C1>O1CCCC1>[Br:23][C:11]1[CH:12]=[N:13][N:14]([CH3:15])[C:10]=1[C:3]1[CH:4]=[C:5]([C:7]([OH:9])=[O:8])[S:6][C:2]=1[Cl:1]

Participants

4

Reactant 2

HCID 67184N-bromobutanimideHCID 578263895-chloro-4-(1-methyl-1H-pyrazol-5-yl)thiophene-2-carboxylic acid

Product 1

HCID 578264444-(4-bromo-1-methyl-1H-pyrazol-5-yl)-5-chloro-2-thiophenecarboxylic acidYield 79%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

A solution of 5-chloro-4-(1-methyl-1H-pyrazol-5-yl)-2-thiophenecarboxylic acid (50 mg, 0.21 mmol)[prepared in Example 95] and NBS (36.7 mg, 0.21 mmol) in tetrahydrofuran (2.06 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 and concentrated yielding 4-(4-bromo-1-methyl-1H-pyrazol-5-yl)-5-chloro-2-thiophenecarboxylic acid (82 mg, 0.16 mmol, 79% yield) as a yellow oil: LCMS (ES) m/e 257, 259 (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

Sources & evidence

ORD record
ord-c9b84cc808f7443f9b1b414116aaf705
Source dataset
uspto-grants-2013_04
Patent number
US08410158B2

Reaction notes

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